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Sample records for infrared background experiment

  1. The Cosmic Infrared Background Experiment

    CERN Document Server

    Bock, J; Cooray, A R; Kawada, M; Keating, B; Lange, A; Lee, D H; Matsumoto, T; Matsuura, S; Pak, S; Renbarger, T; Sullivan, I; Tsumura, K; Wada, T; Watabe, T; Bock, James; Battle, John; Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hea; Matsumoto, Toshio; Matsuura, Shuji; Pak, Soojong; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Watabe, Toyoki

    2006-01-01

    We are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The cameras will search for spatial fluctuations in the background on angular scales from 7 arcseconds to 2 degrees over a range of angular scales poorly covered by previous experiments. CIBER will determine if the fluctuations reported by the IRTS arise from first-light galaxies or have a local origin. In a short rocket flight CIBER has sensitivity to probe fluctuations 100 times fainter than IRTS/DIRBE. By jointly observing regions of the sky studied by Spitzer and ASTRO-F, CIBER will build a multi-color view of the near-infrared background, accurately assessing the contribution of local (z = 1-3) galaxies to the observed background fluctuations, allowing a de...

  2. The Cosmic Infrared Background Experiment

    Science.gov (United States)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  3. Fluctuations In The Cosmic Infrared Background Using the Cosmic Infrared Background ExpeRiment (CIBER).

    Science.gov (United States)

    Smidt, Joseph; Arai, T.; Battle, J.; Bock, J. J.; Cooray, A.; Frazer, C.; Hristov, V.; Keating, B.; Kim, M.; Lee, D.; Mason, P.; Matsumoto, T.; Mitchell-Wynne, K.; Nam, U.; Renbarger, T.; Smith, A.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2012-01-01

    The clustering properties of faint unresolved sources may be probed by examining the anisotropies they create in the Cosmic Infrared Background (CIB). Using information from fluctuations in the CIB at different wavelengths allows us to disentangle how clustering relates to redshift. In this talk, preliminary measurements of clustering using data from the Cosmic Infrared Background ExpeRiment (CIBER), a rocket-borne experiment designed to detect the signatures of unresolved infrared galaxies during reionization, will be discussed. The CIBER payload contains four instruments including two wide field imagers designed to measure fluctuations in the near IR cosmic infrared background (CIB) at 1.0 and 1.6 microns on scales between 0.2 and 100 arcmin in both bands, where the clustering of high-redshift sources is expected to peak. CIBER observations may be combined with Akari/NEP and Spitzer/NDWFS near-infrared surveys to check systematic errors and to fully characterize the electromagnetic spectrum of CIB fluctuations.

  4. International Cooperation of the Cosmic Infrared Background Experiment

    Science.gov (United States)

    Lee, D.-H.; Nam, U.-W.; Lee, S.; Jin, H.; Yuk, I.-S.; Kim, K.-H.; Pak, S.

    2006-12-01

    A Korean team (Korea Astronomy and Space Science Institute, Korea Basic Science Institute, and Kyung Hee University) takes part in an international cooperation project called CIBER (Cosmic Infrared Background ExpeRiment), which has begun with Jet Propulsion Laboratory (JPL) in USA and Institute of Space and Astronautical Science (ISAS) in Japan. CIBER is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The Korean team is in charge of the ground support electronics and manufacturing of optical parts of the narrow-band spectrometer, which will provide excellent opportunities for science and technology to Korean infrared groups.

  5. Stray light analysis of the Diffuse Infrared Background Experiment (DIRBE)

    Science.gov (United States)

    Breault, R. P.

    1984-01-01

    The straylight analysis of the diffuse infrared background experiment (DIRBE) on the cosmic background explorer (COBE) mission is discussed. From the statement of work (SOW), the purpose of DIRBE is to measure, or set upper limits on, the spectral and spatial character of the diffuse extra galactic infrared radiation. Diffuse infrared sources within our own galaxy are measured. The required reduction of the unwanted radiation imposes severe design and operating restrictions on the DIRBE instrument. To accomplish its missions, it will operate at a multitude of wavelengths ranging from 1.25 um out to 200 to 300 microns. The operating bands and the required point source normalized irradiance transmittance (PSNIT) are shown. The important straylight concepts in the DIRBE design are reviewed. The model and assumptions used in APART analysis are explained. The limitations due to the scalar theory used in the analysis are outlined.

  6. The COBE Diffuse Infrared Background Experiment search for thecosmic infrared background. I. Limits and detections

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, M.G.; Arendt, R.G.; Kelsall, T.; Dwek, E.; Odegard, N.; Weiland, J.L.; Freudenreich, H.T.; Reach, W.T.; Silverberg, R.F.; Moseley, S.H.; Pei, Y.C.; Lubin, P.; Mather, J.C.; Shafer, R.A.; Smoot,G.F.; Weiss, R.; Wilkinson, D.T.; Wright, E.L.

    1998-01-06

    The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) spacecraft was designed primarily to conduct a systematic search for an isotropic cosmic infrared background (CIB) in 10 photometric bands from 1.25 to 240 mu m. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 mu m(nu l nu<64 nW m-2 sr-1, 95 percent confidence level) and at 240 mu m (nu l nu < 28 nW m-1 sr-1, 95 percent confidence level). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the CIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 mum data provide candidate detections of the CIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 mu m. No plausible solar system or Galactic source of the observed 140 and 240 mu m residuals can be identified, leading to the conclusion that the CIB has been detected at levels of nu l nu = 25 +- 7 and 14 +- 3 nW m-2 sr-1 at 140 and 240 mu m, respectively. The integrated energy from 140 to 240 mu m, 10.3 nW m-2sr-1, is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust production since the decoupling of the cosmic microwave background from matter.

  7. COBE diffuse infrared background experiment observations of the galactic bulge

    Science.gov (United States)

    Weiland, J. L.; Arendt, R. G.; Berriman, G. B.; Dwek, E.; Freudenreich, H. T.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Mitra, M.; Moseley, S. H.

    1994-01-01

    Low angular resolution maps of the Galactic bulge at 1.25, 2.2, 3.5, and 4.9 micrometers obtained by the Diffuse Infrared Background Experiment (DIRBE) onboard NASA's Cosmic Background Explorer (COBE) are presented. After correction for extinction and subtraction of an empirical model for the Galactic disk, the surface brightness distribution of the bulge resembles a flattened ellipse with a minor-to-major axis ratio of approximately 0.6. The bulge minor axis scale height is found to be 2.1 deg +/- 0.2 deg for all four near-infrared wavelengths. Asymmetries in the longitudinal distribution of bulge brightness contours are qualitatively consistent with those expected for a triaxial bar with its near end in the first Galactic quadrant (0 deg less than l less than 90 deg). There is no evidence for an out-of-plane tilt of such a bar.

  8. The Cosmic Infrared Background Experiment (CIBER): The Low Resolution Spectrometer

    CERN Document Server

    Tsumura, K; Battle, J; Bock, J; Brown, S; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lee, D H; Levenson, L R; Lykke, K; Mason, P; Matsumoto, T; Matsuura, S; Murata, K; Nam, U W; Renbarger, T; Smith, A; Sullivan, I; Suzuki, K; Wada, T; Zemcov, M

    2011-01-01

    Absolute spectrophotometric measurements of diffuse radiation at 1 \\mu m to 2 \\mu m are crucial to our understanding of the radiative content of the Universe from nucleosynthesis since the epoch of reionization, the composition and structure of the Zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment (CIBER) is a \\lambda / \\Delta \\lambda \\sim 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 \\mu m < \\lambda < 2.1 \\mu m. This paper presents the optical, mechanical and electronic design of the LRS, as well as the ground testing, characterization and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding a...

  9. The Cosmic Infrared Background Experiment (CIBER): The Low Resolution Spectrometer

    Science.gov (United States)

    Tsumura, K.; Arai, T.; Battle, J.; Bock, J.; Brown, S.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Lykke, K.; Mason, P.; Matsumoto, T.; Matsuura, S.; Murata, K.; Nam, U. W.; Renbarger, T.; Smith, A.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2013-08-01

    Absolute spectrophotometric measurements of diffuse radiation at 1 μm to 2 μm are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a λ/Δλ ~ 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 μm <λ < 2.1 μm. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

  10. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE LOW RESOLUTION SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Tsumura, K.; Arai, T.; Matsumoto, T.; Matsuura, S.; Murata, K. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronoutical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Brown, S.; Lykke, K.; Smith, A. [Optical Technology Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Hristov, V.; Levenson, L. R.; Mason, P. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Sullivan, I., E-mail: tsumura@ir.isas.jaxa.jp [Department of Physics, The University of Washington, Seattle, WA 98195 (United States); and others

    2013-08-15

    Absolute spectrophotometric measurements of diffuse radiation at 1 {mu}m to 2 {mu}m are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a {lambda}/{Delta}{lambda} {approx} 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 {mu}m <{lambda} < 2.1 {mu}m. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

  11. The cosmic infrared background experiment (CIBER): instrumentation and first results

    Science.gov (United States)

    Zemcov, M.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Lee, D. H.; Levenson, L.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.

    2010-07-01

    Ultraviolet emission from the first generation of stars in the Universe ionized the intergalactic medium in a process which was completed by z ~ 6; the wavelength of these photons has been redshifted by (1 + z) into the near infrared today and can be measured using instruments situated above the Earth's atmosphere. First flying in February 2009, the Cosmic Infrared Background ExpeRiment (CIBER) comprises four instruments housed in a single reusable sounding rocket borne payload. CIBER will measure spatial anisotropies in the extragalactic IR background caused by cosmological structure from the epoch of reionization using two broadband imaging instruments, make a detailed characterization of the spectral shape of the IR background using a low resolution spectrometer, and measure the absolute brightness of the Zodiacal light foreground with a high resolution spectrometer in each of our six science fields. The scientific motivation for CIBER and details of its first and second flight instrumentation will be discussed. First flight results on the color of the zodiacal light around 1 μm and plans for the future will also be presented.

  12. Low-Resolution Near-infrared Stellar Spectra Observed by the Cosmic Infrared Background Experiment (CIBER)

    Science.gov (United States)

    Kim, Min Gyu; Lee, Hyung Mok; Arai, Toshiaki; Bock, James; Cooray, Asantha; Jeong, Woong-Seob; Kim, Seong Jin; Korngut, Phillip; Lanz, Alicia; Lee, Dae Hee; Lee, Myung Gyoon; Matsumoto, Toshio; Matsuura, Shuji; Nam, Uk Won; Onishi, Yosuke; Shirahata, Mai; Smidt, Joseph; Tsumura, Kohji; Yamamura, Issei; Zemcov, Michael

    2017-02-01

    We present near-infrared (0.8–1.8 μm) spectra of 105 bright ({m}J < 10) stars observed with the low-resolution spectrometer on the rocket-borne Cosmic Infrared Background Experiment. As our observations are performed above the Earth's atmosphere, our spectra are free from telluric contamination, which makes them a unique resource for near-infrared spectral calibration. Two-Micron All-Sky Survey photometry information is used to identify cross-matched stars after reduction and extraction of the spectra. We identify the spectral types of the observed stars by comparing them with spectral templates from the Infrared Telescope Facility library. All the observed spectra are consistent with late F to M stellar spectral types, and we identify various infrared absorption lines.

  13. The Cosmic Infrared Background Experiment (CIBER): A Sounding Rocket Payload to Study the Near Infrared Extragalactic Background Light

    CERN Document Server

    Zemcov, M; Battle, J; Bock, J; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lee, D H; Levenson, L R; Mason, P; Matsumoto, T; Matsuura, S; Nam, U W; Renbarger, T; Sullivan, I; Suzuki, K; Tsumura, K; Wada, T

    2011-01-01

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the Zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recover...

  14. Studying extragalactic background fluctuations with the Cosmic Infrared Background ExpeRiment 2 (CIBER-2)

    Science.gov (United States)

    Lanz, Alicia; Arai, Toshiaki; Battle, John; Bock, James; Cooray, Asantha; Hristov, Viktor; Korngut, Phillip; Lee, Dae Hee; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Morford, Tracy; Onishi, Yosuke; Shirahata, Mai; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2014-08-01

    Fluctuations in the extragalactic background light trace emission from the history of galaxy formation, including the emission from the earliest sources from the epoch of reionization. A number of recent near-infrared measure- ments show excess spatial power at large angular scales inconsistent with models of z CIBER-2) will measure spatial anisotropies in the extra- galactic infrared background caused by cosmological structure using six broad spectral bands. The experiment uses three 2048 x 2048 Hawaii-2RG near-infrared arrays in three cameras coupled to a single 28.5 cm telescope housed in a reusable sounding rocket-borne payload. A small portion of each array will also be combined with a linear-variable filter to make absolute measurements of the spectrum of the extragalactic background with high spatial resolution for deep subtraction of Galactic starlight. The large field of view and multiple spectral bands make CIBER-2 unique in its sensitivity to fluctuations predicted by models of lower limits on the luminosity of the first stars and galaxies and in its ability to distinguish between primordial and foreground anisotropies. In this paper the scientific motivation for CIBER-2 and details of its first flight instrumentation will be discussed, including detailed designs of the mechanical, cryogenic, and electrical systems. Plans for the future will also be presented.

  15. The Cosmic Infrared Background Experiment (CIBER): A Sounding Rocket Payload to Study the near Infrared Extragalactic Background Light

    Science.gov (United States)

    Zemcov, M.; Arai, T.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Tsumura, K.; Wada, T.

    2013-08-01

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  16. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): A SOUNDING ROCKET PAYLOAD TO STUDY THE NEAR INFRARED EXTRAGALACTIC BACKGROUND LIGHT

    Energy Technology Data Exchange (ETDEWEB)

    Zemcov, M.; Bock, J.; Hristov, V.; Levenson, L. R.; Mason, P. [Department of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Arai, T.; Matsumoto, T.; Matsuura, S.; Tsumura, K.; Wada, T. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Sullivan, I. [Department of Physics, The University of Washington, Seattle, WA 98195 (United States); Suzuki, K., E-mail: zemcov@caltech.edu [Instrument Development Group of Technical Center, Nagoya University, Nagoya, Aichi 464-8602 (Japan)

    2013-08-15

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  17. Cosmic Infrared Background ExpeRiment (CIBER): A Probe of Extragalactic Background Light from Reionization

    CERN Document Server

    Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hee; Levenson, Louis; Matsumoto, Toshio; Matsuura, Shuji; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2009-01-01

    The Cosmic Infrared Background ExpeRiment (CIBER) is a rocket-borne absolute photometry imaging and spectroscopy experiment optimized to detect signatures of first-light galaxies present during reionization in the unresolved IR background. CIBER-I consists of a wide-field two-color camera for fluctuation measurements, a low-resolution absolute spectrometer for absolute EBL measurements, and a narrow-band imaging spectrometer to measure and correct scattered emission from the foreground zodiacal cloud. CIBER-I was successfully flown on February 25th, 2009 and has one more planned flight in early 2010. We propose, after several additional flights of CIBER-I, an improved CIBER-II camera consisting of a wide-field 30 cm imager operating in 4 bands between 0.5 and 2.1 microns. It is designed for a high significance detection of unresolved IR background fluctuations at the minimum level necessary for reionization. With a FOV 50 to 2000 times largerthan existing IR instruments on satellites, CIBER-II will carry out ...

  18. Cosmic Infrared Background ExpeRiment (CIBER): A probe of Extragalactic Background Light from reionization

    Science.gov (United States)

    Cooray, Asantha; Bock, Jamie; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hee; Levenson, Louis; Matsumoto, Toshio; Matsuura, Shuji; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2012-08-01

    The Cosmic Infrared Background ExpeRiment (CIBER) is a rocket-borne absolute photometry imaging and spectroscopy experiment optimized to detect signatures of first-light galaxies present during reionization in the unresolved IR background. CIBER-I consists of a wide-field two-color camera for fluctuation measurements, a low-resolution absolute spectrometer for absolute EBL measurements, and a narrow-band imaging spectrometer to measure and correct scattered emission from the foreground zodiacal cloud. CIBER-I was successfully flown in February 2009 and July 2010 and four more flights are planned by 2014, including an upgrade (CIBER-II). We propose, after several additional flights of CIBER-I, an improved CIBER-II camera consisting of a wide-field 30 cm imager operating in 4 bands between 0.5 and 2.1 microns. It is designed for a high significance detection of unresolved IR background fluctuations at the minimum level necessary for reionization. With a FOV 50 to 2000 times larger than existing IR instruments on satellites, CIBER-II will carry out the definitive study to establish the surface density of sources responsible for reionization.

  19. The Cosmic Infrared Background Experiment (CIBER): the Narrow Band Spectrometer

    CERN Document Server

    Korngut, P M; Arai, T; Battle, J; Bock, J; Brown, S W; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lanz, A; Lee, D H; Levenson, L R; Lykke, K R; Mason, P; Matsumoto, T; Matsuura, S; Nam, U W; Shultz, B; Smith, A W; Sullivan, I; Tsumura, K; Wada, T; Zemcov, M

    2013-01-01

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the Solar 854.2 nm CaII Fraunhofer line, scattered by interplanetary dust, in the Zodiacal light spectrum. Based on the known equivalent line width in the Solar spectrum, this measurement can derive the Zodiacal brightness, testing models of the Zodiacal light based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute Zodiacal light brightness, the measured laboratory characterization, and the instrument performance in flight.

  20. The cosmic infrared background experiment-2 (CIBER-2) for studying the near-infrared extragalactic background light

    Science.gov (United States)

    Shirahata, Mai; Arai, Toshiaki; Battle, John; Bock, James; Cooray, Asantha; Enokuchi, Akito; Hristov, Viktor; Kanai, Yoshikazu; Kim, Min Gyu; Korngut, Phillip; Lanz, Alicia; Lee, Dae-Hee; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Morford, Tracy; Ohnishi, Yosuke; Park, Won-Kee; Sano, Kei; Takeyama, Norihide; Tsumura, Kohji; Wada, Takehiko; Wang, Shiang-Yu; Zemcov, Michael

    2016-07-01

    We present the current status of the Cosmic Infrared Background ExpeRiment-2 (CIBER-2) project, whose goal is to make a rocket-borne measurement of the near-infrared Extragalactic Background Light (EBL), under a collaboration with U.S.A., Japan, South Korea, and Taiwan. The EBL is the integrated light of all extragalactic sources of emission back to the early Universe. At near-infrared wavelengths, measurement of the EBL is a promising way to detect the diffuse light from the first collapsed structures at redshift z˜10, which are impossible to detect as individual sources. However, recently, the intra-halo light (IHL) model is advocated as the main contribution to the EBL, and our new result of the EBL fluctuation from CIBER-1 experiment is also supporting this model. In this model, EBL is contributed by accumulated light from stars in the dark halo regions of low- redshift (zCIBER- 1 experiment, we are now developing a new instrument CIBER-2, which is comprised of a 28.5-cm aluminum telescope and three broad-band, wide-field imaging cameras. The three wide-field (2.3×2.3 degrees) imaging cameras use the 2K×2K HgCdTe HAWAII-2RG arrays, and cover the optical and near-infrared wavelength range of 0.5-0.9 μm, 1.0-1.4 μm and 1.5-2.0 μm, respectively. Combining a large area telescope with the high sensitivity detectors, CIBER-2 will be able to measure the spatial fluctuations in the EBL at much fainter levels than those detected in previous CIBER-1 experiment. Additionally, we will use a linear variable filter installed just above the detectors so that a measurement of the absolute spectrum of the EBL is also possible. In this paper, the scientific motivation and the expected performance for CIBER-2 will be presented. The detailed designs of the telescope and imaging cameras will also be discussed, including the designs of the mechanical, cryogenic, and electrical systems.

  1. Near-IR Extragalactic Background Results from the Cosmic Infrared Background Experiment (CIBER)

    Science.gov (United States)

    Zemcov, Michael B.; CIBER

    2016-01-01

    The near IR extragalactic background light (EBL) encodes the integrated light production over cosmic history, so represents the total emission from all galaxies along the line of sight up to ancient first-light objects present during the epoch of reionization (EOR). This EOR emission necessarily comprises part of the background, and indeed a minimum level is required to supply enough photons to ionize the intergalactic medium, corresponding to an EBL brightness less than 1 nW m^-2 sr^-1, about one tenth of the integrated galactic light (IGL). In addition to emission from these IGL and EOR populations, low surface brightness tidal streams of stars stripped by gravitational interactions during galaxy formation at low redshifts, called intrahalo light (IHL), may also contribute a significant fraction of the EBL. Models for these components can be constrained both through direct photometric measurements, as well as the new technique of EBL anisotropy intensity mapping that takes advantage of the fact that the Zodiacal Light is spatially smooth while distant populations produce anisotropies with distinct spatial and spectral characteristics. This talk will present recent results from the Cosmic Infrared Background Experiment (CIBER), a sounding rocket borne payload designed to measure both the fluctuations and direct photometric emission of the extra-galactic background light. The anisotropy of the near-IR EBL suggests the presence of a bright component approximately as bright as the IGL component near 1 micron which we interpret as the aggregate emission from low-redshift IHL. New direct photometric measurements from CIBER's low resolution spectrometer will also be discussed.

  2. The {ital COBE} Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. I. Limits and Detections

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, M.G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Arendt, R.G. [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelsall, T.; Dwek, E. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Odegard, N.; Weiland, J.L.; Freudenreich, H.T. [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Reach, W.T. [California Institute of Technology, IPAC/JPL, MS 100-22, Pasadena, CA 91125 (United States); Silverberg, R.F.; Moseley, S.H. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pei, Y.C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lubin, P. [Physics Department, University of California at Santa Barbara, Santa Barbara, CA 93106 (United States); Mather, J.C.; Shafer, R.A. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Smoot, G.F. [Lawrence Berkeley Laboratory, Space Sciences Laboratory, Department of Physics, UC Berkeley, CA 94720 (United States); Weiss, R. [Massachusetts Institute of Technology, Room 20F-001, Department of Physics, Cambridge, MA 02139 (United States); Wilkinson, D.T. [Princeton University, Department of Physics, Jadwin Hall, Box 708, Princeton, NJ 08544 (United States); Wright, E.L. [UCLA, Astronomy Department, Los Angeles, CA 90024-1562 (United States)

    1998-11-01

    The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer ({ital COBE}) spacecraft was designed primarily to conduct a systematic search for an isotropic cosmic infrared background (CIB) in 10 photometric bands from 1.25 to 240 {mu}m. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 {mu}m ({nu}{ital I}{sub {nu}} {lt} 64 nW m{sup {minus}2} sr{sup {minus}1}, 95{percent} confidence level) and at 240 {mu}m ({nu}{ital I}{sub {nu}} {lt} 28 nW m{sup {minus}2} sr{sup {minus}1}, 95{percent} confidence level). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the CIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 {mu}m data provide candidate detections of the CIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 {mu}m. No plausible solar system or Galactic source of the observed 140 and 240 {mu}m residuals can be identified, leading to the conclusion that the CIB has been detected at levels of {nu}{ital I}{sub {nu}} = 25 {plus_minus} 7 and 14 {plus_minus} 3 nW m{sup {minus}2} sr{sup {minus}1} at 140 and 240 {mu}m, respectively. The integrated energy from 140 to 240 {mu}m, 10.3 nW m{sup {minus}2} sr{sup {minus}1}, is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust

  3. Infrared observations of Comet Austin (1990 V) by the COBE/Diffuse Infrared Background Experiment

    Science.gov (United States)

    Lisse, C. M.; Freudenreich, H. T.; Hauser, M. G.; Kelsall, T.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    Comet Austin was observed by the Cosmic Background Explorer (COBE)/Diffuse Infrared Background Experiment (DIRBE) with broadband photometry at 1-240 micrometers during the comet's close passage by Earth in 1990 May. A 6 deg long (6 x 10(exp 6) km) dust tail was found at 12 and 25 micrometers, with detailed structure due to variations in particle properties and mass-loss rate. The spectrum of the central 42 x 42 sq arcmin pixel was found to agree with that of a graybody of temperature 309 +/- 5 K and optical depth 7.3 +/- 10(exp -8). Comparison with IUE and ground-based obervations indicates that particles of radius greater than 20 micrometers predominate by surface area. A mass-loss rate of 510 (+510/-205) kg/s and a total tail mass of 7 +/- 2 x 10(exp 10) kg was found for a model dust tail composed of Mie spheres with a differential particle mass distribution dn/d log m approx. m(exp -0.63) and 2:1 silicate:amorphous carbon composition by mass.

  4. The Cosmic Infrared Background Experiment (CIBER): The Wide-Field Imagers

    CERN Document Server

    Bock, J; Arai, T; Battle, J; Cooray, A; Hristov, V; Keating, B; Kim, M G; Lam, A C; Lee, D H; Levenson, L R; Mason, P; Matsumoto, T; Matsuura, S; Mitchell-Wynne, K; Nam, U W; Renbarger, T; Smidt, J; Suzuki, K; Tsumura, K; Wada, T; Zemcov, M

    2012-01-01

    We have developed and characterized an imaging instrument to measure the spatial properties of the diffuse near-infrared extragalactic background light in a search for fluctuations from z > 6 galaxies during the epoch of reionization. The instrument is part of the Cosmic Infrared Background Experiment (CIBER), designed to observe the extragalactic background light above the Earth's atmosphere during a suborbital sounding rocket flight. The imaging instrument incorporates a 2x2 degree field of view, to measure fluctuations over the predicted peak of the spatial power spectrum at 10 arcminutes, and 7"x7" pixels, to remove lower redshift galaxies to a depth sufficient to reduce the low-redshift galaxy clustering foreground below instrumental sensitivity. The imaging instrument employs two cameras with \\Delta \\lambda / \\lambda ~0.5 bandpasses centered at 1.1 and 1.6 microns to spectrally discriminate reionization extragalactic background fluctuations from local foreground fluctuations. CIBER operates at wavelengt...

  5. Measuring Light from the Epoch of Reionization with CIBER, the Cosmic Infrared Background Experiment

    CERN Document Server

    Zemcov, Michael; Battle, John; Bock, James J; Cooray, Asantha; Hristov, Viktor; Keating, Brian; Kim, Min-Gyu; Lee, Dae-Hee; Levenson, Louis; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Mitchell-Wynne, Ketron; Nam, Uk Won; Renbarger, Tom; Smidt, Joseph; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko

    2011-01-01

    Ultraviolet emission from the first generation of stars in the Universe ionized the intergalactic medium in a process which was completed by z~6; the wavelength of these photons has been redshifted by (1+z) into the near infrared today and can be measured using instruments situated above the Earth's atmosphere. First flying in February 2009, the Cosmic Infrared Background Experiment (CIBER) comprises four instruments housed in a single reusable sounding rocket borne payload. CIBER will measure spatial anisotropies in the extragalactic IR background caused by cosmological structure from the epoch of reionization using two broadband imaging instruments, make a detailed characterization of the spectral shape of the IR background using a low resolution spectrometer, and measure the absolute brightness of the Zodical light foreground with a high resolution spectrometer in each of our six science fields. This paper presents the scientific motivation for CIBER and details of its first two flights, including a review...

  6. Build up and integration of the rocket-borne Cosmic Infrared Background ExpeRiment-2

    Science.gov (United States)

    Lanz, Alicia E.; Arai, Toshiaki; Battle, John; Bock, James; Cooray, Asantha R.; Hristov, Viktor; Kojima, Tomoya; Korngut, Phillip; Lee, Dae Hee; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Nguyen, Chi; Shirahata, Mai; Takahashi, Aoi; Tsumurai, Kohji; Wada, Takehiko; Wang, Shiang-Yu; Zemcov, Michael B.

    2017-01-01

    The Cosmic Infrared Background ExpeRiment, CIBER-2, is a near-infrared rocket-borne instrument designed to conduct comprehensive multi-band measurements of extragalactic background light anisotropy on arcsecond to degree angular scales. Recent measurements of the near-infrared Extragalactic Background Light (EBL) anisotropy find excess spatial power above the level predicted by known galaxy populations at large angular scales. CIBER-2 is designed to make measurements of the EBL anisotropy with the sensitivity, spectral range, and spectral resolution required to disentangle the contributions to the EBL from various sources throughout cosmic history.CIBER-2 consists of a 28.5 cm Cassegrain telescope assembly, imaging optics, and cryogenics mounted aboard a sounding rocket. Two dichroic beam-splitters spectrally subdivide the incident radiation into three optical paths, which are further subdivided in two wavelength bands per path, for a total of six observational wavelength bands that span the optical to the near-infrared and produce six 1.2 by 2.4 degree images recorded by three 2048 x 2048 HAWAII-2RG detector arrays. A small portion of each detector is also dedicated to absolute spectrophotometric imaging provided by a linear-variable filter. The instrument has several novel cryogenic mechanisms, a cryogenically-cooled pop-up baffle that extends during observations to provide radiative shielding and an electromagnetic cold shutter. We provide an overview of the instrument and current integration.

  7. The Cosmic Infrared Background Experiment: Flight Characterization Of The Ciber Narrow Band Spectrometer.

    Science.gov (United States)

    Levenson, Louis R.; Battle, J.; Bock, J. J.; Cooray, A.; Hristov, V.; Keating, B.; Lee, D.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2011-01-01

    Subtraction of the Zodiacal light foreground is the dominant source of uncertainty in absolute photometric measurements of the extra-galactic background at near-infrared to optical wavelengths. The second flight of the Cosmic Infrared Background ExpeRiment (CIBER) occurred on July 10th, 2010. CIBER is a NASA sounding rocket experiment carrying four co-aligned instruments including two imaging telescopes with wide passbands centered at 1 and 1.6 microns, respectively, as well as a low resolution spectrometer and a narrow-band spectrometer. THE CIBER spectrometers are absolutely calibrated in collaboration with NIST. The narrow-band spectrometer filter is centered on the Ca II solar Fraunhofer line at 854.2 nm and is designed to measure the equivalent width of the solar line reflected by the interplanetary dust in order to obtain an absolute measurement of the Zodiacal contribution to the infrared sky at that wavelength. In conjunction with measured low resolution spectrum from 700 to 1900 nm, this will provide an accurate independent check of the DIRBE Zodiacal light models. Here we describe the NBS instrument, calibration and in-flight characterization.

  8. The Cosmic Infrared Background Experiment (CIBER): The Wide-field Imagers

    Science.gov (United States)

    Bock, J.; Sullivan, I.; Arai, T.; Battle, J.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lam, A. C.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Mitchell-Wynne, K.; Nam, U. W.; Renbarger, T.; Smidt, J.; Suzuki, K.; Tsumura, K.; Wada, T.; Zemcov, M.

    2013-08-01

    We have developed and characterized an imaging instrument to measure the spatial properties of the diffuse near-infrared extragalactic background light (EBL) in a search for fluctuations from z > 6 galaxies during the epoch of reionization. The instrument is part of the Cosmic Infrared Background Experiment (CIBER), designed to observe the EBL above Earth's atmosphere during a suborbital sounding rocket flight. The imaging instrument incorporates a 2° × 2° field of view to measure fluctuations over the predicted peak of the spatial power spectrum at 10 arcmin, and 7'' × 7'' pixels, to remove lower redshift galaxies to a depth sufficient to reduce the low-redshift galaxy clustering foreground below instrumental sensitivity. The imaging instrument employs two cameras with Δλ/λ ~ 0.5 bandpasses centered at 1.1 μm and 1.6 μm to spectrally discriminate reionization extragalactic background fluctuations from local foreground fluctuations. CIBER operates at wavelengths where the electromagnetic spectrum of the reionization extragalactic background is thought to peak, and complements fluctuation measurements by AKARI and Spitzer at longer wavelengths. We have characterized the instrument in the laboratory, including measurements of the sensitivity, flat-field response, stray light performance, and noise properties. Several modifications were made to the instrument following a first flight in 2009 February. The instrument performed to specifications in three subsequent flights, and the scientific data are now being analyzed.

  9. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE WIDE-FIELD IMAGERS

    Energy Technology Data Exchange (ETDEWEB)

    Bock, J.; Battle, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Sullivan, I. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Arai, T.; Matsumoto, T.; Matsuura, S.; Tsumura, K. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Cooray, A.; Mitchell-Wynne, K.; Smidt, J. [Center for Cosmology, University of California, Irvine, CA 92697 (United States); Hristov, V.; Lam, A. C.; Levenson, L. R.; Mason, P. [Department of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H. [Institute of Astronomy and Astrophysics, Academia Sinica, National Taiwan University, Taipei 10617, Taiwan (China); Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Suzuki, K. [Instrument Development Group of Technical Center, Nagoya University, Nagoya, Aichi 464-8602 (Japan); and others

    2013-08-15

    We have developed and characterized an imaging instrument to measure the spatial properties of the diffuse near-infrared extragalactic background light (EBL) in a search for fluctuations from z > 6 galaxies during the epoch of reionization. The instrument is part of the Cosmic Infrared Background Experiment (CIBER), designed to observe the EBL above Earth's atmosphere during a suborbital sounding rocket flight. The imaging instrument incorporates a 2 Degree-Sign Multiplication-Sign 2 Degree-Sign field of view to measure fluctuations over the predicted peak of the spatial power spectrum at 10 arcmin, and 7'' Multiplication-Sign 7'' pixels, to remove lower redshift galaxies to a depth sufficient to reduce the low-redshift galaxy clustering foreground below instrumental sensitivity. The imaging instrument employs two cameras with {Delta}{lambda}/{lambda} {approx} 0.5 bandpasses centered at 1.1 {mu}m and 1.6 {mu}m to spectrally discriminate reionization extragalactic background fluctuations from local foreground fluctuations. CIBER operates at wavelengths where the electromagnetic spectrum of the reionization extragalactic background is thought to peak, and complements fluctuation measurements by AKARI and Spitzer at longer wavelengths. We have characterized the instrument in the laboratory, including measurements of the sensitivity, flat-field response, stray light performance, and noise properties. Several modifications were made to the instrument following a first flight in 2009 February. The instrument performed to specifications in three subsequent flights, and the scientific data are now being analyzed.

  10. COBE diffuse infrared background experiment observations of Galactic reddening and stellar populations

    Science.gov (United States)

    Arendt, R. G.; Berriman, G. B.; Boggess, N.; Dwek, E.; Hauser, M. G.; Kelsall, T.; Moseley, S. H.; Murdock, T. L.; Odegard, N.; Silverberg, R. F.

    1994-01-01

    This Letter describes the results of an initial study of Galactic extinction and the colors of Galactic stellar populations in the near-IR using the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The near-IR reddening observed by DIRBE is consistent with the extinction law tabulated by Rieke & Lebofsky (1985). The distribution of dust and stars in most of the first and fourth quadrants of the Galactic plane (0 deg less than l less than 90 deg, and 270 deg less than l less than 360 deg, respectively) can be modeled as a stellar background source seen through up to approximately 4 mag of extinction at 1.25 micrometers. The unreddened near-IR colors of the Galactic disk are similar to those of late-K and M giants. The Galactic bulge exhibits slightly bluer colors in the 2.2-3.5 micrometers range, as noted by Terndrup et al. (1991). Star-forming regions exhibit colors that indicate the presence of a approximately 900 K continuum produced by hot dust or polycyclic aromatic hydrocarbons (PAHs) contributing at wavelengths as short as 3.5 micrometers.

  11. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  12. The Cosmic Infrared Background Experiment (CIBER): The Narrow-Band Spectrometer

    Science.gov (United States)

    Korngut, P. M.; Renbarger, T.; Arai, T.; Battle, J.; Bock, J.; Brown, S. W.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lanz, A.; Lee, D. H.; Levenson, L. R.; Lykke, K. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Shultz, B.; Smith, A. W.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2013-08-01

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the solar 854.2 nm Ca II Fraunhofer line, scattered by interplanetary dust, in the zodiacal light (ZL) spectrum. Based on the known equivalent line width in the solar spectrum, this measurement can derive the zodiacal brightness, testing models of the ZL based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute ZL brightness, the measured laboratory characterization, and the instrument performance in flight.

  13. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE NARROW-BAND SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Korngut, P. M.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Renbarger, T.; Keating, B. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Arai, T.; Matsumoto, T.; Matsuura, S. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Hristov, V.; Lanz, A.; Levenson, L. R.; Mason, P. [Department of Physics, California Institute of Technology, Pasadena, CA 91125 (United States); Brown, S. W.; Lykke, K. R.; Smith, A. W. [Sensor Science Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Shultz, B., E-mail: pkorngut@caltech.edu [Materion Barr Precision Optics and Thin Film Coatings, Westford, MA 01886 (United States); and others

    2013-08-15

    We have developed a near-infrared spectrometer designed to measure the absolute intensity of the solar 854.2 nm Ca II Fraunhofer line, scattered by interplanetary dust, in the zodiacal light (ZL) spectrum. Based on the known equivalent line width in the solar spectrum, this measurement can derive the zodiacal brightness, testing models of the ZL based on morphology that are used to determine the extragalactic background light in absolute photometry measurements. The spectrometer is based on a simple high-resolution tipped filter placed in front of a compact camera with wide-field refractive optics to provide the large optical throughput and high sensitivity required for rocket-borne observations. We discuss the instrument requirements for an accurate measurement of the absolute ZL brightness, the measured laboratory characterization, and the instrument performance in flight.

  14. Principles of stray light suppression and conceptual application to the design of the Diffuse Infrared Background Experiment for NASA's Cosmic Background Explorer

    Science.gov (United States)

    Evans, D. C.

    1983-01-01

    The Diffuse Infrared Background Experiment (DIRBE) is a 10 band filter photometer that will operate at superfluid helium temperatures. Diffuse galactic and extragalactic infrared radiation in the 1-300 micrometer wavelength region will be measured by the instrument. Polarization measurements will be made for 3 bands in the 1-4 micrometer spectral region. The main sources of unwanted radiation are the sun, earth, thermal radiation from an external sun shield, the moon, the brighter planets and stars, and sky light itself from outside the instrument's nominal one degree square field of view. The system level engineering concepts and the principles of stray light suppression that resulted in the instrument design are presented.

  15. Intensity Mapping of the History of Stellar Emission with the Cosmic Infrared Background ExpeRiment-2

    Science.gov (United States)

    Lanz, Alicia E.; Arai, Toshiaki; Battle, John; Bock, James; Cooray, Asantha R.; Hristov, Viktor; Korngut, Phillip; Lee, Dae Hee; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Onishi, Yosuke; Shirahata, Mai; Tsumurai, Kohji; Wada, Takehiko; Zemcov, Michael B.

    2016-01-01

    Recent measurements of the near-infrared Extragalactic Background Light (EBL) anisotropy find excess spatial power above the level predicted by known galaxy populations at large angular scales. These anisotropies trace spatial variations in integrated photon production, so measurements of EBL surface brightness fluctuations provide a complete census of the emission from stars summed over cosmic history. As a result, EBL fluctuations contain contributions from objects forming during the Epoch of Reionization (EOR), from the integrated galactic light (IGL), and faint, extended components such as intra-halo light (IHL) from stars tidally stripped from galaxies during merger events. Additional measurements with greater sensitivity, spectral range, and spectral resolution are required to disentangle these contributions.The Cosmic Infrared Background ExpeRiment 2 (CIBER-2) is an instrument optimized for the measurement of near-infrared EBL anisotropies. As the Earth's atmosphere generates time-varying near-infrared emission, CIBER-2 is launched on a sounding rocket from which it will carry out multiwavelength imaging in six spectral bands that span the visible to near-infrared. The 2.4 square degree images allow CIBER-2 to produce measurements of EBL fluctuations with high fidelity on large angular scales. The Lyman break feature from EOR sources provides a unique spectral feature which can be used to disentangle the high from the low redshift contributions to the anisotropy signal. Measurement in six independent wavebands allows detailed cross-correlation studies to constrain the source of the excess fluctuations at large angular scales. We provide an overview of the CIBER-2 instrument and explain CIBER-2 spectral feature identification and cross-correlation study methodologies.

  16. COBE Observations of the Cosmic Infrared Background

    CERN Document Server

    Wright, E L

    2004-01-01

    The Diffuse InfraRed Background Experiment on COBE measured the total infrared signal seen from space at a distance of 1 astronomical unit from the Sun. Using time variations as the Earth orbits the Sun, it is possible to remove most of the foreground signal produced by the interplanetary dust cloud [zodiacal light]. By correlating the DIRBE signal with the column density of atomic hydrogen measured using the 21 cm line, it is possible to remove most of the foreground signal produced by interstellar dust, although one must still be concerned by dust associated with H_2 (molecular gas) and H II (the warm ionized medium). DIRBE was not able to determine the CIRB in the 5-60 micron wavelength range, but did detect both a far infrared background and a near infrared background. The far infrared background has an integrated intensity of about 34 nW/m^2/sr, while the near infrared and optical extragalactic background has about 59 nW/m^2/sr. The Far InfraRed Absolute Spectrophotometer (FIRAS) on COBE has been used to...

  17. Anisotropies of the infrared background and primordial galaxies

    Science.gov (United States)

    Cooray, Asantha R.

    2007-08-01

    We discuss anisotropies in the near-IR background between 1 to a few microns. This background is expected to contain a signature of primordial galaxies. We have measured fluctuations of resolved galaxies with Spitzer imaging data and we are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background.

  18. The Far Infrared and Submillimeter Diffuse Extragalactic Background

    CERN Document Server

    Hauser, M G

    2001-01-01

    The cosmic infrared background (CIB) radiation was a long-sought fossil of energetic processes associated with structure formation and chemical evolution since the Big Bang. The COBE Diffuse Infrared Background Experiment (DIRBE) and Far Infrared Absolute Spectrophotometer (FIRAS) were specifically designed to search for this background from 1.25 microns to millimeter wavelengths. These two instruments provided high quality, absolutely calibrated all-sky maps which have enabled the first detections of the CIB, initially at far infrared and submillimeter wavelengths, and more recently in the near infrared as well. The aim of this paper is to review the status of determinations of the CIB based upon COBE measurements. The results show that the energy in the CIB from far infrared to millimeter wavelengths is comparable to that in the integrated light of galaxies from UV to near infrared wavelengths: the universe had a luminous but dusty past. On the assumption that nucleosynthesis in stars is the energy source f...

  19. Infrared clutter measurements of marine backgrounds

    NARCIS (Netherlands)

    Schwering, Piet B.

    1991-01-01

    Observations in the infrared wavelength band between 8 and 12 μm of sea backgrounds have been recorded with a CCIR compatible imager for a large number of sea states (0 - 6). Recordings took place in coastal areas as well as on open seas. The behavior of clutter in the infrared data was analyzed in

  20. The cosmic infrared background resolved by Spitzer - Contributions of mid-infrared galaxies to the far-infrared background

    NARCIS (Netherlands)

    Dole, H; Lagache, G; Puget, JL; Caputi, KI; Fernandez-Conde, N; Le Floc'h, E; Papovich, C; Perez-Gonzalez, PG; Rieke, GH; Blaylock, M

    Aims. We quantify the contributions of 24 mu m galaxies to the Far-Infrared ( FIR) Background at 70 and 160 mu m. We provide new estimates of the Cosmic Infrared Background ( CIB), and compare it with the Cosmic Optical Background ( COB). Methods. Using Spitzer data at 24, 70 and 160 mu m in three

  1. Cosmic Infrared Background Fluctuations and Zodiacal Light

    Science.gov (United States)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2017-01-01

    We performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR (near-infrared)background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution or from IRAC (Infrared Array Camera) observations of high-latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS (Cosmic Evolution Survey) field at low ecliptic latitude where the zodiacal light intensity varies by factors of approximately 2 over the range of solar elongations at which the field can be observed. We find that the white-noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales (greater than or approximately equal to 100 arcseconds) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large-scale power in the infrared background is not being caused by the zodiacal light.

  2. Cosmic Infrared Background Fluctuations and Zodiacal Light

    Science.gov (United States)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2017-01-01

    We performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR (near-infrared)background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution or from IRAC (Infrared Array Camera) observations of high-latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS (Cosmic Evolution Survey) field at low ecliptic latitude where the zodiacal light intensity varies by factors of approximately 2 over the range of solar elongations at which the field can be observed. We find that the white-noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales (greater than or approximately equal to 100 arcseconds) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large-scale power in the infrared background is not being caused by the zodiacal light.

  3. Cross correlations of the cosmic infrared background

    CERN Document Server

    Zhang, P

    2003-01-01

    Cosmic infrared background (CIB) is a sensitive measure of the structure formation of the universe, especially the star formation history. But this background is overwhelmed by foregrounds. The cross correlation of CIB with galaxies is able to eliminate such foregrounds, minimize and localize several backgrounds which could bias the study of the star formation history. The cross correlation study of CIB has three advantages. (1) Combining the galaxy photometric redshift information, it directly measures the structure formation history. (2) The sky area used for CIB analysis is no long limited to the relatively clean sky. The utilization of CIB full sky data minimizes the sample variance. (3) The CIB measurement is no longer limited to several narrow frequency windows. This allows the measurement of CIB based on integrated intensity, whose theoretical prediction is based on energy conservation, thus is fairly model independent and robust. The cross correlation can be measured with 10% accuracy (statistical and...

  4. Z > 6 Galaxy Signatures in the Infrared Background and the 21-cm background

    Science.gov (United States)

    Cooray, A.

    2006-08-01

    We will discuss the signatures of the high-redshift galaxy formation in the near-infrared background. Ionizing sources at high redshift generically imprint a distinctive Lyman-cutoff feature and a unique spatial anisotropy signature to the IRB, both of which may be detectable in a short rocket flight. We will discuss the Cosmic Infrared Background ExpeRiment (CIBER), a rocket-borne instrument to probe the absolute spectrum and spatial anisotropy of the extragalactic InfraRed Background (IRB) optimized for detection of the integrated spatial anisotropies in the IR background from high-redshift galaxies. We will also discuss the signatures of first galaxies in the low radio frequency 21-cm background from the neutral Hydrogen distribution at z > 6; When combined with arcminute-scale temperature anisotropy and the polarization of the cosmic microwave background, the 21-cm background will allow a determination of inhomogeneous distribution of Lyman-alpha photons from first galaxies. We will discuss these and other possibilities to understand the first galaxy population with IR, 21-cm, and CMB backgrounds.

  5. Can decaying particle explain cosmic infrared background excess?

    Directory of Open Access Journals (Sweden)

    Kazunori Kohri

    2017-09-01

    Full Text Available Recently the CIBER experiment measured the diffuse cosmic infrared background (CIB flux and claimed an excess compared with integrated emission from galaxies. We show that the CIB spectrum can be fitted by the additional photons produced by the decay of a new particle. However, it also contributes too much to the anisotropy of the CIB, which is in contradiction with the anisotropy measurements by the CIBER and Hubble Space Telescope.

  6. Can decaying particle explain cosmic infrared background excess?

    Science.gov (United States)

    Kohri, Kazunori; Moroi, Takeo; Nakayama, Kazunori

    2017-09-01

    Recently the CIBER experiment measured the diffuse cosmic infrared background (CIB) flux and claimed an excess compared with integrated emission from galaxies. We show that the CIB spectrum can be fitted by the additional photons produced by the decay of a new particle. However, it also contributes too much to the anisotropy of the CIB, which is in contradiction with the anisotropy measurements by the CIBER and Hubble Space Telescope.

  7. The diffuse infrared background - COBE and other observations

    Science.gov (United States)

    Hauser, M. G.; Kelsall, T.; Moseley, S. H., Jr.; Silverberg, R. F.; Murdock, T.; Toller, G.; Spiesman, W.; Weiland, J.

    1991-01-01

    The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) satellite is designed to conduct a sensitive search for an isotropic cosmic infrared background radiation over the spectral range from 1 to 300 micrometers. The cumulative emissions of pregalactic, protogalactic, and evolving galactic systems are expected to be recorded in this background. The DIRBE instrument, a 10 spectral band absolute photometer with an 0.7 deg field of view, maps the full sky with high redundancy at solar elongation angles ranging from 64 to 124 degrees to facilitate separation of interplanetary, Galactic, and extragalactic sources of emission. Initial sky maps show the expected character of the foreground emissions, with relative minima at wavelengths of 3.4 micrometers and longward of 100 micrometers. Extensive modelling of the foregrounds, just beginning, will be required to isolate the extragalactic component. In this paper, we summarize the status of diffuse infrared background observations from the DIRBE, and compare preliminary results with those of recent rocket and satellite instruments.

  8. Infrared dim target detection technology based on background estimate

    Science.gov (United States)

    Lei, Liu; Zhijian, Huang

    2014-01-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, two new algorithms - background estimate and frame difference fusion method, and building background with neighborhood mean method are presented. The basic principles and the implementing procedure of these algorithms for target detection are described. Using these algorithms, the experiments on some real-life IR images are performed. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective view and objective view. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  9. IRST infrared background analysis of bay environments

    CSIR Research Space (South Africa)

    Schwering, PBW

    2008-04-01

    Full Text Available threats can be present in environments with cluttered backgrounds as well as rapidly varying atmospheric conditions. During trials executed in False Bay a large amount of target, background and atmosphere data was gathered that is of use in analysis...

  10. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-11-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.

  11. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-12-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.Defence Science Journal, 2013, 63(6, pp.611-615, DOI:http://dx.doi.org/10.14429/dsj.63.5762

  12. Far Infrared Spectrometry of the Cosmic Background Radiation

    Science.gov (United States)

    Mather, J. C.

    1974-01-01

    I describe two experiments to measure the cosmic background radiation near 1 mm wavelength. The first was a ground-based search for spectral lines, made with a Fabry-Perot interferometer and an InSb detector. The second is a measurement of the spectrum from 3 to 18 cm{sup -1}, made with a balloon-borne Fourier transform spectrometer. It is a polarizing Michelson interferometer, cooled in liquid helium, and operated with a germanium bolometer. I give the theory of operation, construction details, and experimental results. The first experiment was successfully completed but the second suffered equipment malfunction on its first flight. I describe the theory of Fourier transformations and give a new understanding of convolutional phase correction computations. I discuss for infrared bolometer calibration procedures, and tabulate test results on nine detectors. I describe methods of improving bolometer sensitivity with immersion optics and with conductive film blackening.

  13. Cosmic Infrared Background Fluctuations and Zodiacal Light

    CERN Document Server

    Arendt, Richard G; Moseley, S H; Mather, J

    2016-01-01

    We have performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution, or from IRAC observations of high latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS field, at low ecliptic latitude where the zodiacal light intensity varies by factors of $\\sim2$ over the range of solar elongations at which the field can be observed. We find that the white noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that ...

  14. IRAS observations of the diffuse infrared background

    Science.gov (United States)

    Hauser, M. G.; Gillett, F. C.; Low, F. J.; Gautier, T. N.; Beichman, C. A.; Aumann, H. H.; Neugebauer, G.; Baud, B.; Boggess, N.; Emerson, J. P.

    1984-01-01

    IRAS data reveal bright emission from interplanetary dust which dominates the celestial background at 12, 25, and 60 microns except near the galactic plane. At 100 microns, interplanetary dust emission is prominent only near the ecliptic plane; diffuse galactic emission is found over the rest of the sky. At the galactic poles, the observed brightness implies that A(v) is likely to be of order 0.1 mag. The angular variation of the zodiacal emission in the ecliptic plane and in the plane at elongation 90 deg, and an annual modulation of the ecliptic pole brightness, are generally consistent with previously determined interplanetary dust distributions.

  15. IRST testing methodologies: Maritime Infrared Background Simulator

    NARCIS (Netherlands)

    Schwering, P.B.W.

    2006-01-01

    In this paper we discuss methodologies to incorporate the effects of environments and scenarios in the testing of IRST systems. The proposed methodology is based on experience with sea based IRST trials combining the possibilities of performance assessment in required scenarios to the real

  16. Probing Reionization through Near-Infrared Background Fluctuations with CIBER

    Science.gov (United States)

    Sullivan, Ian S.

    2010-01-01

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed with foreground subtraction and control of systematics in mind. In addition, the platform of a sounding rocket enables observations of the NIRB outside of narrow atmospheric windows that are uncontaminated by airglow. We will present preliminary results from the first flight. CIBER seeks to measure the absolute brightness spectrum of the extragalactic NIRB, and has two spectrometers dedicated to that purpose. One, a high-resolution Fabry-Perot spectometer, is tuned to the 8545 nm Ca II line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the NIRB spectrum. The second spectrometer measures the NIRB spectrum from 700nm to 1800nm, which spans the wavelength range where a Lyman cutoff feature from Reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2º x 2º field of views with 7 arcsec pixels, but have different band defining filters. The first imager has a wide band centered at 1600nm, and images the background at the expected peak of the spectrum. The imagers’ wide field of view allows them to measure the distinctive power spectrum peaking at 10 arcminutes. The second imager has a wide band centered at 1000nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600nm / 1000nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or low-redshift galaxies.

  17. Delensing the CMB with the Cosmic Infrared Background

    CERN Document Server

    Sherwin, Blake D

    2015-01-01

    As confusion with lensing B-modes begins to limit experiments that search for primordial B-mode polarization, robust methods for delensing the CMB polarization sky are becoming increasingly important. We investigate in detail the possibility of delensing the CMB with the cosmic infrared background (CIB), emission from dusty star-forming galaxies that is an excellent tracer of the CMB lensing signal, in order to improve constraints on the tensor-to-scalar ratio $r$. We find that the maps of the CIB, such as current Planck satellite maps at 545 GHz, can be used to remove more than half of the lensing B-mode power. Calculating optimal combinations of different large-scale-structure tracers for delensing, we find that co-adding CIB data and external arcminute-resolution CMB lensing reconstruction can lead to significant additional improvements in delensing performance. We investigate whether measurement uncertainty in the CIB spectra will degrade the delensing performance if no model of the CIB spectra is assumed...

  18. Planck 2013 results. XVIII. Gravitational lensing-infrared background correlation

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Basak, S.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bethermin, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lacasa, F.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leonardi, R.; Leon-Tavares, J.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Serra, P.; Shellard, E.P.S.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    The multi-frequency capability of the Planck satellite provides information both on the integrated history of star formation (via the cosmic infrared background, or CIB) and on the distribution of dark matter (via the lensing effect on the cosmic microwave background, or CMB). The conjunction of these two unique probes allows us to measure directly the connection between dark and luminous matter in the high redshift (1 1. We measure directly the SFR density with around 2 sigma significance for three redshift bins between z=1 and 7, thus opening a new window into the study of the formation of stars at early times.

  19. An Empirically Based Calculation of the Extragalactic Infrared Background

    CERN Document Server

    Malkan, M A

    1998-01-01

    Using the excellent observed correlations among various infrared wavebands with 12 and 60 micron luminosities, we calculate the 2-300 micron spectra of galaxies as a function of luminosity. We then use 12 micron and 60 micron galaxy luminosity functions derived from IRAS data, together with recent data on the redshift evolution of galaxy emissivity, to derive a new, empirically based IR background spectrum from stellar and dust emission in galaxies. Our best estimate for the IR background is of order 2-3 nW/m^2/sr with a peak around 200 microns reaching 6-8 nW/m^2/sr. Our empirically derived background spectrum is fairly flat in the mid-IR, as opposed to spectra based on modeling with discrete temperatures which exhibit a "valley" in the mid-IR. We also derive a conservative lower limit to the IR background which is more than a factor of 2 lower than our derived flux.

  20. Probing the Universe's Tilt with the Cosmic Infrared Background Dipole

    CERN Document Server

    Fixsen, D J

    2011-01-01

    Conventional interpretation of the observed cosmic microwave background (CMB) dipole is that all of it is produced by local peculiar motions. Alternative explanations requiring part of the dipole to be primordial have received support from measurements of large-scale bulk flows. A test of the two hypothesis is whether other cosmic dipoles produced by collapsed structures later than last scattering coincide with the CMB dipole. One background is the cosmic infrared background (CIB) whose absolute spectrum was measured to ~30% by the COBE satellite. Over the 100 to 500 um wavelength range its spectral energy distribution can provide a probe of its alignment with CMB. This is tested with the COBE FIRAS dataset which is available for such a measurement because of its low noise and frequency resolution important for Galaxy subtraction. Although the FIRAS instrument noise is in principle low enough to determine the CIB dipole, the Galactic foreground is sufficiently close spectrally to keep the CIB dipole hidden. A...

  1. A background free double beta decay experiment

    OpenAIRE

    Giomataris, Ioannis

    2010-01-01

    We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this conc...

  2. Local Signal Impedes the Definition of the Cosmic Infrared Background

    Science.gov (United States)

    Kelsall, Thomas

    2010-01-01

    It was noted (ApJ 508, 44, 1998) when developing a COBE/DIRBE-data-based model for the infrared (IR) signal from the interplanetary dust cloud (IPD) that there were clear evidences of unexpected time-variable wavelength-dependent signals in all the ten DIRBE bands (1.2 to 240 μm). The amplitudes of these signals range in magnitude from the order of one-half to a few percent of the respective-wavelength IPD signal. This presentation provides selected details on the nature of these signals as regards their wavelength-dependent periodicities, time-variable amplitudes, and complex spatial configurations. Particular attention is devoted to describing the consequences imposed by these signals which impede the observational determination of and/or the setting of limits on the cosmic IR background.

  3. Background modeling for the GERDA experiment

    CERN Document Server

    Becerici-Schmidt, N

    2013-01-01

    The neutrinoless double beta (0nubb) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0nubb decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qbb come from Bi-214, Th-228, K-42, Co-60 and alpha emitting isotopes in the Ra-226 decay chain, with a fraction depending on the assumed source positions.

  4. The projected background for the CUORE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Alfonso, K.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Banks, T. I.; Bari, G.; Beeman, J. W.; Bellini, F.; Benato, G.; Bersani, A.; Biassoni, M.; Branca, A.; Brofferio, C.; Bucci, C.; Camacho, A.; Caminata, A.; Canonica, L.; Cao, X. G.; Capelli, S.; Cappelli, L.; Carbone, L.; Cardani, L.; Carniti, P.; Casali, N.; Cassina, L.; Chiesa, D.; Chott, N.; Clemenza, M.; Copello, S.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Cushman, J. S.; D’Addabbo, A.; Dafinei, I.; Davis, C. J.; Dell’Oro, S.; Deninno, M. M.; Di Domizio, S.; Di Vacri, M. L.; Drobizhev, A.; Fang, D. Q.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M. A.; Freedman, S. J.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gladstone, L.; Gorla, P.; Gotti, C.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Hansen, E.; Heeger, K. M.; Hennings-Yeomans, R.; Hickerson, K. P.; Huang, H. Z.; Kadel, R.; Keppel, G.; Kolomensky, Yu. G.; Leder, A.; Ligi, C.; Lim, K. E.; Ma, Y. G.; Maino, M.; Marini, L.; Martinez, M.; Maruyama, R. H.; Mei, Y.; Moggi, N.; Morganti, S.; Mosteiro, P. J.; Napolitano, T.; Nastasi, M.; Nones, C.; Norman, E. B.; Novati, V.; Nucciotti, A.; O’Donnell, T.; Ouellet, J. L.; Pagliarone, C. E.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pessina, G.; Pettinacci, V.; Piperno, G.; Pira, C.; Pirro, S.; Pozzi, S.; Previtali, E.; Rosenfeld, C.; Rusconi, C.; Sakai, M.; Sangiorgio, S.; Santone, D.; Schmidt, B.; Schmidt, J.; Scielzo, N. D.; Singh, V.; Sisti, M.; Smith, A. R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tomei, C.; Trentalange, S.; Vignati, M.; Wagaarachchi, S. L.; Wang, B. S.; Wang, H. W.; Welliver, B.; Wilson, J.; Winslow, L. A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zhang, G. Q.; Zhu, B. X.; Zimmermann, S.; Zucchelli, S.; Laubenstein, M.

    2017-08-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is designed to search for neutrinoless double beta decay of 130 Te with an array of 988 TeO 2 bolometers operating at temperatures around 10 mK. The experiment is currently being commissioned in Hall A of Laboratori Nazionali del Gran Sasso, Italy. The goal of CUORE is to reach a 90% C.L. exclusion sensitivity on the 130Te decay half-life of 9 × 10 25 years after 5 years of data taking. The main issue to be addressed to accomplish this aim is the rate of background events in the region of interest, which must not be higher than 10 -2 counts/keV/kg/year. We developed a detailed Monte Carlo simulation, based on results from a campaign of material screening, radioassays, and bolometric measurements, to evaluate the expected background. This was used over the years to guide the construction strategies of the experiment and we use it here to project a background model for CUORE. In this paper we report the results of our study and our expectations for the background rate in the energy region where the peak signature of neutrinoless double beta decay of 130 Te is expected.

  5. Updated analysis of near-infrared background fluctuations

    CERN Document Server

    Yue, Bin; Salvaterra, Ruben

    2016-01-01

    The power spectrum of Near InfraRed Background (NIRB) fluctuations measured at 3.6 $\\mu$m by {\\tt Spitzer} shows a clustering excess over the known galaxies signal that has been interpreted in terms of early ($z\\simgt 13$), accreting (direct collapse) black holes (DCBH) or low-$z$ intrahalo light (IHL). In addition, these fluctuations correlate with the cosmic X-ray background (CXB) measured at (0.5-2) keV, supporting the black hole explanation. This scenario has been questioned by the recent detection of a correlation between the two {\\tt CIBER} 1.1/1.6 $\\mu$m bands with the 3.6 $\\mu$m {\\tt Spitzer} one. This correlation is hardly explained by early DCBHs that, due to intergalactic absorption, cannot contribute to the shortest wavelength bands. Here we show that the new correlation is caused instead by a Diffuse Galactic Light (DGL) component arising from Galactic stellar light scattered by dust. The black hole interpretation of the excess remains perfectly valid and, actually, the inclusion of DGL allows le...

  6. An Empirically Based Model for Predicting Infrared Luminosity Functions, Deep Infrared Galaxy Counts and the Diffuse Infrared Background

    CERN Document Server

    Malkan, M A

    2001-01-01

    We predict luminosity functions and number counts for extragalactic infrared sources at various wavelengths using our empirically based model. This is the same model which we used successfully to predict the spectral energy distribution of the diffuse infrared background. Comparisons of galaxy count results with existing data indicate that either galaxy luminosity evolution is not stronger that Q=3.1 (where L is proportional to (1+z)^{Q}) or that this evolution does not continue beyond a redshift of 2. However, measurements of the far infrared background from COBE-DIRBE seem to suggest a stronger evolution for far infrared emission with Q > 4 in the redshift range beteen 0 and 1. We discuss several interpretations of these results and also discuss how future observations can reconcile this apparent conflict. We also make predictions of the redshift distributions of extragalactic infrared sources at selected flux levels which can be tested by planned detectors. Finally, we predict the fluxes at which various f...

  7. Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.

    Science.gov (United States)

    Ade, P A R; Akiba, Y; Anthony, A E; Arnold, K; Atlas, M; Barron, D; Boettger, D; Borrill, J; Borys, C; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Le Jeune, M; Lee, A T; Leitch, E M; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Poletti, D; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K; Schanning, I; Schenck, D E; Sherwin, B D; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tikhomirov, A; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2014-04-04

    We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

  8. Evidence for Gravitational Lensing of the Cosmic Microwave Background Polarization from Cross-correlation with the Cosmic Infrared Background

    CERN Document Server

    Ade, P A R; Anthony, A E; Arnold, K; Barron, D; Boettger, D; Borrill, J; Borys, C; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K; Schanning, I; Schenck, D E; Sherwin, B D; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tikhomirov, A; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2013-01-01

    We reconstruct the gravitational lensing convergence signal from Cosmic Microwave Background (CMB) polarization data taken by the POLARBEAR experiment and cross-correlate it with Cosmic Infrared Background (CIB) maps from the Herschel satellite. From the cross-spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0$\\sigma$ and evidence for the presence of a lensing $B$-mode signal at a significance of 2.3$\\sigma$. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null-tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

  9. Probing the Universe's Tilt with the Cosmic Infrared Background Dipole

    Science.gov (United States)

    Fixsen, D. J.; Kashlinsky, A.

    2011-06-01

    Conventional interpretation of the observed cosmic microwave background (CMB) dipole is that all of it is produced by local peculiar motions. Alternative explanations requiring part of the dipole to be primordial have received support from measurements of large-scale bulk flows. A test of the two hypotheses is whether other cosmic dipoles produced by collapsed structures later than the last scattering coincide with the CMB dipole. One background is the cosmic infrared background (CIB) whose absolute spectrum was measured to ~30% by the COBE satellite. Over the 100-500 μm wavelength range its spectral energy distribution can provide a probe of its alignment with the CMB. This is tested with the COBE FIRAS data set which is available for such a measurement because of its low noise and frequency resolution which are important for Galaxy subtraction. Although the FIRAS instrument noise is in principle low enough to determine the CIB dipole, the Galactic foreground is sufficiently close spectrally to keep the CIB dipole hidden. A similar analysis is performed with DIRBE, which—because of the limited frequency coverage—provides a poorer data set. We discuss strategies for measuring the CIB dipole with future instruments to probe the tilt and apply it to the Planck, Herschel, and the proposed Pixie missions. We demonstrate that a future FIRAS-like instrument with instrument noise a factor of ~10 lower than FIRAS would make a statistically significant measurement of the CIB dipole. We find that the Planck and Herschel data sets will not allow a robust CIB dipole measurement. The Pixie instrument promises a determination of the CIB dipole and its alignment with either the CMB dipole or the dipole galaxy acceleration vector.

  10. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  11. A background free double beta decay experiment

    Science.gov (United States)

    Giomataris, I.

    2011-08-01

    We present a new detection scheme for rejecting backgrounds in neutrino-less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is the high-pressure 136Xe emitter where the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is the use of the Spherical Proportional Counter that provides, using a single read-out channel, two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of its higher density, the considered process is out of energy range. An escape will be the fabrication of double decay emitters having lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.

  12. Data analysis of cosmic microwave background experiments

    Science.gov (United States)

    Abroe, Matthew Edmund

    2004-12-01

    The cosmic microwave background (CMB) is a powerful tool for determining and constraining the fundamental properties of our universe. In this thesis we present various computational and statistical techniques used to analyze datasets from CMB experiments, and apply them to both simulated and actual datasets. The algorithms presented in this thesis perform a variety of tasks in relation to the goal of extracting scientific information from CMB data sets. The CMB anisotropy power spectrum is sensitive to numerous parameters that determine the evolutionary and large scale properties of our universe. Now that numerous experiments have mapped the CMB intensity fluctuations on overlapping regions of the sky it is important to ensure that the various experiments are indeed observing the same signal. We cross-correlate the cosmic microwave background temperature anisotropy maps from the WMAP, MAXIMA-I, and MAXIMA-II experiments. The results conclusively show that the three experiments not only display the same statistical properties of the CMB anisotropy, but also detect the same features wherever the observed sky areas overlap. We conclude that the contribution of systematic errors to these maps is negligible and that MAXIMA and WMAP have accurately mapped the cosmic microwave background anisotropy. Due to a quadrapole anisotropy at last scattering it is predicted that the CMB photons should be linearly polarized, and that the polarization intensity will be roughly an order of magnitude lower than the intensity fluctuations. Two computationally intensive methods for simulating the CMB polarization signal on the sky are presented. Now that CMB polarization experiments are currently producing data sets new algorithms for analyzing polarization time stream data must be developed and tested. We demonstrate how to generate simulations of a polarization experiment in the temporal domain and apply these simulations to the MAXIPOL case. We develop a maximum likelihood map making

  13. Contribution of Lensed SCUBA Galaxies to the Cosmic Infrared Background

    Science.gov (United States)

    Zemcov, Michael; Blain, Andrew; Halpern, Mark; Levenson, Louis

    2010-09-01

    The surface density of submillimeter (sub-mm) galaxies as a function of flux, usually termed the source number counts, constrains models of the evolution of the density and luminosity of starburst galaxies. At the faint end of the distribution, direct detection and counting of galaxies are not possible. However, gravitational lensing by clusters of galaxies allows detection of sources which would otherwise be too dim to study. We have used the largest catalog of sub-mm-selected sources along the line of sight to galaxy clusters to estimate the faint end of the 850 μm number counts; integrating to S = 0.10 mJy, the equivalent flux density at 850 μm is νI ν = 0.24 ± 0.03 nW m-2 sr-1. This provides a lower limit to the extragalactic far-infrared background and is consistent with direct estimates of the full intensity from the FIRAS. The results presented here can help to guide strategies for upcoming surveys carried out with single-dish sub-mm instruments.

  14. Contribution of Lensed SCUBA Galaxies to the Cosmic Infrared Background

    CERN Document Server

    Zemcov, M; Halpern, M; Levenson, L

    2010-01-01

    The surface density of sub-millimeter galaxies as a function of flux, usually termed the source number counts, constrains models of the evolution of the density and luminosty of starburst galaxies. At the faint end of the distribution, direct detection and counting of galaxies is not possible. However, gravitational lensing by clusters of galaxies allows detection of sources which would otherwise be too dim to study. We have used the largest catalog of sub-mm-selected sources along the line of sight to galaxy clusters to estimate the faint end of the 850 micron number counts; the equivalent flux density at 850 microns is v I_v = 3.9 +/- 0.7 x 10^-10 W/m^2/sr. This provides a lower limit to the extragalactic far infrared background and is consistent with direct estimates of the full intensity from the FIRAS. The results presented here can help to guide strategies for upcoming surveys carried out with single dish sub-mm instruments.

  15. History of Space-Based Infrared Astronomy and the Air Force Infrared Celestial Backgrounds Program

    Science.gov (United States)

    2008-04-18

    supported the high resolution investigations conducted under the AFGL backgrounds characterization program. Finally, Alan Bentley (1989) was given...Jr., J.R. Pier, P.S. Prieto , A. Prosapio, C. Rivetta, D.P. Schneider, S. Snedden & S. Wang (2006) The 2.5 m Telescope of the Sloan Digital Sky Survey...Espinosa (1984) Further Ground-Based Studies of Sources from the AFGL Infrared Sky Survey, AFGL–TR–84–0114. ADA156189 Jones, A.W., M.J. Selby, M. Prieto

  16. Infrared small target and background separation via column-wise weighted robust principal component analysis

    Science.gov (United States)

    Dai, Yimian; Wu, Yiquan; Song, Yu

    2016-07-01

    When facing extremely complex infrared background, due to the defect of l1 norm based sparsity measure, the state-of-the-art infrared patch-image (IPI) model would be in a dilemma where either the dim targets are over-shrinked in the separation or the strong cloud edges remains in the target image. In order to suppress the strong edges while preserving the dim targets, a weighted infrared patch-image (WIPI) model is proposed, incorporating structural prior information into the process of infrared small target and background separation. Instead of adopting a global weight, we allocate adaptive weight to each column of the target patch-image according to its patch structure. Then the proposed WIPI model is converted to a column-wise weighted robust principal component analysis (CWRPCA) problem. In addition, a target unlikelihood coefficient is designed based on the steering kernel, serving as the adaptive weight for each column. Finally, in order to solve the CWPRCA problem, a solution algorithm is developed based on Alternating Direction Method (ADM). Detailed experiment results demonstrate that the proposed method has a significant improvement over the other nine classical or state-of-the-art methods in terms of subjective visual quality, quantitative evaluation indexes and convergence rate.

  17. A background free double beta decay experiment

    CERN Document Server

    Giomataris, Ioannis

    2010-01-01

    We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a te...

  18. Background simulation for the COBRA-experiment

    Energy Technology Data Exchange (ETDEWEB)

    Quante, Thomas [TU Dortmund, Institut fuer Physik (Germany); Collaboration: COBRA-Collaboration

    2015-07-01

    COBRA is a next-generation experiment searching for neutrinoless double beta (0νββ) decay using CdZnTe semiconductor detectors. The main focus is on {sup 116}Cd, with a Q-value of 2813.5 keV well above the highest dominant naturally occurring gamma lines. By measuring the half-life of the 0νββ decay, it is possible to clarify the nature of the neutrino as either Dirac or Majorana particle and furthermore to determine the effective Majorana mass. COBRA is currently in the demonstrator phase to study possible background contributions and gain information about the longterm stability of the used detectors. For this purpose a demonstrator array made up of 64 Cadmium-Zinc-Telluride (CdZnTe) semiconductor detectors in coplanar grid configuration was designed and realised at the Gran Sasso Underground laboratory (LNGS) in Italy. Simulations of the whole demonstrator setup are ongoing to reproduce the measured spectra for each detector. This is done in two steps. The first uses the Geant4 based framework VENOM for tracking and energy deposition inside each detector. Detector effects like the energy resolution and electron trapping have to be applied in the second step. The used detector geometry has to be verified against calibration measurements. This talk gives an overview of the current simulation status.

  19. Ratio-model for the simulation of infrared spectra of pollution gases in complicated background

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A ratio-model for the computer simulation of infrared spectra of pollution gases in complicated background is proposed. The characteristic spectrum of the hazardous pollution gas is simulated with background spectra which are measured by passive Fourier transform infrared spectrometer. The simulated results agree well with the experimental results.

  20. Fourier transform infrared spectrometery: an undergraduate experiment

    Science.gov (United States)

    Lerner, L.

    2016-11-01

    Simple apparatus is developed, providing undergraduate students with a solid understanding of Fourier transform (FT) infrared (IR) spectroscopy in a hands on experiment. Apart from its application to measuring the mid-IR spectra of organic molecules, the experiment introduces several techniques with wide applicability in physics, including interferometry, the FT, digital data analysis, and control theory.

  1. The Bolund Experiment: Overview and Background

    DEFF Research Database (Denmark)

    Bechmann, Andreas; Berg, Jacob; Courtney, Michael;

    The Bolund experiment is a measuring campaign performed in 2007 and 2008. The aim of the experiment is to measure the flow field around the Bolund hill in order to provide a dataset for validating numerical flow models. The present report gives an overview of the whole experiment including a desc...

  2. On the origin of near-infrared extragalactic background light anisotropy.

    Science.gov (United States)

    Zemcov, Michael; Smidt, Joseph; Arai, Toshiaki; Bock, James; Cooray, Asantha; Gong, Yan; Kim, Min Gyu; Korngut, Phillip; Lam, Anson; Lee, Dae Hee; Matsumoto, Toshio; Matsuura, Shuji; Nam, Uk Won; Roudier, Gael; Tsumura, Kohji; Wada, Takehiko

    2014-11-07

    Extragalactic background light (EBL) anisotropy traces variations in the total production of photons over cosmic history and may contain faint, extended components missed in galaxy point-source surveys. Infrared EBL fluctuations have been attributed to primordial galaxies and black holes at the epoch of reionization (EOR) or, alternately, intrahalo light (IHL) from stars tidally stripped from their parent galaxies at low redshift. We report new EBL anisotropy measurements from a specialized sounding rocket experiment at 1.1 and 1.6 micrometers. The observed fluctuations exceed the amplitude from known galaxy populations, are inconsistent with EOR galaxies and black holes, and are largely explained by IHL emission. The measured fluctuations are associated with an EBL intensity that is comparable to the background from known galaxies measured through number counts and therefore a substantial contribution to the energy contained in photons in the cosmos.

  3. Infrared radiation scene generation of stars and planets in celestial background

    Science.gov (United States)

    Guo, Feng; Hong, Yaohui; Xu, Xiaojian

    2014-10-01

    An infrared (IR) radiation generation model of stars and planets in celestial background is proposed in this paper. Cohen's spectral template1 is modified for high spectral resolution and accuracy. Based on the improved spectral template for stars and the blackbody assumption for planets, an IR radiation model is developed which is able to generate the celestial IR background for stars and planets appearing in sensor's field of view (FOV) for specified observing date and time, location, viewpoint and spectral band over 1.2μm ~ 35μm. In the current model, the initial locations of stars are calculated based on midcourse space experiment (MSX) IR astronomical catalogue (MSX-IRAC) 2 , while the initial locations of planets are calculated using secular variations of the planetary orbits (VSOP) theory. Simulation results show that the new IR radiation model has higher resolution and accuracy than common model.

  4. Modeling the evolution of infrared galaxies : clustering of galaxies in the Cosmic Infrared Background

    CERN Document Server

    Pénin, Aurélie; Lagache, Guilaine; Béthermin, Matthieu

    2011-01-01

    Star-forming galaxies are a highly biased tracer of the underlying dark matter density field. Their clustering can be studied through the cosmic infrared background anisotropies. These anisotropies have been measured from 100 \\mum to 2 mm in the last few years. In this paper, we present a fully parametric model allowing a joint analysis of these recent observations. In order to develop a coherent model at various wavelengths, we rely on two building blocks. The first one is a parametric model that describes the redshift evolution of the luminosity function of star-forming galaxies. It compares favorably to measured differential number counts and luminosity functions. The second one is a halo model based description of the clustering of galaxies. Starting from a fiducial model, we investigate parameter degeneracies using a Fisher analysis. We then discuss how halo of different mass and redshift, how LIRGs and ULIRGs, contribute to the CIB angular power spectra. From the Fisher analysis, we conclude that we can...

  5. Dewey's "Art as Experience": The Psychological Background

    Science.gov (United States)

    Shusterman, Richard

    2010-01-01

    The year 2009 marks the 150th anniversary of John Dewey's birth and also the 75th anniversary of the publication of his aesthetic masterpiece "Art as Experience"--a book that has been extremely influential within the field of aesthetics, not only in philosophical aesthetics and aesthetic education but also in the arts themselves. In this essay,…

  6. Study on Optical Filter Heating in Background Limited Detector Experiments

    Science.gov (United States)

    Bueno, J.; de Visser, P. J.; Doyle, S.; Baselmans, J. J. A.

    2014-09-01

    Cryogenic test setups with controlled stray light environments capable of reaching ultra-low radiative background levels are required to test far infrared (FIR) and submillimeter (sub-mm) wave radiation detectors for future space based observatories. In recent experiments (Nature Commun 5:3130, 2014), in which 1.54 THz radiation was coupled onto an antenna-coupled kinetic inductance detector (KID), we found a higher than expected optical loading. We show that this can be explained by assuming heating of the metal mesh IR filters and re-radiation onto the KID. Note that the total power from the cryogenic black body source used in the experiments (at T = - K) is much larger than the power inside the - THz band we use to calibrate our detector. The out-of-band radiation can have up to 5 orders of magnitude more power than inside the - THz band of interest. A strategy to mitigate the filter heating problem is presented, and when it is implemented, the validated upper limit for stray light at the detector level is down to few aW.

  7. Detecting high-$z$ galaxies in the Near Infrared Background

    CERN Document Server

    Yue, Bin; Helgason, Kári

    2015-01-01

    Emission from high-$z$ galaxies must unquestionably contribute to the Near-InfraRed Background (NIRB). However, this contribution has so far proven difficult to isolate even after subtracting resolved galaxies to deep levels. Remaining NIRB fluctuations are dominated by unresolved low-redshift galaxies on small angular scales, and by an unidentified component of unclear origin on large scales ($\\approx 1000"$). In this paper, by analyzing mock maps generated from semi-numerical simulations and empirically determined $L_{\\rm UV} - M_{\\rm h}$ relations, we find that fluctuations associated with galaxies at $5 < z < 10$ amount to several percent of the unresolved NIRB flux. We investigate the properties of this component for different survey areas and limiting magnitudes. In all cases, we show that this signal can be efficiently, and most easily at small angular scales, isolated by cross-correlating the source-subtracted NIRB with Lyman Break Galaxies (LBGs) detected in the same field by {\\tt HST} surveys....

  8. 24 CFR 3282.357 - Background and experience.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Background and experience. 3282.357... § 3282.357 Background and experience. All private organizations shall submit statements of the organizations' experience in the housing industry, including a list of housing products, equipment, and...

  9. Research on Gaussian distribution preprocess method of infrared multispectral image background clutter

    Institute of Scientific and Technical Information of China (English)

    张伟; 武春风; 邓盼; 范宁

    2004-01-01

    This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on the skewness-kurtosis test. In the end, a multivariate Gaussian distribution mathematical expression of background clutter image is given.

  10. Background correction in near-infrared spectra of plant extracts by orthogonal signal correction

    Institute of Scientific and Technical Information of China (English)

    QU Hai-bin; OU Dan-lin; CHENG Yi-yu

    2005-01-01

    In near-infrared (NIR) analysis of plant extracts, excessive background often exists in near-infrared spectra. The detection of active constituents is difficult because of excessive background, and correction of this problem remains difficult. In this work, the orthogonal signal correction (OSC) method was used to correct excessive background. The method was also compared with several classical background correction methods, such as offset correction, multiplicative scatter correction (MSC),standard normal variate (SNV) transformation, de-trending (DT), first derivative, second derivative and wavelet methods. A simulated dataset and a real NIR spectral dataset were used to test the efficiency of different background correction methods. The results showed that OSC is the only effective method for correcting excessive background.

  11. In-frame and inter-frame information based infrared moving small target detection under complex cloud backgrounds

    Science.gov (United States)

    Wan, Minjie; Gu, Guohua; Cao, Ercong; Hu, Xiaobo; Qian, Weixian; Ren, Kan

    2016-05-01

    Infrared moving small target detection under complex cloud backgrounds is one of the key techniques of infrared search and track (IRST) systems. This paper proposes a novel method based on in-frame inter-frame information to detect infrared moving small targets accurately. For a single frame, in the spatial domain, a directional max-median filter is developed to make a pre-processing and a background suppression filtering template is utilized on the denoised image to highlight target. Then, targets in cloud regions and non-cloud regions are extracted by different thresholds according to a cloud discrimination method so that a spatial domain map (SDM) is acquired. In the frequency domain, we design an α-DoB band-pass filter to conduct coarse saliency detection and make an amplitude transformation with smoothing processing which is the so-called elaborate saliency detection. Furthermore, a frequency domain map (FDM) is acquired by an adaptive binary segmentation method. Lastly, candidate targets in single frame are extracted by a discrimination based on intensity and spatial distance criteria. For consecutive frames, a false alarm suppression is conducted on account of differences of motion features between moving target and false alarms to improve detection accuracy again. Large numbers of experiments demonstrate that the proposed method has satisfying detection effectiveness and robustness for infrared moving small target detection under complex cloud backgrounds.

  12. Non-negative infrared patch-image model: Robust target-background separation via partial sum minimization of singular values

    Science.gov (United States)

    Dai, Yimian; Wu, Yiquan; Song, Yu; Guo, Jun

    2017-03-01

    To further enhance the small targets and suppress the heavy clutters simultaneously, a robust non-negative infrared patch-image model via partial sum minimization of singular values is proposed. First, the intrinsic reason behind the undesirable performance of the state-of-the-art infrared patch-image (IPI) model when facing extremely complex backgrounds is analyzed. We point out that it lies in the mismatching of IPI model's implicit assumption of a large number of observations with the reality of deficient observations of strong edges. To fix this problem, instead of the nuclear norm, we adopt the partial sum of singular values to constrain the low-rank background patch-image, which could provide a more accurate background estimation and almost eliminate all the salient residuals in the decomposed target image. In addition, considering the fact that the infrared small target is always brighter than its adjacent background, we propose an additional non-negative constraint to the sparse target patch-image, which could not only wipe off more undesirable components ulteriorly but also accelerate the convergence rate. Finally, an algorithm based on inexact augmented Lagrange multiplier method is developed to solve the proposed model. A large number of experiments are conducted demonstrating that the proposed model has a significant improvement over the other nine competitive methods in terms of both clutter suppressing performance and convergence rate.

  13. Planck early results. XVIII. The power spectrum of cosmic infrared background anisotropies

    DEFF Research Database (Denmark)

    Bucher, M.; Delabrouille, J.; Giraud-Héraud, Y.

    2011-01-01

    Using Planck maps of six regions of low Galactic dust emission with a total area of about 140 deg2, we determine the angular power spectra of cosmic infrared background (CIB) anisotropies from multipole = 200 to = 2000 at 217, 353, 545 and 857 GHz. We use 21-cm observations of Hi as a tracer of t...

  14. Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.

    2014-01-01

    We present new measurements of cosmic infrared background (CIB) anisotropies using Planck. Combining HFI data with IRAS, the angular auto-and cross-frequency power spectrum is measured from 143 to 3000 GHz, and the auto-bispectrum from 217 to 545 GHz. The total areas used to compute the CIB power...

  15. The effects of camera jitter for background subtraction algorithms on fused infrared-visible video streams

    Science.gov (United States)

    Becker, Stefan; Scherer-Negenborn, Norbert; Thakkar, Pooja; Hübner, Wolfgang; Arens, Michael

    2016-10-01

    This paper is a continuation of the work of Becker et al.1 In their work, they analyzed the robustness of various background subtraction algorithms on fused video streams originating from visible and infrared cameras. In order to cover a broader range of background subtraction applications, we show the effects of fusing infrared-visible video streams from vibrating cameras on a large set of background subtraction algorithms. The effectiveness is quantitatively analyzed on recorded data of a typical outdoor sequence with a fine-grained and accurate annotation of the images. Thereby, we identify approaches which can benefit from fused sensor signals with camera jitter. Finally conclusions on what fusion strategies should be preferred under such conditions are given.

  16. Planck 2015 results. XXIII. The thermal Sunyaev-Zeldovich effect--cosmic infrared background correlation

    CERN Document Server

    Ade, P A R; Arnaud, M; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Benabed, K; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Burigana, C; Butler, R C; Calabrese, E; Catalano, A; Chamballu, A; Chiang, H C; Christensen, P R; Churazov, E; Clements, D L; Colombo, L P L; Combet, C; Comis, B; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Ducout, A; Dupac, X; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Finelli, F; Flores-Cacho, I; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Galeotta, S; Galli, S; Ganga, K; Génova-Santos, R T; Giard, M; Giraud-Héraud, Y; Gjerløw, E; González-Nuevo, J; Górski, K M; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Hansen, F K; Harrison, D L; Helou, G; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Hornstrup, A; Hovest, W; Huffenberger, K M; Hurier, G; Jaffe, A H; Jaffe, T R; Jones, W C; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Langer, M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leonardi, R; Levrier, F; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Maggio, G; Maino, D; Mak, D S Y; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Melchiorri, A; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Nati, F; Natoli, P; Noviello, F; Novikov, D; Novikov, I; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Partridge, B; Pasian, F; Pearson, T J; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Piat, M; Pierpaoli, E; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Pratt, G W; Prunet, S; Puget, J -L; Rachen, J P; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Ristorcelli, I; Rocha, G; Rosset, C; Rossetti, M; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Scott, D; Spencer, L D; Stolyarov, V; Stompor, R; Sunyaev, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Wehus, I K; Welikala, N; Yvon, D; Zacchei, A; Zonca, A

    2015-01-01

    We use Planck data to detect the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planck-confirmed galaxy clusters. We detect infrared emission produced by dusty galaxies inside these clusters and demonstrate that the infrared emission is about 50% more extended than the tSZ effect. Modelling the emission with a Navarro--Frenk--White profile, we find that the radial profile concentration parameter is $c_{500} = 1.00^{+0.18}_{-0.15}$. This indicates that infrared galaxies in the outskirts of clusters have higher infrared flux than cluster-core galaxies. We also study the cross-correlation between tSZ and CIB anisotropies, following three alternative approaches based on power spectrum analyses: (i) using a catalogue of confirmed clusters detected in Planck data; (ii) using an all-sky tSZ map built from Planck frequency maps; and (iii) using cross-spe...

  17. Limits on the cosmic infrared background from clustering in COBE/DIRBE maps

    CERN Document Server

    Kashlinsky, A; Odenwald, S

    1997-01-01

    We discuss a new method of estimating the cosmic infrared background (CIB) from the spatial properties of infrared maps and give the limits on the CIB from applying it to the COBE/DIRBE maps. The strongest limits are obtained at mid- to far-IR where foregrounds are bright, but smooth. If the CIB comes from matter clustered like galaxies, the smoothness of the maps implies CIB levels less than $\\sim$(10-15) nW/m$^2$/sr over this wavelength range.

  18. Tank segmentation of infrared images with complex background for the homing anti-tank missile

    Science.gov (United States)

    Zhou, Yulong; Gao, Min; Fang, Dan; Zhang, Baoquan

    2016-07-01

    In an effort to achieve fast and effective tank segmentation of infrared images under complex background for the homing anti-tank missile, the threshold of the maximum between-class variance method (i.e., the Otsu method) is experimentally analyzed, and the working mechanism of the Otsu method is revealed. Subsequently, a fast and effective method for tank segmentation under complex background is proposed based on the Otsu method by constraining the image background pixels and gray levels. Firstly, with the prior information of the tank, derive the equation to calculate the number of pixels of tank according to optical imaging principle, and then use the calculated tank size to constrain the image background pixels. Secondly, employ the golden section to restrict the background gray levels. Finally, use the Otsu method to implement the segmentation of the tank. Experimental results demonstrate that the proposed method can get as an ideal result as the manual segmentation with less running time.

  19. Planck 2015 results: XXIII. The thermal Sunyaev-Zeldovich effect-cosmic infrared background correlation

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    We use Planck data to detect the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planck-confirmed galaxy clusters. We detect infrared...... data; (ii) using an all-sky tSZ map built from Planck frequency maps; and (iii) using cross-spectra between Planck frequency maps. With the three different methods, we detect the tSZ-CIB cross-power spectrum at significance levels of (i) 6σ; (ii) 3σ; and (iii) 4σ. We model the tSZ-CIB cross...

  20. A minimal empirical model for the cosmic far-infrared background anisotropies

    CERN Document Server

    Wu, Hao-Yi

    2016-01-01

    Cosmic far-infrared background (CFIRB) probes unresolved dusty star-forming galaxies across cosmic time and is complementary to ultraviolet/optical probes of galaxy evolution. In this work, we interpret the observed CFIRB anisotropies using an empirical model based on recent galaxy survey results, including stellar mass functions, star-forming main sequence, and dust attenuation. Without introducing new parameters, our model agrees well with the CFIRB anisotropies observed by Planck and the submillimeter number counts observed by Herschel. We find that the commonly used linear relation between infrared luminosity and star-formation rate over-produces the observed CFIRB amplitudes, and lower infrared luminosities from low-mass galaxies are required. Our results indicate that CFIRB not only provides a consistency check for galaxy evolution models but also informs the star-formation rate and dust content for low-mass galaxies.

  1. Radio Wavelength Constraints on the Sources of the Far Infrared Background

    CERN Document Server

    Haarsma, D B

    1998-01-01

    The cosmic far infrared background detected recently by the COBE-DIRBE team is presumably due, in large part, to the far infrared (FIR) emission from all galaxies. We take the well-established correlation between FIR and radio luminosity for individual galaxies and apply it to the FIR background. We find that these sources make up about half of the extragalactic radio background, the other half being due to AGN. This is in agreement with other radio observations, which leads us to conclude that the FIR-radio correlation holds well for the very faint sources making up the FIR background, and that the FIR background is indeed due to star-formation activity (not AGN or other possible sources). If these star-forming galaxies have a radio spectral index between 0.4 and 0.8, and make up 40 to 60% of the extragalactic radio background, we find that they have redshifts between roughly 1 and 2, in agreement with recent estimates by Madau et al. of the redshift of peak star-formation activity. We compare the observed e...

  2. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Bellini, F.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carbone, L.; Carrettoni, M.; Clemenza, M.; Cremonesi, O.; Creswick, R. J.; Domizio, S. Di; Dolinski, M. J.; Ejzak, L.; Faccini, R.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Kadel, R.; Kazkaz, K.; Kraft, S.; Kogler, L.; Kolomensky, Yu. G.; Maiano, C.; Maruyama, R. H.; Martinez, C.; Martinez, M.; Mizouni, L.; Morganti, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Risegari, L.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Tomei, C.; Ventura, G.; Vignati, M.

    2010-04-15

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.

  3. A low background Micromegas detector for the CAST experiment

    CERN Document Server

    Abbon, P.; Aune, S.; Besin, D.; Cazaux, S.; Contrepois, P.; Duportail, N.; Ferrer Ribas, E.; Gros, M.; Irastorza, I.G.; Giganon, A.; Giomataris, I.; Riallot, M.; Zaffanela, G.; Fanourakis, G.; Geralis, T.; Kousouris, K.; Zachariadou, K.; Dafni, T.; Decker, T.; Hill, R.; Pivovaroff, M.; Soufli, R.; Morales, J.

    2005-01-01

    A low background Micromegas detector has been operating on the CAST experiment at CERN for the search of solar axions during the first phase of the experiment (2002-2004). The detector operated efficiently and achieved a very low level of background rejection ($5\\times 10^{-5}$ counts keV$^{-1}$cm$^{-2}$s$^{-1}$) thanks to its good spatial and energy resolution as well as the low radioactivity materials used in the construction of the detector. For the second phase of the experiment (2005-2007), the detector will be upgraded by adding a shielding and including focusing optics. These improvements should allow for a background rejection better than two orders of magnitude.

  4. Reference analysis of the signal + background model in counting experiments

    Science.gov (United States)

    Casadei, D.

    2012-01-01

    The model representing two independent Poisson processes, labelled as ``signal'' and ``background'' and both contributing additively to the total number of counted events, is considered from a Bayesian point of view. This is a widely used model for the searches of rare or exotic events in presence of a background source, as for example in the searches performed by high-energy physics experiments. In the assumption of prior knowledge about the background yield, a reference prior is obtained for the signal alone and its properties are studied. Finally, the properties of the full solution, the marginal reference posterior, are illustrated with few examples.

  5. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Bloxham, T; Brofferio, C; Bryant, A; Bucci, C; Canonica, L; Capelli, S; Carbone, L; Carrettoni, M; Clemenza, M; Cremonesi, O; Creswick, R J; Domizio, S D; Dolinski, M J; Ejzak, L; Faccini, R; Farach, H A; Ferri, E; Ferroni, F; Firoini, E; Foggetta, L; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Kadel, R; Kazkaz, K; Kraft, S; Kogler, L; Kolomensky, Y G; Maiano, C; Maruyama, R H; Martinez, C; Martinez, M; Mizouni, L; Morganti, S; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Orio, F; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Rusconi, C; Salvioni, C; Sangiorgio, S; Schaeffer, D; Scielzo, N D; Sisti, M; Smith, A R; Tomei, C; Ventura, G; Vignati, M

    2009-11-16

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.

  6. Cross-correlations between 21 cm,X-ray and infrared backgrounds

    Institute of Scientific and Technical Information of China (English)

    Huan-Yuan Shan; Bo Qin

    2009-01-01

    The history of the cosmological reionization is still unclear. Two ionizing sources, stars and QSOs, are believed to play important roles during this epoch. Besides the 21 cm signals, the infrared emission from Pop Ⅲ stars and X-ray photons from QSOs can be powerful probes of the reionization. Here we present a cross-correlation study of the 21 cm, infrared and X-ray backgrounds. The advantage of doing such cross-correlations is that we could highlight the correlated signals and eliminate irrelevant fore-grounds. We develop a shell model to describe the 21 cm signals and find that PopⅢ stars can provide higher 21 cm signals than QSOs. Using the ROSAT data for X-ray and AKARI data for infrared, we predict various cross power spectra analytically and dis-cuss prospects for detecting these cross-correlation signals in future low frequency radio surveys. We find that, although these cross-correlational signals have distinct features, so far, they have been difficult to detect due to the high noise of the soft X-ray and infrared backgrounds given by ROSAT and AKARI.

  7. Background limited mid-infrared photodetection with photovoltaic HgTe colloidal quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Guyot-Sionnest, Philippe, E-mail: pgs@uchicago.edu; Roberts, John Andris [James Franck Institute, 929 E. 57th Street, The University of Chicago, Chicago, Illinois 60637 (United States)

    2015-12-21

    The photovoltaic response of thin films of HgTe colloidal quantum dots in the 3–5 μm range is observed. With no applied bias, internal quantum efficiency exceeding 40%, specific detectivity above 10{sup 10} Jones and microseconds response times are obtained at 140 K. The cooled devices detect the ambient thermal radiation. A detector with 5.25 μm cut-off achieves Background Limited Infrared Photodetection at 90 K.

  8. Planck 2013 results. XVIII. The gravitational lensing-infrared background correlation

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.

    2013-01-01

    The multi-frequency capability of the Planck satellite provides information both on the integrated history of star formation (via the cosmic infrared background, or CIB) and on the distribution of dark matter (via the lensing effect on the cosmic microwave background, or CMB). The conjunction...... of these two unique probes allows us to measure directly the connection between dark and luminous matter in the high redshift (1 = 1. We measure directly the SFR density with around 2 sigma significance for three redshift bins between z = 1 and 7, thus opening a new window into the study of the formation...

  9. Multi-Color Anisotropy Measurements of the Cosmic Near-Infrared Extragalactic Background Light with CIBER2

    Science.gov (United States)

    Bock, James

    We propose to carry out a program of observations with the Cosmic Infrared Background Experiment (CIBER-2), a sounding rocket instrument designed to measure anisotropy in the extragalactic background light in multiple optical to near-infrared spectral bands. Scientifically, CIBER-2 follows on the results of CIBER-1, which has detected near-infrared background anisotropy. CIBER-1 has also produced leading results on the absolute brightness of the background, the spectrum of diffuse galactic light, the spectrum of Zodiacal light, and constraints on the Zodiacal light foreground from Fraunhofer line observations. CIBER-2 builds on the measurement techniques developed and successfully demonstrated by CIBER-1. With high-sensitivity, multi-color anisotropy measurements, CIBER-2 will elucidate the history of interhalo light production and carry out a deep search for extragalactic background fluctuations associated with the epoch of reionization. A plausible interpretation of the infrared background anisotropy detected by CIBER-1, Spitzer and AKARI is interhalo light from stars tidally stripped from their parent galaxies during galaxy mergers. Based on the rms amplitude of the anisotropy, interhalo light produces approximately half of the background, representing a major branch of light production. Probing the history of interhalo light through improved anisotropy measurements using multiple bands and correlating with tracers of large-scale structure is essential to understand its role in the cosmic history of star formation. The first generation of stars and their remnants are likely responsible for the reionization of the intergalactic medium, observed to be ionized out to distant quasars at a redshift of 6. The total luminosity produced by first stars is uncertain, but a lower limit can be placed assuming a minimal number of photons to produce and sustain reionization. This 'minimal' extragalactic background component associated with reionization is detectable in

  10. Contribution of the first galaxies to the cosmic far-infrared/sub-millimeter background - I. Mean background level

    Science.gov (United States)

    De Rossi, María Emilia; Bromm, Volker

    2017-03-01

    We study the contribution of the first galaxies to the far-infrared/sub-millimeter (FIR/sub-mm) extragalactic background light (EBL) by implementing an analytical model for dust emission. We explore different dust models, assuming different grain-size distributions and chemical compositions. According to our findings, observed reradiated emission from dust in dwarf-size galaxies at z ∼ 10 would peak at a wavelength of ∼ 500 μm with observed fluxes of ∼10-3-10-2 nJy, which is below the capabilities of current observatories. In order to be detectable, model sources at these high redshifts should exhibit luminosities of ≳1012 L⊙, comparable to that of local ultraluminous systems. The FIR/sub-mm-EBL generated by primeval galaxies peaks at ∼ 500 μm, with an intensity ranging from ∼10-4 to 10-3 nW m-2 sr-1, depending on dust properties. These values are ∼3-4 orders of magnitude below the absolute measured cosmic background level, suggesting that the first galaxies would not contribute significantly to the observed FIR/sub-mm-EBL. Our model EBL exhibits a strong correlation with the dust-to-metal ratio, where we assume a fiducial value of D = 0.005, increasing almost proportionally to it. Thus, measurements of the FIR/sub-mm-EBL could provide constraints on the amount of dust in the early Universe. Even if the absolute signal from primeval dust emission may be undetectable, it might still be possible to obtain information about it by exploring angular fluctuations at ∼ 500 μm, close to the peak of dust emission from the first galaxies.

  11. Contribution of the first galaxies to the cosmic far-infrared/sub-millimeter background - I. Mean background level

    CERN Document Server

    De Rossi, Maria Emilia

    2016-01-01

    We study the contribution of the first galaxies to the far-infrared/sub-millimeter (FIR/sub-mm) extragalactic background light (EBL) by implementing an analytical model for dust emission. We explore different dust models, assuming different grain size distributions and chemical compositions. According to our findings, observed re-radiated emission from dust in dwarf-size galaxies at $z \\sim 10$ would peak at a wavelength of $\\sim 500 \\mu {\\rm m}$ with observed fluxes of $\\sim 10^{-3} - 10^{-2}$ nJy, which is below the capabilities of current observatories. In order to be detectable, model sources at these high redshifts should exhibit luminosities of $\\gtrsim 10^{12} L_{\\odot}$, comparable to that of local ultra-luminous systems. The FIR/sub-mm EBL generated by primeval galaxies peaks at $\\sim 500 \\mu {\\rm m}$, with an intensity ranging from $\\sim 10^{-4}$ to $10^{-3} {\\rm nW \\ m^{-2} \\ sr^{-1}}$, depending on dust properties. These values are $\\sim 3 - 4$ orders of magnitude below the absolute measured cosmi...

  12. Planck 2015 results. XXIII. The thermal Sunyaev-Zeldovich effect-cosmic infrared background correlation

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Butler, R. C.; Calabrese, E.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Churazov, E.; Clements, D. L.; Colombo, L. P. L.; Combet, C.; Comis, B.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Harrison, D. L.; Helou, G.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Levrier, F.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maggio, G.; Maino, D.; Mak, D. S. Y.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Melchiorri, A.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Nati, F.; Natoli, P.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Welikala, N.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-08-01

    We use Planck data to detect the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planck-confirmed galaxy clusters. We detect infrared emission produced by dusty galaxies inside these clusters and demonstrate that the infrared emission is about 50% more extended than the tSZ effect. Modelling the emission with a Navarro-Frenk-White profile, we find that the radial profile concentration parameter is c500 = 1.00+0.18-0.15 . This indicates that infrared galaxies in the outskirts of clusters have higher infrared flux than cluster-core galaxies. We also study the cross-correlation between tSZ and CIB anisotropies, following three alternative approaches based on power spectrum analyses: (i) using a catalogue of confirmed clusters detected in Planck data; (ii) using an all-sky tSZ map built from Planck frequency maps; and (iii) using cross-spectra between Planck frequency maps. With the three different methods, we detect the tSZ-CIB cross-power spectrum at significance levels of (i) 6σ; (ii) 3σ; and (iii) 4σ. We model the tSZ-CIB cross-correlation signature and compare predictions with the measurements. The amplitude of the cross-correlation relative to the fiducial model is AtSZ-CIB = 1.2 ± 0.3. This result is consistent with predictions for the tSZ-CIB cross-correlation assuming the best-fit cosmological model from Planck 2015 results along with the tSZ and CIB scaling relations.

  13. Background Studies for the MINER Coherent Neutrino Scattering Reactor Experiment

    CERN Document Server

    Agnolet, G; Barker, D; Beck, R; Carroll, T J; Cesar, J; Cushman, P; Dent, J B; De Rijck, S; Dutta, B; Flanagan, W; Fritts, M; Gao, Y; Harris, H R; Hays, C C; Iyer, V; Jastram, A; Kadribasic, F; Kennedy, A; Kubik, A; Ogawa, I; Lang, K; Mahapatra, R; Mandic, V; Martin, R D; Mast, N; McDeavitt, S; Mirabolfathi, N; Mohanty, B; Nakajima, K; Newhouse, J; Newstead, J L; Phan, D; Proga, M; Roberts, A; Rogachev, G; Salazar, R; Sander, J; Senapati, K; Shimada, M; Strigari, L; Tamagawa, Y; Teizer, W; Vermaak, J I C; Villano, A N; Walker, J; Webb, B; Wetzel, Z; Yadavalli, S A

    2016-01-01

    The proposed Mitchell Institute Neutrino Experiment at Reactor (MINER) experiment at the Nuclear Science Center at Texas A&M University will search for coherent elastic neutrino-nucleus scattering within close proximity (about 2 meters) of a 1 MW TRIGA nuclear reactor core using low threshold, cryogenic germanium and silicon detectors. Given the Standard Model cross section of the scattering process and the proposed experimental proximity to the reactor, as many as 5 to 20 events/kg/day are expected. We discuss the status of preliminary measurements to characterize the main backgrounds for the proposed experiment. Both in situ measurements at the experimental site and simulations using the MCNP and GEANT4 codes are described. A strategy for monitoring backgrounds during data taking is briefly discussed.

  14. Benchmarking the Particle Background in the LHC Experiments

    CERN Document Server

    Gschwendtner, E

    2000-01-01

    The experiments for the Large Hadron Collider LHC at CERN have to work for 15 years in the presence of a very high particle background of photons in the energy range from 100\\,keV to 10\\,MeV and neutrons in the range from thermal energies ($\\approx 0.025\\,$eV) to 20\\,MeV. \\\\ The background is so high that it becomes a major design criterion for the ATLAS ex\\-peri\\-ment, a general purpose experiment at LHC that will be operational in the year 2005. The exact level of this background is poorly known. At present an uncertainty factor of five has to be assumed to which the limited knowledge of the shower processes in the absorber material and the ensueing neutron and photon production is estimated to contribute with a factor 2.5. \\\\ So far, the background has been assessed only through extensive Monte Carlo evaluation with the particle transport code FLUKA. The lack of relevant measurements, which were not done up to now, are to a large extent responsible for this uncertainty. Hence it is essential to benchmark t...

  15. Systematics and background suppression in the KATRIN experiment

    CERN Document Server

    Valerius, Kathrin

    2007-01-01

    Recent neutrino mass experiments at Mainz and Troitsk using tritium beta-decay have reached their sensitivity potential, yielding upper limits of about 2 eV/c^2 for the electron antineutrino mass. The KArlsruhe TRItium Neutrino experiment (KATRIN), designed to reach a sensitivity of 0.2 eV/c^2 (90% C.L.), will improve the signal rate by a factor of about 100 with respect to previous experiments while maintaining the same low background level at an enhanced energy resolution of 0.93 eV of the spectrometer which is scaled up by a factor of 10 in linear dimensions. This low background rate can only be achieved by active and passive reduction of the background components induced by the spectrometer itself and in the detector region. Furthermore, sources of systematic errors such as energy losses inside the tritium source or fluctuations of the energy scale of the spectrometer need to be carefully controlled and analysed. An overview of KATRIN's method to reduce the background rate and to determine the systematics...

  16. Interpreting the cosmic far-infrared background anisotropies using a gas regulator model

    CERN Document Server

    Wu, Hao-Yi; Teyssier, Romain

    2016-01-01

    Cosmic far-infrared background (CFIRB) is a powerful probe of the history of star formation rate and the connection between baryons and dark matter. In this work, we explore to which extent the CFIRB anisotropies can be reproduced by a simple physical framework for galaxy evolution, the gas regulator (bathtub) model. The model is based on continuity equations for gas, stars, and metals, taking into account cosmic gas accretion, star formation, and gas ejection. Our model not only provides a good fit to the CFIRB power spectra measured by Planck, but also agrees well with the correlation between CFIRB and gravitational lensing, far-infrared galaxy number counts, and bolometric infrared luminosity functions. The strong clustering of CFIRB indicates a large galaxy bias, which corresponds to haloes of mass 10^12.5 Msun at z=2; thus, CFIRB favors strong infrared emission in massive haloes, which is higher than the expectation from the star formation rate. We provide constraints and fitting functions for the cosmic...

  17. A novel infrared small moving target detection method based on tracking interest points under complicated background

    Science.gov (United States)

    Dong, Xiabin; Huang, Xinsheng; Zheng, Yongbin; Bai, Shengjian; Xu, Wanying

    2014-07-01

    Infrared moving target detection is an important part of infrared technology. We introduce a novel infrared small moving target detection method based on tracking interest points under complicated background. Firstly, Difference of Gaussians (DOG) filters are used to detect a group of interest points (including the moving targets). Secondly, a sort of small targets tracking method inspired by Human Visual System (HVS) is used to track these interest points for several frames, and then the correlations between interest points in the first frame and the last frame are obtained. Last, a new clustering method named as R-means is proposed to divide these interest points into two groups according to the correlations, one is target points and another is background points. In experimental results, the target-to-clutter ratio (TCR) and the receiver operating characteristics (ROC) curves are computed experimentally to compare the performances of the proposed method and other five sophisticated methods. From the results, the proposed method shows a better discrimination of targets and clutters and has a lower false alarm rate than the existing moving target detection methods.

  18. Cosmogenic Induced Background Estimation for the MAJORANA DEMONSTRATOR Experiment

    Science.gov (United States)

    White, Brandon; Majorana Collaboration

    2016-09-01

    Neutrino-less double beta (0 νββ) decay experiments probe for such rare events that the suppression and understanding of backgrounds are major experimental concerns. Cosmogenic induced isotopes have the potential to be a major background for such experiments. For the MAJORANA DEMONSTRATOR Experiment 76Ge isotope is used as both detector and source and pure electroformed copper is primarily used for detector housing. The isotopes 68Ge and 60Co are cosmogenically produced when the Germanium and Copper components are near Earth's surface. The decay of these isotopes can mimic events in the region of interest. The experiment is located at the 4850 foot level at the Sanford Underground Research Facility in Lead, South Dakota to suppress cosmogenic activation. In this talk I will present the calculations of cosmogenic backgrounds for the enriched 76Ge and electroformed Copper materials used in the MAJORANA DEMONSTRATOR. The activation is determined by the surface exposure time of materials. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics and Nuclear Physics Programs of the National Science Foundation, and the Sanford Underground Research Facility.

  19. Reducing 68Ge Background in Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Orrell, John L.

    2011-03-01

    Experimental searches for dark matter include experiments with sub-0.5 keV-energy threshold high purity germanium detectors. Experimental efforts, in partnership with the CoGeNT Collaboration operating at the Soudan Underground Laboratory, are focusing on energy threshold reduction via noise abatement, reduction of backgrounds from cosmic ray generated isotopes, and ubiquitous environmental radioactive sources. The most significant cosmic ray produced radionuclide is 68Ge. This paper evaluates reducing this background by freshly mining and processing germanium ore. The most probable outcome is a reduction of the background by a factor of two, and at most a factor of four. A very cost effective alternative is to obtain processed Ge as soon as possible and store it underground for 18 months.

  20. Reducing 68Ge Background in Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Orrell, John L.

    2011-03-01

    Experimental searches for dark matter include experiments with sub-0.5 keV-energy threshold high purity germanium detectors. Experimental efforts, in partnership with the CoGeNT Collaboration operating at the Soudan Underground Laboratory, are focusing on energy threshold reduction via noise abatement, reduction of backgrounds from cosmic ray generated isotopes, and ubiquitous environmental radioactive sources. The most significant cosmic ray produced radionuclide is 68Ge. This paper evaluates reducing this background by freshly mining and processing germanium ore. The most probable outcome is a reduction of the background by a factor of two, and at most a factor of four. A very cost effective alternative is to obtain processed Ge as soon as possible and store it underground for 18 months.

  1. Dark and background response stability for the Landsat 8 Thermal Infrared Sensor

    Science.gov (United States)

    Vanderwerff, Kelly; Montanaro, Matthew

    2012-01-01

    The Thermal Infrared Sensor (TIRS) is a pushbroom sensor that will be a part of the Landsat Data Continuity Mission (LDCM), which is a joint mission between NASA and the USGS. The TIRS instrument will continue to collect the thermal infrared data that are currently being collected by the Thematic Mapper and the Enhanced Thematic Mapper Plus on Landsats 5 and 7, respectively. One of the key requirements of the new sensor is that the dark and background response be stable to ensure proper data continuity from the legacy Landsat instruments. Pre launch testing of the instrument has recently been completed at the NASA Goddard Space Flight Center (GSFC), which included calibration collects that mimic those that will be performed on orbit. These collects include images of a cold plate meant to simulate the deep space calibration source as viewed by the instrument in flight. The data from these collects give insight into the stability of the instrument’s dark and background response, as well as factors that may cause these responses to vary. This paper quantifies the measured background and dark response of TIRS as well as its stability.

  2. The muon induced background in the GALLEX experiment

    Science.gov (United States)

    Cribier, M.; Pichard, B.; Rich, J.; Soirat, J. P.; Spiro, M.; Stolarczyk, Th.; Tao, C.; Vignaud, D.; Anselmann, P.; Lenzing, A.; Schlosser, C.; Wink, R.; Rowley, J. K.

    1997-02-01

    The production of germanium radioisotopes by high energy muons in GaCl 3 has been measured in a tank containing 851 of a GaCl 3HCl solution, irradiated in the CERN muon beam. From the measured cross-section, the background induced by cosmic muons in the GALLEX experiment in the Gran Sasso Underground Laboratory has been determined to be equivalent to (2.8 ± 0.6) SNU . This represents about 4% of the solar neutrino signal measured by the GALLEX experiment. 1 SUN = 1 neutrino capture per 10 36 target atoms per second.

  3. Probing reionization with the cross power spectrum of 21 cm and near-infrared radiation backgrounds

    CERN Document Server

    Mao, Xiao-Chun

    2014-01-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from the high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then the intensity of NIR background is estimated by collecting emission from stars in the first-light galaxies. On large scales, we find the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolut...

  4. Cosmological Constant or Intergalactic Dust? Constraints from the Cosmic Far Infrared Background

    CERN Document Server

    Aguirre, A N; Aguirre, Anthony; Haiman, Zoltan

    1999-01-01

    Recent observations of Type Ia SNe at redshifts 0 ~ 0.1 micron dust grains with a mass density of Omega_dust ~ (few) * 10^{-5} in the intergalactic (IG) medium. The same dust that dims the SNe absorbs the cosmic UV/optical background radiation around ~ 1 micron, and re-emits it at far infrared (FIR) wavelengths. Here we compare the FIR emission from IG dust with observations of the cosmic microwave (CMB) and cosmic far infrared backgrounds (FIRB) by the DIRBE/FIRAS instruments. We find that the emission would not lead to measurable distortion to the CMB, but would represent a substantial fraction (> 50 %) of the measured value of the FIRB in the 300-1000 micron range. This contribution would be consistent with the present unresolved fraction of the observed FIRB in an open universe. However, we find that IG dust probably could not reconcile the standard Omega=1 CDM model with the SN observations, even if the necessary quantity of dust existed. Future observations able to resolve the FIRB to a flux limit of ~ ...

  5. The PYTHON Microwave Background Anisotropy Experiment: Instrumentation and Analysis

    Science.gov (United States)

    Ruhl, J.; Dragovan, M.; Novak, G.; Platt, S. R.; Crone, B.; Pernic, R.

    1993-05-01

    We will discuss the instrumentation and data analysis for the PYTHON microwave background anisotropy experiment. This instrument was used at the South Pole from 1/1 to 1/15 1993 for observations of the microwave sky at a frequency of 90 GHz. The telescope has a FWHM beam of 45', and a chop of 2.75(deg) . This work was supported by The Center for Astrophysics in Antarctica, PYI grant NSF AST-9057089, the James S. McDonnell Foundation, and NASA grant NGT-50622.

  6. The background in the neutrinoless double beta decay experiment GERDA

    CERN Document Server

    Agostini, M; Andreotti, E; Bakalyarov, A M; Balata, M; Barabanov, I; Heider, M Barnabe; Barros, N; Baudis, L; Bauer, C; Becerici-Schmidt, N; Bellotti, E; Belogurov, S; Belyaev, S T; Benato, G; Bettini, A; Bezrukov, L; Bode, T; Brudanin, V; Brugnera, R; Budjas, D; Caldwell, A; Cattadori, C; Chernogorov, A; Cossavella, F; Demidova, E V; Domula, A; Egorov, V; Falkenstein, R; Ferella, A; Freund, K; Frodyma, N; Gangapshev, A; Garfagnini, A; Gotti, C; Grabmayr, P; Gurentsov, V; Gusev, K; Guthikonda, K K; Hampel, W; Hegai, A; Heisel, M; Hemmer, S; Heusser, G; Hofmann, W; Hult, M; Inzhechik, L V; Ioannucci, L; Csathy, J Janicsko; Jochum, J; Junker, M; Kihm, T; Kirpichnikov, I V; Kirsch, A; Klimenko, A; Knoepfle, K T; Kochetov, O; Kornoukhov, V N; Kuzminov, V V; Laubenstein, M; Lazzaro, A; Lebedev, V I; Lehnert, B; Liao, H Y; Lindner, M; Lippi, I; Liu, X; Lubashevskiy, A; Lubsandorzhiev, B; Lutter, G; Macolino, C; Machado, A A; Majorovits, B; Maneschg, W; Nemchenok, I; Nisi, S; O'Shaughnessy, C; Palioselitis, D; Pandola, L; Pelczar, K; Pessina, G; Pullia, A; Riboldi, S; Sada, C; Salathe, M; Schmitt, C; Schreiner, J; Schulz, O; Schwingenheuer, B; Schoenert, S; Shevchik, E; Shirchenko, M; Simgen, H; Smolnikov, A; Stanco, L; Strecker, H; Tarka, M; Ur, C A; Vasenko, A A; Volynets, O; von Sturm, K; Wagner, V; Walter, M; Wegmann, A; Wester, T; Wojcik, M; Yanovich, E; Zavarise, P; Zhitnikov, I; Zhukov, S V; Zinatulina, D; Zuber, K; Zuzel, G

    2014-01-01

    The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay of 76Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the Q-value of the decay, Q_bb. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around Q_bb. The main parameters needed for the neutrinoless double beta decay analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around Q_bb with a background index ranging from 17.6 to 23.8*10^{-3} counts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model...

  7. High-Energy Neutron Backgrounds for Underground Dark Matter Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu [Syracuse Univ., NY (United States)

    2016-01-01

    Direct dark matter detection experiments usually have excellent capability to distinguish nuclear recoils, expected interactions with Weakly Interacting Massive Particle (WIMP) dark matter, and electronic recoils, so that they can efficiently reject background events such as gamma-rays and charged particles. However, both WIMPs and neutrons can induce nuclear recoils. Neutrons are then the most crucial background for direct dark matter detection. It is important to understand and account for all sources of neutron backgrounds when claiming a discovery of dark matter detection or reporting limits on the WIMP-nucleon cross section. One type of neutron background that is not well understood is the cosmogenic neutrons from muons interacting with the underground cavern rock and materials surrounding a dark matter detector. The Neutron Multiplicity Meter (NMM) is a water Cherenkov detector capable of measuring the cosmogenic neutron flux at the Soudan Underground Laboratory, which has an overburden of 2090 meters water equivalent. The NMM consists of two 2.2-tonne gadolinium-doped water tanks situated atop a 20-tonne lead target. It detects a high-energy (>~ 50 MeV) neutron via moderation and capture of the multiple secondary neutrons released when the former interacts in the lead target. The multiplicity of secondary neutrons for the high-energy neutron provides a benchmark for comparison to the current Monte Carlo predictions. Combining with the Monte Carlo simulation, the muon-induced high-energy neutron flux above 50 MeV is measured to be (1.3 ± 0.2) ~ 10-9 cm-2s-1, in reasonable agreement with the model prediction. The measured multiplicity spectrum agrees well with that of Monte Carlo simulation for multiplicity below 10, but shows an excess of approximately a factor of three over Monte Carlo prediction for multiplicities ~ 10 - 20. In an effort to reduce neutron backgrounds for the dark matter experiment SuperCDMS SNO- LAB, an active neutron veto was developed

  8. Atmospheric transmission and thermal background emission in the mid-infrared at Mauna Kea

    Science.gov (United States)

    Otárola, A.; Richter, M.; Packham, C.; Chun, M.

    2015-04-01

    We present results of a preliminary study intended to quantitatively estimate the atmospheric transmission and thermal background emission in the mid-infrared (MIR), 7 μm - 26 μm, at the 13N TMT site in Mauna Kea. This is in the interest of supporting the planning of MIR instrumentation for the posible second-generation of astronomical instruments for the Thirty Meter Telescope (TMT) project. Mauna Kea, located at high altitude (4,050 m above sea level), enjoys natural conditions that make it an outstanding location for astronomical observations in the mid-infrared. The goal of this work is to produce a dataset and model that shows the atmospheric transmission and thermal emission for two cases of precipitable water vapor (PWV), a low value of 0.3 mm, and at 1.5 mm which represent near median conditions at the site. Besides, and driven by the interest of the MIR community to exploit the daily twilight times, we look at the specific atmospheric conditions around twilight as a function of season. The best conditions are found for cold and dry winter days, and in particular the morning twilight offers the best conditions. The analysis of PWV data, shows the median value for the site (all year conditions between 6:00 PM and 7:30AM) is 1.8 mm and that periods of water vapor lower than 1.0 mm are common, these supports the opportunity and discovery potential of the TMT project in the mid-infrared bands.

  9. Research on the algorithm of infrared target detection based on the frame difference and background subtraction method

    Science.gov (United States)

    Liu, Yun; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Hui, Mei; Liu, Xiaohua; Wu, Yijian

    2015-09-01

    As an important branch of infrared imaging technology, infrared target tracking and detection has a very important scientific value and a wide range of applications in both military and civilian areas. For the infrared image which is characterized by low SNR and serious disturbance of background noise, an innovative and effective target detection algorithm is proposed in this paper, according to the correlation of moving target frame-to-frame and the irrelevance of noise in sequential images based on OpenCV. Firstly, since the temporal differencing and background subtraction are very complementary, we use a combined detection method of frame difference and background subtraction which is based on adaptive background updating. Results indicate that it is simple and can extract the foreground moving target from the video sequence stably. For the background updating mechanism continuously updating each pixel, we can detect the infrared moving target more accurately. It paves the way for eventually realizing real-time infrared target detection and tracking, when transplanting the algorithms on OpenCV to the DSP platform. Afterwards, we use the optimal thresholding arithmetic to segment image. It transforms the gray images to black-white images in order to provide a better condition for the image sequences detection. Finally, according to the relevance of moving objects between different frames and mathematical morphology processing, we can eliminate noise, decrease the area, and smooth region boundaries. Experimental results proves that our algorithm precisely achieve the purpose of rapid detection of small infrared target.

  10. Probing the High-Redshift Universe Using Fluctuations in the Cosmic Microwave and Infrared Backgrounds

    Science.gov (United States)

    Smidt, Joseph Michael

    Background (CIB) continues to be one of the best probes of physics at the early stages of the universe. If the CMB were a purely Gaussian field, all statistical information would be contained in the power spectrum or two-point correlation function. However, non-Gaussianities ensure that new physics may be extracted from higher n-point correlation functions including the bispectrum and trispectrum of the CMB. In this thesis discuss new estimators we have formulated to probe primordial non-Gaussianity in the bispectrum and trispectrum of CMB data and the constraints we have made using WMAP data while discussing implications for inflationary models. I discuss how these same methods may be used to probe CMB Lensing. Finally, I discuss how upcoming measurements of near and far-infrared CIB fluctuations may be used to constrain the redshift of reionization and clustering of various populations of galaxies. Some preliminary results involving CANDELS, Spitzer SDWFS, CIBER and Herschel datasets is presented.

  11. The research on infrared small-target detection technology under complex background

    Science.gov (United States)

    Liu, Lei; Wang, Xin; Chen, Jilu; Huang, Zhijian

    2011-06-01

    In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detecting are described. Then, according to actual needs and the comparison results of those algorithms, some of them are optimized in combination with the image pre-processing. On the foundation of above works, a moving target detecting and tracking software base on the OpenCV is developed by the software developing platform MFC. Three kinds of detecting algorithms are integrated in this software. These three detecting algorithms are Frame Difference method, Background Estimation method and Mixture Gaussian Modeling method. In order to explain the software clearly, the framework and the function are described in this paper. At last, the implementing processes and results are analyzed, and those algorithms for detecting targets are evaluated from the two aspects of subjective and objective. This paper is very significant in the application of the infrared target detecting technology.

  12. Cosmic Infrared Background Fluctuations in Deep Spitzer IRAC Images: Data Processing and Analysis

    CERN Document Server

    Arendt, R G; Moseley, S H; Mather, J

    2009-01-01

    This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer IRAC observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations which would otherwise corrupt our results. The procedures and results for masking bright sources, and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large scale (>~30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power law components. Our measurements of spatial fluctuations ...

  13. AKARI near-infrared background fluctuations arise from normal galaxy populations

    CERN Document Server

    Helgason, Kári

    2016-01-01

    We show that measurements of the fluctuations in the near-infrared background (NIRB) from the AKARI satellite can be explained by faint galaxy populations at low redshifts. We demonstrate this using reconstructed images from deep galaxy catalogs (HUGS/S-CANDELS) and two independent galaxy population models. In all cases, we find that the NIRB fluctuations measured by AKARI are consistent with faint galaxies and there is no need for a contribution from unknown populations. We find no evidence for a steep Rayleigh-Jeans spectrum for the underlying sources as previously reported. The apparent Rayleigh-Jeans spectrum at large angular scales is likely a consequence of galaxies being removed systematically to deeper levels in the longer wavelength channels.

  14. New CMOS readout circuit with background suppression and CDS for infrared focal plane array applications

    Institute of Scientific and Technical Information of China (English)

    LI Xin-yi; ZHAO Yi-qiang; YAO Su-ying

    2009-01-01

    A high injection, large dynamic range, stable detector bias, small area and low power consumption CMOS readout circuit with background current suppression and correlated double sampling (CDS) for a high-resolution infrared focal plane array applications is proposed. The detector bias error in this structure is less than 0.1 mV. The input resistance is ideally zero, which is important to obtain high injection efficiency. Unit-cell occupies 10 μm × 15 μm area and consumes less than 0.4 mW power. Charge storage capacity is 3 × 108 electrons. The function and performance of the proposed readout circuit have been verified by experimental results.

  15. Planck intermediate results: XLVIII. Disentangling Galactic dust emission and cosmic infrared background anisotropies

    DEFF Research Database (Denmark)

    Aghanim, N.; Ashdown, M.; Aumont, J.

    2016-01-01

    Using the Planck 2015 data release (PR2) temperature maps, we separate Galactic thermal dust emission from cosmic infrared background (CIB) anisotropies. For this purpose, we implement a specifically tailored component-separation method, the so-called generalized needlet internal linear combination...... (GNILC) method, which uses spatial information (the angular powerspectra) to disentangle the Galactic dust emission and CIB anisotropies. We produce significantly improved all-sky maps of Planck thermal dust emission, with reduced CIB contamination, at 353, 545, and 857 GHz. By reducing the CIB...... contamination of the thermal dust maps, we provide more accurate estimates of the local dust temperature and dust spectral index over the sky with reduced dispersion, especially at high Galactic latitudes above b = ±20°. We find that the dust temperature is T = (19.4 ± 1.3) K and the dust spectral index is β...

  16. Analysis of auroral infrared emissions observed during the ELIAS experiment

    Directory of Open Access Journals (Sweden)

    G. E. Caledonia

    Full Text Available The ELIAS (Earth Limb Infrared Atmospheric Structure experiment was flown from the Poker Flat Research Range, Alaska in 1983 and successfully monitored visible and infrared emissions from an IBC III+ aurora. Measurements were performed in both staring and scanning modes over several hundred seconds. The data for short- and mid-wave infrared regions have been analyzed in terms of auroral excitation of the NO and NO+ vibrational bands. Auroral excitation efficiencies and kinetic implications are presented.

  17. Cross-correlation between X-ray and optical/near-infrared background intensity fluctuations

    CERN Document Server

    Mitchell-Wynne, Ketron; Xue, Yongquan; Luo, Bin; Brandt, William; Koekemoer, Anton

    2016-01-01

    Angular power spectra of optical and infrared background anisotropies at wavelengths between 0.5 to 5 $\\mu$m are a useful probe of faint sources present during reionization, in addition to faint galaxies and diffuse signals at low redshift. The cross-correlation of these fluctuations with backgrounds at other wavelengths can be used to separate some of these signals. A previous study on the cross-correlation between X-ray and $Spitzer$ fluctuations at 3.6 $\\mu$m and 4.5 $\\mu$m has been interpreted as evidence for direct collapse blackholes (DCBHs) present at $z > 12$. Here we return to this cross-correlation and study its wavelength dependence from 0.5 to 4.5 $\\mu$m using $Hubble$ and $Spitzer$ data in combination with a subset of the 4 Ms $Chandra$ observations in GOODS-S/ECDFS. Our study involves five $Hubble$ bands at 0.6, 0.7, 0.85, 1.25 and 1.6 $\\mu$m, and two $Spitzer$-IRAC bands at 3.6 $\\mu$m and 4.5 $\\mu$m. We confirm the previously seen cross-correlation between 3.6 $\\mu$m (4.5 $\\mu$m) and X-rays wit...

  18. Thermal Infrared Sky Background for a High-Arctic Mountain Observatory

    CERN Document Server

    Steinbring, Eric

    2016-01-01

    Nighttime zenith sky spectral brightness in the 3.3 to 20 micron wavelength region is reported for an observatory site nearby Eureka, on Ellesmere Island in the Canadian High Arctic. Measurements derive from an automated Fourier-transform spectrograph which operated continuously there over three consecutive winters. During that time the median through the most transparent portion of the Q window was 460 Jy/square-arcsec, falling below 32 Jy/square-arcsec in N band, and to sub-Jansky levels by M and shortwards; reaching only 36 mJy/square-arcsec within L. Nearly six decades of twice-daily balloonsonde launches from Eureka, together with contemporaneous meteorological data plus a simple model allows characterization of background stability and extrapolation into K band. This suggests the study location has dark skies across the whole thermal infrared spectrum, typically sub-200 micro-Jy/square-arcsec at 2.4 microns. That background is comparable to South Pole, and more than an order of magnitude less than estim...

  19. Thermal Infrared Sky Background for a High-Arctic Mountain Observatory

    Science.gov (United States)

    Steinbring, Eric

    2017-01-01

    Nighttime zenith sky spectral brightness in the 3.3-20 μm wavelength region is reported for an observatory site nearby Eureka on Ellesmere Island in the Canadian High Arctic. Measurements are derived from an automated Fourier-transform spectrograph that operated there continuously over three consecutive winters. During that time, the median through the most transparent portion of the Q window was 460 {Jy} {{arcsec}}-2, falling below 32 {Jy} {{arcsec}}-2 in the N band, and to sub-Jansky levels by M and shortward, reaching only 36 {mJy} {{arcsec}}-2 within L. Nearly six decades of twice-daily balloonsonde launches from Eureka, together with contemporaneous meteorological data plus a simple model, allows characterization of background stability and extrapolation into K band. This suggests that the study location has dark skies across the whole thermal infrared spectrum, typically sub-200 μ {Jy} {{arcsec}}-2 at 2.4 μm. That background is comparable to South Pole and more than an order of magnitude less than estimates for the best temperate astronomical sites, all at much higher elevation. Considerations relevant to future facilities, including for polar transient surveys, are discussed.

  20. Modelling the correlation between the thermal Sunyaev Zel'dovich effect and the cosmic infrared background

    CERN Document Server

    Addison, Graeme E; Spergel, David N

    2012-01-01

    We show how the correlation between the thermal Sunyaev Zel'dovich effect (tSZ) from galaxy clusters and dust emission from cosmic infrared background (CIB) sources can be calculated in a halo model framework. Using recent tSZ and CIB models, we find that the size of the tSZ x CIB cross-correlation is approximately 10 per cent at 150 GHz. The contribution to the total angular power spectrum is of order -1 \\mu K^2 at ell=3000, however, this value is uncertain by a factor of two to three, primarily because of CIB source modelling uncertainties. We expect the large uncertainty in this component to degrade upper limits on the kinematic Sunyaev Zel'dovich effect (kSZ), due to similarity in the frequency dependence of the tSZ x CIB and kSZ across the frequency range probed by current Cosmic Microwave Background missions. We also find that the degree of tSZ x CIB correlation is higher for mm x sub-mm spectra than mm x mm, because more of the sub-mm CIB originates at lower redshifts (z<2), where most tSZ clusters ...

  1. H-ATLAS: THE COSMIC ABUNDANCE OF DUST FROM THE FAR-INFRARED BACKGROUND POWER SPECTRUM

    Energy Technology Data Exchange (ETDEWEB)

    Thacker, Cameron; Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Mitchell-Wynne, K. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Amblard, A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Auld, R.; Eales, S.; Pascale, E. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA (United Kingdom); Baes, M.; Michalowski, M. J. [Sterrenkundig Observatorium, Universiteit Gent, KrijgslAAn 281 S9, B-9000 Gent (Belgium); Clements, D. L.; Dariush, A.; Hopwood, R. [Physics Department, Imperial College London, South Kensington campus, London, SW7 2AZ (United Kingdom); De Zotti, G. [INAF, Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Dunne, L.; Maddox, S. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Hoyos, C. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Ibar, E. [UK Astronomy Technology Centre, The Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Jarvis, M. [Astrophysics, Department of Physics, Keble Road, Oxford, OX1 3RH (United Kingdom); and others

    2013-05-01

    We present a measurement of the angular power spectrum of the cosmic far-infrared background (CFIRB) anisotropies in one of the extragalactic fields of the Herschel Astrophysical Terahertz Large Area Survey at 250, 350, and 500 {mu}m bands. Consistent with recent measurements of the CFIRB power spectrum in Herschel-SPIRE maps, we confirm the existence of a clear one-halo term of galaxy clustering on arcminute angular scales with large-scale two-halo term of clustering at 30 arcmin to angular scales of a few degrees. The power spectrum at the largest angular scales, especially at 250 {mu}m, is contaminated by the Galactic cirrus. The angular power spectrum is modeled using a conditional luminosity function approach to describe the spatial distribution of unresolved galaxies that make up the bulk of the CFIRB. Integrating over the dusty galaxy population responsible for the background anisotropies, we find that the cosmic abundance of dust, relative to the critical density, to be between {Omega}{sub dust} = 10{sup -6} and 8 Multiplication-Sign 10{sup -6} in the redshift range z {approx} 0-3. This dust abundance is consistent with estimates of the dust content in the universe using quasar reddening and magnification measurements in the Sloan Digital Sky Survey.

  2. Planck Early Results: The Power Spectrum Of Cosmic Infrared Background Anisotropies

    CERN Document Server

    Ade, P A R; Arnaud, M; Ashdown, M; Aumont, J; Baccigalupi, C; Balbi, A; Banday, A J; Barreiro, R B; Bartlett, J G; Battaner, E; Benabed, K; Benoit, A; Bernard, J -P; Bersanelli, M; Bhatia, R; Blagrave, K; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Bucher, M; Burigana, C; Cabella, P; Cardoso, J -F; Catalano, A; Cayon, L; Challinor, A; Chamballu, A; Chiang, L -Y; Chiang, C; Christensen, P R; Clements, D L; Colombi, S; Couchot, F; Coulais, A; Crill, B P; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Gasperis, G; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J -M; Desert, F -X; Dole, H; Donzelli, S; Dore, O; Dorl, U; Douspis, M; Dupac, X; Efstathiou, G; Ensslin, T A; Eriksen, H K; Finelli, F; Forni, O; Fosalba, P; Frailis, M; Franceschi, E; Galeotta, S; Ganga, K; Giard, M; Giardino, G; Giraud-Heraud, Y; Gonzalez-Nuevo, J; Gorski, K M; Grain, J; Gratton, S; Gregorio, A; Gruppuso, A; Hansen, F K; Harrison, D; Helou, G; Henrot-Versille, S; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hovest, W; Hoyland, R J; Huffenberger, K M; Jaffe, A H; Jones, W C; Juvela, M; Keihanen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knox, L; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Laureijs, R J; Lawrence, C R; Leach, S; Leonardi, R; Leroy, C; Lilje, P B; Linden-Vornle, M; Lockman, F J; Lopez-Caniego, M; Lubin, P M; Macias-Perez, J F; MacTavish, C J; Maffei, B; Maino, D; Mandolesi, N; Mann, R; Maris, M; Martin, P; Martinez-Gonzalez, E; Masi, S; Matarrese, S; Matthai, F; Mazzotta, P; Melchiorri, A; Mendes, L; Mennella, A; Mitra, S; Miville-Deschenes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, A; Naselsky, P; Natoli, P; Netterfield, C B; Norgaard-Nielsen, H U; Novikov, D; Novikov, I; O'Dwyer, I J; Oliver, S; Osborne, S; Pajot, F; Pasian, F; Patanchon, G; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Piat, M; Goncalves, D Pinheiro; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Poutanen, T; Prezeau, G; Prunet, S; Puget, J -L; Rachen, J P; Reach, W T; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Rowan-Robinson, M; Rubino-Martin, J A; Rusholme, B; Sandri, M; Santos, D; Savini, G; Scott, D; Seiffert, M D; Shellard, P; Smoot, G F; Starck, J -L; Stivoli, F; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Torre, J -P; Tristram, M; Tuovinen, J; Umana, G; Valenziano, L; Vielva, P; Villa, F; Vittorio, N; Wade, L A; Wandelt, B D; White, M; Yvon, D; Zacchei, A; Zonca, A

    2011-01-01

    Using Planck maps of six regions of low Galactic dust emission with a total area of about 140 square degrees, we determine the angular power spectra of Cosmic Infrared Background (CIB) anisotropies from multipole l = 200 to l = 2000 at 217, 353, 545 and 857 GHz. We use observations of HI emission as a tracer of thermal dust emission in order to reduce the already low level of Galactic dust emission and use the 143 GHz Planck maps in these fields to clean out cosmic microwave background anisotropies. Both of these cleaning processes are necessary in order to avoid significant contamination of the CIB signal. We measure correlated CIB structure across frequencies. As expected, the correlation decreases with increasing frequency separation as the contribution of high-redshift galaxies to CIB anisotropies increases with wavelengths. We find no significant difference between the frequency spectrum of the CIB anisotropies and the CIB mean, with dI/I=15% from 217 to 857 GHz. In terms of clustering properties, the Pl...

  3. Assembling the Infrared Extragalactic Background Light with CIBER-2: Probing Inter-Halo Light and the Epoch of Reionization.

    Science.gov (United States)

    Bock, James

    We propose to carry out a program of observations with the Cosmic Infrared Background Experiment (CIBER-2). CIBER-2 is a near-infrared sounding rocket experiment designed to measure spatial fluctuations in the extragalactic background light. CIBER-2 scientifically follows on the detection of fluctuations with the CIBER-1 imaging instrument, and will use measurement techniques developed and successfully demonstrated by CIBER-1. With high-sensitivity, multi-band imaging measurements, CIBER-2 will elucidate the history of interhalo light (IHL) production and carry out a deep search for extragalactic background fluctuations associated with the epoch of reionization (EOR). CIBER-1 has made high-quality detections of large-scale fluctuations over 4 sounding rocket flights. CIBER-1 measured the amplitude and spatial power spectrum of fluctuations, and observed an electromagnetic spectrum that is close to Rayleigh-Jeans, but with a statistically significant turnover at 1.1 um. The fluctuations cross-correlate with Spitzer images and are significantly bluer than the spectrum of the integrated background derived from galaxy counts. We interpret the CIBER-1 fluctuations as arising from IHL, low-mass stars tidally stripped from their parent galaxies during galaxy mergers. The first generation of stars and their remnants are likely responsible for the for the reionization of the intergalactic medium, observed to be ionized out to the most distant quasars at a redshift of 6. The total luminosity produced by first stars is uncertain, but a lower limit can be placed assuming a minimal number of photons to produce and sustain reionization. This 'minimal' extragalactic background component associated with reionization is detectable in fluctuations at the design sensitivity of CIBER-2. The CIBER-2 instrument is optimized for sensitivity to surface brightness in a short sounding rocket flight. The instrument consists of a 28 cm wide-field telescope operating in 6 spectral bands

  4. Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bethermin, M.; Bielewicz, P.; Blagrave, K.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chen, X.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Kalberla, P.; Keihänen, E.; Kerp, J.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lacasa, F.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leonardi, R.; León-Tavares, J.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M. D.; Serra, P.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Welikala, N.; White, M.; White, S. D. M.; Winkel, B.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    We present new measurements of cosmic infrared background (CIB) anisotropies using Planck. Combining HFI data with IRAS, the angular auto- and cross-frequency power spectrum is measured from 143 to 3000 GHz, and the auto-bispectrum from 217 to 545 GHz. The total areas used to compute the CIB power spectrum and bispectrum are about 2240 and 4400 deg2, respectively. After careful removal of the contaminants (cosmic microwave background anisotropies, Galactic dust, and Sunyaev-Zeldovich emission), and a complete study of systematics, the CIB power spectrum is measured with unprecedented signal to noise ratio from angular multipoles ℓ ~ 150 to 2500. The bispectrum due to the clustering of dusty, star-forming galaxies is measured from ℓ ~ 130 to 1100, with a total signal to noise ratio of around 6, 19, and 29 at 217, 353, and 545 GHz, respectively. Two approaches are developed for modelling CIB power spectrum anisotropies. The first approach takes advantage of the unique measurements by Planck at large angular scales, and models only the linear part of the power spectrum, with a mean bias of dark matter haloes hosting dusty galaxies at a given redshift weighted by their contribution to the emissivities. The second approach is based on a model that associates star-forming galaxies with dark matter haloes and their subhaloes, using a parametrized relation between the dust-processed infrared luminosity and (sub-)halo mass. The two approaches simultaneously fit all auto- and cross-power spectra very well. We find that the star formation history is well constrained up to redshifts around 2, and agrees with recent estimates of the obscured star-formation density using Spitzer and Herschel. However, at higher redshift, the accuracy of the star formation history measurement is strongly degraded by the uncertainty in the spectral energy distribution of CIB galaxies. We also find that the mean halo mass which is most efficient at hosting star formation is log (Meff/M⊙) = 12

  5. Purification of cerium, neodymium and gadolinium for low background experiments

    Directory of Open Access Journals (Sweden)

    Boiko R.S.

    2014-01-01

    Full Text Available Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search, 136Ce (2β+ candidate with one of the highest Q2β. The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  6. Multichroic Bolometric Detector Architecture for Cosmic Microwave Background Polarimetry Experiments

    Science.gov (United States)

    Suzuki, Aritoki

    Characterization of the Cosmic Microwave Background (CMB) B-mode polarization signal will test models of inflationary cosmology, as well as constrain the sum of the neutrino masses and other cosmological parameters. The low intensity of the B-mode signal combined with the need to remove polarized galactic foregrounds requires a sensitive millimeter receiver and effective methods of foreground removal. Current bolometric detector technology is reaching the sensitivity limit set by the CMB photon noise. Thus, we need to increase the optical throughput to increase an experiment's sensitivity. To increase the throughput without increasing the focal plane size, we can increase the frequency coverage of each pixel. Increased frequency coverage per pixel has additional advantage that we can split the signal into frequency bands to obtain spectral information. The detection of multiple frequency bands allows for removal of the polarized foreground emission from synchrotron radiation and thermal dust emission, by utilizing its spectral dependence. Traditionally, spectral information has been captured with a multi-chroic focal plane consisting of a heterogeneous mix of single-color pixels. To maximize the efficiency of the focal plane area, we developed a multi-chroic pixel. This increases the number of pixels per frequency with same focal plane area. We developed multi-chroic antenna-coupled transition edge sensor (TES) detector array for the CMB polarimetry. In each pixel, a silicon lens-coupled dual polarized sinuous antenna collects light over a two-octave frequency band. The antenna couples the broadband millimeter wave signal into microstrip transmission lines, and on-chip filter banks split the broadband signal into several frequency bands. Separate TES bolometers detect the power in each frequency band and linear polarization. We will describe the design and performance of these devices and present optical data taken with prototype pixels and detector arrays. Our

  7. A Joint Model Of X-ray And Infrared Backgrounds. II. Compton-Thick AGN Abundance

    CERN Document Server

    Shi, Yong; Armus, Lee

    2013-01-01

    We estimate the abundance of Compton-thick (CT) active galactic nuclei (AGN) based on our joint model of X-ray and infrared backgrounds. At L_{rest 2-10 keV} > 10^42 erg/s, the CT AGN density predicted by our model is a few 10^-4 Mpc^-3 from z=0 up to z=3. CT AGN with higher luminosity cuts (> 10^43, 10^44 & 10^45 erg/s) peak at higher z and show a rapid increase in the number density from z=0 to z~2-3. The CT to all AGN ratio appears to be low (2-5%) at f_{2-10keV} > 10^-15 erg/s/cm^2 but rises rapidly toward fainter flux levels. The CT AGN account for ~ 38% of the total accreted SMBH mass and contribute ~ 25% of the cosmic X-ray background spectrum at 20 keV. Our model predicts that the majority (90%) of luminous and bright CT AGN (L_{rest 2-10 keV} > 10^44 erg/s or f_{2-10keV} > 10^-15 erg/s/cm^2) have detectable hot dust 5-10 um emission which we associate with a dusty torus. The fraction drops for fainter objects, to around 30% at L_{rest 2-10 keV} > 10^42 erg/s or f_{2-10keV} > 10^-17 erg/s/cm^2. Ou...

  8. LIGO Gravitational Wave Detection, Primordial Black Holes, and the Near-IR Cosmic Infrared Background Anisotropies

    Science.gov (United States)

    Kashlinsky, A.

    2016-06-01

    LIGO's discovery of a gravitational wave from two merging black holes (BHs) of similar masses rekindled suggestions that primordial BHs (PBHs) make up the dark matter (DM). If so, PBHs would add a Poissonian isocurvature density fluctuation component to the inflation-produced adiabatic density fluctuations. For LIGO's BH parameters, this extra component would dominate the small-scale power responsible for collapse of early DM halos at z ≳ 10, where first luminous sources formed. We quantify the resultant increase in high-z abundances of collapsed halos that are suitable for producing the first generation of stars and luminous sources. The significantly increased abundance of the early halos would naturally explain the observed source-subtracted near-IR cosmic infrared background (CIB) fluctuations, which cannot be accounted for by known galaxy populations. For LIGO's BH parameters, this increase is such that the observed CIB fluctuation levels at 2-5 μm can be produced if only a tiny fraction of baryons in the collapsed DM halos forms luminous sources. Gas accretion onto these PBHs in collapsed halos, where first stars should also form, would straightforwardly account for the observed high coherence between the CIB and unresolved cosmic X-ray background in soft X-rays. We discuss modifications possibly required in the processes of first star formation if LIGO-type BHs indeed make up the bulk or all of DM. The arguments are valid only if the PBHs make up all, or at least most, of DM, but at the same time the mechanism appears inevitable if DM is made of PBHs.

  9. Near-infrared background anisotropies from diffuse intrahalo light of galaxies.

    Science.gov (United States)

    Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Gong, Yan; Stern, Daniel; Ashby, Matthew L N; Eisenhardt, Peter R; Frazer, Christopher C; Gonzalez, Anthony H; Kochanek, Christopher S; Kozłowski, Szymon; Wright, Edward L

    2012-10-25

    Unresolved anisotropies of the cosmic near-infrared background radiation are expected to have contributions from the earliest galaxies during the epoch of reionization and from faint, dwarf galaxies at intermediate redshifts. Previous measurements were unable to pinpoint conclusively the dominant origin because they did not sample spatial scales that were sufficiently large to distinguish between these two possibilities. Here we report a measurement of the anisotropy power spectrum from subarcminute to one-degree angular scales, and find the clustering amplitude to be larger than predicted by the models based on the two existing explanations. As the shot-noise level of the power spectrum is consistent with that expected from faint galaxies, a new source population on the sky is not necessary to explain the observations. However, a physical mechanism that increases the clustering amplitude is needed. Motivated by recent results related to the extended stellar light profile in dark-matter haloes, we consider the possibility that the fluctuations originate from intrahalo stars of all galaxies. We find that the measured power spectrum can be explained by an intrahalo light fraction of 0.07 to 0.2 per cent relative to the total luminosity in dark-matter haloes of 10(9) to 10(12) solar masses at redshifts of about 1 to 4.

  10. HerMES: Cosmic Infrared Background Anisotropies and the Clustering of Dusty Star-Forming Galaxies

    CERN Document Server

    Viero, M P; Zemcov, M; Addison, G; Amblard, A; Arumugam, V; Aussel, H; Bethermin, M; Bock, J; Boselli, A; Buat, V; Burgarella, D; Casey, C M; Clements, D L; Conley, A; Conversi, L; Cooray, A; De Zotti, G; Dowell, C D; Farrah, D; Franceschini, A; Glenn, J; Griffin, M; Hatziminaoglou, E; Heinis, S; Ibar, E; Ivision, R J; Lagache, G; Levenson, L; Marchetti, L; Marsden, G; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Papageorgiou, A; Peason, C P; Perez-Fournon, I; Pohlen, M; Rigopoulou, D; Roseboom, I G; Rowan-Robinson, M; Scott, D; Seymour, N; Schulz, B; Shupe, D L; Smith, A J; Symeonidis, M; Vaccari, M; Valtchanov, I; Vieira, J D; Wardlow, J; Xu, C K

    2012-01-01

    We present measurements of the auto- and cross-frequency power spectra of the cosmic infrared background (CIB) at 250, 350, and 500um (1200, 860, and 600 GHz) from observations totaling ~ 70 deg^2 made with the SPIRE instrument aboard the Herschel Space Observatory. We measure a fractional anisotropy dI / I = 14 +- 4%, detecting signatures arising from the clustering of dusty star-forming galaxies in both the linear (2-halo) and non-linear (1-halo) regimes to unprecedented levels; and that the transition from the 2- to 1-halo terms, below which power originates predominantly from multiple galaxies within dark matter halos, occurs at k_theta ~ 0.1 arcmin^-1 (l ~ 2200). New to this paper is clear evidence of a dependence of the Poisson and 1-halo power on the flux-cut level of masked sources --- suggesting that some fraction of the more luminous sources occupy more massive halos as satellites. We measure the cross-correlation power spectra between bands, finding that bands which are farthest apart are the least...

  11. Planck intermediate results. XLVIII. Disentangling Galactic dust emission and cosmic infrared background anisotropies

    CERN Document Server

    Aghanim, N; Aumont, J; Baccigalupi, C; Ballardini, M; Banday, A J; Barreiro, R B; Bartolo, N; Basak, S; Benabed, K; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Burigana, C; Calabrese, E; Cardoso, J -F; Carron, J; Chiang, H C; Colombo, L P L; Comis, B; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; de Bernardis, P; de Zotti, G; Delabrouille, J; Di Valentino, E; Dickinson, C; Diego, J M; Doré, O; Douspis, M; Ducout, A; Dupac, X; Dusini, S; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Fantaye, Y; Finelli, F; Forastieri, F; Frailis, M; Fraisse, A A; Franceschi, E; Frolov, A; Galeotta, S; Galli, S; Ganga, K; Génova-Santos, R T; Gerbino, M; Ghosh, T; Giraud-Héraud, Y; González-Nuevo, J; Górski, K M; Gruppuso, A; Gudmundsson, J E; Hansen, F K; Helou, G; Henrot-Versillé, S; Herranz, D; Hivon, E; Huang, Z; Jaffe, A H; Jones, W C; Keihänen, E; Keskitalo, R; Kiiveri, K; Kisner, T S; Krachmalnicoff, N; Kunz, M; Kurki-Suonio, H; Lamarre, J -M; Langer, M; Lasenby, A; Lattanzi, M; Lawrence, C R; Jeune, M Le; Levrier, F; Lilje, P B; Lilley, M; Lindholm, V; López-Caniego, M; Ma, Y -Z; Macías-Pérez, J F; Maggio, G; Maino, D; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Matarrese, S; Mauri, N; McEwen, J D; Melchiorri, A; Mennella, A; Migliaccio, M; Miville-Deschênes, M -A; Molinari, D; Moneti, A; Montier, L; Morgante, G; Moss, A; Natoli, P; Oxborrow, C A; Pagano, L; Paoletti, D; Patanchon, G; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Plaszczynski, S; Polastri, L; Polenta, G; Puget, J -L; Rachen, J P; Racine, B; Reinecke, M; Remazeilles, M; Renzi, A; Rocha, G; Rosset, C; Rossetti, M; Roudier, G; Rubiño-Martín, J A; Ruiz-Granados, B; Salvati, L; Sandri, M; Savelainen, M; Scott, D; Sirignano, C; Sirri, G; Soler, J D; Spencer, L D; Suur-Uski, A -S; Tauber, J A; Tavagnacco, D; Tenti, M; Toffolatti, L; Tomasi, M; Tristram, M; Trombetti, T; Valiviita, J; Van Tent, F; Vielva, P; Villa, F; Vittorio, N; Wandelt, B D; Wehus, I K; Zacchei, A; Zonca, A

    2016-01-01

    Using the Planck 2015 data release (PR2) temperature observations, we perform the separation of Galactic thermal dust emission and cosmic infrared background (CIB) anisotropies. For this purpose, we implement a specifically tailored component-separation method, the so-called generalized needlet internal linear combination (GNILC) method. This makes use of the spatial information (angular power spectrum) to disentangle the Galactic dust emission and CIB anisotropies. A significantly improved all-sky map of the Planck thermal dust, with reduced CIB contamination, is produced at 353, 545, and 857 GHz. From the reduction of the CIB contamination in the thermal dust maps, we are able to provide a more accurate estimate of the local dust temperature and dust spectral index over the sky with reduced dispersion at high latitudes. We find that $T = (19.4 \\pm 1.3)$ K and $\\beta = 1.6 \\pm 0.1$ on the whole sky, while $T = (19.4 \\pm 1.5)$ K and $\\beta = 1.6 \\pm 0.2$ on 21 % of the sky at high latitudes, where the error b...

  12. LIGO gravitational wave detection, primordial black holes and the near-IR cosmic infrared background anisotropies

    CERN Document Server

    Kashlinsky, A

    2016-01-01

    LIGO's discovery of a gravitational wave from two merging black holes (BHs) of similar masses rekindled suggestions that primordial BHs (PBHs) make up the dark matter (DM). If so, PBHs would add a Poissonian isocurvature density fluctuation component to the inflation-produced adiabatic density fluctuations. For LIGO's BH parameters, this extra component would dominate the small-scale power responsible for collapse of early DM halos at z>10, where first luminous sources formed. We quantify the resultant increase in high-z abundances of collapsed halos that are suitable for producing the first generation of stars and luminous sources. The significantly increased abundance of the early halos would naturally explain the observed source-subtracted near-IR cosmic infrared background (CIB) fluctuations, which cannot be accounted for by known galaxy populations. For LIGO's BH parameters this increase is such that the observed CIB fluctuation levels at 2 to 5 micron can be produced if only a tiny fraction of baryons i...

  13. Power spectrum of the cosmic infrared background at 60 and 100 microns with IRAS

    CERN Document Server

    Miville-Deschênes, M A; Puget, J L

    2002-01-01

    Based on a power spectrum analysis of the IRAS ISSA maps, we present the first detection of the Cosmic far-Infrared Background (CIB) fluctuations at 60 and 100 microns. The power spectrum of 12 low cirrus emission regions is characterized by a power excess at spatial frequencies higher than k~0.02 arcmin^{-1}. Most of this excess is due to noise and to nearby point sources with a flux stronger than 1 Jy. But we show that when these contributions are carefully removed, there is still a power excess that is the signature of the CIB fluctuations. The power spectrum of the CIB at 60 and 100 microns is compatible with a Poissonian distribution, at spatial frequencies between 0.025 and 0.2 arcmin^{-1}. The fluctuation level is ~1.6x10^3 Jy^2/sr and ~5.8x10^3 Jy^2/sr at 60 and 100 microns respectively. The levels of the fluctuations are used in a larger framework, with other observationnal data, to constrain the evolution of IR galaxies (Lagache et al. 2002). The detections reported here, coupled with the level of t...

  14. Determination of the Cosmic Infrared Background from COBE/FIRAS and Planck HFI Data

    Science.gov (United States)

    Kogut, Alan

    Current determinations of the cosmic infrared background (CIB) at far-infrared to millimeter wavelengths have large uncertainties, on the order of 30%. We propose to make new, more accurate determinations of the CIB at these wavelengths using COBE /FIRAS and Planck High Frequency Instrument (HFI) Data. This work will enable a factor of two improvement in our understanding of the CIB. Planck was not designed to measure the monopole component of sky brightness, so the FIRAS data will be used to recalibrate the zero level of the HFI maps. Correlation of the recalibrated HFI maps with Galactic H I 21-cm line emission will be used to separate the Galactic foreground emission and determine the CIB in the HFI bands from 217 to 857 GHz, or 1380 to 350 microns. The high angular resolution and sensitivity of the HFI data will allow the correlations with H I to be established more accurately and to lower H I column density than is possible with the 7± resolution FIRAS data, resulting in significant improvement in the accuracy of the derived CIB. Correlations of the CIB-subtracted 857 GHz map with FIRAS maps averaged over broad frequency bins will then be used to determine CIB values at frequencies not observed by Planck. Uncertainties in the CIB results are expected to be as low as 14% for the HFI 857 GHz band. Our results will allow more accurate determination of the fraction of the CIB that is resolved by deep source surveys, and a tighter limit to be placed on the contribution to the CIB of any diffuse emission such as emission from intergalactic dust. Possible gray extinction by intergalactic dust may produce significant systematic error in determinations of dark energy parameters from type Ia supernova measurements, and our results will be important for placing a tighter upper limit on such extinction. Our CIB results will also provide tighter constraints on models of the evolution of star-forming galaxies, and will be important in constraining the evolution in

  15. New Spectral Evidence of an Unaccounted Component of the Near-infrared Extragalactic Background Light from the CIBER

    Science.gov (United States)

    Matsuura, Shuji; Arai, Toshiaki; Bock, James J.; Cooray, Asantha; Korngut, Phillip M.; Kim, Min Gyu; Lee, Hyung Mok; Lee, Dae Hee; Levenson, Louis R.; Matsumoto, Toshio; Onishi, Yosuke; Shirahata, Mai; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2017-04-01

    The extragalactic background light (EBL) captures the total integrated emission from stars and galaxies throughout the cosmic history. The amplitude of the near-infrared EBL from space absolute photometry observations has been controversial and depends strongly on the modeling and subtraction of the zodiacal light (ZL) foreground. We report the first measurement of the diffuse background spectrum at 0.8-1.7 μm from the CIBER experiment. The observations were obtained with an absolute spectrometer over two flights in multiple sky fields to enable the subtraction of ZL, stars, terrestrial emission, and diffuse Galactic light. After subtracting foregrounds and accounting for systematic errors, we find the nominal EBL brightness, assuming the Kelsall ZL model, is {42.7}-10.6+11.9 nW m-2 sr-1 at 1.4 μm. We also analyzed the data using the Wright ZL model, which results in a worse statistical fit to the data and an unphysical EBL, falling below the known background light from galaxies at λ EBL brightness, we find an EBL brightness of {28.7}-3.3+5.1 nWm-2 sr-1 at 1.4 μm. While the derived EBL amplitude strongly depends on the ZL model, we find that we cannot fit the spectral data to ZL, Galactic emission, and EBL from solely integrated galactic light from galaxy counts. The results require a new diffuse component, such as an additional foreground or an excess EBL with a redder spectrum than that of ZL.

  16. Stars and reionization: the cross-correlation of the 21 cm line and the near-infrared background

    NARCIS (Netherlands)

    Fernandez, Elizabeth R.; Zaroubi, Saleem; Iliev, Ilian T.; Mellema, Garrelt; Jelić, Vibor

    2014-01-01

    With improving telescopes, it may now be possible to observe the Epoch of Reionization in multiple ways. We examine two of these observables - the excess light in the near-infrared background that may be due to high-redshift stars and ionized HII bubbles, and the 21 cm emission from neutral hydrogen

  17. Stars and reionization: the cross-correlation of the 21 cm line and the near-infrared background

    NARCIS (Netherlands)

    Fernandez, Elizabeth R.; Zaroubi, Saleem; Iliev, Ilian T.; Mellema, Garrelt; Jelic, Vibor

    With improving telescopes, it may now be possible to observe the Epoch of Reionization in multiple ways. We examine two of these observables - the excess light in the near-infrared background that may be due to high-redshift stars and ionized HII bubbles, and the 21 cm emission from neutral

  18. The end of an era : The Population III to Population II transition and the near-infrared background

    NARCIS (Netherlands)

    Fernandez, Elizabeth R.; Zaroubi, Saleem

    2013-01-01

    There are only a few ways to constrain the era of reionization and the properties of high-redshift (z greater than or similar to 6) stars through observations. Here, we discuss one of these observables - the spectrum of the near-infrared background - and how it is potentially affected by the transit

  19. The Midcourse Space Experiment Infrared-Dark Cloud Catalog

    Science.gov (United States)

    Carey, S. J.; Egan, M. P.; Kuchar, T. A.; Mizuno, D.; Feldman, P. A.; Redman, R. O.; Price, S. D.

    2000-12-01

    We present a preliminary catalog of infrared-dark clouds (IRDCs) that were identified in the Midcourse Space Experiment (MSX) Galactic Plane Survey images. These objects are clearly visible as absorption features against the diffuse Galactic emission in the 8.3 micron MSX images. IRDCs are cold (T CS, C18O and HCO+. IRDC have a wide variety of shapes from globule-like to filamentary. We will present the filling factors, fractal dimension and other morphological identifiers for the IRDCs. In particular, the fractal dimension will be compared to the dimensions of other components of the ISM including GMCs and infrared cirrus. Few IRDCs are associated with previously observed star formation tracers such as far-infrared point sources and maser emission. The catalog will be cross-referenced with published observations of star formation tracers and the properties of previously identified star forming regions will be contrasted with the new objects detected by MSX.

  20. A near-infrared SETI experiment: instrument overview

    CERN Document Server

    Wright, Shelley A; Treffers, Richard R; Maire, Jerome; Marcy, Geoffrey W; Stone, Remington P S; Drake, Frank; Meyer, Elliot; Dorval, Patrick; Siemion, Andrew

    2014-01-01

    We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design builds upon our past optical SETI experiences, and is the first step toward a new, more versatile and sophisticated generation of very fast optical and near-infrared pulse search devices. We present our instrumental design by giving an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. This project makes use of near-infrared (950-1650 nm) discrete amplification Avalanche Photodiodes (APD) that have greater than 1 GHz bandwidths with low noise characteristics and moderate gain (~10^4). We have investigated the use of single versus multiple detectors in our instrument (see Maire et al., this conference), and have optimized the system to have both high sensitivity and low false coincidence rates. Our ...

  1. Reconstructing Emission from Pre-Reionization Sources with Cosmic Infrared Background Fluctuation Measurements by the JWST

    Science.gov (United States)

    Kashlinsky, A.; Mather, J. C.; Helgason, K.; Arendt, R. G.; Bromm, V.; Moseley, S. H.

    2015-01-01

    We present new methodology to use cosmic infrared background (CIB) fluctuations to probe sources at 10 less than or approx. equal to z less than or approx. equal to 30 from a James Webb Space Telescope (JWST) NIRCam configuration that will isolate known galaxies to 28 AB mag at 0.55 m. At present significant mutually consistent source-subtracted CIB fluctuations have been identified in the Spitzer and AKARI data at 25 m, but we demonstrate internal inconsistencies at shorter wavelengths in the recent CIBER data. We evaluate CIB contributions from remaining galaxies and show that the bulk of the high-z sources will be in the confusion noise of the NIRCam beam, requiring CIB studies. The accurate measurement of the angular spectrum of the fluctuations and probing the dependence of its clustering component on the remaining shot noise power would discriminate between the various currently proposed models for their origin and probe the flux distribution of its sources. We show that the contribution to CIB fluctuations from remaining galaxies is large at visible wavelengths for the current instruments precluding probing the putative Lyman-break of the CIB fluctuations. We demonstrate that with the proposed JWST configuration such measurements will enable probing the Lyman-break. We develop a Lyman-break tomography method to use the NIRCam wavelength coverage to identify or constrain, via the adjacent two-band subtraction, the history of emissions over 10 less than or approx. equal to z less than or approx. equal to 30 as the universe comes out of the Dark Ages. We apply the proposed tomography to the current SpitzerIRAC measurements at 3.6 and 4.5 m, to find that it already leads to interestingly low upper limit on emissions at z greater than or approx. equal to 30.

  2. Reconstructing Emission from Pre-reionization Sources with Cosmic Infrared Background Fluctuation Measurements by the JWST

    Science.gov (United States)

    Kashlinsky, A.; Mather, J. C.; Helgason, K.; Arendt, R. G.; Bromm, V.; Moseley, S. H.

    2015-05-01

    We present new methodology to use cosmic infrared background (CIB) fluctuations to probe sources at 10≲ z≲ 30 from a James Webb Space Telescope (JWST)/NIRCam configuration that will isolate known galaxies to 28 AB mag at 0.5-5 μm. At present significant mutually consistent source-subtracted CIB fluctuations have been identified in the Spitzer and AKARI data at ˜2-5 μm, but we demonstrate internal inconsistencies at shorter wavelengths in the recent CIBER data. We evaluate CIB contributions from remaining galaxies and show that the bulk of the high-z sources will be in the confusion noise of the NIRCam beam, requiring CIB studies. The accurate measurement of the angular spectrum of the fluctuations and probing the dependence of its clustering component on the remaining shot noise power would discriminate between the various currently proposed models for their origin and probe the flux distribution of its sources. We show that the contribution to CIB fluctuations from remaining galaxies is large at visible wavelengths for the current instruments precluding probing the putative Lyman-break of the CIB fluctuations. We demonstrate that with the proposed JWST configuration such measurements will enable probing the Lyman-break. We develop a Lyman-break tomography method to use the NIRCam wavelength coverage to identify or constrain, via the adjacent two-band subtraction, the history of emissions over 10≲ z≲ 30 as the universe comes out of the “Dark Ages.” We apply the proposed tomography to the current Spitzer/IRAC measurements at 3.6 and 4.5 μm, to find that it already leads to interestingly low upper limit on emissions at z≳ 30.

  3. Planck Lensing and Cosmic Infrared Background Cross-Correlation with Fermi-LAT: Tracing Dark Matter Signals in the $\\gamma$-ray Background

    CERN Document Server

    Feng, Chang; Keating, Brian

    2016-01-01

    The extragalactic $\\gamma$-ray background, and its spatial anisotropy, could potentially contain a signature of dark matter annihilation or particle decay. Astrophysical foregrounds, such as blazars and star-forming galaxies, however, dominate the $\\gamma$-ray background, precluding an easy detection of the signal associated with the dark matter annihilation or decay in the background intensity spectrum. The dark matter imprint on the $\\gamma$-ray background is expected to be correlated with large-scale structure tracers. In some cases such a cross-correlation is even expected to have a higher signal-to-noise ratio than the auto-correlation. A reliable tracer of the dark matter distribution in the large-scale structure is lensing of the cosmic microwave background (CMB) and the cosmic infrared background (CIB) is a reliable tracer of star-forming galaxies. We analyze Fermi-LAT data taken over 92 months and study the cross-correlation with Planck CMB lensing, Planck CIB, and Fermi-$\\gamma$ maps. We put upper l...

  4. Cosmic Muon Induced Backgrounds in the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Dengjie, Li

    2014-01-01

    Muon induced neutrons and long-lived radioactive isotopes are important background sources for low-energy underground experiments. We study the produced processes and properties of cosmic muon induced backgrounds, show the muon veto system used for rejecting these backgrounds and the methods to estimate residual backgrounds in the Daya Bay Reactor Neutrino Experiment.

  5. Sea-Based Infrared Scene Interpretation by Background Type Classification and Coastal Region Detection for Small Target Detection

    Directory of Open Access Journals (Sweden)

    Sungho Kim

    2015-09-01

    Full Text Available Sea-based infrared search and track (IRST is important for homeland security by detecting missiles and asymmetric boats. This paper proposes a novel scheme to interpret various infrared scenes by classifying the infrared background types and detecting the coastal regions in omni-directional images. The background type or region-selective small infrared target detector should be deployed to maximize the detection rate and to minimize the number of false alarms. A spatial filter-based small target detector is suitable for identifying stationary incoming targets in remote sea areas with sky only. Many false detections can occur if there is an image sector containing a coastal region, due to ground clutter and the difficulty in finding true targets using the same spatial filter-based detector. A temporal filter-based detector was used to handle these problems. Therefore, the scene type and coastal region information is critical to the success of IRST in real-world applications. In this paper, the infrared scene type was determined using the relationships between the sensor line-of-sight (LOS and a horizontal line in an image. The proposed coastal region detector can be activated if the background type of the probing sector is determined to be a coastal region. Coastal regions can be detected by fusing the region map and curve map. The experimental results on real infrared images highlight the feasibility of the proposed sea-based scene interpretation. In addition, the effects of the proposed scheme were analyzed further by applying region-adaptive small target detection.

  6. A Bridge from Optical to Infrared Galaxies Explaining Local Properties, Predicting Galaxy Counts and the Cosmic Background Radiation

    CERN Document Server

    Totani, T; Totani, Tomonori; Takeuchi, Tsutomu T.

    2002-01-01

    We give an explanation for the origin of various properties observed in local infrared galaxies, and make predictions for galaxy counts and cosmic background radiation (CBR), by a new model extended from that for optical/near-infrared galaxies. Important new characteristics of this study are that (1) mass scale dependence of dust extinction is introduced based on the size-luminosity relation of optical galaxies, and that (2) the big grain dust temperature T_dust is calculated based on a physical consideration for energy balance, rather than using the empirical relation between T_dust and total infrared luminosity L_IR found in local galaxies, which has been employed in most of previous works. Consequently, the local properties of infrared galaxies, i.e., optical/infrared luminosity ratios, L_IR-T_dust correlation, and infrared luminosity function are outputs predicted by the model. Our model indeed reproduces these local properties reasonably well. We then found considerably different results for MIR-submm co...

  7. Planck Lensing and Cosmic Infrared Background Cross-correlation with Fermi-LAT: Tracing Dark Matter Signals in the Gamma-ray Background

    Science.gov (United States)

    Feng, Chang; Cooray, Asantha; Keating, Brian

    2017-02-01

    The extragalactic γ-ray background and its spatial anisotropy could potentially contain a signature of dark matter (DM) annihilation or particle decay. Astrophysical foregrounds, such as blazars and star-forming galaxies (SFGs), however, dominate the γ-ray background, precluding an easy detection of the signal associated with the DM annihilation or decay in the background intensity spectrum. The DM imprint on the γ-ray background is expected to be correlated with large-scale structure tracers. In some cases, such a cross-correlation is even expected to have a higher signal-to-noise ratio than the auto-correlation. One reliable tracer of the DM distribution in the large-scale structure is lensing of the cosmic microwave background (CMB), and the cosmic infrared background (CIB) is a reliable tracer of SFGs. We analyze Fermi-LAT data taken over 92 months and study the cross-correlation with Planck CMB lensing, Planck CIB, and Fermi-γ maps. We put upper limits on the DM annihilation cross-section from the cross-power spectra with the γ-ray background anisotropies. The unbiased power spectrum estimation is validated with simulations that include cross-correlated signals. We also provide a set of systematic tests and show that no significant contaminations are found for the measurements presented here. Using γ-ray background map from data gathered over 92 months, we find the best constraint on the DM annihilation with a 1σ confidence level upper limit of 10‑25–10‑24 cm3 s‑1, when the mass of DM particles is between 20 and 100 GeV.

  8. The ultra-pure Ti for the low background experiments

    Science.gov (United States)

    Chepurnov, Alexander; Nisi, Stefano; di Vacri, Maria Laura; Suvorov, Yury

    2013-08-01

    The constant increase in mass of the cryostats, containment tanks, passive shielding and other mechanical elements of the modern low background detectors put more stringent requirements on their radiopurity levels. In general they have to be ˜1 mBq/kg of 238U/232Th or lower, which means that mass concentration should be manufactory line.

  9. Experiences of School Belonging for Young Children with Refugee Backgrounds

    Science.gov (United States)

    Due, Clemence; Riggs, Damien W.; Augoustinos, Martha

    2016-01-01

    Previous research with adolescents with refugee backgrounds living in countries of resettlement has found that school belonging has an impact on a range of well-being and developmental outcomes, including mental health, peer relationships, self-esteem and self-efficacy, and academic achievement. However, very little research has explored school…

  10. First-Light Galaxies or Intrahalo Stars: Multi-Wavelength Measurements of the Infrared Background Anisotropies

    Science.gov (United States)

    Cooray, Asantha

    explained with DGL. The proposed research supports Goal 2 of the NASA 2011 Strategic Plan to Expand scientific understanding of the Earth and the universe which we live, specifically to address the sub-goal 2.4 to discover how the universe works and explore how it began and evolved. The proposal is relevant to NASA's 2007 Science Plan in addressing the Science Question How do planets, stars, galaxies, and cosmic structure come into being?. The training of next-generation astrophysicists in the form of undergraduate students, graduate students, and postdoctoral fellows leading to experience and background in the analysis and interpretation of space-based astronomical data support the Goal 6 of the NASA 2011 Strategic Plan to Share NASA with the public, educators, and students to provide opportunities to participate in our Mission, foster innovation, and contribute to a strong national economy. The PI's efforts to involve undergraduates in his research programs will specifically improve retention of students in STEM disciplines by providing opportunities and activities along the full length of the education pipeline (subgoal 6.1). The IR fluctuation study supports JWST, Euclid, and WFIRST since we study the ensemble properties of the faint emission buried in existing deep and wide space-based IR data. We expect some fraction of the fluctuations to be from first-light galaxies that JWST seeks to detect and characterize individually. Euclid and WFIRST can make very deep and wide multi-band fluctuation measurements, depending on the final choice of bands (WFIRST) and observation/deep-field strategy (Euclid and WFIRST). This work could also motivate a small instrument for space-borne measurement of the absolute sky brightness from 5 AU, where the Zodiacal foreground is expected to be 100 times fainter than at 1.

  11. The ultra-pure Ti for the low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chepurnov, Alexander [Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Moscow 119234 (Russian Federation); Nisi, Stefano; Vacri, Maria Laura di [INFN Laboratori Nazionali del Gran Sasso, SS 17 bis km 18-910, 6010 Assergi (AQ) (Italy); Suvorov, Yury [Physics and Astronomy Department, University of California Los Angeles, Los Angeles, CA 90095 (United States)

    2013-08-08

    The constant increase in mass of the cryostats, containment tanks, passive shielding and other mechanical elements of the modern low background detectors put more stringent requirements on their radiopurity levels. In general they have to be ∼1 mBq/kg of {sup 238}U/{sup 232}Th or lower, which means that mass concentration should be < 0.1 ppb for {sup 238}U and < 0.25 ppb for {sup 232}Th. Traditionally, the field relies on specially selected low background stainless steel, electrochemical oxygen-free copper, or a combination of the two. However, the most promising material in terms of physical and mechanical properties is Titanium. Our study of various Ti samples show that the levels of contaminations of commercially available industrial titanium can varies from 0.2 to 100 mBq/kg for U/Th. Therefore, the only possible way to obtain the material with a low and controlled level of contamination is to develop (or improve the existing) the production technology and to build the dedicated manufactory line.

  12. Background studies for the EDELWEISS dark matter experiment

    CERN Document Server

    Armengaud, E; Beno\\^\\it, A; Bergé, L; Bergmann, T; Blümer, J; Broniatowski, A; Brudanin, V; Censier, B; Chapellier, M; Charlieux, F; Couedo, F; Coulter, P; Cox, G A; De Jesus, M; Domange, J; Drilien, A -A; Dumoulin, L; Eitel, K; Filosofov, D; Fourches, N; Gascon, J; Gerbier, G; Gros, M; Henry, S; Hervé, S; Heuermann, G; Holtzer, N; Juillard, A; Kleifges, M; Kluck, H; Kozlov, V; Kraus, H; Kudryavtsev, V A; Sueur, H Le; Loaiza, P; Marnieros, S; Menshikov, A; Navick, X-F; Nones, C; Olivieri, E; Pari, P; Paul, B; Rigaut, O; Robinson, M; Rozov, S; Sanglard, V; Schmidt, B; Scorza, S; Siebenborn, B; Semikh, S; Tcherniakhovski, D; Torrento-Coello, A S; Vagneron, L; Walker, R J; Weber, M; Yakushev, E; Zhang, X

    2013-01-01

    The EDELWEISS-II collaboration has completed a direct search for WIMP dark matter using cryogenic Ge detectors (400 g each) and 384 kg$\\times$days of effective exposure. A cross-section of $4.4 \\times 10^{-8}$ pb is excluded at 90% C.L. for a WIMP mass of 85 GeV. The next phase, EDELWEISS-III, aims to probe spin-independent WIMP-nucleon cross-sections down to a few $\\times10^{-9}$ pb. We present here the study of gamma and neutron background coming from radioactive decays in the set-up and shielding materials. We have carried out Monte Carlo simulations for the completed EDELWEISS-II setup with GEANT4 and normalised the expected background rates to the measured radioactivity levels (or their upper limits) of all materials and components. The expected gamma-ray event rate in EDELWEISS-II at 20-200 keV agrees with the observed rate of 82 events/kg/day within the uncertainties in the measured concentrations. The calculated neutron rate from radioactivity of 1.0-3.1 events (90% C.L.) at 20-200 keV in the EDELWEIS...

  13. On the radiative and thermodynamic properties of the extragalactic far infrared background radiation using COBE FIRAS instrument data

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Using the explicit form of the function to describe the average spectrum of the extragalactic far infrared background (FIRB) radiation measured by the COBE FIRAS instrument in the 0.15 - 2.4 THz frequency interval, the radiative and thermodynamic properties, such as the total emissivity, total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density are calculated. The calculated value of the total intensity received in the 0.15 - 2.4 THz frequency interval is 13.6 nW m^-2 sr^-1, and comprises about 19.4 % of the total intensity expected from the energy released by stellar nucleosynthesis over cosmic history. The radiative and thermodynamic functions of the extragalactic far infrared background (FIRB) radiation are calculated at redshift z = 1.5.

  14. Stray light test station for measuring point source transmission and thermal background of visible and infrared sensors

    Science.gov (United States)

    Peterson, Gary L.

    2008-08-01

    Breault Research Organization has designed and built a stray light test station. The station measures the point source transmission and background thermal irradiance of visible and infrared sensors. Two beam expanders, including a large 0.89 meter spherical mirror, expand and collimate light from laser sources at 0.658 and 10.6 µm. The large mirror is mounted on a gimbal to illuminate sensors at off-axis angles from 0° to 10°, and azimuths from 0° to 180°. Sensors with apertures as large as 0.3 meters can be tested with the existing facility. The large mirror is placed within a vacuum chamber so cryogenic infrared sensors can be tested in a vacuum environment. A dark cryogenic cold plate can be translated into the field of view of a sensor to measure its background thermal irradiance.

  15. [Reflective writing in nursing education: background, experiences and methods].

    Science.gov (United States)

    Montagna, Licia; Benaglio, Carla; Zannini, Lucia

    2010-01-01

    In the nursing field, writing one's own educational/professional experience has been utilized for a long time, to develop reflection and therefore learning. Reflective writing has been fostered to sustain the development of nurses' clinical, relational and ethical competence, and to promote self knowledge. To de scribe reflective writing experiences published in the literature, focussing on the educational contexts and the writing strategies used in the nursing field. Method. Narrative analysis of the international literature, based on the MedLine and Cinahl data sources. Reflective writing is used in undergraduate, post-graduate and continuing nursing education, to develop clinical learning or a professional and/or personal growth. In the former, short written assignments (also starting from scenarios) are given, while diaries and journals, with prompts focalizing on specific aspects of the experience, support a more global growth of the student/professional. These prompts are useful with individuals not used to write. Critical incidents or meaningful episodes from the clinical practice are also used. Many papers underline the importance of sharing writings with peers and/or a teacher/facilitator. Nursing students/professionals can be effectively supported by reflective writing in their experiential learning. However, their attitude to reflective writing should be considered with care and a feedback by peers and/or a facilitator must be provided. Since giving feedback requires adequate human resources, the implementation of writing activities in the nursing training should be carefully evaluated.

  16. 基于背景最佳滤波尺度的红外图像复杂度评价准则∗%An evaluation criterion of infrared image complexity based on background optimal filter scale

    Institute of Scientific and Technical Information of China (English)

    侯旺; 梅风华; 陈国军; 邓喜文

    2015-01-01

    An evaluation of infrared image complexity is proposed based on the background optimal filtering to solve the problem that the traditional methods have given poor results in the background evaluation. Meanwhile, the optimal filtering scale for infrared image filtering can be given by this method, it will provide a guidance for optimal infrared image filtering. First, we generate the Gaussian simulated target and fuse it to the infrared image to obtain the real infrared image with the simulated target. Then, this image is filtered in different scales and the signal-to-noise ratio of the target after filtering is calculated. Finally, the maximal value of signal-to-noise ratio of the target is used as the background optimal filter scale, to evaluate the infrared image complexity. Besides, the infrared filtering scale is deduced by establishing the mathematic model, and then the mathematical expression of optimal filtering scale is obtained. A lot of experiments indicate that: 1) The mathematical expression of optimal filtering scale agrees with the experimental results. 2) The result of our method is better than that of the traditional methods based on information entropy. Because the optimal filtering scale is obtained by using our method, we can use this scale to filter the infrared image to effectively detect a small target. 3) When the scale of simulated target increases, the optimal filtering scale increases accordingly. So, when we calculate the infrared image complexity, the scale of simulated target must be the same. We can compare the infrared image complexity between different images. Moreover, the optimal filtering scale is independent of the intensity of simulated target. 4) The effect of Gaussian and Butterworth high-pass filter is better than that of the ideal high-pass filter in the proposed method. 5) The infrared image complexity can be analyzed by the proposed method effectively. Moreover, changes of different image contents can be analyzed by using

  17. Flying the Infrared Skies: An Authentic SOFIA Educator Experience

    Science.gov (United States)

    Manning, J. G.

    2015-11-01

    The NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA) flagship education effort is its Airborne Astronomy Ambassadors (AAA) program. The program flies teams of teachers on SOFIA research flights as part of an educator professional development effort enabling these teachers to experience first-hand the workings of the airborne observatory, to interact with scientists and technologists, to observe research in progress and how scientists use technology—all in support of national STEM goals. The presenter will share his own experience as an EPO escort on a recent SOFIA flight including two educator teams, providing a first-hand account of how an “authentic” science experience can exploit unique NASA assets to improve science teaching, inspire students, inform local communities, and contribute to the elevation of public science literacy.

  18. BACKGROUND AND STATE OF THEE ART OF NEAR INFRARED SPECTROSCOPY IN THE FOREST SECTOR BASE

    Directory of Open Access Journals (Sweden)

    Graciela Inês Bolzon de Muñiz

    2012-12-01

    Full Text Available http://dx.doi.org/10.5902/198050987567The knowledge of wood properties is the fundamental importance for the indication of the potential and use of this material. In the search for new alternatives for a fast, simple and reliable characterization, there are the non-destructive evaluations of wood. The near infrared spectroscopy (NIRS has been used as a non-destructive method that allows qualitative and quantitative information of the constituents of biomass through the interaction of electromagnetic waves with near-infrared next to the sample. This work aims to provide a review of the technique of near infrared spectroscopy and its application in forestry. The technique is used in virtually all areas due to the level of development that this technology has reached in recent years. NIR spectroscopy has proved a quick and efficient replacement of several tests that determine the quality of the wood. This is a literature review and state of the art on the theme.

  19. An accurate measurement of the anisotropies and mean level of the Cosmic Infrared Background at 100 and 160 um

    CERN Document Server

    Pénin, Aurélie; Noriega-Crepo, Alberto; Grain, Julien; Miville-Deschênes, Marc-Antoine; Ponthieu, Nicolas; Martin, Peter; Blagrave, Kevin; Lockman, Felix J

    2011-01-01

    The anisotropies of the cosmic infrared background (CIB) are a powerful tool to study the evolution of galaxies and large-scale structures. However one of the main limitations to an accurate measurement is the contamination by Galactic dust emission. Our goal is to show that we can remove the Galactic cirrus contamination using HI data, and thus measure accurately the clustering of starburst galaxies in the CIB. We use observations of the extragalactic N1 field at far-infrared (100 and 160 um) and radio (21 cm) wavelengths. We compute the correlation between dust emission, as traced by far-infrared observations, and HI gas, and derive dust emissivities which enable us to subtract the cirrus emission from the far-infrared maps. We then derive the power spectrum of the CIB anisotropies and its mean level. We compute dust emissivities for each of the HI-velocity components. Using IRIS/IRAS data at 100 um, we demonstrate that we can use the measured emissivities to determine and remove the cirrus contribution to ...

  20. Simulation of signal and background processes for collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, S.

    2008-10-08

    In this thesis new theoretical tools for the accurate simulation of scattering processes at present and future collider experiments have been developed. Special emphasis has thereby to be given to multi-particle/multi-jet final states that often constitute signals for interesting (new) physics. Considering final states with a number of hard jets, there seems to be enough evidence that the traditional simulation tools HERWIG and PYTHIA cannot fully accomplish their description. Starting from a 2{yields}2 core process, they account only for soft and collinear QCD emissions through parton-shower models. Only recently, theoretical prescriptions have been found to consistently combine tree-level matrix-element calculations with the existing parton-shower algorithms. The gain of such methods is that phase-space regions covered by hard and by soft parton kinematics are simultaneously well described. In Chapter 2 of this thesis the working principles of such prescriptions have been discussed with special attention being paid to the merging scheme implemented in the SHERPA Monte Carlo. To consistently match QCD higher-order calculations (at one-loop or tree-level) with parton showers, a good analytical control over the perturbative terms present in the latter is required. This has triggered the demand for improved parton-shower models that facilitate the inclusion of exact matrix elements. In this line a completely new shower algorithm has been presented in Chapter 3. It is based on the Catani-Seymour dipole subtraction formalism, a universal method for calculating arbitrary processes at next-to-leading order in QCD. The splitting kernels used in the shower are justified approximations of the Catani-Seymour dipole functions. The kinematics of the individual splittings is accomplished such that exact four-momentum conservation can be ensured for each single branching. Accordingly, the shower can be stopped and started again at each intermediate stage of the evolution. The

  1. X-Ray Shadowing Experiments Toward Infrared Dark Clouds

    Science.gov (United States)

    Anderson, L. E.; Snowden, S.; Bania, T. M.

    2009-01-01

    We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 keY photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30 deg Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 ke V emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the ISM, and to the birth of stars.

  2. The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. I. Background and Justification

    Science.gov (United States)

    Wright, J. T.; Mullan, B.; Sigurdsson, S.; Povich, M. S.

    2014-09-01

    We motivate the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. We discuss some philosophical difficulties of the search for extraterrestrial intelligence (SETI), and how communication SETI circumvents them. We review "Dysonian SETI," the search for artifacts of alien civilizations, and find that it is highly complementary to traditional communication SETI; the two together might succeed where either one alone has not. We discuss the argument of Hart that spacefaring life in the Milky Way should be either galaxy-spanning or non-existent, and examine a portion of his argument that we call the "monocultural fallacy." We discuss some rebuttals to Hart that invoke sustainability and predict long Galaxy colonization timescales. We find that the maximum Galaxy colonization timescale is actually much shorter than previous work has found (counter-arguments to Hart's thesis suffer from the monocultural fallacy. We extend Hart's argument to alien energy supplies and argue that detectably large energy supplies can plausibly be expected to exist because life has the potential for exponential growth until checked by resources or other limitations, and intelligence implies the ability to overcome such limitations. As such, if Hart's thesis is correct, then searches for large alien civilizations in other galaxies may be fruitful; if it is incorrect, then searches for civilizations within the Milky Way are more likely to succeed than Hart argued. We review some past Dysonian SETI efforts and discuss the promise of new mid-infrared surveys, such as that of WISE.

  3. The \\^G Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. I. Background and Justification

    CERN Document Server

    Wright, J T; Sigurðsson, S; Povich, M S

    2014-01-01

    We motivate the \\^G infrared search for extraterrestrial civilizations with large energy supplies. We discuss some philosophical difficulties of SETI, and how communication SETI circumvents them. We review "Dysonian SETI", the search for artifacts of alien civilizations, and find that it is highly complementary to traditional communication SETI; the two together might succeed where either one, alone, has not. We discuss the argument of Hart (1975) that spacefaring life in the Milky Way should be either galaxy-spanning or non-existent, and examine a portion of his argument that we dub the "monocultural fallacy". We discuss some rebuttals to Hart that invoke sustainability and predict long Galaxy colonization timescales. We find that the maximum Galaxy colonization timescale is actually much shorter than previous work has found ($< 10^9$ yr), and that many "sustainability" counter-arguments to Hart's thesis suffer from the monocultural fallacy. We extend Hart's argument to alien energy supplies, and argue th...

  4. Research on infrared small-target tracking technology under complex background

    Science.gov (United States)

    Liu, Lei; Wang, Xin; Chen, Jilu; Pan, Tao

    2012-10-01

    In this paper, some basic principles and the implementing flow charts of a series of algorithms for target tracking are described. On the foundation of above works, a moving target tracking software base on the OpenCV is developed by the software developing platform MFC. Three kinds of tracking algorithms are integrated in this software. These two tracking algorithms are Kalman Filter tracking method and Camshift tracking method. In order to explain the software clearly, the framework and the function are described in this paper. At last, the implementing processes and results are analyzed, and those algorithms for tracking targets are evaluated from the two aspects of subjective and objective. This paper is very significant in the application of the infrared target tracking technology.

  5. The Ĝ infrared search for extraterrestrial civilizations with large energy supplies. I. Background and justification

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J. T.; Mullan, B.; Sigurdsson, S. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Povich, M. S. [Department of Physics and Astronomy, California State Polytechnic University, Pomona, 3801 West Temple Avenue, Pomona, CA 91768 (United States)

    2014-09-01

    We motivate the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. We discuss some philosophical difficulties of the search for extraterrestrial intelligence (SETI), and how communication SETI circumvents them. We review 'Dysonian SETI', the search for artifacts of alien civilizations, and find that it is highly complementary to traditional communication SETI; the two together might succeed where either one alone has not. We discuss the argument of Hart that spacefaring life in the Milky Way should be either galaxy-spanning or non-existent, and examine a portion of his argument that we call the 'monocultural fallacy'. We discuss some rebuttals to Hart that invoke sustainability and predict long Galaxy colonization timescales. We find that the maximum Galaxy colonization timescale is actually much shorter than previous work has found (<10{sup 9} yr), and that many 'sustainability' counter-arguments to Hart's thesis suffer from the monocultural fallacy. We extend Hart's argument to alien energy supplies and argue that detectably large energy supplies can plausibly be expected to exist because life has the potential for exponential growth until checked by resources or other limitations, and intelligence implies the ability to overcome such limitations. As such, if Hart's thesis is correct, then searches for large alien civilizations in other galaxies may be fruitful; if it is incorrect, then searches for civilizations within the Milky Way are more likely to succeed than Hart argued. We review some past Dysonian SETI efforts and discuss the promise of new mid-infrared surveys, such as that of WISE.

  6. Measurement of the background in the NEMO 3 double beta decay experiment

    CERN Document Server

    Argyriades, J; Augier, C; Baker, J; Barabash, A S; Bongrand, M; Broudin-Bay, G; Brudanin, V B; Caffrey, A J; Chapon, A; Chauveau, E; Daraktchieva, Z; Durand, D; Egorov, V G; Fatemi-Ghomi, N; Flack, R; Freshville, A; Guillon, B; Hubert, Ph; Jullian, S; Kauer, M; King, S; Kochetov, O I; Konovalov, S I; Kovalenko, V E; Lalanne, D; Lang, K; Lemi`ere, Y; Lutter, G; Mamedov, F; Marquet, Ch; Martín-Albo, J; Mauger, F; Nachab, A; Nasteva, I; Nemchenok, I B; Nova, F; Novella, P; Ohsumi, H; Pahlka, R B; Perrot, F; Piquemal, F; Reyss, J L; Ricol, J S; Saakyan, R; Sarazin, X; Simard, L; Shitov, Yu A; Smolnikov, A A; Snow, S; Söldner-Rembold, S; Stekl, I; Sutton, C S; Szklarz, G; Thomas, J; Timkin, V V; Tretyak, V I; Tretyak, Vl I; Umatov, V I; Vàla, L; Vanyushin, I A; Vasiliev, V A; Vorobel, V; Vylov, Ts

    2009-01-01

    In the double beta decay experiment NEMO~3 a precise knowledge of the background in the signal region is of outstanding importance. This article presents the methods used in NEMO~3 to evaluate the backgrounds resulting from most if not all possible origins. It also illustrates the power of the combined tracking-calorimetry technique used in the experiment.

  7. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-mm Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M .; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda=35-435 micron and with R=lambda/delta lambda approximately equals 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10 (sup -20) W/Hz(exp 1/2) and response time tau = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(sub 1/2) and Tau approximately equals 5ms for straight-beam TESs. In fact, we expected NEP approximately equals 1.5x10(exp -19)?W/Hz(sup 1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10 (sup -19)W/Hz(exp 1/2) in our single-pixel test system and NEP=(1.6+/-0.3)x10(sup -19)W/Hz(sup 1/2) in our array test system.

  8. Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-Millimetre Spectrograph (BLISS) for SPICA

    Science.gov (United States)

    Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M.; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

    2012-01-01

    We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda = 35-435 microns and with R = lambda/(delta)lambda approx. 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10(exp -20) W/Hz(1/2) and response time t or = 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(1/2) and tapprox.5ms for straight-beam TESs. In fact, we expected NEPapprox.1.5x10(exp -19)W/Hz(1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10(exp -19)W/Hz(1/2) in our single-pixel test system and NEP=(1.6+0.3)x10(exp -19)W/Hz(1/2) in our array test system.

  9. AKARI Observation of the Sub-degree Scale Fluctuation of the Near-infrared Background

    CERN Document Server

    Seo, H J; Matsumoto, T; Jeong, W -S; Lee, Myung Gyoon; Pyo, J

    2015-01-01

    We report spatial fluctuation analysis of the sky brightness in near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 micron. As a follow up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000". We found residual fluctuation over the estimated shot noise at larger angles than the angular scale of the Monitor field. The excess fluctuation of the NEP deep field smoothly connects with that of the Monitor field at angular scales with a few hundreds arcseconds and extends without any significant variation to larger angular scales up to 1000". By comparing excess fluctuations at two wavelengths, we confirm a blue spectrum feature similar to the result of the Monitor field. We find that the result of this study is consistent with Spitzer Space Telescope observations at 3.6 micron. The origin of the excess fluctua...

  10. Thermo-optical characterization of a low-background infrared chamber and wideband infrared scene projector (WISP) array for hardware-in-the-loop testing

    Science.gov (United States)

    Lippert, Jack R.; Flynn, David S.; Jones, Lawrence E.; Kircher, James R.

    1999-07-01

    The KHILS Vacuum Cold Chamber (KVACC) provides the capability of testing IR seekers with scenes involving a `cold' background, more closely simulating a high altitude/exoatmospheric engagement. During the past year, a gaseous helium refrigeration system has been installed to simplify the logistics of cooling the chamber. An antechamber has also been installed to serve as a chamber for the sensor under test. A WISP array was installed in the Source Chamber. A thermal control system was developed by connecting the array to a cold surface by way of a thermal choke, then actively controlling the temperature with heating elements. This made it possible to operate the array at user selected, stable substrate temperatures ranging from ambient temperature to below 150 K. This capability makes it possible to select the infrared background level that the array operates at, and to operate with background levels that are adequate for testing the high altitude/exoatmospheric engagements. WISP arrays were designed for room temperature operation, but predicted performance at reduced temperatures appears acceptable. Tests were performed with a Phase I prototype WISP array inside the KVACC Source Chamber. Data on this array's radiometric response at various substrate temperatures are presented. It is demonstrated that the arrays can be operated at substrate temperatures as low as 145 K. Currently two Phase 3 WISP arrays and a dichroic beam combiner are being installed in the Source Chamber for 2- color testing.

  11. The extragalactic background and its fluctuations in the far-infrared wavelengths

    CERN Document Server

    Lagache, G; Abergel, A; Bouchet, F R; Boulanger, F; Ciliegi, P; Clements, D L; Césarsky, C J; Désert, F X; Dole, H; Elbaz, D; Franceschini, A; Gispert, R; Guiderdoni, B; Haffner, L M; Harwit, M; Laureijs, R J; Lemke, D; Moorwood, A F M; Oliver, S; Reach, W T; Reynolds, R J; Rowan-Robinson, M; Stickel, M; Tufte, S L

    2000-01-01

    A Cosmic Far-InfraRed Background (CFIRB) has long been predicted that wouldtraces the intial phases of galaxy formation. It has been first detected byPuget et al.(1996) using COBE data and has been later confirmed by severalrecent studies (Fixsen et al. 1998, Hauser et al. 1998, Lagache et al. 1999).We will present a new determination of the CFIRB that uses for the first time,in addition to COBE data, two independent gas tracers: the HI survey ofLeiden/Dwingeloo (hartmann, 1998) and the WHAM H$_{\\alpha}$ survey (Reynolds etal 1998). We will see that the CFIRB above 100 micron is now very wellconstrained. The next step is to see if we can detect its fluctuations. Tosearch for the CFIRB fluctuations, we have used the FIRBACK observations.FIRBACK is a deep cosmological survey conducted at 170 micron with ISOPHOT(Dole et al., 2000). We show that the emission of unresolved extra-galacticsources clearly dominates, at arcminute scales, the background fluctuations inthe lowest galactic emission regions. This is the f...

  12. Probing reionization with the cross-power spectrum of 21 cm and near-infrared radiation backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Xiao-Chun, E-mail: xcmao@bao.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-08-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross-power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then, the intensity of the NIR background is estimated by collecting emission from stars in first-light galaxies. On large scales, we find that the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolute value of the cross-power spectrum is |Δ{sub 21,NIR}{sup 2}|∼10{sup −4} mK nW m{sup –2} sr{sup –1}, reached at ℓ ∼ 1000 when the mean fraction of ionized hydrogen is x-bar{sub i}∼0.9. We find that Square Kilometer Array can measure the 21 cm-NIR cross-power spectrum in conjunction with mild extensions to the existing CIBER survey, provided that the integration time independently adds up to 1000 and 1 hr for 21 cm and NIR observations, and that the sky coverage fraction of the CIBER survey is extended from 4 × 10{sup –4} to 0.1. Measuring the cross-correlation signal as a function of redshift provides valuable information on reionization and helps confirm the origin of the 'missing' NIR background.

  13. Probing Reionization with the Cross-power Spectrum of 21 cm and Near-infrared Radiation Backgrounds

    Science.gov (United States)

    Mao, Xiao-Chun

    2014-08-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross-power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then, the intensity of the NIR background is estimated by collecting emission from stars in first-light galaxies. On large scales, we find that the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolute value of the cross-power spectrum is |\\Delta ^2_{21,NIR}|\\sim 10^{-4} mK nW m-2 sr-1, reached at l ~ 1000 when the mean fraction of ionized hydrogen is \\bar{x}_{i}\\sim 0.9. We find that Square Kilometer Array can measure the 21 cm-NIR cross-power spectrum in conjunction with mild extensions to the existing CIBER survey, provided that the integration time independently adds up to 1000 and 1 hr for 21 cm and NIR observations, and that the sky coverage fraction of the CIBER survey is extended from 4 × 10-4 to 0.1. Measuring the cross-correlation signal as a function of redshift provides valuable information on reionization and helps confirm the origin of the "missing" NIR background.

  14. Kinetics experiments and bench-scale system: Background, design, and preliminary experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rofer, C.K.

    1987-10-01

    The project, Supercritical Water Oxidation of Hazardous Chemical Waste, is a Hazardous Waste Remedial Actions Program (HAZWRAP) Research and Development task being carried out by the Los Alamos National Laboratory. Its objective is to obtain information for use in understanding the basic technology and for scaling up and applying oxidation in supercritical water as a viable process for treating a variety of DOE-DP waste streams. This report gives the background and rationale for kinetics experiments on oxidation in supercritical water being carried out as a part of this HAZWRAP Research and Development task. It discusses supercritical fluid properties and their relevance to applying this process to the destruction of hazardous wastes. An overview is given of the small emerging industry based on applications of supercritical water oxidation. Factors that could lead to additional applications are listed. Modeling studies are described as a basis for the experimental design. The report describes plug flow reactor and batch reactor systems, and presents preliminary results. 28 refs., 4 figs., 5 tabs.

  15. Environmental {sup 222}Rn as a background source in the solar neutrino experiment GALLEX

    Energy Technology Data Exchange (ETDEWEB)

    Wojcik, M. [Uniwersytet Jagiellonski, Cracow (Poland). Inst. Fizyki; BOREXINO

    1996-12-31

    The radiochemical neutrino experiment GALLEX is described. Its aim is to measure the flux of low energy solar neutrinos. In this experiment it is essential to suppress strongly the background of environmental origin, like charged cosmic rays, neutrons and gamma rays. In low-level radioactivity measurements performed in deep underground laboratory where flux of charged comic rays is strongly reduced, radon (Rn) exhaled from rock or concrete walls forms a most important strong, time-dependent background component. In this work the impact of Rn on the GALLEX experiment has been discussed and attempts to recognize and minimize its influence on the counter background were described. 63 refs, 22 figs, 11 tabs.

  16. Modeling the fluctuations of the cosmic infrared background: what did we learn from Planck?

    Science.gov (United States)

    Bethermin, Matthieu

    2015-08-01

    The CIB is the relic emission of the dust heated by young stars across. It is a powerful probe of the star formation history in the Universe. The distribution of star-forming galaxies in the large-scale structures is imprinted in the anisotropies of the CIB. They are thus one of the keys to understand how large-scale structures shaped the evolution of the galaxies. Planck measured these anisotropies with an unprecedented accuracy. However, the CIB is an integrated emission and a model is necessary to disentangle the contribution of the different redshifts.Large-scale anisotropies can be interpreted using a linear model. This simple approach relies on a minimal number of hypotheses. We found a star formation history consistent with the extrapolation of the Herschel luminosity function. This rules out any major contribution of faint IR galaxies. We also constrained the mean mass of the dark matter halos hosting the galaxies, which emit the CIB. This mass is almost constant from z=4 to z=0, while dark matter halos grew very quickly during this interval of time. The structures hosting star formation are thus not the same at low and high redshifts. This also suggests the existence of a halo mass for which the star formation is most efficient.Halo occupation models can describe in details how dark matter halos are populated by infrared galaxies. We coupled a phenomenological model of galaxy evolution calibrated on Herschel data with a halo model, using the technique of abundance matching. This approach allows to naturally reproduce the CIB anisotropies. We found that the efficiency of halos to convert accreted baryons into stars varies strongly with halo mass, but not with time. This highlights the role played by host halos as regulator of the star formation in galaxies.I will finally explain how we could have access to 3D information with future instruments and isolate more efficiently the highest redshift using intensity mapping of bright sub-millimeter lines. I will

  17. Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds

    Science.gov (United States)

    Schlegel, David J.; Finkbeiner, Douglas P.; Davis, Marc

    1998-06-01

    We present a full-sky 100 μm map that is a reprocessed composite of the COBE/DIRBE and IRAS/ISSA maps, with the zodiacal foreground and confirmed point sources removed. Before using the ISSA maps, we remove the remaining artifacts from the IRAS scan pattern. Using the DIRBE 100 and 240 μm data, we have constructed a map of the dust temperature so that the 100 μm map may be converted to a map proportional to dust column density. The dust temperature varies from 17 to 21 K, which is modest but does modify the estimate of the dust column by a factor of 5. The result of these manipulations is a map with DIRBE quality calibration and IRAS resolution. A wealth of filamentary detail is apparent on many different scales at all Galactic latitudes. In high-latitude regions, the dust map correlates well with maps of H I emission, but deviations are coherent in the sky and are especially conspicuous in regions of saturation of H I emission toward denser clouds and of formation of H2 in molecular clouds. In contrast, high-velocity H I clouds are deficient in dust emission, as expected. To generate the full-sky dust maps, we must first remove zodiacal light contamination, as well as a possible cosmic infrared background (CIB). This is done via a regression analysis of the 100 μm DIRBE map against the Leiden-Dwingeloo map of H I emission, with corrections for the zodiacal light via a suitable expansion of the DIRBE 25 μm flux. This procedure removes virtually all traces of the zodiacal foreground. For the 100 μm map no significant CIB is detected. At longer wavelengths, where the zodiacal contamination is weaker, we detect the CIB at surprisingly high flux levels of 32 +/- 13 nW m-2 sr-1 at 140 μm and of 17 +/- 4 nW m-2 sr-1 at 240 μm (95% confidence). This integrated flux ~2 times that extrapolated from optical galaxies in the Hubble Deep Field. The primary use of these maps is likely to be as a new estimator of Galactic extinction. To calibrate our maps, we assume a

  18. Fingerprints of the first black holes? Crosscorrelationg the Near-Infrared and X-ray background in COSMOS

    Science.gov (United States)

    Hasinger, Guenther

    Unresolved cosmic backgrounds carry information about the populations of stars and black holes not accessible by any other current observational technique. Studies using both Spitzer and AKARI have revealed large-scale fluctuations in the Cosmic Infrared Background (CIB) after subtracting resolved sources to faint levels. The signal, which is stronger than all foreground contributions, has been attributed to the earliest light in the universe. Other teams, by using Spitzer and CIBER, suggested that this signal could originate from stars tidally stripped from their parent galaxies at low redshift as a result of mergers. Only sensitive multi-wavelength observations can distinguish between these radically different interpretations. Recently our team discovered an intriguing cross-correlation signal between the unresolved CIB and X-ray background (CXB) suggesting significant black hole populations among the CIB sources (C13). The analysis used data from Spitzer and Chandra in an overlapping 8'x45' region of the All-Wavelength Extended Groth strip International Survey (AEGIS), probing the clustering of the underlying sources to angular scales 20', but the experiment is limited by the size and the elongated configuration of the field. Here we propose to use the much more extended multiwavelength observations in the COSMOS field to obtain new constraints on this important debate. Spitzer has recently completed the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH), which observed the full 2 square degree COSMOS field to about half the depth of the AEGIS field, but a 20 times larger sky area. SPLASH, focusing on the COSMOS field with excellent multi-wavelength coverage from space and ground-based observatories, is ideally suited to study the CIB to better precision and at larger scales than available so far. We propose to cross-correlate the Spitzer unresolved CIB to the unresolved CXB observed by Chandra and XMM-Newton. Chandra has covered the full 2 deg2 COSMOS

  19. A monochromatized chopped beam of cold neutrons for low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bussiere, A. (Lab. de Physique des Particules, 74 - Annecy le Vieux (France)); Grivot, P. (Inst. des Sciences Nucleaires, 38 - Grenoble (France)); Kossakowski, R. (Lab. de Physique des Particules, 74 - Annecy le Vieux (France)); Liaud, P. (Lab. de Physique des Particules, 74 - Annecy le Vieux (France)); Saintignon, P. de (Inst. des Sciences Nucleaires, 38 - Grenoble (France)); Schreckenbach, K. (Inst. Laue-Langevin, 38 - Grenoble (France))

    1993-07-15

    The design and performance of a monochromatized, chopped beam of cold neutrons are described. The beam is particularly suited for experiments where a low level of gamma ray and diffused neutron background is required. (orig.)

  20. Krypton and radon background in the PandaX-I dark matter experiment

    Science.gov (United States)

    Li, S.; Chen, X.; Cui, X.; Fu, C.; Ji, X.; Lin, Q.; Liu, J.; Liu, X.; Tan, A.; Wang, X.; Xiao, M.; Xie, P.

    2017-02-01

    We discuss an in-situ evaluation of the 85Kr, 222Rn, and 220Rn background in PandaX-I, a 120-kg liquid xenon dark matter direct detection experiment. Combining with a simulation, their contributions to the low energy electron-recoil background in the dark matter search region are obtained.

  1. Simulations of the cosmic infrared and submillimeter background for future large surveys: II. Removing the low-redshift contribution to the anisotropies using stacking

    CERN Document Server

    Fernandez-Conde, N; Puget, J-L; Dole, H; 10.1051/0004-6361/200912924

    2010-01-01

    Herschel and Planck are surveying the sky at unprecedented angular scales and sensitivities over large areas. But both experiments are limited by source confusion in the submillimeter. The high confusion noise in particular restricts the study of the clustering properties of the sources that dominate the cosmic infrared background. At these wavelengths, it is more appropriate to consider the statistics of the unresolved component. In particular, high clustering will contribute in excess of Poisson noise in the power spectra of CIB anisotropies. These power spectra contain contributions from sources at all redshift. We show how the stacking technique can be used to separate the different redshift contributions to the power spectra. We use simulations of CIB representative of realistic Spitzer, Herschel, Planck, and SCUBA-2 observations. We stack the 24um sources in longer wavelengths maps to measure mean colors per redshift and flux bins. The information retrieved on the mean spectral energy distribution obtai...

  2. HerMES: The Contribution to the Cosmic Infrared Background from Galaxies Selected by Mass and Redshift

    CERN Document Server

    Viero, M P; Quadri, R F; Arumugam, V; Assef, R J; Bethermin, M; Bock, J; Bridge, C; Conley, A; Cooray, A; Farrah, D; Heinis, S; Ikarashi, S; Ivison, R J; Kohno, K; Marsden, G; Oliver, S J; Roseboom, I G; Schulz, B; Scott, D; Serra, P; Vaccari, M; Vieira, J D; Wang, L; Wardlow, J; Williams, R J; Wilson, G W; Yun, M S; Zemcov, M

    2013-01-01

    We quantify the fraction of the cosmic infrared background (CIB) that originates from galaxies identified in the UV/optical/near-infrared by stacking 81,250 (~35.7 arcmin^2) K-selected sources, split according to their rest-frame U - V vs. V - J colors into 72,216 star-forming and 9,034 quiescent galaxies, on maps from Spitzer/MIPS (24, 70, 160 {\\mu}m), Herschel/SPIRE (250, 350, 500 {\\mu}m), and AzTEC (1100 {\\mu}m). The fraction of the CIB resolved by our catalog is (67 \\pm 16)% at 24 {\\mu}m, (72 \\pm 17)% at 70 {\\mu}m, (76 \\pm 18)% at 160 {\\mu}m, (78 \\pm 18)% at 250 {\\mu}m, (70 \\pm 15)% at 350 {\\mu}m, (67 \\pm 13)% at 500 {\\mu}m, and (52 \\pm 9)% at 1100 {\\mu}m. Of that total, about 95% originates from star-forming galaxies, while the remaining 5% is from apparently quiescent galaxies. The CIB at {\\lambda} 200 {\\mu}m the bulk originates from 1 350{\\mu}m. The contribution from galaxies in the log(M/ M_sun)=9.0$-9.5 (highest) and log(M/ M_sun)=11.0-12.0 (lowest) stellar mass bins contribute the least, both of o...

  3. GOODS-$Herschel$: identification of the individual galaxies responsible for the 80-290$\\mu$m cosmic infrared background

    CERN Document Server

    Leiton, R; Okumura, K; Hwang, H S; Magdis, G; Magnelli, B; Valtchanov, I; Dickinson, M; Béthermin, M; Schreiber, C; Charmandaris, V; Dole, H; Juneau, S; Borgne, D Le; Pannella, M; Pope, A; Popesso, P

    2015-01-01

    We propose a new method of pushing $Herschel$ to its faintest detection limits using universal trends in the redshift evolution of the far infrared over 24$\\mu$m colours in the well-sampled GOODS-North field. An extension to other fields with less multi-wavelength information is presented. This method is applied here to raise the contribution of individually detected $Herschel$ sources to the cosmic infrared background (CIRB) by a factor 5 close to its peak at 250$\\mu$m and more than 3 in the 350$\\mu$m and 500$\\mu$m bands. We produce realistic mock $Herschel$ images of the deep PACS and SPIRE images of the GOODS-North field from the GOODS-$Herschel$ Key Program and use them to quantify the confusion noise at the position of individual sources, i.e., estimate a "local confusion noise". Two methods are used to identify sources with reliable photometric accuracy extracted using 24$\\mu$m prior positions. The clean index (CI), previously defined but validated here with simulations, which measures the presence of b...

  4. Infrared-Faint Radio Sources: A Cosmological View - AGN Number Counts, the Cosmic X-Ray Background and SMBH Formation

    CERN Document Server

    Zinn, Peter-Christian; Ibar, Edo

    2011-01-01

    Context. Infrared Faint Radio Sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5 sigma sensitivities as low as 1 uJy. Aims. Recent SED-modelling and analysis of their radio properties shows that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3Background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simula...

  5. Non-Gaussianity of the Cosmic Infrared Background anisotropies II : Predictions of the bispectrum and constraints forecast

    CERN Document Server

    Pénin, Aurélie; Aghanim, Nabila

    2013-01-01

    Using a full analytical computation of the bispectrum based on the halo model together with the halo occupation number, we derive the bispectrum of the cos- mic infrared background (CIB) anisotropies that trace the clustering of dusty-star- forming galaxies. We focus our analysis on wavelengths in the far-infrared and the sub-millimeter typical of the Planck/HFI and Herschel/SPIRE instruments, 350, 550, 850, and 1380 um. We explore the bispectrum behaviour as a function of several models of evolution of galaxies and show that it is strongly sensitive to that ingredient. Contrary to the power spectrum, the bispectrum, at the four wavelengths, seems dominated by low redshift galaxies. Such a contribution can be hardly limited by applying low flux cuts. We also discuss the contributions of halo mass as a function of the redshift and the wavelength, recovering that each term is sensitive to a different mass range. Furthermore, we show that the CIB bispectrum is a strong contaminant of the Cosmic Microwave Backgro...

  6. Infrared-faint radio sources: a cosmological view. AGN number counts, the cosmic X-ray background and SMBH formation

    Science.gov (United States)

    Zinn, P.-C.; Middelberg, E.; Ibar, E.

    2011-07-01

    Context. Infrared-faint radio sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5σ sensitivities as low as 1 μJy. Aims: Spectral energy distribution (hereafter SED) modelling and analyses of their radio properties indicate that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3 ≤ z ≤ 6. We demonstrate some astrophysical implications of this population and compare them to predictions from models of galaxy evolution and structure formation. Methods: We compiled a list of IFRS from four deep extragalactic surveys and extrapolated the IFRS number density to a survey-independent value of (30.8 ± 15.0) deg-2. We computed the IFRS contribution to the total number of AGN in the Universe to account for the cosmic X-ray background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simulations of structure formation after the Big Bang. Results: The number density of AGN derived from the IFRS density was found to be ~310 deg-2, which is equivalent to a SMBH mass density of the order of 103 M⊙ Mpc-3 in the redshift range 3 ≤ z ≤ 6. This produces an X-ray flux of 9 × 10-16 W m-2 deg-2 in the 0.5-2.0 keV band and 3 × 10-15 W m-2 deg-2 in the 2.0-10 keV band, in agreement with the missing unresolved components of the Cosmic X-ray Background. To address SMBH formation after the Big Bang we invoke a scenario involving both halo gas accretion and major mergers.

  7. The cosmic far-infrared background buildup since redshift 2 at 70 and 160 microns in the COSMOS and GOODS fields

    NARCIS (Netherlands)

    Jauzac, M.; Dole, H.; Le Floc'h, E.; Aussel, H.; Caputi, K.; Ilbert, O.; Salvato, M.; Bavouzet, N.; Beelen, A.; Bethermin, M.; Kneib, J. -P.; Lagache, G.; Puget, J. -L.

    2011-01-01

    Context. The cosmic far-infrared background (CIB) at wavelengths around 160 mu m corresponds to the peak intensity of the whole extragalactic background light, which is being measured with increasing accuracy. However, the build up of the CIB emission as a function of redshift is still not well know

  8. HerMES: A DEFICIT IN THE SURFACE BRIGHTNESS OF THE COSMIC INFRARED BACKGROUND DUE TO GALAXY CLUSTER GRAVITATIONAL LENSING

    Energy Technology Data Exchange (ETDEWEB)

    Zemcov, M.; Cooray, A.; Bock, J.; Dowell, C. D.; Nguyen, H. T. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Blain, A. [Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Bethermin, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Universite Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Conley, A.; Glenn, J. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); Conversi, L. [Herschel Science Centre, European Space Astronomy Centre, Villanueva de la Canada, E-28691 Madrid (Spain); Farrah, D.; Oliver, S. J.; Roseboom, I. G. [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); Griffin, M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Halpern, M.; Marsden, G. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Jullo, E.; Kneib, J.-P. [Aix-Marseille Universite, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR7326, F-13388 Marseille (France); Richard, J., E-mail: zemcov@caltech.edu [Centre de Recherche Astronomique de Lyon, Universite Lyon 1, 9 avenue Charles Andre, F-69230 Saint-Genis Laval (France); and others

    2013-06-01

    We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after removing detected sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I{sub 250{mu}m}>0.69{sub -0.03}{sup +0.03}(stat.){sub -0.06}{sup +0.11}(sys.) MJy sr{sup -1}, with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe this effect in existing high angular resolution data at other wavelengths where the CIB is bright, which would allow tests of models of the faint source component of the CIB.

  9. PROBING THE EPOCH OF PRE-REIONIZATION BY CROSS-CORRELATING COSMIC MICROWAVE AND INFRARED BACKGROUND ANISOTROPIES

    Energy Technology Data Exchange (ETDEWEB)

    Atrio-Barandela, F. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kashlinsky, A., E-mail: atrio@usal.es, E-mail: Alexander.Kashlinsky@nasa.gov [Observational Cosmology Lab, NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

    2014-12-20

    The epoch of first star formation and the state of the intergalactic medium (IGM) at that time are not directly observable with current telescopes. The radiation from those early sources is now part of the cosmic infrared background (CIB) and, as these sources ionize the gas around them, the IGM plasma would produce faint temperature anisotropies in the cosmic microwave background (CMB) via the thermal Sunyaev-Zeldovich (TSZ) effect. While these TSZ anisotropies are too faint to be detected, we show that the cross-correlation of maps of source-subtracted CIB fluctuations from Euclid, with suitably constructed microwave maps at different frequencies, can probe the physical state of the gas during reionization and test/constrain models of the early CIB sources. We identify the frequency-combined, CMB-subtracted microwave maps from space- and ground-based instruments to show that they can be cross-correlated with the forthcoming all-sky Euclid CIB maps to detect the cross-power at scales ∼5'-60' with signal-to-noise ratios (S/Ns) of up to S/N ∼ 4-8 depending on the contribution to the Thomson optical depth during those pre-reionization epochs (Δτ ≅ 0.05) and the temperature of the IGM (up to ∼10{sup 4} K). Such a measurement would offer a new window to explore the emergence and physical properties of these first light sources.

  10. HerMES: A Deficit in the Surface Brightness of the Cosmic Infrared Background Due to Galaxy Cluster Gravitational Lensing

    CERN Document Server

    Zemcov, M; Cooray, A; Bethermin, M; Bock, J; Clements, D L; Conley, A; Conversi, L; Dowell, C D; Farrah, D; Glenn, J; Griffin, M; Halpern, M; Jullo, E; Kneib, J -P; Marsden, G; Nguyen, H T; Richard, S J Oliver J; Roseboom, I G; Schulz, B; Scott, Douglas; Shupe, D L; Smith, A J; Valtchanov, I; Viero, M; Wang, L; Wardlow, J

    2013-01-01

    We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after subtracting sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I(250 microns) > 0.69_(-0.03)^(+0.03) (stat.)_(-0.06)^(+0.11) (sys.) MJy/sr, with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe th...

  11. Comparing submillimeter polarized emission with near-infrared polarization of background stars for the Vela C molecular cloud

    CERN Document Server

    Santos, Fabio P; Angile, Francesco E; Ashton, Peter; Benton, Steven J; Devlin, Mark J; Dober, Bradley; Fissel, Laura M; Fukui, Yasuo; Galitzki, Nicholas; Gandilo, Natalie N; Klein, Jeffrey; Korotkov, Andrei L; Li, Zhi-Yun; Martin, Peter G; Matthews, Tristan G; Moncelsi, Lorenzo; Nakamura, Fumitaka; Netterfield, Calvin B; Novak, Giles; Pascale, Enzo; Poidevin, Frederick; Savini, Giorgio; Scott, Douglas; Shariff, Jamil A; Soler, Juan Diego; Thomas, Nicholas E; Tucker, Carole E; Tucker, Gregory S; Ward-Thompson, Derek

    2016-01-01

    We present the first large-scale quantitative combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter (sub-mm) wavelengths for a molecular cloud. Sub-mm data for the Vela C molecular cloud were obtained in Antartica by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol). The near-IR data consist of more than 6700 detections in the $I$-band, distributed in and around the cloud in the range of visual extinctions between $2$ and $20\\,$mag. The main goal was to determine the polarization efficiency ratio $R_{\\mathrm{eff}}$, defined as $p_{500}/(p_{I}/\\tau_{V})$, where $p_{500}$ and $p_{I}$ are polarization fractions at $500\\,\\mu$m and $I$-band, respectively, and $\\tau_{V}$ is the optical depth. To ensure that the same column density of material is producing both polarization from emission and from extinction, we introduce a new method to select stars that are located in the near-background, the Ga...

  12. Probing the epoch of pre-reionization by cross-correlating cosmic microwave and infrared background anisotropies

    CERN Document Server

    Atrio-Barandela, Fernando

    2014-01-01

    The epoch of first star formation and the state of the intergalactic medium (IGM) at that time are not directly observable with current telescopes. The radiation from those early sources is now part of the Cosmic Infrared Background (CIB) and, as these sources ionize the gas around them, the IGM plasma would produce faint temperature anisotropies in the Cosmic Microwave Background (CMB) via the thermal Sunyaev-Zeldovich (TSZ) effect. While these TSZ anisotropies are too faint to be detected, we show that the cross-correlation of maps of source-subtracted CIB fluctuations from {\\it Euclid}, with suitably constructed microwave maps at different frequencies can probe the physical state of the gas during reionization and test/constrain models of the early CIB sources. We identify the frequency-combined CMB-subtracted microwave maps from space and ground-based instruments to show that they can be cross-correlated with the forthcoming all-sky {\\it Euclid} CIB maps to detect the cross-power at scales $\\sim 5'-60'$ w...

  13. Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud

    Science.gov (United States)

    Santos, Fabio P.; Ade, Peter A. R.; Angilè, Francesco E.; Ashton, Peter; Benton, Steven J.; Devlin, Mark J.; Dober, Bradley; Fissel, Laura M.; Fukui, Yasuo; Galitzki, Nicholas; Gandilo, Natalie N.; Klein, Jeffrey; Korotkov, Andrei L.; Li, Zhi-Yun; Martin, Peter G.; Matthews, Tristan G.; Moncelsi, Lorenzo; Nakamura, Fumitaka; Netterfield, Calvin B.; Novak, Giles; Pascale, Enzo; Poidevin, Frédérick; Savini, Giorgio; Scott, Douglas; Shariff, Jamil A.; Diego Soler, Juan; Thomas, Nicholas E.; Tucker, Carole E.; Tucker, Gregory S.; Ward-Thompson, Derek

    2017-03-01

    We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctions between 2 and 20 {mag} in and around the cloud. The submillimeter data were collected in Antarctica by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry. This is the first direct combination of near-IR and submillimeter polarization data for a molecular cloud aimed at measuring the “polarization efficiency ratio” ({R}{eff}), a quantity that is expected to depend only on grain-intrinsic physical properties. It is defined as {p}500/({p}I/{τ }V), where p 500 and p I are polarization fractions at 500 μ {{m}} and the I band, respectively, and {τ }V is the optical depth. To ensure that the same column density of material is producing both polarization from emission and from extinction, we conducted a careful selection of near-background stars using 2MASS, Herschel, and Planck data. This selection excludes objects contaminated by the Galactic diffuse background material as well as objects located in the foreground. Accounting for statistical and systematic uncertainties, we estimate an average {R}{eff} value of 2.4 ± 0.8, which can be used to test the predictions of dust grain models designed for molecular clouds when such predictions become available. The ratio {R}{eff} appears to be relatively flat as a function of the cloud depth for the range of visual extinctions probed.

  14. Comparing submillimeter polarized emission with near-infrared polarization of background stars for the Vela C molecular cloud

    Science.gov (United States)

    Santos, Fabio P.; Ade, Peter; Angilè, Francesco E.; Ashton, Peter; Benton, Steven J.; Devlin, Mark J.; Dober, Bradley; Fissel, Laura M.; Fukui, Yasuo; Galitzki, Nicholas; Gandilo, Natalie; Klein, Jeffrey; Li, Zhi-Yun; Korotkov, Andrei; Martin, Peter G.; Matthews, Tristan; Moncelsi, Lorenzo; nakamura, fumitaka; Barth Netterfield, Calvin; Novak, Giles; Pascale, Enzo; Poidevin, Frédérick; Savini, Giorgio; Scott, Douglas; Shariff, Jamil; Soler, Juan D.; Thomas, Nicholas; tucker, carole; Tucker, Gregory S.; Ward-Thompson, Derek; BLASTPOL

    2016-06-01

    We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight, with polarized emission data at sub-millimetric (sub-mm) bands for the Vela C molecular cloud. The sub-mm data were obtained by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) during the 2012 flight in Antartica. The near-IR data consist of more than 6700 detections in the I-band, covering a wide area around the cloud, mostly in the range of visual extinctions between 2 and 16 mag. The main goal was to determine the polarization efficiency ratio Reff , defined as p500/(pI/τV), where p500 is the polarization fraction at 500 μm and optical depths τV are estimated from cataloged near-IR photometry. To ensure that the same column density of material is producing both polarization from emission and extinction, we introduce a new method to select stars that are located in the near-background, the Gaussian-logistic (GL) technique. The polarization efficiency ratio is critically affected by stellar objects with background contamination from the diffuse Galactic material, emphasizing the need for a careful selection. Accounting for the statistical and systematic uncertainties from the GL method, we estimate an average Reff value of 2.4 ± 0.8, which can be used to test dust grain models designed specifically for molecular clouds. Reff appears to be relatively flat as a function of the cloud depth, suggesting that significant grain modification might occur only at higher densities.

  15. Revisiting the Young's double slit experiment for background-free nonlinear Raman spectroscopy and microscopy.

    Science.gov (United States)

    Gachet, David; Brustlein, Sophie; Rigneault, Hervé

    2010-05-28

    In the Young's double slit experiment, the spatial shift of the interference pattern projected onto a screen is directly related to the phase difference between the fields diffracted by the two slits. We apply this property to fields emitted by nonlinear processes and thus demonstrate background-free coherent anti-Stokes Raman scattering microscopy near an axial interface between a resonant and a nonresonant medium. This method is relevant to remove the nonresonant background in other coherent resonant processes.

  16. Radon backgrounds in the DRIFT-II directional dark matter experiments

    CERN Document Server

    Daw, E; Gauvreau, J -L; Gold, M; Harmon, L J; Landers, J M; Lee, E R; Loomba, D; Miller, E H; Murphy, A StJ; Paling, S M; Pipe, M; Robinson, M; Sadler, S; Scarff, A; Snowden-Ifft, D P; Spooner, N J C; Walker, D

    2013-01-01

    Low pressure gas Time Projection Chambers being developed for directional Dark Matter searches offer a technology with high particle identification power, combined with poten- tial to produce a definitive detection of galactic Weakly Interacting Massive Particle (WIMP) Dark Matter. A source of background events in such experiments, able to mimic genuine WIMP in- duced nuclear recoil tracks, arises from potential radon contamination and the recoils that result from associated daughter nuclei, termed Radon Progeny Recoils (RPRs). We present here experi- mental data from a long-term study of this background using the DRIFT-II directional dark matter experiment at the Boulby Underground Laboratory. By detailed examination of event classes in both spatial and time coordinates using 5.5 years of data we show ability to determine the origin of 4 specific background populations and describe development of new technology and mitigation strategies to suppress them.

  17. Cosmic infrared background fluctuations of the COSMOS field in the SPLASH survey: new measurements and the cosmological explanations

    Science.gov (United States)

    Li, Yanxia

    2017-01-01

    The cosmic infrared background (CIB) is the integrated emission of all sources through cosmic time and carries an abundance of information about the star formation and galaxy growth in the Universe. Due to significant and complex foregrounds from our Galaxy, the optimal way to study the unresolved background is to actually study its fluctuations, especially at large angular scales where they reflect the clustering of unresolved galaxies. Our new measurements of the CIB fluctuations reach the largest angular scale to date for such a study, thanks to new observations of the COSMOS field from the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH). We analyzed Spitzer IRAC 3.6 and 4.5 um data of the whole field, with an average depth of 1.33 hour/pixel over 4 epochs spanning 2 years. We found that the auto-power spectra are consistent among various epochs and are correlated at the two channels. We confirmed the previously detected excess flux at large scales of the power spectra.The cross-correlation of the CIB fluctuations with backgrounds at other wavelengths is an extremely useful technique to understand the excess flux. The previously seen CIB and X-ray background (CXB) cross-correlation suggests significant contribution to the CIB fluctuations from accreting black holes that is much higher than among any known populations, and such a cross-correlation is also used as an evidence for the existence of direct collapse black holes in the early Universe.In this talk, we will present the first CIB fluctuation measurements of the COSMOS field using the new SPLASH data and we will also revisit the CIB and CXB cross-correlation in this field, which is about 20 times larger than the previous study and therefore with much improved significance levels. Measuring CIB fluctuations is a powerful tool to study the large-scale structure of the Universe. The CIB and CXB cross-correlation can not only provide observational constrains on the theoretical modeling of the CIB

  18. The Majorana experiment: an ultra-low background search for neutrinoless double-beta decay

    CERN Document Server

    Phillips, D G; Avignone, F T; Back, H O; Barabash, A S; Bergevin, M; Bertrand, F E; Boswell, M; Brudanin, V; Busch, M; Chan, Y -D; Christofferson, C D; Collar, J I; Combs, D C; Cooper, R J; Detwiler, J A; Doe, P J; Efremenko, Y; Egorov, V; Ejiri, H; Elliott, S R; Esterline, J; Fast, J E; Fields, N; Finnerty, P; Fraenkle, F M; Gehman, V M; Giovanetti, G K; Green, M P; Guiseppe, V E; Gusey, K; Hallin, A L; Hazama, R; Henning, R; Hime, A; Hoppe, E W; Horton, M; Howard, S; Howe, M A; Johnson, R A; Keeter, K J; Keller, C; Kidd, M F; Knecht, A; Kochetov, O; Konovalov, S I; Kouzes, R T; LaFerriere, B; LaRoque, B H; Leon, J; Leviner, L E; Loach, J C; MacMullin, S; Marino, M G; Martin, R D; Mei, D -M; Merriman, J; Miller, M L; Mizouni, L; Nomachi, M; Orrell, J L; Overman, N R; Poon, A W P; Perumpilly, G; Prior, G; Radford, D C; Rielage, K; Robertson, R G H; Ronquest, M C; Schubert, A G; Shima, T; Shirchenko, M; Snavely, K J; Steele, D; Strain, J; Thomas, K; Timkin, V; Tornow, W; Vanyushin, I; Varner, R L; Vetter, K; Vorren, K; Wilkerson, J F; Wolfe, B A; Yakushev, E; Young, A R; Yu, C -H; Yumatov, V; Zhang, C

    2011-01-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  19. The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.; Aguayo Navarrete, Estanislao; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor; Giovanetti, G. K.; Green, Matthew P.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keller, C.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2012-12-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana Experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to validate whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  20. NEW MEASUREMENTS OF THE COSMIC INFRARED BACKGROUND FLUCTUATIONS IN DEEP SPITZER/IRAC SURVEY DATA AND THEIR COSMOLOGICAL IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kashlinsky, A. [SSAI, Lanham MD 20706 (United States); Arendt, R. G.; Mather, J.; Moseley, S. H. [Observational Cosmology Laboratory, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ashby, M. L. N.; Fazio, G. G., E-mail: alexander.kashlinsky@nasa.gov [Center for Astrophysics, Cambridge, MA 02138 (United States)

    2012-07-01

    We extend previous measurements of cosmic infrared background (CIB) fluctuations to {approx}< 1 Degree-Sign using new data from the Spitzer Extended Deep Survey. Two fields with depths of {approx_equal} 12 hr pixel{sup -1} over three epochs are analyzed at 3.6 and 4.5 {mu}m. Maps of the fields were assembled using a self-calibration method uniquely suitable for probing faint diffuse backgrounds. Resolved sources were removed from the maps to a magnitude limit of mag{sub AB} {approx_equal} 25, as indicated by the level of the remaining shot noise. The maps were then Fourier transformed and their power spectra were evaluated. Instrumental noise was estimated from the time-differenced data, and subtracting this isolates the spatial fluctuations of the actual sky. The power spectra of the source-subtracted fields remain identical (within the observational uncertainties) for the three epochs indicating that zodiacal light contributes negligibly to the fluctuations. Comparing to 8 {mu}m power spectra shows that Galactic cirrus cannot account for the fluctuations. The signal appears isotropically distributed on the sky as required for an extragalactic origin. The CIB fluctuations continue to diverge to >10 times those of known galaxy populations on angular scales out to {approx}< 1 Degree-Sign . The low shot-noise levels remaining in the diffuse maps indicate that the large-scale fluctuations arise from the spatial clustering of faint sources well below the confusion noise. The spatial spectrum of these fluctuations is in reasonable agreement with an origin in populations clustered according to the standard cosmological model ({Lambda}CDM) at epochs coinciding with the first stars era.

  1. A near-infrared SETI experiment: probability distribution of false coincidences

    Science.gov (United States)

    Maire, Jérôme; Wright, Shelley A.; Werthimer, Dan; Treffers, Richard R.; Marcy, Geoffrey W.; Stone, Remington P. S.; Drake, Frank; Siemion, Andrew

    2014-07-01

    A Search for Extraterrestrial Life (SETI), based on the possibility of interstellar communication via laser signals, is being designed to extend the search into the near-infrared spectral region (Wright et al, this conference). The dedicated near-infrared (900 to 1700 nm) instrument takes advantage of a new generation of avalanche photodiodes (APD), based on internal discrete amplification. These discrete APD (DAPD) detectors have a high speed response (laser light pulse detection in our experiment. These criteria are defined to optimize the trade between high detection efficiency and low false positive coincident signals, which can be produced by detector dark noise, background light, cosmic rays, and astronomical sources. We investigate experimentally how false coincidence rates depend on the number of detectors in parallel, and on the signal pulse height and width. We also look into the corresponding threshold to each of the signals to optimize the sensitivity while also reducing the false coincidence rates. Lastly, we discuss the analytical solution used to predict the probability of laser pulse detection with multiple detectors.

  2. The Effect of AGN and SNe Feedback on Star Formation,Reionization and the Near Infrared Background

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Feedback from supernovae (SNe) and from active galactic nuclei (AGN) accom-panies the history of star formation and galaxy evolution. We present an analytic model to explain how and when the SNe and AGN exert their feedback effects on the star formation and galaxy evolution processes. By using SNe and AGN kinetic feedback mechanisms based on the Lambda Cold Dark Matter (LCDM) model, we explore how these feedback mecha-nisms affect the star formation history (SFH), the Near-Infrared Background (NIRB) flux and the cosmological reionization. We find the values of the feedback strengths, ∈AGN =1.0+0.50.3and ∈SN=0.04+0.02-0.02, can provide a reasonable explanation of most of the observational re-suits, and that the AGN feedback effect on star formation history is quite different from the SNe feedback at high redshifts. Our conclusions manifest quantitatively that these feedback effects decrease star formation rate density (SFRD) and the NIRB flux (in 1.4 - 4.0μm), and postpone the time of completion of the cosmological reionization.

  3. Non-Gaussianity of the Cosmic Infrared Background anisotropies I : Diagrammatic formalism and application to the angular bispectrum

    CERN Document Server

    Lacasa, Fabien; Aghanim, Nabila

    2013-01-01

    We present the first halo model based description of the Cosmic Infrared Background (CIB) non-Gaussianity (NG) that is fully parametric. To this end, we introduce, for the first time, a diagrammatic method to compute high order polyspectra of the 3D galaxy density field. It allows an easy derivation and visualisation of the different terms of the polyspectrum. We apply this framework to the power spectrum and bispectrum, and we show how to project them on the celestial sphere in the purpose of the application to the CIB angular anisotropies. Furthermore, we show how to take into account the particular case of the shot noise terms in that framework. Eventually, we compute the CIB angular bispectrum at 857 GHz and study its scale and configuration dependencies, as well as its variations with the halo occupation distribution parameters. Compared to a previously proposed empirical prescription, such physically motivated model is required to describe fully the CIB anisotropies bispectrum. Finally, we compare the C...

  4. Lyman-tomography of cosmic infrared background fluctuations with Euclid: probing emissions and baryonic acoustic oscillations at z>10

    CERN Document Server

    Kashlinsky, A; Atrio-Barandela, F; Helgason, K

    2015-01-01

    The Euclid space mission, designed to probe evolution of the Dark Energy, will map a large area of the sky at three adjacent near-IR filters, Y, J and H. This coverage will also enable mapping source-subtracted cosmic infrared background (CIB) fluctuations with unprecedented accuracy on sub-degree angular scales. Here we propose methodology, using the Lyman-break tomography applied to the Euclid-based CIB maps, to accurately isolate the history of CIB emissions as a function of redshift from 10 ~ 400 sq deg. The method can isolate the CIB spatial spectrum by z to sub-percent statistical accuracy. We illustrate this with a specific model of CIB production at high z normalized to reproduce the measured Spitzer-based CIB fluctuation. We show that even if the latter contain only a small component from high-z sources, the amplitude of that component can be accurately isolated with the methodology proposed here and the BAO signatures at z>~ 10 are recovered well from the CIB fluctuation spatial spectrum. Probing th...

  5. HerMES: Current Cosmic Infrared Background Estimates are Consistent with Correlated Emission from Known Galaxies at z < 4

    CERN Document Server

    Viero, M P; Quadri, R F; Béthermin, M; Bock, J J; Burgarella, D; Chapman, S C; Clements, D L; Conley, A; Conversi, L; Duivenvoorden, S; Dunlop, J S; Farrah, D; Franceschini, A; Ivison, R J; Lagache, G; Magdis, G; Marchetti, L; Álvarez-Márquez, J; Marsden, G; Oliver, S J; Page, M J; Pérez-Fournon, I; Schulz, B; Scott, Douglas; Valtchanov, I; Vieira, J D; Wang, L; Wardlow, J; Zemcov, M

    2015-01-01

    We report contributions to cosmic infrared background (CIB) intensities originating from known galaxies, and their companions, at submillimeter wavelengths. Using the publicly-available UltraVISTA catalog, and maps at 250, 350, and 500 {\\mu}m from Herschel/SPIRE, we perform a novel measurement that exploits the fact that correlated sources will bias stacked flux densities if the resolution of the image is poor; i.e., we intentionally smooth the image - in effect degrading the angular resolution - before stacking and summing intensities. By smoothing the maps we are capturing the contribution of faint (undetected in K_S ~ 23.4) sources that are physically associated with the detected sources. We find that the cumulative CIB increases with increased smoothing, reaching 9.82 +- 0.78, 5.77 +- 0.43, and 2.32 +- 0.19 nWm^-2/sr at 250, 350, and 500 {\\mu}m at 300 arcsec full width half maximum. This corresponds to a fraction of the fiducial CIB of 0.94 +- 0.23, 1.07 +- 0.31, and 0.97 +- 0.26 at 250, 350, and 500 {\\mu...

  6. On the Physical Requirements for a Pre-Reionization Origin of the Unresolved Near-Infrared Background

    CERN Document Server

    Helgason, Kari; Kashlinsky, Alexander; Bromm, Volker

    2015-01-01

    The study of the Cosmic Near-Infrared Background (CIB) light after subtraction of resolved sources can push the limits of current observations and infer the level of galaxy and black hole activity in the early universe. However, disentangling the relative contribution from low- and high-redshift sources is not trivial. Spatial fluctuations of the CIB exhibit a clustering excess at angular scales $\\sim 1^\\circ$ whose origin has not been conclusively identified. We explore the likelihood that this signal is dominated by emission from galaxies and accreting black holes in the early Universe. We find that, if the first small mass galaxies have a normal IMF, the light of their ageing stars (fossils) integrated over cosmic time contributes a comparable amount to the CIB as their pre-reionization progenitors. However, the measured fluctuation signal is too large to be produced by galaxies at redshifts $z>8$ unless their star formation efficiencies are much larger than those inferred from the observed Lyman-dropout p...

  7. Detection of small scale fluctuations in the near-IR cosmic infrared background from long exposure 2MASS fields

    CERN Document Server

    Kashlinsky, A; Mather, J; Skrutskie, M F; Cutri, R M

    2002-01-01

    We report first results for the cosmic infrared background (CIB) fluctuations at 1.25, 1.65 and 2.17 micron obtained from long exposures constructed from 2MASS standard star fields. We have co-added and analyzed scans from one such field with a total exposure time > 1 hour, and removed sources and other artifacts. The stars and galaxies were clipped out to K_s~19^m leaving only high-z galaxies (or possibly local low-surface-brightness systems). The residual component of the diffuse emission on scales from a few arc-sec to a few arc-min has a power-law slope consistent with emission produced by clustered galaxies. The noise (and residual artifacts) contribution to the signal is small and the colors of the signal are very different from Galactic stars or air-glow. We therefore identify the signal as CIB fluctuations from the faint unresolved galaxies. We show that the present-day galaxies with no evolution would produce a significant deficit in the observed CIB fluctuations. Thus the dominant contribution to th...

  8. Analysis of the diffuse near-IR emission from 2MASS deep integration data foregrounds vs the cosmic infrared background

    CERN Document Server

    Odenwald, S; Mather, J C; Skrutskie, M F; Cutri, R M

    2003-01-01

    This is one of two papers in which we report the detection of structure in the cosmic infrared background (CIB) between 1.25 - 2.2 micron through the use of data from the Two Micron Sky Survey (2MASS). This paper concentrates on data assembly, analysis and the estimate of the various foreground contributions; the companion paper (Kashlinsky, Odenwald, Mather, Skrutskie, Cutri 2002, hereafter KOMSC) presents the cosmological results for the CIB fluctuations and their implications. By using repeated observations of a specific calibration star field, we were able to achieve integration times in excess of 3900 seconds compared to the 7.8 seconds in the standard 2MASS data product. This yielded a point source detection limit (3 \\sigma) of +18.5^m in K_s band. The resulting co-added images were processed to remove point sources to a limiting surface brightness of +20^m/arcsec$^2 or 40 nW/m^2/sr. The remaining maps contained over 90% of the pixels and were Fourier transformed to study the spatial structure of the di...

  9. Status and research objectives of the Dutch free electron laser for infrared experiments

    Science.gov (United States)

    Van Amersfoort, P. W.; Best, R. W. B.; Van Buuren, R.; Delmee, P. F. M.; Faatz, B.; Van Der Geer, C. A. J.; Jaroszynski, D. A.; Manintveld, P.; Mastop, W. J.; Meddens, B. J. H.; Van Der Meer, A. F. G.; Oepts, D.; Pluygers, J.; Van Der Wiel, M. J.

    1990-10-01

    We review the status and research objectives of the free electron laser for infrared experiments (FELIX), which will be operated as a users facility for the far-infrared and submillimeter spectral regions. The spectral region between 8 and 80 μm will be covered in the first stage of the project.

  10. Early Results on Radioactive Background Characterization for Sanford Laboratory and DUSEL Experiments

    CERN Document Server

    Mei, D -M; Thomas, K; Gray, F

    2009-01-01

    Measuring external sources of background for a deep underground laboratory at the Homestake Mine is an important step for the planned low-background experiments. The naturally occurring $\\gamma$-ray fluxes at different levels in the Homestake Mine are studied using NaI detectors and Monte Carlo simulations. A simple algorithm is developed to convert the measured $\\gamma$-ray rates into $\\gamma$-ray fluxes. A good agreement between the measured and simulated $\\gamma$-ray fluxes is achieved with the knowledge of the chemical composition and radioactivity levels in the rock. The neutron fluxes and $\\gamma$-ray fluxes are predicted by Monte Carlo simulations for different levels including inaccessible levels that are under construction for the planned low background experiments.

  11. Simulation Studies of Backgrounds for the Fermilab SeaQuest Experiment (E906)

    Science.gov (United States)

    Ma, Puyang; Aidala, Christine; E906/SeaQuest Collaboration

    2016-09-01

    The Fermilab SeaQuest experiment uses a 120 GeV proton beam on targets of liquid hydrogen, liquid deuterium, and solid nuclear targets of carbon, iron, and tungsten. The experiment measures the Drell-Yan process of quark-antiquark annihilation to produce muon pairs, with the main physics goal of studying the sea quark distributions in the nucleon and nuclei. Since quark and antiquark annihilation to dimuons is a rare process, there are significant backgrounds due to muons from the decay of pions produced in the target and beam dump. These backgrounds are being studied via simulated proton interactions in a GEANT implementation of the experimental setup. Full simulation of these backgrounds has proved to be difficult because of the extensive computer time needed. Studies to speed up the simulation process will be presented. NSF.

  12. Development of High Pressure Xe Scintillation Proportional Counter for Experiments in "Low-Background" Physics

    OpenAIRE

    Akimov, D.Yu.; Burenkov, A. A; Churakov, D. L.; Kuzichev, V. F.; Morgunov, V. L.; Smirnov, G. N.; Solovov, V.N.

    1997-01-01

    Characteristics of a scintillation proportional counter with WLS fiber optics readout is described. The possibility of detection of the proportional scintillation signal produced by the single electron of primary ionization is shown. The counter can be applied for the experiments in "low--background" physics which require a low energy threshold.

  13. Low-Background Experiments with High Pressure Gas Scintillation Proportional Detector

    OpenAIRE

    Akimov, D.Yu.; Burenkov, A. A; Kuzichev, V. F.; Morgunov, V. L.; Solovov, V.N.

    1997-01-01

    A scintillation proportional counter with wavelength shifting fiber readout filled with Xe or Kr under a pressure of up to 20 atm is proposed for the low-background experiments on search for dark matter of the Universe and 2K-decay of 78 Kr.

  14. Innovative Training in Pediatrics, General Psychiatry, and Child Psychiatry: Background, Outcomes, and Experiences

    Science.gov (United States)

    Gleason, Mary Margaret; Fritz, Gregory K.

    2009-01-01

    Objectives: The authors describe the history, rationale, and outcomes of combined training programs in pediatrics, psychiatry, and child psychiatry ("triple board"), including narrative feedback from graduates and reflections upon the important components of the program. Methods: This article reviews the background and experiences of triple board…

  15. Estimating background-subtracted fluorescence transients in calcium imaging experiments: a quantitative approach.

    Science.gov (United States)

    Joucla, Sébastien; Franconville, Romain; Pippow, Andreas; Kloppenburg, Peter; Pouzat, Christophe

    2013-08-01

    Calcium imaging has become a routine technique in neuroscience for subcellular to network level investigations. The fast progresses in the development of new indicators and imaging techniques call for dedicated reliable analysis methods. In particular, efficient and quantitative background fluorescence subtraction routines would be beneficial to most of the calcium imaging research field. A background-subtracted fluorescence transients estimation method that does not require any independent background measurement is therefore developed. This method is based on a fluorescence model fitted to single-trial data using a classical nonlinear regression approach. The model includes an appropriate probabilistic description of the acquisition system's noise leading to accurate confidence intervals on all quantities of interest (background fluorescence, normalized background-subtracted fluorescence time course) when background fluorescence is homogeneous. An automatic procedure detecting background inhomogeneities inside the region of interest is also developed and is shown to be efficient on simulated data. The implementation and performances of the proposed method on experimental recordings from the mouse hypothalamus are presented in details. This method, which applies to both single-cell and bulk-stained tissues recordings, should help improving the statistical comparison of fluorescence calcium signals between experiments and studies.

  16. An experiment using mid and thermal infrared in quantum remote sensing

    Institute of Scientific and Technical Information of China (English)

    BI; Siwen; HAN; Jixia

    2006-01-01

    The concept of quantum remote sensing and the differences between quantum remote sensing and remote sensing is introduced, an experiment about the uses of mid and thermal infrared in quantum remote sensing is described and results are analyzed.

  17. A simulation-based study of the neutron backgrounds for NaI dark matter experiments

    CERN Document Server

    Jeon, Eunju

    2015-01-01

    Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.

  18. 13C(alpha,n)16O background in a liquid scintillator based neutrino experiment

    CERN Document Server

    Zhao, Jie; Liu, Jianglai; Li, Xiaobo; Zhang, Feihong; Xia, Dongmei

    2013-01-01

    Alpha from natural radioactivity may interact with a nucleus and emit a neutron. The reaction introduces background to the liquid scintillator (LS) based neutrino experiments. In the LS detector, alpha comes from 238U, 232Th and 210Po decay chains. For Gadolinium-doped LS (Gd-LS) detector, alpha also comes from 227Ac. The nucleus 13C is a natural component of Carbon which is rich in the LS. The background rate and spectrum should be subtracted carefully from the neutrino candidates. This paper describes the calculation of neutron yield and spectrum with uncertainty estimated. The results are relevant for many existing neutrino experiments and future LS or Gd-LS based experiments.

  19. Musical experience limits the degradative effects of background noise on the neural processing of sound.

    Science.gov (United States)

    Parbery-Clark, Alexandra; Skoe, Erika; Kraus, Nina

    2009-11-11

    Musicians have lifelong experience parsing melodies from background harmonies, which can be considered a process analogous to speech perception in noise. To investigate the effect of musical experience on the neural representation of speech-in-noise, we compared subcortical neurophysiological responses to speech in quiet and noise in a group of highly trained musicians and nonmusician controls. Musicians were found to have a more robust subcortical representation of the acoustic stimulus in the presence of noise. Specifically, musicians demonstrated faster neural timing, enhanced representation of speech harmonics, and less degraded response morphology in noise. Neural measures were associated with better behavioral performance on the Hearing in Noise Test (HINT) for which musicians outperformed the nonmusician controls. These findings suggest that musical experience limits the negative effects of competing background noise, thereby providing the first biological evidence for musicians' perceptual advantage for speech-in-noise.

  20. Infrared experiments under laser excitations at SPring-8

    CERN Document Server

    Okamura, H; Matsunami, M; Terakami, K; Koyanagi, M; Koretsune, T; Moriwaki, T; Kimura, H; Nakagawa, H; Kondo, Y; Nanba, T

    2001-01-01

    The infrared (IR) beamline BL43IR at SPring-8 has recently become available to general users. It has four experimental stations, one of which is the absorption and reflection spectroscopy station (ARSS). ARSS is designed primarily for absorption and reflection IR spectroscopies under laser excitations, in particular for laser-pump, IR SR-probe time-resolved spectroscopies. We describe the instrumentations at ARSS, and the expected future projects.

  1. THE COSMIC NEAR INFRARED BACKGROUND. III. FLUCTUATIONS, REIONIZATION, AND THE EFFECTS OF MINIMUM MASS AND SELF-REGULATION

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Elizabeth R. [Univ Paris-Sud, Institut d' Astrophysique Spatiale, UMR8617, 91405 Orsay Cedex (France); Iliev, Ilian T. [Astronomy Centre, Department of Physics and Astronomy, Pevensey II Building, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Komatsu, Eiichiro; Shapiro, Paul R., E-mail: Elizabeth.Fernandez@ias.u-psud.fr [Texas Cosmology Center and the Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States)

    2012-05-01

    Current observations suggest that the universe was reionized sometime before z {approx} 6. One way to observe this epoch of the universe is through the Near Infrared Background (NIRB), which contains information about galaxies which may be too faint to be observed individually. We calculate the angular power spectrum (C{sub l} ) of the NIRB fluctuations caused by the distribution of these galaxies. Assuming a complete subtraction of any post-reionization component, C{sub l} will be dominated by galaxies responsible for completing reionization (e.g., z {approx} 6). The shape of C{sub l} at high l is sensitive to the amount of nonlinear bias of dark matter halos hosting galaxies. As the nonlinear bias depends on the mass of these halos, we can use the shape of C{sub l} to infer typical masses of dark matter halos responsible for completing reionization. We extend our previous study by using a higher-resolution N-body simulation, which can resolve halos down to 10{sup 8} M{sub Sun }. We also include improved radiative transfer, which allows for the suppression of star formation in small-mass halos due to photoionization heating. As the nonlinear bias enhances the dark matter halo power spectrum on small scales, we find that C{sub l} is steeper for the case with a complete suppression of small sources or partial suppression of star formation in small halos (the minimum galaxy mass is M{sub min} = 10{sup 9} M{sub Sun} in ionized regions and M{sub min} = 10{sup 8} M{sub Sun} in neutral regions) than for the case in which these small halos were unsuppressed. In all cases, we do not see a turnover toward high l in the shape of l{sup 2} C{sub l} .

  2. Measuring the X-ray Background in the Reionization Era with First Generation 21 cm Experiments

    OpenAIRE

    Christian, Pierre; Loeb, Abraham

    2013-01-01

    The X-ray background during the epoch of reionization is currently poorly constrained. We demonstrate that it is possible to use first generation 21 cm experiments to calibrate it. Using the semi-numerical simulation, 21cmFAST, we calculate the dependence of the 21 cm power spectrum on the X-ray background flux. Comparing the signal to the sensitivity of the Murchison Widefield Array (MWA) we find that in the redshift interval z=8-14 the 21 cm signal is detectable based on the upper limit set...

  3. SXDF-ALMA 2 arcmin2 deep survey: Resolving and characterizing the infrared extragalactic background light down to 0.5 mJy

    Science.gov (United States)

    Yamaguchi, Yuki; Tamura, Yoichi; Kohno, Kotaro; Aretxaga, Itziar; Dunlop, James S.; Hatsukade, Bunyo; Hughes, David; Ikarashi, Soh; Ishii, Shun; Ivison, Rob J.; Izumi, Takuma; Kawabe, Ryohei; Kodama, Tadayuki; Lee, Minju; Makiya, Ryu; Matsuda, Yuichi; Nakanishi, Kouichiro; Ohta, Kouji; Rujopakarn, Wiphu; Tadaki, Ken-ichi; Umehata, Hideki; Wang, Wei-Hao; Wilson, Grant W.; Yabe, Kiyoto; Yun, Min S.

    2016-10-01

    We present a multiwavelength analysis of five submillimeter sources (S1.1mm = 0.54-2.02 mJy) that were detected during our 1.1 mm deep continuum survey in the Subaru/XMM-Newton Deep Survey Field (SXDF)-UDS-CANDELS field (2 arcmin2, 1σ = 0.055 mJy beam-1) using the Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy (SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If we exclude the two brightest sources, the contribution of the ALMA-detected faint SMGs to the infrared extragalactic background light is estimated to be ˜ 4.1^{+5.4}_{-3.0}Jy deg-2, which corresponds to ˜ 16^{+22}_{-12}% of the infrared extragalactic background light. This suggests that their contribution to the infrared extragalactic background light is as large as that of bright SMGs. We identified multiwavelength counterparts of the five ALMA sources. One of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared region despite its infrared luminosity (L_IR˜eq 1× 10^{12} L_{⊙} or SFR ≃ 100 M⊙ yr-1). By fitting the spectral energy distributions at the optical-to-near-infrared wavelengths of the remaining four ALMA sources, we obtained the photometric redshifts (zphoto) and stellar masses (M*): zphoto ≃ 1.3-2.5, M* ≃ (3.5-9.5) × 1010 M⊙. We also derived their star formation rates (SFRs) and specific SFRs as ≃30-200 M⊙ yr-1 and ≃0.8-2 Gyr-1, respectively. These values imply that they are main sequence star-forming galaxies.

  4. SXDF-ALMA 2 Arcmin^2 Deep Survey: Resolving and Characterizing the Infrared Extragalactic Background Light Down to 0.5 mJy

    CERN Document Server

    Yamaguchi, Yuki; Kohno, Kotaro; Aretxaga, Itziar; Dunlop, James S; Hatsukade, Bunyo; Hughes, David; Ikarashi, Soh; Ishii, Shun; Ivison, Rob J; Izumi, Takuma; Kawabe, Ryohei; Kodama, Tadayuki; Lee, Minju; Makiya, Ryu; Matsuda, Yuichi; Nakanishi, Kouichiro; Ohta, Kouji; Rujopakarn, Wiphu; Tadaki, Ken-ichi; Umehata, Hideki; Wang, Wei-Hao; Wilson, Grant W; Yabe, Kiyoto; Yun, Min S

    2016-01-01

    We present a multi-wavelength analysis of five submillimeter sources (S_1.1mm = 0.54-2.02 mJy) that were detected during our 1.1-mm-deep continuum survey in the SXDF-UDS-CANDELS field (2 arcmin^2, 1sigma = 0.055 mJy beam^-1) using the Atacama Large Millimeter/submillimeter Array (ALMA). The two brightest sources correspond to a known single-dish (AzTEC) selected bright submillimeter galaxy (SMG), whereas the remaining three are faint SMGs newly uncovered by ALMA. If we exclude the two brightest sources, the contribution of the ALMA-detected faint SMGs to the infrared extragalactic background light is estimated to be ~ 4.1^{+5.4}_{-3.0} Jy deg^{-2}, which corresponds to ~ 16^{+22}_{-12}% of the infrared extragalactic background light. This suggests that their contribution to the infrared extragalactic background light is as large as that of bright SMGs. We identified multi-wavelength counterparts of the five ALMA sources. One of the sources (SXDF-ALMA3) is extremely faint in the optical to near-infrared region...

  5. Assessment of backgrounds of the ANAIS experiment for dark matter direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Amare, J.; Cebrian, S.; Garcia, E.; Olivan, M.A.; Ortigoza, Y.; Ortiz de Solorzano, A.; Puimedon, J.; Sarsa, M.L.; Villar, J.A.; Villar, P. [Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Laboratorio Subterraneo de Canfranc, Huesca (Spain); Cuesta, C. [Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Laboratorio Subterraneo de Canfranc, Huesca (Spain); University of Washington, Department of Physics, Center for Experimental Nuclear Physics and Astrophysics, Seattle, WA (United States); Martinez, M. [Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Laboratorio Subterraneo de Canfranc, Huesca (Spain); Universita di Roma La Sapienza, Rome (Italy)

    2016-08-15

    A large effort has been carried out to characterize the background of sodium iodide crystals within the Annual modulation with NaI Scintillators (ANAIS) project. In this paper, the background models developed for three 12.5 kg NaI(Tl) scintillators produced by Alpha Spectra Inc. and operated at the Canfranc Underground Laboratory are presented together with an evaluation of the background prospects for the full experiment. Measured spectra from threshold to high energy in different conditions are well described by the models based on quantified activities. At the region of interest, crystal bulk contamination is the dominant background source. Contributions from {sup 210}Pb, {sup 40}K, {sup 22}Na and {sup 3}H are the most relevant. Those from {sup 40}K and {sup 22}Na could be efficiently suppressed thanks to anticoincidence operation in a crystals matrix or inside a liquid scintillator veto (LSV), while that from {sup 210}Pb has been reduced by improving crystal production methods and {sup 3}H production could be reduced by shielding against cosmic rays during production. Assuming the activities of the last characterized detector, for nine crystals with a total mass of 112.5 kg the expected background rate is 2.5 counts/(keV kg day) in the region from 1 to 4 keV, which could be reduced at 1.4 counts/(keV kg day) by using a LSV. (orig.)

  6. The background in the 0νββ experiment GERDA

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, M.; Bode, T.; Budjas, D.; Csathy, J.J.; Lazzaro, A.; Schoenert, S. [Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Allardt, M.; Barros, N.; Domula, A.; Lehnert, B.; Wester, T.; Zuber, K. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); Andreotti, E. [Institute for Reference Materials and Measurements, Geel (Belgium); Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Bakalyarov, A.M.; Belyaev, S.T.; Lebedev, V.I.; Zhukov, S.V. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Balata, M.; Ioannucci, L.; Junker, M.; Laubenstein, M.; Macolino, C.; Nisi, S.; Pandola, L.; Zavarise, P. [INFN Laboratori Nazionali del Gran Sasso, LNGS, Assergi (Italy); Barabanov, I.; Bezrukov, L.; Gurentsov, V.; Inzhechik, L.V.; Kuzminov, V.V.; Lubsandorzhiev, B.; Yanovich, E. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Barnabe Heider, M. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Baudis, L.; Benato, G.; Ferella, A.; Guthikonda, K.K.; Tarka, M.; Walter, M. [Physik Institut der Universitaet Zuerich, Zurich (Switzerland); Bauer, C.; Hampel, W.; Heisel, M.; Heusser, G.; Hofmann, W.; Kihm, T.; Kirsch, A.; Knoepfle, K.T.; Lindner, M.; Lubashevskiy, A.; Machado, A.A.; Maneschg, W.; Salathe, M.; Schreiner, J.; Schwingenheuer, B.; Simgen, H.; Smolnikov, A.; Strecker, H.; Wagner, V.; Wegmann, A. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Becerici-Schmidt, N.; Caldwell, A.; Cossavella, F.; Liao, H.Y.; Liu, X.; Majorovits, B.; O' Shaughnessy, C.; Palioselitis, D.; Schulz, O.; Volynets, O. [Max-Planck-Institut fuer Physik, Muenchen (Germany); Bellotti, E.; Pessina, G. [Universita Milano Bicocca, Dipartimento di Fisica, Milan (Italy); INFN Milano Bicocca, Milan (Italy); Belogurov, S.; Kornoukhov, V.N. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bettini, A.; Brugnera, R.; Garfagnini, A.; Hemmer, S.; Sada, C. [Dipartimento di Fisica e Astronomia dell' Universita di Padova, Padua (Italy); INFN Padova, Padua (Italy); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Shevchik, E.; Zhitnikov, I.; Zinatulina, D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Cattadori, C.; Gotti, C. [INFN Milano Bicocca, Milan (Italy); Chernogorov, A.; Demidova, E.V.; Kirpichnikov, I.V.; Vasenko, A.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Falkenstein, R.; Freund, K.; Grabmayr, P.; Hegai, A.; Jochum, J.; Schmitt, C. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Frodyma, N.; Pelczar, K.; Wojcik, M.; Zuzel, G. [Jagiellonian University, Institute of Physics, Cracow (Poland); Gangapshev, A. [Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Muenchen (Germany); Hult, M.; Lutter, G. [Institute for Reference Materials and Measurements, Geel (Belgium); Klimenko, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Max Planck Institut fuer Kernphysik, Heidelberg (Germany); Lippi, I.; Stanco, L.; Ur, C.A. [INFN Padova, Padua (Italy); Pullia, A.; Riboldi, S. [Universita degli Studi di Milano (IT); INFN Milano, Dipartimento di Fisica, Milan (IT); Shirchenko, M. [Joint Institute for Nuclear Research, Dubna (RU); National Research Centre ' ' Kurchatov Institute' ' , Moscow (RU); Sturm, K. von [Dipartimento di Fisica e Astronomia dell' Universita di Padova, Padua (IT); INFN Padova, Padua (IT); Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (DE)

    2014-04-15

    The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta (0νββ) decay of {sup 76}Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the Q{sub ββ} value of the decay. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around Q{sub ββ}. The main parameters needed for the 0νββ analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around Q{sub ββ} with a background index ranging from 17.6 to 23.8 x 10{sup -3} cts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model are consistent. The observed number of events in this energy region is consistent with the background model. The background at Q{sub ββ} is dominated by close sources,mainly due to {sup 42}K, {sup 214}Bi, {sup 228}Th, {sup 60}Co and α emitting isotopes from the {sup 226}Ra decay chain. The individual fractions depend on the assumed locations of the contaminants. It is shown, that after removal of the known γ peaks, the energy spectrum can be fitted in an energy range of 200 keV around Q{sub ββ} with a constant background. This gives a background index consistent with the full model and uncertainties of the same size. (orig.)

  7. Experiences of international students from Asian backgrounds studying occupational therapy in Australia.

    Science.gov (United States)

    Lim, Jung Wook; Honey, Anne; Du Toit, Sanet; Chen, Yu-Wei; Mackenzie, Lynette

    2016-10-01

    International students from culturally and linguistically diverse backgrounds experience personal and academic challenges when studying health sciences in Australia. Given recent discussions about cultural specificity in occupational therapy and its status as an emerging profession in most Asian countries, this study aimed to explore and describe the experiences of international students from Asian backgrounds studying occupational therapy in Australia. A phenomenological approach was used to understand the experiences of participants. In-depth interviews were conducted with eight international occupational therapy students from Asian countries studying in Australia. Data were analysed using hermeneutic methods. Participants described three interlinked and ongoing experiences: (1) Discovering and engaging with occupational therapy; (2) Fitting into my new role; and (3) Anticipating my role at home. Whilst theoretical aspects of occupational therapy were seen as compatible with participants' home cultures, application was seen as problematic due to the differences in structure and institutional culture of the healthcare systems. Although students made adaptations to fit in as occupational therapy students in Australia, they continued to see themselves as different, and their adaptation also influenced how they saw themselves in relation to their home culture. Findings can contribute to creating culturally sensitive education for occupational therapy students from Asian countries. To best serve these students, educators should consider ways to facilitate transitions both out of and back into students' home cultures. © 2016 Occupational Therapy Australia.

  8. Neutron Background Characterization for a Coherent Neutrino-Nucleus Scattering experiment at SNS

    Science.gov (United States)

    Gerling, Mark

    2014-03-01

    Coherent Neutrino Nucleus Scattering (CNNS) is a theoretical well-grounded, but as-yet unverified process. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) may provide an optimal platform for detection of CNNS, possibly with existing detector technology. A proto-collaboration of groups from several institutions has come together to investigate this option and propose an experiment for the first-time observation of CNNS. Currently, the largest risk to such an experiment comes from an unknown background of beam-induced high-energy neutrons that penetrate the existing SNS concrete shielding. We have deployed a neutron scatter camera at the SNS during beam operation and performed preliminary measurements of the neutron backgrounds at a promising experimental location. In order to measure neutrons as high as 100 MeV, we needed to make modifications to the neutron scatter camera and expand its capabilities beyond its standard operating range of 1-14MeV. We have identified sources of high-energy neutrons and continue to investigate other possible locations that may allow a successful CNNS experiment to go forward. The imaging capabilities of the neutron scatter camera will allow more optimal shielding designs that take into account neutron flux anisotropies at the selected experiment locations.

  9. Assessment of backgrounds of the ANAIS experiment for dark matter direct detection

    CERN Document Server

    Amare, J; Cuesta, C; Garcia, E; Martinez, M; Olivan, M A; Ortigoza, Y; de Solorzano, A Ortiz; Puimedon, J; Sarsa, M L; Villar, J A; Villar, P

    2016-01-01

    A large effort has been carried out to characterize the background of sodium iodide crystals within the ANAIS (Annual modulation with NaI Scintillators) project. In this paper, the background models developed for three 12.5-kg NaI(Tl) detectors produced by Alpha Spectra Inc. and operated at the Canfranc Underground Laboratory are presented together with an evaluation of the background prospects for the full experiment. Measured spectra from threshold to high energy in different conditions are well described by the models based on quantified activities. At the region of interest, crystal bulk contamination is the dominant background source. Contributions from 210Pb, 40K, 22Na and 3H are the most relevant. Those from 40K and 22Na could be efficiently suppressed thanks to anticoincidence operation in a crystals matrix or inside a Liquid Scintillator Veto (LSV), while that from 210Pb has been reduced by improving crystal production methods and 3H production could be reduced by shielding against cosmic rays during...

  10. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  11. On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: II. Extragalactic far infrared background radiation

    Science.gov (United States)

    Fisenko, Anatoliy I.; Lemberg, Vladimir

    2014-07-01

    Using formula to describe the average spectrum of the extragalactic far infrared background (FIRB) radiation measured by the COBE FIRAS instrument in the 0.15-2.4 THz frequency interval at mean temperature T=18.5 K, the radiative and thermodynamic properties, such as the total emissivity, total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure are calculated. The value for the total intensity received in the 0.15-2.4 THz frequency interval is equal to 13.6 nW m-2 sr-1. This value is about 19.4 % of the total intensity expected from the energy released by stellar nucleosynthesis over cosmic history. The radiative and thermodynamic functions of the extragalactic far infrared background (FIRB) radiation are calculated at redshift z=1.5.

  12. Cosmogenic activation of Germanium and its reduction for low background experiments

    CERN Document Server

    Barabanov, I; Bezrukov, L; Denisov, A; Kornoukhov, V; Sobolevsky, N

    2006-01-01

    Production of $^{60}$Co and $^{68}$Ge from stable isotopes of Germanium by nuclear active component of cosmic rays is a principal background source for a new generation of $^{76}$Ge double beta decay experiments like GERDA and Majorana. The biggest amount of cosmogenic activity is expected to be produced during transportation of either enriched material or already grown crystal. In this letter properties and feasibility of a movable iron shield are discussed. Activation reduction factor of about 10 is predicted by simulations with SHIELD code for a simple cylindrical configuration. It is sufficient for GERDA Phase II background requirements. Possibility of further increase of reduction factor and physical limitations are considered. Importance of activation reduction during Germanium purification and detector manufacturing is emphasized.

  13. Fieldable Fourier Transform Spectrometer: System Construction, Background Variability Measurements, and Chemical Attack Warning Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, Brian K.; Harper, Warren W.; Batishko, Charles R.; Johnson, Timothy J.; Sheen, David M.; Stewart, Timothy L.; Schultz, John F.

    2002-10-01

    The infrared sensors task at the Pacific Northwest National Laboratory (PNNL) is focused on the science and technology of remote and in-situ chemical sensors for detecting proliferation and countering terrorism. Missions to be addressed by remote chemical sensor development will include detecting proliferation of nuclear or chemical weapons, and providing warning of terrorist use of chemical weapons. Missions to be addressed by in-situ chemical sensor development include countering terrorism by screening luggage, personnel, and shipping containers for explosives, firearms, narcotics, chemical weapons, or chemical weapons residues, and mapping contaminated areas. The science and technology relevant to these primary missions is also likely to be useful for battlefield chemical weapons defense, air operations support, monitoring emissions from chemical weapons destruction facilities or industrial chemical plants, and law enforcement applications. PNNL will seek to serve organizations with direct interest in these missions through collaborative research and development efforts approved by NA-22. During FY02, PNNL began assembling a remote IR detection capability that would allow field experiments to be conducted. The capability consists of a commercially available FTIR (Fourier Transform Infrared) emission spectrometer and a frequency-modulation differential-absorption LIDAR (FM-DIAL) system being developed at PNNL. To provide environmental protection for these systems, a large, well insulated, temperature controlled trailer was specified and procured. While the FTIR system was field-ready, the FM-DIAL system required many modifications to prepare for field deployment. This document provides an overview of the FTIR system, summarizes the modifications made to the FM-DIAL system, and describes the salient features of the remote systems trailer.

  14. FRC translation experiment into the neutral gas background in the FIX device

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, Mamoru; Kodera, Fuji; Asai, Tomohiko; Okada, Shigefumi; Goto, Seiichi [Osaka Univ., Graduate School of Engineering, Plasma Physics Laboratory, Osaka (Japan)

    2003-07-01

    Translating an FRC plasma through a neutral gas background is equivalent to the injection of a warm neutral beam end-on into the FRC. Controlling a translated FRC density and rethermalization of the kinetic energy of that are expected by gas puffing without complex NBI device. We carried out FRC translation experiment into the neutral gas background based on this point of view. In the FIX device, the FRC produced in the quartz formation region is translated into the metal confinement region. The translated FRC is reflected by the downstream mirror field. The FRC reaches equilibrium state after one or two bounces. Typical translation velocity of FIX-FRC is about 1.5 x 10{sup 5} m/sec, which is equivalent to a 200 eV incident neutral D beam. The neutral gas (D{sub 2}) pressures of {approx}10{sup -2} Pa averaged inside the confinement region can be introduced using a piezo electric valve which is installed on the end of FIX-device. An FRC is translated into neutral gas background whose averaged density is about 1{approx}3 x 10{sup -2} Pa. The mean free path {lambda}{sub ionize} ({approx}0.1 m) of D{sub 2} is shorter than FRC separatrix length l{sub s} under the parameters of FIX-FRC plasma. As the result of this experiment, the radii of the FRC increase 10{approx}20 % of those of normal FRC after the 1st reflection. An increasing in the particle number inside the separatrix is observed after the translation into the neutral gas background. The total energy inside the FRC after translation is also observed to increase a little. (author)

  15. The charged current neutrino cross section for solar neutrinos, and background to \\BBz\\ experiments

    CERN Document Server

    Ejiri, H

    2013-01-01

    Solar neutrinos can interact with the source isotope in neutrinoless double beta decay experiments through charged current and neutral current interactions. The charged-current product nucleus will then beta decay with a Q-value larger than the double beta decay Q-value. As a result, this process can populate the region of interest and be a background to the double beta decay signal. In this paper we estimate the solar neutrino capture rates on three commonly used double beta decay isotopes, \

  16. Evaluation of (alpha,n) Induced Neutrons as a Background for Dark Matter Experiments

    CERN Document Server

    Mei, D -M; Hime, A

    2008-01-01

    Neutrons from ($\\alpha$,n) reaction through thorium and uranium decays are important sources of background for direct dark matter detection. Neutron yield and energy spectrum from a range of materials that are used to build dark matter detectors are calculated and tabulated. In addition to thorium and uranium decays, we found that $\\alpha$ particles from samarium that is often doped in the window material of photomultiplier (PMT) are also an important source of neutron yield. The results in this paper can be used as the input in the Monte Carlo simulation for many materials that will be used for next generation experiments.

  17. Simulation of Cosmic Microwave Background Polarization Fields for AMiBA Experiment

    CERN Document Server

    Park, C G; Park, Chan-Gyung; Park, Changbom

    2002-01-01

    We have made a topological study of cosmic microwave background (CMB) polarization maps by simulating the AMiBA experiment results. A $\\Lambda$CDM CMB sky is adopted to make mock interferometric observations designed for the AMiBA experiment. CMB polarization fields are reconstructed from the AMiBA mock visibility data using the maximum entropy method. We have also considered effects of Galactic foregrounds on the CMB polarization fields. The genus statistic is calculated from the simulated $Q$ and $U$ polarization maps, where $Q$ and $U$ are Stokes parameters. Our study shows that the Galactic foreground emission, even at low Galactic latitude, is expected to have small effects on the CMB polarization field. Increasing survey area and integration time is essential to detect non-Gaussian signals of cosmological origin through genus measurement.

  18. Ship Effect Neutron Measurements And Impacts On Low-Background Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

    2013-10-01

    The primary particles entering the upper atmosphere as cosmic rays create showers in the atmosphere that include a broad spectrum of secondary neutrons, muons and protons. These cosmic-ray secondaries interact with materials at the surface of the Earth, yielding prompt backgrounds in radiation detection systems, as well as inducing long-lived activities through spallation events, dominated by the higher-energy neutron secondaries. For historical reasons, the multiple neutrons produced in spallation cascade events are referred to as “ship effect” neutrons. Quantifying the background from cosmic ray induced activities is important to low-background experiments, such as neutrino-less double beta decay. Since direct measurements of the effects of shielding on the cosmic-ray neutron spectrum are not available, Monte Carlo modeling is used to compute such effects. However, there are large uncertainties (orders of magnitude) in the possible cross-section libraries and the cosmic-ray neutron spectrum for the energy range needed in such calculations. The measurements reported here were initiated to validate results from Monte Carlo models through experimental measurements in order to provide some confidence in the model results. The results indicate that the models provide the correct trends of neutron production with increasing density, but there is substantial disagreement between the model and experimental results for the lower-density materials of Al, Fe and Cu.

  19. Combined study of evaporation from liquid surface by background oriented schlieren, infrared thermal imaging and numerical simulation

    Directory of Open Access Journals (Sweden)

    Plaksina Yu.Yu.

    2013-04-01

    Full Text Available Temperature fields in evaporating liquids are measured by simultaneous use of Background Oriented Schlieren (BOS technique for the side view and IR thermal imaging for the surface distribution. Good agreement between the two methods is obtained with typical measurement error less than 0.1 K. Two configurations of surface layer are observed: thermocapillary convection state with moving liquid surface and small thermal cells, associated with Marangoni convection, and “cool skin” with negligible velocity at the surface, larger cells and dramatic increase of velocity within 0.1 mm layer beneath the surface. These configurations are shown to be formed in various liquids (water with various degrees of purification, ethanol, butanol, decane, kerosene, glycerine depending rather on initial conditions and ambient parameters than on the liquid. Water, which has been considered as the liquid without observable Marangoni convection, actually can exhibit both kinds of behavior during the same experimental run. Evaporation is also studied by means of numerical simulations. Separate problemsin air and liquid are considered, with thermal imaging data of surface temperature making the separation possible. It is shown that evaporation rate can be predicted by numerical simulation of the air side with appropriate boundary conditions. Comparison is made with known empirical correlations for Sherwood-Rayleigh relationship. Numerical simulations of water-side problem reveal the issue of velocity boundary conditions at the free surface, determining the structure of surface layer. Flow field similar to observed in the experiments is obtained with special boundary conditions of third kind, presenting a combination of no-slip and surface tension boundary conditions.

  20. New background correction method for liquid chromatography with diode array detection, infrared spectroscopic detection and Raman spectroscopic detection

    NARCIS (Netherlands)

    Boelens, H.; Dijkstra, R.J.; Eilers, P.H.C.; Fitzpatrick, F.; Westerhuis, J.A.

    2004-01-01

    A new method to eliminate the background spectrum (EBS) during analyte elution in column liquid chromatography (LC) coupled to spectroscopic techniques is proposed. This method takes into account the shape and also intensity differences of the background eluent spectrum. This allows the EBS method t

  1. The cosmic background: evolution of infrared galaxies and dust properties. A lecture dedicated to the memory of Mayo Greenberg

    CERN Document Server

    Puget, J L; Dole, H; Puget, Jean-Loup; Lagache, Guilaine; Dole, Herve

    2004-01-01

    In recent years it became clear that a population of galaxies radiating most of their power in the far-infrared contribute an important part of the whole star formation activity in the universe. These galaxies emit up to 99% of their energy output in the infrared by dust. The optical properties of dust in galaxies are thus very important to understand this population. Mayo Greenberg who has brought many of the ideas underlying our understanding of the physics of interstellar dust has been a pioneer in predicting the important role of organic solid material formed on dust grains in molecular clouds and of potential importance of transient heating of very small particles. It appeared with the ISO data on galaxies and even more today with the first Spitzer data that these mechanisms are important globally for the observations of infrared galaxies at significant redshifts. The understanding of their evolution is one of the keys to the understanding of galaxy built up and evolution.

  2. Background constrains of the SuperNEMO experiment for neutrinoless double beta-decay searches

    Science.gov (United States)

    Povinec, Pavel P.

    2017-02-01

    The SuperNEMO experiment is a new generation of experiments dedicated to the search for neutrinoless double beta-decay, which if observed, would confirm the existence of physics beyond the Standard Model. It is based on the tracking and calorimetry techniques, which allow the reconstruction of the final state topology, including timing and kinematics of the double beta-decay transition events, offering a powerful tool for background rejection. While the basic detection strategy of the SuperNEMO detector remains the same as of the NEMO-3 detector, a number of improvements were accomplished for each of detector main components. Upgrades of the detector technologies and development of low-level counting techniques ensure radiopurity control of construction parts of the SuperNEMO detector. A reference material made of glass pellets has been developed to assure quality management and quality control of radiopurity measurements. The first module of the SuperNEMO detector (Demonstrator) is currently under construction in the Modane underground laboratory. No background event is expected in the neutrinoless double beta-decay region in 2.5 years of its operation using 7 kg of 82Se. The half-life sensitivity of the Demonstrator is expected to be >6.5·1024 y, corresponding to an effective Majorana neutrino mass sensitivity of |0.2-0.4| eV (90% C.L.). The full SuperNEMO experiment comprising of 20 modules with 100 kg of 82Se source should reach an effective Majorana neutrino mass sensitivity of |0.04-0.1| eV, and a half-life limit 1·1026 y.

  3. New Observational Constraints and Modeling of the Infrared Background: Dust Obscured Star-Formation at z>1 and Dust in the Outer Solar System

    CERN Document Server

    Chary, Ranga-Ram

    2010-01-01

    We provide measurements of the integrated galaxy light at 70, 160, 250, 350 and 500 micron using deep far-infrared and submillimeter data from space (Spitzer) and balloon platform (BLAST) extragalactic surveys. We use the technique of stacking at the positions of 24 micron sources, to supplement the fraction of the integrated galaxy light that is directly resolved through direct detections. We demonstrate that the integrated galaxy light even through stacking, falls short by factors of 2-3 in resolving the extragalactic far-infrared background. We also show that previous estimates of the integrated galaxy light (IGL) through stacking, have been biased towards high values. This is primarily due to multiple counting of the far-infrared/submillimeter flux from 24 micron sources which are clustered within the large point spread function of a brighter far-infrared source. Using models for the evolution of the luminosity function at z1, which are remarkably, below the values derived from the extinction corrected ul...

  4. Using 'intimate citizenship' to make sense of the experiences of men with refugee backgrounds in Australia.

    Science.gov (United States)

    Muchoki, Samuel

    2015-01-01

    This paper is based on a study exploring the experiences of men with refugee backgrounds from Sudan, Eritrea, Ethiopia and Somalia (herein referred to as the Horn of Africa countries) during migration and on settlement in Australia. During data analyses, Plummer's concept of 'intimate citizenship' became a useful theoretical framework for understanding participants' experiences. Many men had migrated from traditional societies where individuals pursue intimacies within a constrained framework of acceptability dictated by collective cultures. Ravaged by civil wars, they were forced to flee their homelands and seek asylum in neighbouring countries. Eventually, these men were resettled in Australia, a society that provides a social space for individuals to exercise more choices in their personal lives. On arrival in Australia, participants in this study had to adjust to these new ways of pursuing intimate relationships. Some men found this process overwhelmingly difficult while others saw it as an opportunity to organise their intimate lives beyond the confines of traditions and cultures as well as family and community influences. Intimate citizenship helped in construing the opportunities, conflicts, tensions and ambivalences that characterised participants' experiences in Australia.

  5. The Vinyl Acetate Content of Packaging Film: A Quantitative Infrared Experiment.

    Science.gov (United States)

    Allpress, K. N.; And Others

    1981-01-01

    Presents an experiment used in laboratory technician training courses to illustrate the quantitative use of infrared spectroscopy which is based on industrial and laboratory procedures for the determination of vinyl acetate levels in ethylene vinyl acetate packaging films. Includes three approaches to allow for varying path lengths (film…

  6. ForCent model development and testing using the Enriched Background Isotope Study experiment

    Energy Technology Data Exchange (ETDEWEB)

    Parton, W.J.; Hanson, P. J.; Swanston, C.; Torn, M.; Trumbore, S. E.; Riley, W.; Kelly, R.

    2010-10-01

    The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool {sup 14}C signature ({Delta} {sup 14}C) data from the Enriched Background Isotope Study {sup 14}C experiment (1999-2006) shows that the model correctly simulates the temporal dynamics of the {sup 14}C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass {Delta} {sup 14}C data, and with soil respiration {Delta} {sup 14}C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study {sup 14}C experimental treatments on soil respiration {Delta} {sup 14}C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.

  7. SPOrt an Experiment Aimed at Measuring the Large Scale Cosmic Microwave Background Polarization

    CERN Document Server

    Carretti, E; Bernardi, G; Cecchini, S; Macculi, C; Sbarra, C; Monari, J; Orfei, A; Poloni, M; Poppi, S; Bölla, G; Bonometto, S A; Gervasi, M; Sironi, G; Zannoni, M; Tucci, M; Baralis, M; Peverini, O A; Tascone, R; Virone, G; Fabbri, R; Nicastro, L; Ng, K W; Razin, V A; Vinyajkin, E N; Sazhin, M V; Strukov, I A

    2002-01-01

    SPOrt (Sky Polarization Observatory) is a space experiment to be flown on the International Space Station during Early Utilization Phase aimed at measuring the microwave polarized emission with FWHM = 7deg, in the frequency range 22-90 GHz. The Galactic polarized emission can be observed at the lower frequencies and the polarization of Cosmic Microwave Background (CMB) at 90 GHz, where contaminants are expected to be less important. The extremely low level of the CMB Polarization signal (< 1 uK) calls for intrinsically stable radiometers. The SPOrt instrument is expressly devoted to CMB polarization measurements and the whole design has been optimized for minimizing instrumental polarization effects. In this contribution we present the receiver architecture based on correlation techniques, the analysis showing its intrinsic stability and the custom hardware development carried out to detect such a low signal.

  8. Cosmic background rejection by means of the calorimeter in the Mu2e experiment at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Pezzullo, Gianantonio, E-mail: pezzullo@pi.infn.it [University of Pisa (Italy); INFN sezione di Pisa (Italy); Murat, Pavel [Fermi National Accelerator Laboratory (United States); Sarra, Ivano; Lucà, Alessandra [INFN Laboratori Nazionali di Frascati (Italy)

    2014-03-01

    Mu2e experiment [J.R. Abrams, et al., Mu2e conceptual design report (http://arxiv.org/abs/1211.7019)] searches for coherent, neutrino-less conversion of muons into electrons in the field of a nucleus with a sensitivity of fews parts in 10{sup −17} (a factor of 10{sup 3}–10{sup 4} over existing limits). Mu2e apparatus takes advantage of high intensity muon beams which hit muon stopping targets (devoted for the capture) and uses a basic detector system which is composed by a low-mass straw tubes tracker and by a LYSO crystal calorimeter. One of the main source of background which afflicts this measure is the cosmic induced background. To suppress and keep that source under control the calorimeter operates both: muon identification (with a muon rejection factor of about 10{sup 2}–10{sup 3}) and fake-signal-electron (created via muon interactions with the experimental set-up) rejection. In this paper a description of the calorimeter role in cosmic suppression is reported showing results from GEANT4 simulations.

  9. Double beam near-infrared spectrometer for compensation of background water absorption and instrumental drift in intensity

    Institute of Scientific and Technical Information of China (English)

    CHANG Min; PENG Dan; XU Ke-xin

    2007-01-01

    A double beam near-infrared spectrometer is developed to compensate the water absorption and instrumental drift in intensity. The spectrometer maybe used for both single and double beam measurements, and the two operation modes are compared. The results show that the double beam technique eliminates instrumental drift in the single beam measurement and therefore the stability of the system increases by more than 20%. The compensation of the double beam system on water absorption is verified by the measurement of fat content in milk. The results show that the spectrum data based on double beam mode get better calibration model and lower prediction error than traditional single beam mode.

  10. A Rn-220 source for the calibration of low-background experiments

    CERN Document Server

    Lang, Rafael F; Brown, Ethan; Cervantes, Mayra; Macmullin, Sean; Masson, Darryl; Schreiner, Jochen; Simgen, Hardy

    2016-01-01

    We characterize two 40 kBq sources of electrodeposited Th-228 for use in low-background experiments. The sources efficiently emanate Rn-220, a noble gas that can diffuse in a detector volume. Rn-220 and its daughter isotopes produce alpha, beta, and gamma-radiation, which may used to calibrate a variety of detector responses and features, before decaying completely in only a few days. We perform various tests to place limits on the release of other long-lived isotopes. In particular, we find an emanation of <0.008 atoms/min/kBq (90% CL) for Th-228 and 1.53 atoms/min/kBq for Ra-224. The sources lend themselves in particular to the calibration of detectors employing liquid noble elements such as argon and xenon. With the source mounted in a noble gas system, we demonstrate that filters are highly efficient in reducing the activity of these longer-lived isotopes further. We thus confirm the suitability of these sources even for use in next-generation experiments, such as XENON1T/XENONnT, LZ, and nEXO.

  11. Coronagraphic demonstration experiment using aluminum mirrors for space infrared astronomical observations

    CERN Document Server

    Oseki, Shinji; Ishihara, Daisuke; Enya, Keigo; Haze, Kanae; Kotani, Takayuki; Kaneda, Hidehiro; Nishiyama, Miho; Abe, Lyu; Yamamuro, Tomoyasu

    2015-01-01

    For future space infrared astronomical coronagraphy, we perform experimental studies on the application of aluminum mirrors to a coronagraph. Cooled reflective optics is required for broad-band mid-infrared observations in space, while high-precision optics is required for coronagraphy. For the coronagraph instrument originally proposed for the next-generation infrared astronomical satellite project SPICA (SCI: SPICA Coronagraph Instrument), we fabricated and evaluated the optics consisting of high-precision aluminum off-axis mirrors with diamond-turned surfaces, and conducted a coronagraphic demonstration experiment using the optics with a coronagraph mask. We first measured the wave front errors (WFEs) of the aluminum mirrors with a He-Ne Fizeau interferometer to confirm that the power spectral densities of the WFEs satisfy the SCI requirements. Then we integrated the mirrors into an optical system and evaluated the overall performance of the system. As a result, we estimate the total WFE of the optics to b...

  12. Source extraction and photometry for the far-infrared and sub-millimeter continuum in the presence of complex backgrounds

    CERN Document Server

    Molinari, Sergio; Faustini, Fabiana; Pestalozzi, Michele; DiGiorgio, Anna Maria; Liu, Scige John

    2010-01-01

    (Abridged) We present a new method for detecting and measuring compact sources in conditions of intense, and highly variable, fore/background. While all most commonly used packages carry out the source detection over the signal image, our proposed method builds from the measured image a "curvature" image by double-differentiation in four different directions. In this way point-like as well as resolved, yet relatively compact, objects are easily revealed while the slower varying fore/background is greatly diminished. Candidate sources are then identified by looking for pixels where the curvature exceeds, in absolute terms, a given threshold; the methodology easily allows us to pinpoint breakpoints in the source brightness profile and then derive reliable guesses for the sources extent. Identified peaks are fit with 2D elliptical Gaussians plus an underlying planar inclined plateau, with mild constraints on size and orientation. Mutually contaminating sources are fit with multiple Gaussians simultaneously using...

  13. Final Technical Report [Cosmogenic background and shielding R&D for a Ge Neutrinoless Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Guiseppe, Vince

    2013-10-01

    The USD Majorana group focused all of its effort in support of the MAJORANA DEMONSTRATOR (MJD) experiment. Final designs of the shielding subsystems are complete. Construction of the MJD shielding systems at SURF has begun and the proposed activities directly support the completion of the shield systems. The PI and the group contribute heavily to the onsite construction activities of the MJD experiment. The group led investigations into neutron and neutron-­induced backgrounds, shielding effectiveness and design, and radon backgrounds.

  14. LHCb: Numerical Analysis of Machine Background in the LHCb Experiment for the Early and Nominal Operation of LHC

    CERN Multimedia

    Lieng, M H; Corti, G; Talanov, V

    2010-01-01

    We consider the formation of machine background induced by proton losses in the long straight section of the LHCb experiment at LHC. Both sources showering from the tertiary collimators located in the LHCb insertion region as well as local beam-gas interaction are taken into account. We present the procedure for, and results of, numerical studies of such background for various conditions. Additionally expected impact and on the experiment and signal characteristics are discussed.

  15. Background music in the dissection laboratory: impact on stress associated with the dissection experience.

    Science.gov (United States)

    Anyanwu, Emeka G

    2015-06-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on stress associated with the dissection experience. After 8 wk of normal dissection without BM, various genres of BM were introduced into the cadaver dissection sessions of 260 medical and dental students for 3 wk. Feedback on the impact of BM on students in the CDL and students' attitude were accessed using a questionnaire. Psychological stress assessment was done using Psychological Stress Measure 9. Two batches of 30 students each were made to dissect same areas of the body for 2 h, one batch with BM playing and the other batch without. The same examination was given to both groups at the end. Over 90% of the participants expressed a desire to incorporate BM into the CDL; 87% of the sampled population that expressed love for music also reported BM to be a very useful tool that could be used to enhance learning conditions in the CDL. A strong positive relationship was established between love for music and its perception as a tool for learning in the CDL (P < 0.001). Students that studied under the influence of BM had significantly higher scores (P < 0.001) in the overall examination result. BM reduced the level of stress associated with the dissection experience by ∼33%. Copyright © 2015 The American Physiological Society.

  16. Data Reduction and Analysis of the Python V Cosmic Microwave Background Anisotropy Experiment

    CERN Document Server

    Coble, K A

    1999-01-01

    Observations of the microwave sky using the Python telescope in its fifth season of operation at the Amundsen-Scott South Pole Station in Antarctica are presented. The system consists of a 0.75 m off-axis telescope instrumented with a HEMT amplifier-based radiometer having continuum sensitivity from 37-45 GHz in two frequency bands. With a $0.91^{\\circ} \\times 1.02^{\\circ} $ beam the instrument fully sampled 598 deg$^2$ of sky, including fields measured during the previous four seasons of Python observations. Interpreting the observed fluctuations as anisotropy in the cosmic microwave background, we place constraints on the angular power spectrum of fluctuations in eight multipole bands up to $l \\sim 260$. The observed spectrum is consistent with both the COBE experiment and previous Python results. Total-power Wiener-filtered maps of the CMB are also presented. There is no significant contamination from known foregrounds. The results show a discernible rise in the angular power spectrum from large ($l \\sim 4...

  17. Target Group Segmentation in the Horse Buyers' Market against the Background of Equestrian Experience.

    Science.gov (United States)

    Gille, Claudia; Kayser, Maike; Spiller, Achim

    2010-01-01

    Whereas in former times horses were reserved primarily for people involved in agriculture, elite equestrians or the military, nowadays equestrian sport has become an activity for people with a wide variety of backgrounds. However, as more and more people become involved with equestrian sport today, the knowledge concerning animal husbandry in general is diminishing due to an alienation from agricultural themes in modern societies. As a consequence, this development affects both riding ability and the appraisal of horses, especially with respect to the purchase of horses. In order to analyse which factors influence purchase decisions in the horse market in conjunction with equestrian experience, 739 horse riders were surveyed on their purchase behaviour in this study. Using cluster analysis, a typology was generated that provides a differentiated picture of the preferences of the various rider groups. Three clusters were distinguished: the "amateurs", the "experienced" and the "experts". Taking personal horse riding proficiency into account, it could be concluded that especially the "amateur" group required objective criteria for the evaluation of a horse they are considering purchasing. Alongside "measureable" qualities, such as previous showing success or the level of training of the horse, also other attributes such as the simple handling of the horse should be taken into consideration. As particularly the "amateur" group in equestrian sport is increasing in numbers, it is therefore advisable when preparing a horse for sale to align oneself to the needs of this customer segment in order to ensure an effective and targeted marketing of horses.

  18. Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment.

    Science.gov (United States)

    Ade, P A R; Akiba, Y; Anthony, A E; Arnold, K; Atlas, M; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Le Jeune, M; Lee, A T; Linder, E; Leitch, E M; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Schanning, I; Schenck, D E; Sherwin, B; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2014-07-11

    Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

  19. Muonic background in the GERDA 0νββ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Kai Lorenz

    2014-07-18

    Muons can cause a non-negligible background in rare-event experiments like GERDA which searches for the neutrinoless double-beta decay (0νββ) in the isotope {sup 76}Ge. The kinetic energy of cosmogenic muons depends on the progenitor particle, hence they can have an energy which is high enough to penetrate even the deepest underground laboratory. For this reason GERDA is equipped with a powerful muon veto system which in most parts was developed in Tuebingen. In this work, a plastic scintillator veto was added to the existing water Cherenkov veto in order to protect a weak spot. Existing hardware was maintained, frequently calibrated and faulty modules exchanged when possible. The DAQ and analysis was upgraded in order to run both veto systems simultaneously. The system was simulated with a GEANT4-based Monte-Carlo simulation. Multiplicity and photon spectra of the simulations were found to be in good agreement with the experimental data and give an efficiency for the detection of energy-depositing muons of ε{sup sim}{sub μd}=(99.935±0.015)%. Two external effects were clearly identified in the muon veto data: additional muons originating from the CNGS-beam at CERN and an annual flux modulation due to seasonal atmospheric temperature changes. Both effects were measured with high precision and agree well with other experiments. Coincidences with the germanium detectors were studied and muon-germanium coincidences were clearly identified. By defining a muon cut, a muon rejection efficiency of the germanium detectors of ε{sup Ge}{sub μr}=(99.2{sup +0.3}{sub -0.4})% was found. Two methods were pursued to find radioactive isotopes produced by muons through spallation or neutron activation. The result of both methods is compatible with zero, i.e. no events could be clearly identified. The overall functionality of the muon veto for Phase I of GERDA was successfully maintained and verified.

  20. "Gaining Power through Education": Experiences of Honduran Students from High Poverty Backgrounds

    Science.gov (United States)

    Mather, Peter C.; Zempter, Christy; Ngumbi, Elizabeth; Nakama, Yuki; Manley, David; Cox, Haley

    2017-01-01

    This is a study of students from high-poverty backgrounds attending universities in Honduras. Based on a series of individual and focus group interviews, the researchers found students from high-poverty backgrounds face numerous practical challenges in persisting in higher education. Despite these challenges, participants succeeded due to a…

  1. LArGe: active background suppression using argon scintillation for the GERDA 0νββ-experiment

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, M.; Budjas, D.; Schoenert, S. [Technische Universitaet Muenchen, Munich (Germany); Barnabe-Heider, M. [Technische Universitaet Muenchen, Munich (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Cattadori, C. [Universita degli Studi di Milano, Milan (Italy); INFN, Milan (Italy); Gangapshev, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Institut for Nuclear Research, Moscow (Russian Federation); Gusev, K. [Technische Universitaet Muenchen, Munich (Germany); Joint Institut for Nuclear Research, Dubna (Russian Federation); National Research Center Kurchatov Institut, Moscow (Russian Federation); Heisel, M.; Smolnikov, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Junker, M. [Laboratori Nazionali del Gran Sasso, Assergi (Italy); Klimenko, A.; Lubashevskiy, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Joint Institut for Nuclear Research, Dubna (Russian Federation); Pelczar, K. [Jagellonian University, Cracow (Poland); Zuzel, G. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Jagellonian University, Cracow (Poland)

    2015-10-15

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for future application in the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors submersed into liquid argon (1 m{sup 3}, 1.4tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times 10{sup 3} have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12 - 4.6) x 10{sup -2} cts/(keV kg year) (90 % C.L.), which is at the level of GERDA Phase I. Furthermore, for the first time we monitor the natural {sup 42}Ar abundance (parallel to GERDA), and have indication for the 2νββ-decay in natural germanium. These results show the effectivity of an active liquid argon veto in an ultra-low background environment. As a consequence, the implementation of a liquid argon veto in GERDA Phase II is pursued. (orig.)

  2. Diabetes nurse educators' experiences of providing care for women, with gestational diabetes mellitus, from disadvantaged backgrounds.

    Science.gov (United States)

    Carolan, Mary

    2014-05-01

    To explore diabetes nurse educators' experiences of providing care for women, with gestational diabetes mellitus, from disadvantaged backgrounds and to gather information which would assist with the development of an educational programme that would support both women and diabetes educators. Rates of gestational diabetes mellitus have increased dramatically in recent years. This is concerning as gestational diabetes mellitus is linked to poorer pregnancy outcomes including hypertension, stillbirth, and nursery admission. Poorest outcomes occur among disadvantaged women. gestational diabetes mellitus is also associated with maternal type 2 diabetes and with child obesity and type 2 diabetes among offspring. Effective self-management of gestational diabetes mellitus reduces these risks. Diabetes nurse educators provide most education and support for gestational diabetes mellitus self-management. An interpretative phenomenological analysis approach, as espoused by Smith and Osborn (Qualitative Psychology: A Practical Guide to Research Methods, 2008, Sage, London, 51), provided the framework for this study. The views of six diabetes educators were explored through in-depth interviewing. Interviews were transcribed verbatim and analysed according to steps outlined by Smith and Osborn (Qualitative Psychology: A Practical Guide to Research Methods, 2008, Sage, London, 51). Three themes emerged from the data: (1) working in a suboptimal environment, (2) working to address the difficulties and (3) looking to the future. Throughout, the diabetes nurse educators sought opportunities to connect with women in their care and to make the educational content understandable and meaningful. Low literacy among disadvantaged women has a significant impact on their understanding of gestational diabetes mellitus information. In turn, catering for women with low literacy contributes to increased workloads for diabetes nurse educators, making them vulnerable to burnout. There is a need

  3. Construction, Deployment and Data Analysis of the E and B EXperiment: A Cosmic Microwave Background Polarimeter

    Science.gov (United States)

    Didier, Joy

    The E and B EXperiment (EBEX) is a pointed balloon-borne telescope designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The instrument is equipped with a 1.5 meter aperture Gregorian-Dragone telescope, providing an 8' beam at three frequency bands centered on 150, 250 and 410 GHz. The telescope is designed to measure or place an upper limit on inflationary B-mode signals and to probe B-modes originating from gravitationnal lensing of the CMB. The higher EBEX frequencies are designed to enable the measurement and removal of polarized Galactic dust foregrounds which currently limit the measurement of inflationary B-modes. Polarimetry is achieved by rotating an achromatic half-wave plate (HWP) on a superconducting magnetic bearing. In January 2013, EBEX completed 11 days of observations in a flight over Antarctica covering 6,000 square degrees of the southern sky. This marks the first time that kilo-pixel TES bolometer arrays have made science observations on a balloon-borne platform. In this thesis we report on the construction, deployment and data analysis of EBEX. We review the development of the pointing sensors and software used for real-time attitude determination and control, including pre-flight testing and calibration. We then report on the 2013 long duration flight (LD2013) and review all the major stages of the analysis pipeline used to transform the ˜1 TB of raw data into polarized sky maps. We review "LEAP", the software framework developed to support the analysis pipeline. We discuss in detail the novel program developed to reconstruct the attitude post-flight and estimate the effect of attitude errors on measured B-mode signals. We describe the bolometer time-stream cleaning procedure including removing the HWP-synchronous signal, and we detail the map making procedure. Finally we present a novel method to measure and subtract instrumental polarization, after which we show Galaxy and CMB maps.

  4. Control software and user interface for the Canarias Infrared Camera Experiment (CIRCE)

    Science.gov (United States)

    Marín-Franch, Antonio; Eikenberry, Stephen S.; Charcos-Llorens, Miguel V.; Edwards, Michelle L.; Varosi, Frank; Hon, David B.; Raines, Steven N.; Warner, Craig D.; Rashkin, David

    2006-06-01

    The Canarias InfraRed Camera Experiment (CIRCE) is a near-infrared visitor instrument for the 10.4-meter Gran Telescopio Canarias (GTC). This document shows CIRCE software. It will have two major functions: instrument control and observatory interface. The instrument control software is based on the UFLIB library, currently used to operate FLAMINGOS-1 and T-ReCS (as well as the CanariCam and FLAMINGOS-2 instruments under development in the University of Florida). The software interface with the telescope will be based on a CORBA server-client architecture. Finally, the user interface will consist of two java-based interfaces for the mechanism/detector control, and for quick look and analysis of data.

  5. Static and dynamic thermal infrared signatures measured during the FESTER experiment: first results

    Science.gov (United States)

    Gunter, W. H.; February, F.; Seiffer, D. P.; Eisele, C.

    2016-10-01

    The First European South African Experiment (FESTER) was conducted over about a 10 month period at the Institute of Maritime Technology (IMT) in False Bay, South Africa. One of the principal goals was recording of static and dynamic thermal infrared signatures under different environmental conditions for both validations of existing thermal equilibrium signature prediction codes, but also to aid development of dynamic thermal signature models. A small scientific work boat (called Sea Lab) was used as the principal target and sensor platform. Painted metal plates of different thicknesses were also used as infrared targets on-board Sea Lab to study static/dynamic thermal signatures and were also fitted with pyrgeometers, pyrometers and iButton temperature sensors/loggers. First results focused on the variable of thermal signatures as function of environmental conditions and the accuracy of calculated source temperatures (from measured radiometric temperatures) compared to the physical temperature measurements of the plates.

  6. Experiments on extreme wave generation using the Soliton on Finite Background

    CERN Document Server

    Huijsmans, R H M; Karjanto, N; Andonowati,

    2011-01-01

    A theoretical model of Soliton on Finite Background of a family of exact solution of the nonlinear Schr\\"{o}dinger equation for extreme wave generation is discussed in this paper. Some characteristics and physical properties of this solution are explained. The comparisons with experimental results from MARIN and with the simulation result from nonlinear wave model HUBRIS are also presented. The occurrence of phase singularity is observed, as predicted by the theoretical model of Soliton on Finite Background.

  7. PCDD/PCDF: human background data for Germany, a 10-year experience.

    OpenAIRE

    Päpke, O

    1998-01-01

    This paper gives an overview of the development of the environmental or background exposure of humans to polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in Germany. To determine the background exposure, adipose tissue, human milk, or blood can be used. The good comparability of the matrices analyzed is demonstrated. The daily consumption of low-level contaminated food, mainly of animal origin, leads to the accumulation of PCDDs/PCDFs in the human adipose re...

  8. The Contribution of z < or Approx. 6 Sources to the Spatial Coherence in the Unresolved Cosmic Near-Infrared and X-Ray Backgrounds

    Science.gov (United States)

    Helgason, K.; Cappelluti, N.; Hasinger, G.; Kashlinsky, A.; Ricotti, M.

    2014-01-01

    A spatial clustering signal has been established in Spitzer/IRAC measurements of the unresolved cosmic near-infrared background (CIB) out to large angular scales, approx. 1deg. This CIB signal, while significantly exceeding the contribution from the remaining known galaxies, was further found to be coherent at a highly statistically significant level with the unresolved soft cosmic X-ray background (CXB). This measurement probes the unresolved CXB to very faint source levels using deep near-IR source subtraction.We study contributions from extragalactic populations at low to intermediate redshifts to the measured positive cross-power signal of the CIB fluctuations with the CXB. We model the X-ray emission from active galactic nuclei (AGNs), normal galaxies, and hot gas residing in virialized structures, calculating their CXB contribution including their spatial coherence with all infrared emitting counterparts. We use a halo model framework to calculate the auto and cross-power spectra of the unresolved fluctuations based on the latest constraints of the halo occupation distribution and the biasing of AGNs, galaxies, and diffuse emission. At small angular scales (1), the 4.5microns versus 0.5-2 keV coherence can be explained by shot noise from galaxies and AGNs. However, at large angular scales (approx.10), we find that the net contribution from the modeled populations is only able to account for approx. 3% of the measured CIB×CXB cross-power. The discrepancy suggests that the CIB×CXB signal originates from the same unknown source population producing the CIB clustering signal out to approx. 1deg.

  9. Reference analysis of the signal + background model in counting experiments II. Approximate reference prior

    Science.gov (United States)

    Casadei, D.

    2014-10-01

    The objective Bayesian treatment of a model representing two independent Poisson processes, labelled as ``signal'' and ``background'' and both contributing additively to the total number of counted events, is considered. It is shown that the reference prior for the parameter of interest (the signal intensity) can be well approximated by the widely (ab)used flat prior only when the expected background is very high. On the other hand, a very simple approximation (the limiting form of the reference prior for perfect prior background knowledge) can be safely used over a large portion of the background parameters space. The resulting approximate reference posterior is a Gamma density whose parameters are related to the observed counts. This limiting form is simpler than the result obtained with a flat prior, with the additional advantage of representing a much closer approximation to the reference posterior in all cases. Hence such limiting prior should be considered a better default or conventional prior than the uniform prior. On the computing side, it is shown that a 2-parameter fitting function is able to reproduce extremely well the reference prior for any background prior. Thus, it can be useful in applications requiring the evaluation of the reference prior for a very large number of times.

  10. Laboratory Experiments on Propagating Plasma Bubbles into Vacuum, Vacuum Magnetic Field, and Background Plasmas

    Science.gov (United States)

    Lynn, Alan G.; Zhang, Yue; Gilmore, Mark; Hsu, Scott

    2014-10-01

    We discuss the dynamics of plasma ``bubbles'' as they propagate through a variety of background media. These bubbles are formed by a pulsed coaxial gun with an externally applied magnetic field. Bubble parameters are typically ne ~1020 m-3, Te ~ 5 - 10 eV, and Ti ~ 10 - 15 eV. The structure of the bubbles can range from unmagnetized jet-like structures to spheromak-like structures with complex magnetic flux surfaces. Some of the background media the bubbles interact with are vacuum, vacuum with magnetic field, and other magnetized plasmas. These bubbles exhibit different qualitative behavior depending on coaxial gun parameters such as gas species, gun current, and gun bias magnetic field. Their behavior also depends on the parameters of the background they propagate through. Multi-frame fast camera imaging and magnetic probe data are used to characterize the bubble evolution under various conditions.

  11. The Bolund experiment: Overview and background; Wind conditions in complex terrain

    Energy Technology Data Exchange (ETDEWEB)

    Bechmann, A.; Berg, J.; Courtney, M.S.; Joergensen, Hans E.; Mann, J.; Soerensen, Niels N.

    2009-07-15

    The Bolund experiment is a measuring campaign performed in 2007 and 2008. The aim of the experiment is to measure the flow field around the Bolund hill in order to provide a dataset for validating numerical flow models. The present report gives an overview of the whole experiment including a description of the orography, the instrumentation used and of the data processing. The Actual measurements are available from a database also described. (au)

  12. Background Music in the Dissection Laboratory: Impact on Stress Associated with the Dissection Experience

    Science.gov (United States)

    Anyanwu, Emeka G.

    2015-01-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on…

  13. Reference analysis of the signal + background model in counting experiments II. Approximate reference prior

    CERN Document Server

    Casadei, Diego

    2014-01-01

    The objective Bayesian treatment of a model representing two independent Poisson processes, labelled as "signal" and "background" and both contributing additively to the total number of counted events, is considered. It is shown that the reference prior for the parameter of interest (the signal intensity) is well approximated by the widely (ab)used flat prior only when the expected background is very high. For a large portion of the background parameters space, a very simple approximation (the asymptotic form of the reference prior for the limit of perfect prior background knowledge) can be safely used. In all cases, this approximation outperforms the uniform prior. When the asymptotic prior is not good enough, a simple 1-parameter fitting function is often sufficient to obtain an objective Bayesian solution. Otherwise, it is shown that a 2-parameters fitting function is able to reproduce the reference prior in all other cases. The latter is also useful to speed-up the computing time, which can be useful in a...

  14. Background Music in the Dissection Laboratory: Impact on Stress Associated with the Dissection Experience

    Science.gov (United States)

    Anyanwu, Emeka G.

    2015-01-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on…

  15. Historical Background of Ultrahigh Pressure Shock Compression Experiments at LLNL: 1973 to 2000

    Energy Technology Data Exchange (ETDEWEB)

    Nellis, W.J.

    2000-10-09

    My purpose is to recount the historical development of ultrahigh pressure shock compression experiments at LLNL, which I experienced in the period 1973 to 2000. I used several experimental techniques: shock-impedance-match experiments using planar shock waves driven by nuclear explosives (NIMs), the Janus Laser, a railgun, and a two-stage light-gas gun.

  16. Low Background Stainless Steel for the Pressure Vessel in the PandaX-II Dark Matter Experiment

    CERN Document Server

    Zhang, Tao; Ji, Xiangdong; Liu, Jianglai; Liu, Xiang; Wang, Xuming; Yao, Chunfa; Yuan, Xunhua

    2016-01-01

    We report on the custom produced low radiation background stainless steel and the welding rod for the PandaX experiment, one of the deep underground experiments to search for dark matter and neutrinoless double beta decay using xenon. The anthropogenic 60 Co concentration in these samples is at the range of 1 mBq/kg or lower. We also discuss the radioactivity of nuclear-grade stainless steel from TISCO which has a similar background rate. The PandaX-II pressure vessel was thus fabricated using the stainless steel from CISRI and TISCO. Based on the analysis of the radioactivity data, we also made discussions on potential candidate for low background metal materials for future pressure vessel development.

  17. Low background stainless steel for the pressure vessel in the PandaX-II dark matter experiment

    Science.gov (United States)

    Zhang, T.; Fu, C.; Ji, X.; Liu, J.; Liu, X.; Wang, X.; Yao, C.; Yuan, Xunhua

    2016-09-01

    We report on the custom produced low radiation background stainless steel and the welding rod for the PandaX experiment, one of the deep underground experiments to search for dark matter and neutrinoless double beta decay using xenon. The anthropogenic 60Co concentration in these samples is at the range of 1 mBq/kg or lower. We also discuss the radioactivity of nuclear-grade stainless steel from TISCO which has a similar background rate. The PandaX-II pressure vessel was thus fabricated using the stainless steel from CISRI and TISCO. Based on the analysis of the radioactivity data, we also made discussions on potential candidate for low background metal materials for future pressure vessel development.

  18. The role of background music in the experience of watching YouTube videos about death and dying

    Directory of Open Access Journals (Sweden)

    Panagiotis Pentaris

    2015-12-01

    Full Text Available YouTube is the largest video sharing site live at the moment. It has been used to communicate a vast array of information, while it allows for user-generated content. This paper will focus on YouTube videos that communicate death, and in particular will present findings from a preliminary study undertaken by the authors considering the role that background music plays in these videos. Specifically, this study explores the experiences of the viewers of death-related YouTube videos with and without background music while it makes comparisons in relation to the impact that music has on the viewers’ emotional experiences. We conclude that background music elicits emotions and enhances feelings of sadness and sympathy in relation to the visual content of videos while recommendations for future research are made.

  19. Cosmic microwave background experiments targeting the cosmic strings Doppler peak signal

    CERN Document Server

    Magueijo, J; Magueijo, Joao; Hobson, Mike

    1996-01-01

    We investigate which experiments are better suited to test the robust prediction that cosmic strings do not produce secondary Doppler peaks. We propose a statistic for detecting oscillations in the C^l spectrum, and study its statistical relevance given the truth of an inflationary competitor to cosmic strings. The analysis is performed for single-dish experiments and interferometers, subject to a variety of noise levels and scanning features. A high resolution of 0.2 degrees is found to be required for single-dish experiments with realistic levels of noise. Interferometers appear to be more suitable for detecting this signal.

  20. Target Group Segmentation in the Horse Buyers' Market against the Background of Equestrian Experience

    OpenAIRE

    GILLE, Claudia; Kayser, Maike; Spiller, Achim

    2010-01-01

    Whereas in former times horses were reserved primarily for people involved in agriculture, elite equestrians or the military, nowadays equestrian sport has become an activity for people with a wide variety of backgrounds. However, as more and more people become involved with equestrian sport today, the knowledge concerning animal husbandry in general is diminishing due to an alienation from agricultural themes in modern societies. As a consequence, this development affects both riding ability...

  1. LHCb: Beam and Background Monitoring and the Development of an Online Condition Analysis Tool for the LHCb Experiment at CERN

    CERN Multimedia

    Alessio, F

    2010-01-01

    The LHCb experiment has been taking data since more than half a year at the LHC, recording events from collisions at the highest energy ever achieved. For its physics purposes in the sector of CP violation, the experiment will record data with the best precision achievable. An online and offline beam and background monitoring became therefore essential to understand the performance of the LHC accelerator at CERN, to monitor and study the behavior of the background around the LHCb experiment and to optimize the experimental conditions. During my second year as a Doctoral Student at CERN, I have been working on the timing and readout control as well as on the online Beam, Background, and Luminosity Monitoring of the LHCb experiment in the frame of the LHCb Online group. The group is responsible for the complete data acquisition of the LHCb experiment, from the Front-End Electronics (FEE) to the storage of the data for offline analysis, including the Timing and Fast Control (TFC) system. The latter controls and...

  2. Background, Current Situation and International Experience of Food and Drug Police System

    Institute of Scientific and Technical Information of China (English)

    Hui; QIAO; Xu; WANG; Man; ZHANG; Fengtian; ZHENG

    2015-01-01

    Establishing the food and drug police system is particularly important for effectively striking at illegal and criminal activities related to food and drug. This study firstly revealed actual background of establishment of the food and drug police system. Taking the high profile gutter oil case in 2013 as an example,it analyzed advantages of the police in food safety supervision. Then,it summarized some pilot projects in China and analyzed characteristics of the Office of Criminal Investigations of FDA. Finally,it came up with problems and recommendations for improving food and drug police system.

  3. The Relationship of a Pilot's Educational Background, Aeronautical Experience and Recency of Experience to Performance In Initial Training at a Regional Airline

    Science.gov (United States)

    Shane, Nancy R.

    The purpose of this study was to determine how a pilot's educational background, aeronautical experience and recency of experience relate to their performance during initial training at a regional airline. Results show that variables in pilots' educational background, aeronautical experience and recency of experience do predict performance in training. The most significant predictors include years since graduation from college, multi-engine time, total time and whether or not a pilot had military flying experience. Due to the pilot shortage, the pilots entering regional airline training classes since August 2013 have varied backgrounds, aeronautical experience and recency of experience. As explained by Edward Thorndike's law of exercise and the law of recency, pilots who are actively using their aeronautical knowledge and exercising their flying skills should exhibit strong performance in those areas and pilots who have not been actively using their aeronautical knowledge and exercising their flying skills should exhibit degraded performance in those areas. Through correlation, chi-square and multiple regression analysis, this study tests this theory as it relates to performance in initial training at a regional airline.

  4. 装甲车辆与地面背景的热交互作用及红外仿真%Thermal interactions and infrared simulation of armored vehicles and ground background

    Institute of Scientific and Technical Information of China (English)

    韩玉阁; 成志铎; 任登凤; 宣益民

    2013-01-01

    为了全面揭示装甲车辆与地面背景之间热交互作用对地面背景温度以及红外辐射特性的影响,建立了装甲车辆和地面背景的温度和红外辐射特性的模型,重点考虑了装甲车辆与地面之间的传热.通过对地面和履带相关力学关系的引入,建立运动车辆和地面之间热学以及力学的模型,采用了动网格方法对车辆目标在运动后对地面所产生的沉陷现象及在地面上留下的热痕迹进行模拟仿真.基于红外辐射理论,综合考虑自身辐射、反射辐射以及大气传输特性,计算了车辆在3种不同状态下与地面背景之间的热交互作用及红外辐射特征分布,并比较了模拟温度与实验测量温度的误差,验证了模型的精度.仿真结果表明:该方法对地面目标的隐身设计和隐身技术评估具有十分重要的意义.%In order to fully reveal the influence of thermal interactions between the armored vehicles and ground background on ground background temperature and infrared radiation characteristics, the temperature and infrared signature model of armored vehicles and ground background were established, with focus on heat transfer between armored vehicles and ground.By introducing mechanical relationship between the road and the track, thermal and mechanical models between the moving vehicle and the road were established.Using method of the moving mesh, the subsidence phenomenon and thermal trace on the road after target vehicle moving were simulated.Based on the infrared radiation theory, considering the radiation, reflective radiation and atmospheric transmission characteristic, the thermal interactions and infrared radiation characteristics distribution of armored vehicles and terrain background under three different conditions were calculated.The simulated temperature and measured temperature in the experiment were compared.The model's precision was validated.The simulation results show that this method is

  5. Classification of high-energy antiprotons on electrons background based on calorimeter data in PAMELA experiment

    Science.gov (United States)

    Dunaeva, O. A.; Alekseev, V. V.; Bogomolov, Yu V.; Lukyanov, A. D.; Malakhov, V. V.; Mayorov, A. G.; Rodenko, S. A.

    2017-01-01

    In modern experimental physics a heterogeneous coordinate-sensitive calorimeters are widely used due to their good characteristics and possibilities to obtain a three-dimensional information of particles interactions. Especially it is important at high-energies when electromagnetic or hadron showers are arise. We propose a quit efficient method to identify antiprotons (positrons) with energies more than 10 GeV on electron (proton) background by calorimeter of such kind. We construct the AdaBoost classifier and SVM to separate particles into two classes, different combinations of energy release along reconstructed particle trajectory were used as feature vector. We test a preliminary version of the method on a calorimeter of the PAMELA magnetic spectrometer. For high-energy particles we got a good quality of classification: it lost about 5 · 10‑2 of antiprotons, and less than 4 · 10‑4 of electrons were classified to antiproton class.

  6. The co-evolution of black hole growth and star formation from a cross-correlation analysis between quasars and the cosmic infrared background

    CERN Document Server

    Wang, Lingyu; Ross, Nicholas P; Asboth, Viktoria; Bethermin, Matthieu; Bock, Jamie; Clements, Dave; Conley, Alex; Cooray, Asantha; Farrah, Duncan; Hajian, Amir; Han, Jiaxin; Lagache, Guilaine; Marsden, Gaelen; Myers, Adam; Norberg, Peder; Oliver, Seb; Page, Mat; Symeonidis, Myrto; Schulz, Bernhard; Wang, Wenting; Zemcov, Mike

    2014-01-01

    We present the first cross-correlation measurement between Sloan Digital Sky Survey (SDSS) Type 1 quasars and the cosmic infrared background (CIB) measured by Herschel. The distribution of the quasars at 0.15=1.4) is $11.1^{+1.6}_{-1.4}$, $7.1^{+1.6}_{-1.3}$ and $3.6^{+1.4}_{-1.0}$ mJy at 250, 350 and 500 microns, respectively, while the mean sub-mm flux densities of the DR9 quasars (=2.5) is $5.7^{+0.7}_{-0.6}$, $5.0^{+0.8}_{-0.7}$ and $1.8^{+0.5}_{-0.4}$ mJy. We find that the correlated sub-mm emission includes both the emission from satellite DSFGs in the same halo as the central quasar and the emission from DSFGs in separate halos (correlated with the quasar-hosting halo). The amplitude of the one-halo term is ~10 times smaller than the sub-mm emission of the quasars, implying the the satellites have a lower star-formation rate than the quasars. The satellite fraction for the DR7 quasars is $0.008^{+0.008}_{-0.005}$ and the host halo mass scale for the central and satellite quasars is $10^{12.36\\pm0.87}$ ...

  7. Rechargeable and LED-activated ZnGa2O4 : Cr(3+) near-infrared persistent luminescence nanoprobes for background-free biodetection.

    Science.gov (United States)

    Zhou, Zhihao; Zheng, Wei; Kong, Jintao; Liu, Yan; Huang, Ping; Zhou, Shanyong; Chen, Zhuo; Shi, Jianlin; Chen, Xueyuan

    2017-05-25

    Persistent luminescence nanoparticles (PLNPs) have shown great promise in the field of biomedicine, but are currently limited by the challenge in the synthesis of high-quality PLNPs with bright persistent luminescence and a long afterglow time. Herein, we report a facile strategy for the synthesis of monodisperse, rechargeable and LED-activated ZnGa2O4 : Cr(3+) near-infrared (NIR) PLNPs based on a modified solvothermal liquid-solid-solution method. The as-synthesized PLNPs are not only flexible for bioconjugation, but could also circumvent the limitation of the weak persistent luminescence and short afterglow time that most PLNPs confronted owing to their rechargeable capability. It was unraveled that both thermal activation and quantum tunneling mechanisms contributed to the afterglow decay of the PLNPs, and the quantum tunneling was found to dictate the LED-activated afterglow intensity and lasting time. Furthermore, by utilizing the superior excitation-free persistent luminescence, we demonstrated for the first time the application of biotinylated ZnGa2O4 : Cr(3+) PLNPs as background-free luminescent nano-bioprobes for sensitive and specific detection of avidin in a heterogeneous assay with a limit of detection down to ∼150 pM, thus revealing the great potential of these NIR PLNPs in ultrasensitive biodetection and bioimaging.

  8. The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background

    CERN Document Server

    Geach, J E; Coppin, K E K; Dunlop, J S; Halpern, M; Smail, Ian; van der Werf, P; Serjeant, S; Farrah, D; Roseboom, I; Targett, T; Arumugam, V; Asboth, V; Blain, A; Chrysostomou, A; Clarke, C; Ivison, R J; Jones, S L; Karim, A; Mackenzie, T; Meijerink, R; Michalowski, M J; Scott, D; Simpson, J; Swinbank, A M; Alexander, D; Almaini, O; Aretxaga, I; Best, P; Chapman, S; Clements, D L; Conselice, C; Danielson, A L R; Eales, S; Edge, A C; Gibb, A; Hughes, D; Jenness, T; Knudsen, K K; Lacey, C; Marsden, G; McMahon, R; Oliver, S; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Spaans, M; Stevens, J; Webb, T M A; Willott, C; Wilson, C D; Zemcov, M

    2012-01-01

    The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin^2 of the COSMOS field, in the footprint of the HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate the number counts of 450um-selected galaxies with flux densities S_450>5mJy. The 8-arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at ~200um) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S_450>5mJy we resolve (7.4[+/-]0.7)x10^-2 MJy/sr of the CIB at 450um (equivalent to 16[+/-]7% of the absolute brightness measured by COBE at this wavelength) into point sources. A further ~40% of the CIB can be recovered through a statistical stack of 24um emitters in this field, indicating that the majority (~60%) o...

  9. Infrared variation reduction by simultaneous background suppression and target contrast enhancement for deep convolutional neural network-based automatic target recognition

    Science.gov (United States)

    Kim, Sungho

    2017-06-01

    Automatic target recognition (ATR) is a traditionally challenging problem in military applications because of the wide range of infrared (IR) image variations and the limited number of training images. IR variations are caused by various three-dimensional target poses, noncooperative weather conditions (fog and rain), and difficult target acquisition environments. Recently, deep convolutional neural network-based approaches for RGB images (RGB-CNN) showed breakthrough performance in computer vision problems, such as object detection and classification. The direct use of RGB-CNN to the IR ATR problem fails to work because of the IR database problems (limited database size and IR image variations). An IR variation-reduced deep CNN (IVR-CNN) to cope with the problems is presented. The problem of limited IR database size is solved by a commercial thermal simulator (OKTAL-SE). The second problem of IR variations is mitigated by the proposed shifted ramp function-based intensity transformation. This can suppress the background and enhance the target contrast simultaneously. The experimental results on the synthesized IR images generated by the thermal simulator (OKTAL-SE) validated the feasibility of IVR-CNN for military ATR applications.

  10. Study of the material photon and electron background and the liquid argon detector veto efficiency of the CDEX-10 experiment

    CERN Document Server

    Su, Jian; MA, Hao; Yue, Qian; Cheng, Jian-Ping; Chang, Jian-Ping; Chen, Nan; Chen, Ning; Chen, Qing-Hao; Chen, Yun-Hua; Chuang, Yo-Chun; Deng, Zhi; Du, Qiang; Gong, Hui; Hao, Xi-Qing; He, Qing-Ju; Huang, Han-Xiong; Huang, Teng-Rui; Jiang, Hao; Kang, Ke-Jun; Li, Hau-Bin; Li, Jian-Min; Li, Jin; Li, Jun; Li, Xia; Li, Xin-Ying; Li, Xue-Qian; Li, Yu-Lan; Li, Yuan-Jing; Liao, Heng-Yi; Lin, Fong-Kay; Lin, Shin-Ted; Liu, Shu-Kui; Lü, Lan-Chun; Mao, Shao-Ji; Qin, Jian-Qiang; Ren, Jie; Ren, Jing; Ruan, Xi-Chao; Shen, Man-Bin; Singh, Lakhwinder; Singh, Manoj Kumar; Soma, Arun Kumar; Tang, Chang-Jian; Tseng, Chao-Hsiung; Wang, Ji-Min; Wang, Li; Wang, Qing; Wong, Henry Tsz-King; Wu, Shi-Yong; Wu, Yu-Cheng; Xing, Hao-Yang; Xu, Yin; Xue, Tao; Yang, Li-Tao; Yang, Song-Wei; Yi, Nan; Yu, Chun-Xu; Yu, Hao; Yu, Xun-Zhen; Zeng, Xiong-Hui; Zhang, Lan; Zhang, Yun-Hua; Zhao, Ming-Gang; Zhao, Wei; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Wei-Bin; Zhu, Xue-Zhou; Zhu, Zhong-Hua

    2014-01-01

    The China Dark Matter Experiment (CDEX) is located at the China Jinping underground laboratory (CJPL) and aims to directly detect the WIMP flux with high sensitivity in the low mass region. Here we present a study of the predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within the GEANT4 program. Then the photon and electron background level in the energy region of interest (<10^-2 events kg-1 day-1 keV-1 (cpkkd)) is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of CDEX-10 experiment, 0.1 cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible.

  11. Study of the material photon and electron background and the liquid argon detector veto efficiency of the CDEX-10 experiment

    Science.gov (United States)

    Su, Jian; Zeng, Zhi; Ma, Hao; Yue, Qian; Cheng, Jian-Ping; Chang, Jian-Ping; Chen, Nan; Chen, Ning; Chen, Qing-Hao; Chen, Yun-Hua; Chuang, Yo-Chun; Deng, Zhi; Du, Qiang; Gong, Hui; Hao, Xi-Qing; He, Qing-Ju; Huang, Han-Xiong; Huang, Teng-Rui; Jiang, Hao; Kang, Ke-Jun; Li, Hau-Bin; Li, Jian-Min; Li, Jin; Li, Jun; Li, Xia; Li, Xin-Ying; Li, Xue-Qian; Li, Yu-Lan; Li, Yuan-Jing; Liao, Heng-Yi; Lin, Fong-Kay; Lin, Shin-Ted; Liu, Shu-Kui; Lü, Lan-Chun; Mao, Shao-Ji; Qin, Jian-Qiang; Ren, Jie; Ren, Jing; Ruan, Xi-Chao; Shen, Man-Bin; Lakhwinder, Singh; Manoj, Kumar Singh; Arun, Kumar Soma; Tang, Chang-Jian; Tseng, Chao-Hsiung; Wang, Ji-Min; Wang, Li; Wang, Qing; Wong Tsz-King, Henry; Wu, Shi-Yong; Wu, Yu-Cheng; Xing, Hao-Yang; Xu, Yin; Xue, Tao; Yang, Li-Tao; Yang, Song-Wei; Yi, Nan; Yu, Chun-Xu; Yu, Hao; Yu, Xun-Zhen; Zeng, Xiong-Hui; Zhang, Lan; Zhang, Yun-Hua; Zhao, Ming-Gang; Zhao, Wei; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Wei-Bin; Zhu, Xue-Zhou; Zhu, Zhong-Hua; CDEX Collaboration

    2015-03-01

    The China Dark Matter Experiment (CDEX) is located at the China Jinping Underground Laboratory (CJPL) and aims to directly detect the weakly interacting massive particles (WIMP) flux with high sensitivity in the low mass region. Here we present a study of the predicted photon and electron backgrounds including the background contribution of the structure materials of the germanium detector, the passive shielding materials, and the intrinsic radioactivity of the liquid argon that serves as an anti-Compton active shielding detector. A detailed geometry is modeled and the background contribution has been simulated based on the measured radioactivities of all possible components within the GEANT4 program. Then the photon and electron background level in the energy region of interest (<10-2events·kg1·day-1·keV-1 (cpkkd)) is predicted based on Monte Carlo simulations. The simulated result is consistent with the design goal of the CDEX-10 experiment, 0.1cpkkd, which shows that the active and passive shield design of CDEX-10 is effective and feasible. Supported by National Natural Science Foundation of China (11175099, 10935005, 10945002, 11275107, 11105076) and State Key Development Program of Basic Research of China (2010CB833006)

  12. Cardiotocography interpretation skills and the association with size of maternity unit, years of obstetric work experience and healthcare professional background

    DEFF Research Database (Denmark)

    Thellesen, Line; Sorensen, Jette Led; Hedegaard, Morten

    2017-01-01

    INTRODUCTION: We aimed to examine whether cardiotocography (CTG) knowledge, interpretation skills and decision-making measured by a written assessment were associated with size of maternity unit, years of obstetric work experience and healthcare professional background. MATERIAL AND METHODS.......007; >20 years experience: mean difference -0.9, passociated with working in large maternity units and having......-choice question test. Associations between mean test score and work conditions were analyzed using multivariable robust regression, in which the three variables were mutually adjusted. RESULTS: Participants from units with >3000 deliveries/year scored higher on the test than participants from units with

  13. EXPERIENCE IN THE CORRECTION OF THE INTESTINE MICROBIOTADYS DYSBALANCE ON THE BACKGROUND OF SECONDARY LACTASE DEFICIENCY

    Directory of Open Access Journals (Sweden)

    L.A. Tarasova

    2011-01-01

    Full Text Available One of the main conditions for normal growth and development of the child is a full-grown digestion. In this paper, the authors emphasize the importance of the intestinal microbiota condition for adequate digestion, and they are citing the main causes of disaccharidase deficiency, which contributes to the violations of the microbiota and exacerbates the intestine damage. Scientists share their experience of the correction of biocenosis and functional intestines disorders in infants.Key words: digestion, intestinal microbiota, biologics, intestine biocenosis violations, correction, children.

  14. Characterization, 1064 nm photon signals and background events of a tungsten TES detector for the ALPS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dreyling-Eschweiler, J.; Doebrich, B.; Januschek, F.; Lindner, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Bastidon, N.; Horns, D. [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik

    2015-02-15

    The high efficiency, low-background, and single-photon detection with transition-edge sensors (TES) is making this type of detector attractive in widely different types of application. In this paper, we present first characterizations of a TES to be used in the Any Light Particle Search (ALPS) experiment searching for new fundamental ultra-light particles. Firstly, we describe the setup and the main components of the ALPS TES detector (TES, millikelvin-cryostat and SQUID read-out) and their performances. Secondly, we explain a dedicated analysis method for single-photon spectroscopy and rejection of non-photon background. Finally, we report on results from extensive background measurements. Considering an event-selection, optimized for a wavelength of 1064 nm, we achieved a background suppression of ∝10{sup -3} with a ∝ 50 % efficiency for photons passing the selection. The resulting overall efficiency was 23 % with a dark count rate of 8.6.10{sup -3} s{sup -1}. We observed that pile-up events of thermal photons are the main background component.

  15. Development of a flexible circuit board for low-background experiments

    Science.gov (United States)

    Poon, Alan; Barton, Paul; Dhar, Ankur; Larsen, Joern; Loach, James

    2017-01-01

    Future underground rare-event search experiments, such as neutrinoless double-beta decay searches, have stringent requirements for the radiopurity of materials placed near the active detector medium. Parylene is a polymer that has a high chemical purity and the vapor deposition process by which it is laid down tends to purify it further. In this talk the technique to fabricate a low-mass, flexible circuit board, with conductive traces photoligthographically patterned on a parylene substrate, is discussed. The performance of a proof-of-principle temperature sensor is presented. This work was supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-05CH11231 and by the Shanghai Key Lab for Particle Physics and Cosmology (SKLPPC), Grant No. 15DZ2272100.

  16. The Experiences of Israeli Early Childhood Educators Working With Children of Ethiopian Background

    Directory of Open Access Journals (Sweden)

    Esther Firstater

    2015-09-01

    Full Text Available This study offers an in-depth examination of the experiences of early childhood educators, focusing on their work with Ethiopian immigrant children and their families. We aim to describe and analyze the teachers’ insider views vis-à-vis the challenges faced by these children and their parents in the Israeli preschool system. Using narrative methodology, the analysis of findings is based upon 20 stories written by 10 early childhood educators. It reveals that for these teachers, the chief struggle is their relationship with the parents of their Ethiopian pupils, one characterized by difficulties, frustrations, and burdens. The engagement with parents of Ethiopian children exhibited a range of possibilities: from the expression of patronizing, hierarchical viewpoints, to a search for ad hoc ways of coping with a persistent cultural gap, to the attainment of genuine, successful partnerships. Lack of sufficient knowledge and understanding of the unique cultural attributes of the Ethiopian community appears to be the basis for the teachers’ view of the parents as lacking faith in them and in the educational system as a whole. In addition, suggestions are made about implications for educational practice and for policies that might assist teachers in ameliorating these challenges via the development of, and professional training in, skills which help coping with the problems and dilemmas unique to the multicultural classroom.

  17. A tapered undulator experiment at the ELBE far infrared hybrid-resonator oscillator free electron laser.

    Science.gov (United States)

    Asgekar, V; Lehnert, U; Michel, P

    2012-01-01

    A tapered undulator experiment was carried out at the ELBE far-infrared free electron laser (FEL). The oscillator FEL makes use of a hybrid optical resonator. The main motivation was to see whether the presence of a dispersive medium in the form of a waveguide in the resonator has any effect on the outcome. The FEL saturated power and the wavelength shifts have been measured as a function of both positive as well as negative undulator field amplitude tapering. In contrast to the typical high-gain FELs where positive tapering proves beneficial for the output power we observed an improvement of performance at negative taper. During the same experiments we studied the characteristics of the detuning curves. The width of the curves indicates a maximum small signal gain for zero taper while the output peak power increases with negative taper. The saturated power output, the detuning curve characteristics, and the wavelength shifts agrees with the theoretical predictions. Details of the experiment are presented.

  18. Simulations of the muon-induced neutron background of the EDELWEISS-II experiment for Dark Matter search

    Energy Technology Data Exchange (ETDEWEB)

    Horn, O.M.

    2007-12-21

    In modern astroparticle physics and cosmology, the nature of Dark Matter is one of the central problems. Particle Dark Matter in form of WIMPs is favoured among many proposed candidates. The EDELWEISS direct Dark Matter search uses Germanium bolometers to detect these particles by nuclear recoils. Here, the use of two signal channels on an event-by-event basis, namely the heat and ionisation signal, enables the detectors to discriminate between electron and nuclear recoils. This technique leaves neutrons in the underground laboratory as the main background for the experiment. Besides ({alpha},n) reactions of natural radioactivity, neutrons are produced in electromagnetic and hadronic showers induced by cosmic ray muons in the surrounding rock and shielding material of the Germanium crystals. To reach high sensitivities, the EDELWEISS-II experiment, as well as other direct Dark Matter searches, has to efficiently suppress this neutron background. The present work is devoted to study the muon-induced neutron flux in the underground laboratory LSM and the interaction rate within the Germanium crystals by using the Monte Carlo simulation toolkit Geant4. To ensure reliable results, the implemented physics in the toolkit regarding neutron production is tested in a benchmark geometry and results are compared to experimental data and other simulation codes. Also, the specific energy and angular distribution of the muon flux in the underground laboratory as a consequence of the asymmetric mountain overburden is implemented. A good agreement of the simulated muon flux is shown in a comparison to preliminary experimental data obtained with the EDELWEISS-II muon veto system. Furthermore, within a detailed geometry of the experimental setup, the muon-induced background rate of nuclear recoils in the bolometers is simulated. Coincidences of recoil events in the Germanium with an energy deposit of the muoninduced shower in the plastic scintillators of the veto system are studied

  19. Test of models of the cosmic infrared background with multiwavelength observations of the blazar 1ES 1218+30.4 in 2009

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Arlen, T.; Aune, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Böttcher, M. [Department of Physics and Astronomy, Ohio University, Clippinger 339, Athens, OH 45701-2979 (United States); Bouvier, A. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W.; Feng, Q. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Dumm, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, New York, NY 10027 (United States); Falcone, A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Federici, S., E-mail: krawcz@wuphys.wustl.edu [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); and others

    2014-06-20

    We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and γ-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, >100 GeV) observations, as well as contemporaneous optical and Fermi observations. The 1ES 1218+30.4 broadband energy spectrum—the first with simultaneous X-ray and VHE γ-ray energy spectra—is of particular interest as the source is located at a high cosmological redshift for a VHE source (z = 0.182), leading to strong absorption of VHE gamma rays by photons from the optical/infrared extragalactic background light (EBL) via γ{sub VHE} + γ{sub EBL} → e {sup +} e {sup –} pair-creation processes. We model the data with a one-zone synchrotron self-Compton (SSC) emission model and with the extragalactic absorption predicted by several recent EBL models. We find that the observations are consistent with the SSC scenario and all the EBL models considered in this work. We discuss observational and theoretical avenues to improve on the EBL constraints.

  20. Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment

    CERN Document Server

    Carmona, J M; García, E; Irastorza, I G; Luzón, G; Morales, A; Morales, J; De Solorzano, A O; Puimedón, J; Sarsa, M L; Villar, J A

    2004-01-01

    A quantitative study of the neutron environment in the Canfranc Underground Laboratory has been performed. The analysis is based on a complete set of simulations and, particularly, it is focused on the IGEX-DM dark matter experiment. The simulations are compared to the IGEX-DM low energy data obtained with different shielding conditions. The results of the study allow us to conclude, with respect to the IGEX-DM background, that the main neutron population, coming from radioactivity from the surrounding rock, is practically eliminated after the implementation of a suitable neutron shielding. The remaining neutron background (muon-induced neutrons in the shielding and in the rock) is substantially below the present background level thanks to the muon veto system. In addition, the present analysis gives us a further insight on the effect of neutrons in other current and future experiments at the Canfranc Underground Laboratory. The comparison of simulations with the body of data available has allowed to set the ...

  1. Infrared scintillation yield in gaseous and liquid argon for rare-event experiments

    CERN Document Server

    Buzulutskov, A; Grebenuk, A

    2011-01-01

    The study of primary and secondary scintillations in noble gases and liquids is of paramount importance to rare-event experiments using noble gas media, such those of dark matter search, mu-e-gamma decay search, neutrinoless double-beta decay search and coherent neutrino-nucleus scattering. In the present work, the scintillation yield in gaseous and liquid Ar has for the first time been measured in the near infrared (NIR), both for primary and secondary (proportional) scintillations, using Geiger-mode avalanche photodiodes (G-APDs) and pulsed X-ray irradiation. In the wavelength range of 690-850 nm, the primary NIR-scintillation yield of the fast component was measured to be 17000 photon/MeV in gaseous Ar and 450 photon/MeV in liquid Ar. Proportional NIR scintillations (electroluminescence) in gaseous Ar have been also observed; their amplification parameter at 163 K was measured to be 12 photons per drifting electron per kV. Possible applications of NIR scintillations in high energy physics experiments are d...

  2. \\textsc{MaGe} - a {\\sc Geant4}-based Monte Carlo Application Framework for Low-background Germanium Experiments

    CERN Document Server

    Boswell, Melissa; Detwiler, Jason A; Finnerty, Padraic; Henning, Reyco; Gehman, Victor M; Johnson, Rob A; Jordan, David V; Kazkaz, Kareem; Knapp, Markus; Kröninger, Kevin; Lenz, Daniel; Leviner, Lance; Liu, Jing; Liu, Xiang; MacMullin, Sean; Marino, Michael G; Mokhtarani, Akbar; Pandola, Luciano; Schubert, Alexis G; Schubert, Jens; Tomei, Claudia; Volynets, Oleksandr

    2010-01-01

    We describe a physics simulation software framework, MAGE, that is based on the GEANT4 simulation toolkit. MAGE is used to simulate the response of ultra-low radioactive background radiation detectors to ionizing radiation, specifically the MAJORANA and GERDA neutrinoless double-beta decay experiments. MAJORANA and GERDA use high-purity germanium detectors to search for the neutrinoless double-beta decay of 76Ge, and MAGE is jointly developed between these two collaborations. The MAGE framework contains the geometry models of common objects, prototypes, test stands, and the actual experiments. It also implements customized event generators, GEANT4 physics lists, and output formats. All of these features are available as class libraries that are typically compiled into a single executable. The user selects the particular experimental setup implementation at run-time via macros. The combination of all these common classes into one framework reduces duplication of efforts, eases comparison between simulated data...

  3. Improved background rejection in neutrinoless double beta decay experiments using a magnetic field in a high pressure xenon TPC

    CERN Document Server

    Renner, J; Hernando, J A; Imzaylov, A; Monrabal, F; Muñoz, J; Nygren, D; Gomez-Cadenas, J J

    2015-01-01

    We demonstrate that the application of an external magnetic field could lead to an improved background rejection in neutrinoless double-beta (0nbb) decay experiments using a high pressure xenon (HPXe) TPC. HPXe chambers are capable of imaging electron tracks, a feature that enhances the separation between signal events (the two electrons emitted in the 0nbb decay of 136Xe) and background events, arising chiefly from single electrons of kinetic energy compatible with the end-point of the 0nbb decay (Qbb ). Applying an external magnetic field of sufficiently high intensity (in the range of 0.5-1 Tesla for operating pressures in the range of 5-15 atmospheres) causes the electrons to produce helical tracks. Assuming the tracks can be properly reconstructed, the sign (direction) of curvature can be determined at several points along these tracks, and such information can be used to separate signal (0nbb) events containing two electrons producing a track with two different directions of curvature from background (s...

  4. DAQ Software Contributions, Absolute Scale Energy Calibration and Background Evaluation for the NOvA Experiment at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, Eric Lewis [Univ. of Tennessee, Knoxville, TN (United States)

    2015-08-01

    The NOvA (NuMI Off-axis ve [nu_e] Appearance) Experiment is a long-baseline accelerator neutrino experiment currently in its second year of operations. NOvA uses the Neutrinos from the Main Injector (NuMI) beam at Fermilab, and there are two main off-axis detectors: a Near Detector at Fermilab and a Far Detector 810 km away at Ash River, MN. The work reported herein is in support of the NOvA Experiment, through contributions to the development of data acquisition software, providing an accurate, absolute-scale energy calibration for electromagnetic showers in NOvA detector elements, crucial to the primary electron neutrino search, and through an initial evaluation of the cosmic background rate in the NOvA Far Detector, which is situated on the surface without significant overburden. Additional support work for the NOvA Experiment is also detailed, including DAQ Server Administration duties and a study of NOvA’s sensitivity to neutrino oscillations into a “sterile” state.

  5. Retrieval of spectral and dynamic properties from two-dimensional infrared pump-probe experiments.

    Science.gov (United States)

    Chelli, Riccardo; Volkov, Victor V; Righini, Roberto

    2008-07-15

    We have developed a fitting algorithm able to extract spectral and dynamic properties of a three level oscillator from a two-dimensional infrared spectrum (2D-IR) detected in time resolved nonlinear experiments. Such properties go from the frequencies of the ground-to-first and first-to-second vibrational transitions (and hence anharmonicity) to the frequency-fluctuation correlation function. This last is represented through a general expression that allows one to approach the various strategies of modeling proposed in the literature. The model is based on the Kubo picture of stochastic fluctuations of the transition frequency as a result of perturbations by a fluctuating surrounding. To account for the line-shape broadening due to pump pulse spectral width in double-resonance measurements, we supply the fitting algorithm with the option to perform the convolution of the spectral signal with a Lorentzian function in the pump-frequency dimension. The algorithm is tested here on 2D-IR pump-probe spectra of a Gly-Ala dipeptide recorded at various pump-probe delay times. Speedup benchmarks have been performed on a small Beowulf cluster. The program is written in FORTRAN language for both serial and parallel architectures and is available free of charge to the interested reader.

  6. Mid-infrared laser light nulling experiment using single-mode conductive waveguides

    CERN Document Server

    Labadie, L; Maurand, R; Labeye, P; Kern, P; Arezki, B; Broquin, J -E

    2007-01-01

    Aims: In the context of space interferometry missions devoted to the search of exo-Earths, this paper investigates the capabilities of new single mode conductive waveguides at providing modal filtering in an infrared and monochromatic nulling experiment; Methods: A Michelson laser interferometer with a co-axial beam combination scheme at 10.6 microns is used. After introducing a Pi phase shift using a translating mirror, dynamic and static measurements of the nulling ratio are performed in the two cases where modal filtering is implemented and suppressed. No additional active control of the wavefront errors is involved. Results: We achieve on average a statistical nulling ratio of 2.5e-4 with a 1-sigma upper limit of 6e-4, while a best null of 5.6e-5 is obtained in static mode. At the moment, the impact of external vibrations limits our ability to maintain the null to 10 to 20 seconds.; Conclusions: A positive effect of SM conductive waveguide on modal filtering has been observed in this study. Further improv...

  7. Small Moving Infrared Target Detection Algorithm under Complex Background%复杂背景条件下的红外运动小目标检测算法

    Institute of Scientific and Technical Information of China (English)

    孙小炜; 李言俊; 陈义

    2007-01-01

    在红外成像制导系统中,运动小目标易受到背景和噪声的严重干扰,从而导致较低的信噪比,给目标检测带来了难度.为此,我们首先使用基于Top-Hat变换的数学形态学滤波对红外数字图像进行背景抑制.进而对经过黑、白Top-Hat变换后的图像求取并集,然后,通过自适应门限分割得到小目标.试验结果表明该方法在信噪比接近2的时候仍能够得到较好的目标检测效果.%In an infrared imaging guidance system, a small target infrared image is disturbed by the background and noise, which results in low Signal Noise Ratio(SNR) and brings difficulty to target detection.Therefore, we use mathematical morphology filtering based Top-Hat transform to suppress the background of the digital infrared image, and get the union from White and Black Top-hat transform. And finally, we obtain the small tatget image using adaptive threshold segmentation algorithm. The experimental results prove that this approach is an effective method for small infrared moving target detection when the SNR reaches 2.

  8. Production of low-background CuSn6-bronze for the CRESST dark-matter-search experiment.

    Science.gov (United States)

    Majorovits, B; Kader, H; Kraus, H; Lossin, A; Pantic, E; Petricca, F; Proebst, F; Seidel, W

    2009-01-01

    One of the most intriguing open questions in modern particle physics is the nature of the dark matter in our universe. As hypothetical weakly interacting massive particles (WIMPs) do interact with ordinary matter extremely rarely, their observation requires a very low-background detector environment regarding radioactivity as well as an advanced detector technique that allows for active discrimination of the still present radioactive contaminations. The CRESST experiment uses detectors operating at milli-Kelvin temperature. Energy deposition in the detectors is recorded via the simultaneous measurement of a phonon-mediated signal and scintillation emitted by the CaWO(4) crystal targets. The entire setup is made of carefully selected materials. In this note we report on the development of ultra-pure bronze (CuSn(6)) wire in small quantities for springs and clamps that are currently being used in the CRESST II setup.

  9. Constraining the origin of TeV photons from gamma-ray bursts with delayed MeV-GeV emission formed by interaction with cosmic infrared/microwave background photons

    CERN Document Server

    Wang, X Y; Dai, Z G; Lu, T

    2004-01-01

    It has been suggested that electromagnetic cascade of very high energy gamma-rays from gamma-ray bursts (GRBs) in the infrared/microwave background can produce delayed MeV-GeV photons. This delay could be caused by the angular spreading effect of the scattered microwave photons or deflection of the secondly pairs due to intergalactic magnetic field. Very high energy TeV photons of GRBs could be produced by a few mechanisms including the proton-synchrotron radiation and electron inverse Compton emission from GRB internal shocks as well as external shocks. We suggest that the information provided by the delayed emission could give constraints on models for TeV gamma-rays. A more accurate calculation of the delayed time caused by the angular spreading effect is presented by considering recent observations of the extragalactic infrared background and the theoretic high-redshift infrared background. We also suggest that the dependence of the maximum time delay of scattered photons on their energies, if determined ...

  10. Investigating Lava Properties using Experiments, Video Analysis, Infrared Thermometry and Numerical Flow Models

    Science.gov (United States)

    Lev, E.; Spiegelman, M.; Karson, J.; Wysocki, R.

    2012-12-01

    The thermal and mechanical properties of lava provide primary controls on lava flow behavior and are critical parameters in flow simulations. However, these properties are difficult to measure at field conditions or correctly extrapolate from the scale of small-size samples. We address this challenge by conducting controlled experiments using lab-made, meter scale basaltic lava flows and carefully monitoring their cooling and deformation using high spatial and temporal resolution video and infrared cameras. Our experimental setup is part of the Syracuse University Lava Project (\\url{http://lavaproject.syr.edu}) and includes a large furnace capable of melting up to 450 kg of basalt at temperatures well above the basalt liquidus. The lava is poured onto tilted planes or channels made of sand, steel, clay or gravel, to produce meters-long flows. This experimental setup is probably the only facility that allows such large scale controlled lava flows made of natural basaltic material. We record the motion of the lava using a high-resolution video camera placed directly above the flows, and the temperature using forward-looking infrared (FLIR) cameras and thermocouples. After the experiments, we analyze the images for lava deformation and cooling behavior. We compare the observations with numerical forward-models to constrain the thermal and rheological parameters and laws which best describe the lava. For the video analysis, we employ the technique of differential optical flow, which uses the time-variations of the spatial gradients of the image intensity to estimate velocity between consecutive frames. An important benefit for using optical flow, compared with other velocimetry methods, is that it outputs a spatially coherent flow field rather than point measurements. We demonstrate that the optical flow results agree with other measures of the flow velocity, and estimate the error due to noise and time-variability to be under 30 percent of the measured velocity. Our

  11. Far infrared tangential interferometry/polarimetry on the National Spherical Tokamak Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.K. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Domier, C.W.; Geck, W.R.; Luhmann, N.C. Jr. [Department of Applied Science, University of California at Davis, California 95616 (United States)

    1999-01-01

    Measurement of the core B{sub T}(r,t) value is essential in the National Spherical Tokamak Experiment (NSTX), since the effects of paramagnetism and diamagnetism in the NSTX are expected to be considerably greater than that in higher aspect ratio tokamaks. Therefore, without independent B{sub T}(r,t) measurement, plasma parameters dependent upon B{sub T} such as the {ital q} profile and local {beta} value cannot be evaluated. Tangential interferometer/polarimeter systems (eight channels) [H. Park, L. Guttadora, C. Domier, W. R. Geck, and N. C. Luhman, Jr., First and Second NSTX Research Forums, Princeton, NJ, 1997 (unpublished)] for the NSTX will provide temporally and radially resolved toroidal field profile [B{sub T}(r,t)] and two-dimensional electron density profile [n{sub e}(r,t)] data. The outcome of the proposed system is extremely important to the study of confinement, heating, and stability of the NSTX plasmas. The research task is largely based on utilizing existing hardware from the TFTR multichannel infrared interferometer system [D. K. Mansfield, H. K. Park, L. C. Johnson, H. Anderson, S. Foote, B. Clifton, and C. H. Ma, Appl. Opt. {bold 26}, 4469 (1987) and H. K. Park, D. K. Mansfield, and C. L. Johnson, Proceedings of the 3rd International Symposium on Laser-Aided Plasma Diagnostic, Los Angeles, CA, 28{endash}30 Oct. 1987 (unpublished), pp. 96{endash}104] which will be reconfigured into a tangential system for NSTX, and to develop the additional hardware required to complete the system. {copyright} {ital 1999 American Institute of Physics.}

  12. Simulation studies of muon-produced background events deep underground and consequences for double beta decay experiments

    Science.gov (United States)

    Massarczyk, Ralph; Majorana Collaboration

    2015-10-01

    Cosmic radiation creates a significant background for low count rate experiments. The Majorana demonstrator experiment is located at the Sanford Underground Research Facility at a depth of 4850ft below the surface but it can still be penetrated by cosmic muons with initial energies above the TeV range. The interaction of muons with the rock, the shielding material in the lab and the detector itself can produce showers of secondary particles, like fast neutrons, which are able to travel through shielding material and can produce high-energy γ-rays via capture or inelastic scattering. The energy deposition of these γ rays in the detector can overlap with energy region of interest for the neutrino-less double beta decay. Recent studies for cosmic muons penetrating the Majorana demonstrator are made with the Geant4 code. The results of these simulations will be presented in this talk and an overview of the interaction of the shower particles with the detector, shielding and veto system will be given. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility. Supported by U.S. Department of Energy through the LANL/LDRD Program.

  13. Study of the Kroll-process to produce ultra-pure Ti for the low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mozhevitina, Elena [D. Mendeleyev University of Chemical Technology of Russia, Moscow 125047 (Russian Federation); Chepurnov, Alexander [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow 119234 (Russian Federation); Chub, Alexander [Solikamsk Magnesium Plant, Solikamsk,618541 (Russian Federation); Avetissov, Igor [ARMOLED Ltd, Moscow 125047 (Russian Federation); Glebovsky, Vadim [Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, 142432 (Russian Federation); Nisi, Stefano; Di Vacri, Maria Laura [INFN Laboratori Nazionali del Gran Sasso, SS 17 bis km 18+910, 6010 Assergi (Italy); Suvorov, Yury [Physics and Astronomy Department, University of California, Los Angeles, Los Angeles, CA 90095, U.S.A (United States); National Research Center Kurchatov Institute, Moscow 123182 (Russian Federation)

    2015-08-17

    To construct G2 & G3 low background experiments for direct Dark Matter search, a lot of ultra-pure construction materials will be needed. Our study of various Ti samples shows that the levels of contaminations of commercially available industrial Ti can varies from 0.2 to 100 mBq/kg for U/Th. It means that the metal Ti is such a promising material for future experiments if the way of production in bulk quantities with very low level of contaminations (below ∼1 mBq/kg of {sup 238}U /{sup 232}Th) would be developed. Our study of the industrial Kroll-process is focused on the possible sources of U and Th and their migration during the multistage Kroll process. To understand migration of U and Th during the Kroll process the set of other impurities available due to precise ICP-MS analysis have been studied. Preliminary results confirm that the Kroll process could be used for the ultra pure Ti sponge production while the following stages of the metal Ti production of from the Ti sponge with necessary mechanical properties need to be additionally studied.

  14. The QME AERI LBLRTM: A Closure Experiment for Downwelling High Spectral Resolution Infrared Radiance.

    Science.gov (United States)

    Turner, D. D.; Tobin, D. C.; Clough, S. A.; Brown, P. D.; Ellingson, R. G.; Mlawer, E. J.; Knuteson, R. O.; Revercomb, H. E.; Shippert, T. R.; Smith, W. L.; Shephard, M. W.

    2004-11-01

    Research funded by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has led to significant improvements in longwave radiative transfer modeling over the last decade. These improvements, which have generally come in small incremental changes, were made primarily in the water vapor self- and foreign-broadened continuum and the water vapor absorption line parameters. These changes, when taken as a whole, result in up to a 6 W m-2 improvement in the modeled clear-sky downwelling longwave radiative flux at the surface and significantly better agreement with spectral observations. This paper provides an overview of the history of ARM with regard to clear-sky longwave radiative transfer, and analyzes remaining related uncertainties in the ARM state-of-the-art Line-by-Line Radiative Transfer Model (LBLRTM).A quality measurement experiment (QME) for the downwelling infrared radiance at the ARM Southern Great Plains site has been ongoing since 1994. This experiment has three objectives: 1) to validate and improve the absorption models and spectral line parameters used in line-by-line radiative transfer models, 2) to assess the ability to define the atmospheric state, and 3) to assess the quality of the radiance observations that serve as ground truth for the model. Analysis of data from 1994 to 1997 made significant contributions to optimizing the QME, but is limited by small but significant uncertainties and deficiencies in the atmospheric state and radiance observations. This paper concentrates on the analysis of QME data from 1998 to 2001, wherein the data have been carefully selected to address the uncertainties in the 1994 97 dataset. Analysis of this newer dataset suggests that the representation of self-broadened water vapor continuum absorption is 3% 8% too strong in the 750 1000 cm-1 region. The dataset also provides information on the accuracy of the self- and foreign-broadened continuum absorption in the 1100 1300 cm-1 region. After

  15. The QME AERI LBLRTM: A Closure Experiment for Downwelling High Spectral Resolution Infrared Radiance

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D.; Tobin, D. C.; Clough, Shepard A.; Brown, Patrick D.; Ellingson, Robert G.; Mlawer, Eli J.; Knuteson, Robert O.; Revercomb, Henry E.; Shippert, Timothy R.; Smith, William L.; Shephard, M. W.

    2004-11-01

    Research funded by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has led to significant improvements in longwave radiative transfer modeling over the last decade. These improvements, which have generally come in small incremental changes, were made primarily in the water vapor self- and foreign-broadened continuum and the water vapor absorption line parameters. These changes, when taken as a whole, result in up to a 6 W m2 improvement in the modeled clear-sky downwelling longwave radiative flux at the surface and significantly better agreement with spectral observations. This paper provides an overview of the history of ARM with regard to clear-sky longwave radiative transfer, and analyzes remaining related uncertainties in the ARM state-of-the-art Line-by-Line Radiative Transfer Model (LBLRTM). A Quality Measurement Experiment (QME) for the downwelling infrared radiance at the ARM Southern Great Plains site has been ongoing since 1994. This experiment has three objectives: (1) to validate and improve the absorption models and spectral line parameters used in line-by-line radiative transfer models, (2) to assess the ability to define the atmospheric state, and (3) to assess the quality of the radiance observations that serve as ground-truth for the model. Analysis of data from 1994-1997 made significant contributions to optimizing the QME, but is limited by small but significant uncertainties and deficiencies in the atmospheric state and radiance observations. This paper concentrates on the analysis of QME data from 1998-2001, wherein the data have been carefully selected to address the uncertainties in the 1994-1997 data set. Analysis of this newer data set suggests that the representation of self-broadened water vapor continuum absorption is 3-8% too strong in the 750-1000 cm-1 region. The dataset also provides information on the accuracy of the self and foreign-broadened continuum absorption in the 1100-1300 cm-1 region

  16. Scientific results from the cosmic background explorer (COBE). [Information on cosmic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.L.; Boggess, N.W.; Cheng, E.S.; Hauser, M.G.; Kelsall, T.; Mather, J.C.; Moseley, S.H. Jr.; Shafer, R.A.; Silverberg, R.F. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States)); Murdock, T.L. (General Research Corp., Danvers, MA (United States)); Smoot, G.F. (Lawrence Berkeley Lab., CA (United States)); Weiss, R. (Massachusetts Inst. of Technology, Cambridge (United States)); Wright, E.L. (Univ. of California, Los Angeles (United States))

    1993-06-01

    The National Aeronautics and Space Administration (NASA) has flown the COBE satellite to observe the Big Bang and the subsequent formation of galaxies and large-scale structure. Data from the Far-Infrared Absolute Spectrophotometer (FIRAS) show that the spectrum of the cosmic microwave background is that of a black body of temperature T = 2.73 [+-] 0.06 K, with no deviation from a black-body spectrum greater than 0.25% of the peak brightness. The data from the Differential Microwave Radiometers (DMR) show statistically significant cosmic microwave background anisotropy, consistent with a scale-invariant primordial density fluctuation spectrum. Measurements from the Diffuse Infrared Background Experiment (DIRBE) provide new conservation upper limits to the cosmic infrared background. Extensive modeling of solar system and galactic infrared foregrounds is required for further improvement in the cosmic infrared background limits. 104 refs., 1 tab.

  17. A near-infrared SETI experiment: A multi-time resolution data analysis

    Science.gov (United States)

    Tallis, Melisa; Maire, Jerome; Wright, Shelley; Drake, Frank D.; Duenas, Andres; Marcy, Geoffrey W.; Stone, Remington P. S.; Treffers, Richard R.; Werthimer, Dan; NIROSETI

    2016-06-01

    We present new post-processing routines which are used to detect very fast optical and near-infrared pulsed signals using the latest NIROSETI (Near-Infrared Optical Search for Extraterrestrial Intelligence) instrument. NIROSETI was commissioned in 2015 at Lick Observatory and searches for near-infrared (0.95 to 1.65μ) nanosecond pulsed laser signals transmitted by distant civilizations. Traditional optical SETI searches rely on analysis of coincidences that occur between multiple detectors at a fixed time resolution. We present a multi-time resolution data analysis that extends our search from the 1ns to 1ms range. This new feature greatly improves the versatility of the instrument and its search parameters for near-infrared SETI. We aim to use these algorithms to assist us in our search for signals that have varying duty cycles and pulse widths. We tested the fidelity and robustness of our algorithms using both synthetic embedded pulsed signals, as well as data from a near-infrared pulsed laser installed on the instrument. Applications of NIROSETI are widespread in time domain astrophysics, especially for high time resolution transients, and astronomical objects that emit short-duration high-energy pulses such as pulsars.

  18. Effect of metal stress on the thermal infrared emission of soybeans: A greenhouse experiment - Possible utility in remote sensing

    Science.gov (United States)

    Suresh, R.; Schwaller, M. R.; Foy, C. D.; Weidner, J. R.; Schnetzler, C. S.

    1989-01-01

    Manganese-sensitive forest and manganese-tolerant lee soybean cultivars were subjected to differential manganese stress in loring soil in a greenhouse experiment. Leaf temperature measurements were made using thermistors for forest and lee. Manganese-stressed plants had higher leaf temperatures than control plants in both forest and lee. Results of this experiment have potential applications in metal stress detection using remote sensing thermal infrared data over large areas of vegetation. This technique can be useful in reconnaissance mineral exploration in densely-vegetated regions where conventional ground-based methods are of little help.

  19. Background, training experiences, and career plans of U.S. periodontal residents: report of a web-based survey.

    Science.gov (United States)

    Mawardi, Hani; Fateh, Ardavan; Elbadawi, Lena; Karimbux, Nadeem Y

    2015-01-01

    The purpose of this cross-sectional study was to survey the backgrounds and perspectives of U.S. periodontal residents in 2012. A 64-item web-based survey was distributed to all periodontal residents in the United States (544 residents enrolled in 54 graduate programs) via email in March 2012. Data on the residents' demographics, experiences during graduate periodontal training, and goals were collected and analyzed, and percentages were calculated. The survey had a 19.1% response rate. Most of the respondents (74%) had graduated from international dental schools, and 81.7% were in combined programs (clinical training combined with a Master's degree, PhD, or other doctoral degree). Almost one-fourth of the responding residents (24%) reported a total debt of more than $300,000 after graduation. More than 60% of the respondents planned to practice in a private setting as an associate, partner, or solo practice owner. The responding residents reported having chosen their graduate programs based mainly on the programs' clinical education and reputation (72% and 48%, respectively). Future studies will determine educational trends and outcomes for periodontal residents in the longer term.

  20. Cosmic microwave background theory.

    Science.gov (United States)

    Bond, J R

    1998-01-06

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  1. Intraoperative near infrared fluorescence guided identification of the ureters using low dose methylene blue: a first in human experience.

    Science.gov (United States)

    Verbeek, Floris P R; van der Vorst, Joost R; Schaafsma, Boudewijn E; Swijnenburg, Rutger-Jan; Gaarenstroom, Katja N; Elzevier, Henk W; van de Velde, Cornelis J H; Frangioni, John V; Vahrmeijer, Alexander L

    2013-08-01

    Near infrared fluorescence imaging is a promising technique that offers real-time visual information during surgery. In this study we report the first clinical results to our knowledge of ureteral imaging using near infrared fluorescence after a simple peripheral infusion of methylene blue. Furthermore, we assessed the optimal timing and dose of methylene blue. A total of 12 patients who underwent lower abdominal surgery were included in this prospective feasibility study. Near infrared fluorescence imaging was performed using the Mini-FLARE™ imaging system. To determine optimal timing and dose, methylene blue was injected intravenously at doses of 0.25, 0.5 or 1 mg/kg after exposure of the ureters. Imaging was performed for up to 60 minutes after injection. In all patients both ureters could be clearly visualized within 10 minutes after infusion of methylene blue. The signal lasted at least up to 60 minutes after injection. The mean signal-to-background ratio of the ureter was 2.27 ± 1.22 (4), 2.61 ± 1.88 (4) and 3.58 ± 3.36 (4) for the 0.25, 0.5 and 1 mg/kg groups, respectively. A mixed model analysis was used to compare signal-to-background ratios among dose groups and times, and to assess the relationship between dose and time. A significant difference among time points (p methylene blue for the identification of the ureters during lower abdominal surgery. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  2. Own and parental war experience as a risk factor for mental health problems among adolescents with an immigrant background: results from a cross sectional study in Oslo, Norway

    OpenAIRE

    Hauff Edvard; Haavet Ole; Oppedal Brit; Lien Lars; Thoresen Magne; Bjertness Espen

    2006-01-01

    Background An increasing proportion of immigrants to Western countries in the past decade are from war affected countries. The aim of this study was to estimate the prevalence of war experience among adolescents and their parents and to investigate possible differences in internalizing and externalizing mental health problems between adolescents exposed and unexposed to own and parental war experience. Method ...

  3. A near-infrared SETI experiment: probability distribution of false coincidences

    CERN Document Server

    Maire, Jérôme; Werthimer, Dan; Treffers, Richard R; Marcy, Geoffrey W; Stone, Remington P S; Drake, Frank; Siemion, Andrew

    2014-01-01

    A Search for Extraterrestrial Life (SETI), based on the possibility of interstellar communication via laser signals, is being designed to extend the search into the near-infrared spectral region (Wright et al, this conference). The dedicated near-infrared (900 to 1700 nm) instrument takes advantage of a new generation of avalanche photodiodes (APD), based on internal discrete amplification. These discrete APD (DAPD) detectors have a high speed response ($>$ 1 GHz) and gain comparable to photomultiplier tubes, while also achieving significantly lower noise than previous APDs. We are investigating the use of DAPD detectors in this new astronomical instrument for a SETI search and transient source observations. We investigated experimentally the advantages of using a multiple detector device operating in parallel to remove spurious signals. We present the detector characterization and performance of the instrument in terms of false positive detection rates both theoretically and empirically through lab measureme...

  4. HerMES: deep number counts at 250, 350, and 500 microns in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background

    CERN Document Server

    Béthermin, M; Ilbert, O; Conley, A; Lagache, G; Amblard, A; Arumugam, V; Aussel, H; Berta, S; Bock, J; Boselli, A; Buat, V; Casey, C M; Castro-Rodríguez, N; Cava, A; Clements, D L; Cooray, A; Dowell, C D; Eales, S; Farrah, D; Franceschini, A; Glenn, J; Griffin, M; Hatziminaoglou, E; Heinis, S; Ibar, E; Ivison, R J; Kartaltepe, J S; Levenson, L; Magdis, G; Marchetti, L; Marsden, G; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Rigopoulou, D; Roseboom, I G; Rowan-Robinson, M; Salvato, M; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Smith, A J; Symeonidis, M; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Vieira, J D; Viero, M; Wang, L; Xu, C K; Zemcov, M

    2012-01-01

    ABRIGED Herschel/SPIRE has provided confusion limited maps of deep fields at 250, 350, and 500um, as part of the HerMES survey. Due to confusion, only a small fraction of the Cosmic Infrared Background can be resolved into individually-detected sources. Our goal is to produce deep galaxy number counts and redshift distributions below the confusion limit, which we then use to place strong constraints on the origins of the cosmic infrared background and on models of galaxy evolution. We individually extracted the bright SPIRE with a method using the positions, the flux densities, and the redshifts of the 24um sources as a prior, and derived the number counts and redshift distributions of the bright SPIRE sources. For fainter SPIRE sources, we reconstructed the number counts and the redshift distribution below the confusion limit using the deep 24um catalogs associated with photometric redshift and information provided by the stacking of these sources into the deep SPIRE maps. Finally, by integrating all these c...

  5. Experiences of health care providers managing sexual assault victims in the emergency unit Part 1: Background and methodology

    Directory of Open Access Journals (Sweden)

    Rebecca M. Skhosana

    2009-04-01

    ongevalle-eenheid van 'n gemeenskapshospitaal in die Nkangala-distrik in die provinsie van Mpumalanga hanteer, te verken en te beskryf. ’n Kwalitatiewe fenomenologiese ontwerp  is  toegepas. Doelbewuste  steekproefneming is gebruik  om  deelnemers te  selekteer uit die groep gesondheidsorgverskaffers wat in die ongevalle-eenheid werksaam was en meer as vier slagoffers  van seksuele aanranding hanteer het. Data is by wyse van  individuele onderhoude ingesamel en volgens die Tesch-metode van data-analise deur die navorser en die  onafhanklike medekodeerder geanaliseer.

    Hoofkategorieë, subkategorieë en temas is geïdentifiseer. Deelnemers het uitdrukking gegee aan hulle emosies, uitdagings, die houding en gedrag van polisiebeamptes, teenstrydighede in riglyne en behoefte-identifikasie. Aanbevelings  is dat multidissiplin��re spanlede betrokke moet wees by gemeenskapsaktiwiteite en dat die gemeenskap moet deelneem aan sake wat verband hou met seksuele aanranding. Die regering moet duidelike riglyne ontwikkel wat op landelike en stedelike Suid-Afrika van toepassing is. Gesondheidsorgwetenskappe moet  daarop gerig wees om meer forensiese verpleeg-kundiges op te  lei. Alle toepaslike departemente moet saamwerk om die komplikasies te verlig wat deur voorvalle van seksuele aanranding veroorsaak word.

    How to cite this article:

    Skhosana, R.M. & Peu, D.M., 2009, 'Experiences of health care providers managing sexual assault victims in an emergency unit. Part 1: Background and methodology', Health SA Gesondheid 14(1, Art. #480, 7 pages. DOI: 10.4102/hsag.v14i1.480

     

  6. Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

    Science.gov (United States)

    Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo; Wada, Takehiko; Takita, Jun; Sakatani, Naoya; Horikawa, Yamato; Endo, Ken; Helbert, Jörn; Müller, Thomas G.; Hagermann, Axel

    2016-09-01

    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16 × 12° and a spatial resolution of 0.05° per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.

  7. Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

    Science.gov (United States)

    Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo; Wada, Takehiko; Takita, Jun; Sakatani, Naoya; Horikawa, Yamato; Endo, Ken; Helbert, Jörn; Müller, Thomas G.; Hagermann, Axel

    2017-07-01

    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16 × 12° and a spatial resolution of 0.05° per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.

  8. Acupuncture or low frequency infrared treatment for low back pain in Chinese patients: a discrete choice experiment.

    Directory of Open Access Journals (Sweden)

    Li-Chia Chen

    Full Text Available Acupuncture is a popular but controversial treatment option for low back pain. In China, it is practised as traditional Chinese medicine; other treatment strategies for low back pain are commonly practised as Western medicine. Research on patient preference for low back-pain treatment options has been mainly conducted in Western countries and is limited to a willingness-to-pay approach. A stated-preference, discrete choice experiment was conducted to determine Chinese patient preferences and trade-offs for acupuncture and low frequency infrared treatment in low back pain from September 2011 to August 2012 after approval from the Department of Scientific Research in the study settings. Eight-six adult outpatients who visited the 'traditional medicine department' at a traditional Chinese medicine hospital and the 'rehabilitation department' at a Western medicine hospital in Guangdong Province of China for chronic low back pain during study period participated in an interview survey. A questionnaire containing 10 scenarios (5 attributes in each scenario was used to ask participants' preference for acupuncture, low frequency infrared treatment or neither option. Validated responses were analysed using a nested-logit model. The decision on whether to receive a therapy was not associated with the expected utility of receiving therapy, female gender and higher out-of-pocket payment significantly decreased chance to receive treatments. Of the utility of receiving either acupuncture or low frequency infrared treatment, the treatment sensation was the most important attribute as an indicator of treatment efficacy, followed by the maximum efficacy, maintenance duration and onset of efficacy, and the out-of-pocket payment. The willingness-to-pay for acupuncture and low frequency infrared treatment were about $618.6 and $592.4 USD per course respectively, demonstrated patients' demand of pain management. The treatment sensation was regarded as an indicator

  9. Acupuncture or low frequency infrared treatment for low back pain in Chinese patients: a discrete choice experiment.

    Science.gov (United States)

    Chen, Li-Chia; Cheng, Li-Jen; Zhang, Yan; He, Xin; Knaggs, Roger D

    2015-01-01

    Acupuncture is a popular but controversial treatment option for low back pain. In China, it is practised as traditional Chinese medicine; other treatment strategies for low back pain are commonly practised as Western medicine. Research on patient preference for low back-pain treatment options has been mainly conducted in Western countries and is limited to a willingness-to-pay approach. A stated-preference, discrete choice experiment was conducted to determine Chinese patient preferences and trade-offs for acupuncture and low frequency infrared treatment in low back pain from September 2011 to August 2012 after approval from the Department of Scientific Research in the study settings. Eight-six adult outpatients who visited the 'traditional medicine department' at a traditional Chinese medicine hospital and the 'rehabilitation department' at a Western medicine hospital in Guangdong Province of China for chronic low back pain during study period participated in an interview survey. A questionnaire containing 10 scenarios (5 attributes in each scenario) was used to ask participants' preference for acupuncture, low frequency infrared treatment or neither option. Validated responses were analysed using a nested-logit model. The decision on whether to receive a therapy was not associated with the expected utility of receiving therapy, female gender and higher out-of-pocket payment significantly decreased chance to receive treatments. Of the utility of receiving either acupuncture or low frequency infrared treatment, the treatment sensation was the most important attribute as an indicator of treatment efficacy, followed by the maximum efficacy, maintenance duration and onset of efficacy, and the out-of-pocket payment. The willingness-to-pay for acupuncture and low frequency infrared treatment were about $618.6 and $592.4 USD per course respectively, demonstrated patients' demand of pain management. The treatment sensation was regarded as an indicator of treatment

  10. Development of a multivariate tool to reject background in a WZ diboson search for the CDF experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cremonesi, Matteo [Univ. of of Rome Tor Vergata (Italy)

    2015-08-27

    In the frame of the strong on-going data analysis effort of the CDF collaboration at Fermilab, a method was developed by the candidate to improve the background rejection efficiency in the search for associated pair production of electroweak W, Z bosons. The performaces of the method for vetoing the tt background in a WZ/ZZ → fνq$\\bar{q}$ diboson search are reported. The method was developed in the inclusive 2-jets sample and applied to the “tag-2 jets" region, the subsample defined by the request that the two jets carry beauty flavor. In this region the tt production is one of the largest backgrounds. The tt veto proceeds in two steps: first, a set of pre-selection cuts are applied in a candidate sample where up to two leptons are accepted in addition to a jet pair, and the ZZ component of the signal is thus preserved; next, a Neural Network is trained to indicate the probability that the event be top-pair production. To validate the the method as developed in the inclusive 2-jets sample, it is applied to veto region providing a significant rejection of this important background.

  11. A Case Study of the Experiences of Instructors and Students in a Virtual Learning Environment (VLE) with Different Cultural Backgrounds

    Science.gov (United States)

    Lim, Keol; Kim, Mi Hwa

    2015-01-01

    The use of virtual learning environments (VLEs) has become more common and educators recognized the potential of VLEs as educational environments. The learning community in VLEs can be a mixture of people from all over the world with different cultural backgrounds. However, despite many studies about the use of virtual environments for learning,…

  12. Exploring the Cross-Cultural Experiences of College Students with Diverse Backgrounds Performing International Service-Learning in Myanmar

    Science.gov (United States)

    Liu, Ruo-lan; Lee, Hsin-hua

    2011-01-01

    Background: In view of the growing globalization, volunteer service organizations, local universities, colleges, and student groups have begun extending their service programs from Taiwan to other countries. This study employs a self-organized, self-funded group of university students participating in international service-learning as its subject,…

  13. Infrared experiment on the wall temperature distribution for a particle packed channel with constant heat flux

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With constant heat flux, wall temperature distribution for a particle filled channel was measured using infrared thermal vision technology. It was found that nonuniform relative high-temperature regions were randomly distributed on the heating wall, possibly due to the lower flow velocity, or even due to the blocked flow near the points where particles contact with the heating wall directly. Not only porosity but also the size and shape of the pores are changed in the wall region of particle-packed structures,because of the limitation of the wall, and the changes affect largely the fluid flow and heat transfer. The transition of the flow pattern in pores can be inferred according to the variation of Nu with Re, where the area weighted wall temperature is adopted to calculate the Nu.``

  14. Studies of the Machine Induced Background, simulations for the design of the Beam Condition Monitor and implementation of the Inclusive $\\phi$ Trigger at the LHCb experiment at CERN

    CERN Document Server

    Lieng, Magnus

    2011-01-01

    LHCb is one of the four major experiments of the LHC at CERN, built to perform precision measurements of CP violation and rare decays. In order to protect the sensitive elements of the experiment from adverse beam conditions the Beam Condition Monitor has been created. Such conditions increase the particle flux arriving from the LHC, known as Machine Induced Background. These particles interfere with the experiment, for example through the physics trigger. In this thesis software development and simulations for the design and validation of the Beam Condition Monitor is shown, ranging from LHCb-specific algorithm implementation to beam dump threshold determination. Furthermore, software development in order to attain a complete simulation chain of machine induced background is shown. The results of these simulations are compared to early data collected at LHCb. Lastly, the development and implementation of the Inclusive $\\phi$ trigger line for the High Level Trigger is presented. This line aims to reconstruct ...

  15. Characterization of silicon microstrip sensors with a pulsed infrared laser system for the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Pradeep [Goethe Univ., Frankfurt (Germany); GSI (Germany); Eschke, Juergen [GSI (Germany); FAIR (Germany); Collaboration: CBM-Collaboration

    2014-07-01

    The Silicon Tracking System (STS) for the Compressed Baryonic Matter (CBM) experiment at FAIR will comprise more than 1200 double-sided silicon microstrip sensors. For the quality assurance of the prototype sensors a laser test system has been built up. The aim of the sensor scans with the pulsed infrared laser system is to determine the charge sharing between strips and to measure the uniformity of the sensor response over the whole active area. The laser system measures the sensor response in an automatized procedure at several thousand positions across the sensor with focused infrared laser light (σ∼15 μm, λ=1060 nm). The duration (5 ns) and power (few mW) of the laser pulses are selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24k electrons, which is similar to the charge created by minimum ionizing particles in these sensors. Results from the characterization of monolithic active pixel sensors, to understand the spot-size of the laser, and laser scans for different sensors are presented.

  16. Infrared Spectra of Simple Inorganic Ion Pairs in Solid Solution: A Physical Inorganic Chemistry Experiment.

    Science.gov (United States)

    Miller, Philip J.; Tong, William G.

    1980-01-01

    Presents a physical inorganic experiment in which large single crystals of the alkali halides doped with divalent ion impurities are prepared easily. Demonstrates the ion pairing of inorganic ions in solid solution. (CS)

  17. Background Simulation of a Fission Fragment Chamber in the Experiment of 209^Bi(e, e'K^+)209^hPb

    Institute of Scientific and Technical Information of China (English)

    宋玉收; 刘辉兰; 席印印; 颜强; 胡碧涛

    2012-01-01

    An experiment for measuring the hyperon-related fission rate was carried out with the reaction 209^Bi(e, e'K^+)209^hPb at the Thomas Jefferson National Laboratory (Jlab). In the experiment, the performance of the fission fragment detector (FFD) was dramaticlly crashed by the background particles in comparison with that during the test without beam. The scattering of the high intensity (500 nA) primary electrons was the dominant cause. Using the GEANT4 toolkit, this report simulates the experimental situation of the target chamber in which the FFD was located. The simulation results indicate that the background particles were dominantly (~ electrons, and protons and alpha particles were the important heavy background particles. The performance of the multi-wire proportional chambers (MWPCs) depends not only on the background-particle intensity but also the current density, which was also given by the simulation code. Furthermore, the measures to suppress the background particles were also investigated with the simulation code.

  18. GeSn/SiGeSn photonic devices for mid-infrared applications: experiments and calculations

    Science.gov (United States)

    Han, Genquan; Zhang, Qingfang; Liu, Yan; Zhang, Chunfu; Hao, Yue

    2016-11-01

    In this work, a fully strained GeSn photodetector with Sn atom percent of 8% is fabricated on Ge buffer on Si(001) substrate. The wavelength λ of light signals with obvious optical response for Ge0.92Sn0.08 photodetector is extended to 2 μm. The impacts of compressive strain introduced during the epitaxial growth of GeSn on Ge/Si are studied by simulation. Besides, the tensile strain engineering of GeSn photonic devices is also investigated. Lattice-matched GeSn/SiGeSn double heterostructure light emitting diodes (LEDs) with Si3N4 tensile liner stressor are designed to promote the further mid-infrared applications of GeSn photonic devices. With the releasing of the residual stress in Si3N4 liner, a large biaxial tensile strain is induced in GeSn active layer. Under biaxial tensile strain, the spontaneous emission rate rsp and internal quantum efficiency ηIQE for GeSn/SiGeSn LED are significantly improved.

  19. Infrared spectra of dimethylquinolines in the gas phase: experiment and theory.

    Science.gov (United States)

    Das, Prasanta; Manogaran, S; Arunan, E; Das, Puspendu K

    2010-08-19

    Infrared spectra of atmospherically important dimethylquinolines (DMQs), namely 2,4-DMQ, 2,6-DMQ, 2,7-DMQ, and 2,8-DMQ in the gas phase at 80 degrees C were recorded using a long variable path-length cell. DFT calculations were carried out to assign the bands in the experimentally observed spectra at the B3LYP/6-31G* level of theory. The spectral assignments particularly for the C-H stretching modes could not be made unambiguously using calculated anharmonic or scaled harmonic frequencies. To resolve this problem, a scaled force field method of assignment was used. Assignment of fundamental modes was confirmed by potential energy distributions (PEDs) of the normal modes derived by the scaled force fields using a modified version of the UMAT program in the QCPE package. We demonstrate that for large molecules such as the DMQs, the scaling of the force field is more effective in arriving at the correct assignment of the fundamentals for a quantitative vibrational analysis. An error analysis of the mean deviation of the calculated harmonic, anharmonic, and force field fitted frequencies from the observed frequency provides strong evidence for the correctness of the assignment.

  20. Infrared Dim Target Detection in Single Image Based on Background Suppression by Fuzzy-ART%Fuzzy-ART背景抑制的单帧红外弱小目标检测

    Institute of Scientific and Technical Information of China (English)

    陈炳文; 王文伟; 秦前清

    2012-01-01

    针对现有背景抑制算法未能有效地抑制背景而导致目标检测率低的问题,提出一种基于模糊自适应共振理论(Fuzzy-ART)进行背景抑制、基于行列k均值(k-means)聚类实现阈值分割的单帧红外弱小目标检测算法.首先依据红外成像原理仿真生成红外弱小目标训练样本;然后采用Fuzzy-ART神经网络建立目标模型,并以此分析各像素点的目标模糊隶属度来抑制背景杂波;最后采用基于行列k-means聚类的自适应阈值分割算法来检测真实目标.实验结果表明,该算法能有效地抑制背景杂波和突显目标,并能有效地提高信噪比检测弱小目标.%In order to solve the problem that the current approaches cannot suppress the background clutters effectively and may result in a poor detection performance, a novel infrared dim target detection approach is presented, which is based on background suppression by fuzzy adaptive resonance theory (Fuzzy-ART) and threshold segmentation by k-means cluster of rows and columns. Firstly, infrared dim target training set is simulated according to the principle of thermal imagery. Then a Fuzzy-ART neural network is utilized to build the target models. With these models, the background clutters are suppressed according to the degree of fuzzy match between pixels and models. Lastly, the adaptive segmentation algorithm based on k-means cluster of rows and columns is utilized to detect the true targets. Experimental results show that the proposed approach is able to suppress background clutters and enhance objects effectively. It is capable of improving the signal-to-noise ratio of images and detecting targets effectively.

  1. The Zugspitze radiative closure experiment for quantifying water vapor absorption over the terrestrial and solar infrared - Part 1: Setup, uncertainty analysis, and assessment of far-infrared water vapor continuum

    Science.gov (United States)

    Sussmann, Ralf; Reichert, Andreas; Rettinger, Markus

    2016-09-01

    Quantitative knowledge of water vapor radiative processes in the atmosphere throughout the terrestrial and solar infrared spectrum is still incomplete even though this is crucial input to the radiation codes forming the core of both remote sensing methods and climate simulations. Beside laboratory spectroscopy, ground-based remote sensing field studies in the context of so-called radiative closure experiments are a powerful approach because this is the only way to quantify water absorption under cold atmospheric conditions. For this purpose, we have set up at the Zugspitze (47.42° N, 10.98° E; 2964 m a.s.l.) a long-term radiative closure experiment designed to cover the infrared spectrum between 400 and 7800 cm-1 (1.28-25 µm). As a benefit for such experiments, the atmospheric states at the Zugspitze frequently comprise very low integrated water vapor (IWV; minimum = 0.1 mm, median = 2.3 mm) and very low aerosol optical depth (AOD = 0.0024-0.0032 at 7800 cm-1 at air mass 1). All instruments for radiance measurements and atmospheric-state measurements are described along with their measurement uncertainties. Based on all parameter uncertainties and the corresponding radiance Jacobians, a systematic residual radiance uncertainty budget has been set up to characterize the sensitivity of the radiative closure over the whole infrared spectral range. The dominant uncertainty contribution in the spectral windows used for far-infrared (FIR) continuum quantification is from IWV uncertainties, while T profile uncertainties dominate in the mid-infrared (MIR). Uncertainty contributions to near-infrared (NIR) radiance residuals are dominated by water vapor line parameters in the vicinity of the strong water vapor bands. The window regions in between these bands are dominated by solar Fourier transform infrared (FTIR) calibration uncertainties at low NIR wavenumbers, while uncertainties due to AOD become an increasing and dominant contribution towards higher NIR wavenumbers

  2. Monitoring of microvascular free flaps following oropharyngeal reconstruction using infrared thermography: first clinical experiences.

    Science.gov (United States)

    Just, Maren; Chalopin, Claire; Unger, Michael; Halama, Dirk; Neumuth, Thomas; Dietz, Andreas; Fischer, Miloš

    2016-09-01

    The aim of this study is to investigate static and dynamic infrared (IR) thermography for intra- and postoperative free-flap monitoring following oropharyngeal reconstruction. Sixteen patients with oropharyngeal reconstruction by free radial forearm flap were included in this prospective, clinical study (05/2013-08/2014). Prior ("intraop_pre") and following ("intraop_post") completion of the microvascular anastomoses, IR thermography was performed for intraoperative flap monitoring. Further IR images were acquired one day ("postop_1") and 10 days ("postop_10") after surgery for postoperative flap monitoring. Of the 16, 15 transferred free radial forearm flaps did not show any perfusion failure. A significant decreasing mean temperature difference (∆T: temperature difference between the flap surface and the surrounding tissue in Kelvin) was measured at all investigation points in comparison with the temperature difference at "intraop_pre" (mean values on all patients: ∆T intraop_pre = -2.64 K; ∆T intraop_post = -1.22 K, p < 0.0015; ∆T postop_1 = -0.54 K, p < 0.0001; ∆T postop_10 = -0.58 K, p < 0.0001). Intraoperative dynamic IR thermography showed typical pattern of non-pathological rewarming due to re-established flap perfusion after completion of the microvascular anastomoses. Static and dynamic IR thermography is a promising, objective method for intraoperative and postoperative monitoring of free-flap reconstructions in head and neck surgery and to detect perfusion failure, before macroscopic changes in the tissue surface are obvious. A lack of significant decrease of the temperature difference compared to surrounding tissue following completion of microvascular anastomoses and an atypical rewarming following a thermal challenge are suggestive of flap perfusion failure.

  3. Near-infrared fluorescence sentinel lymph node mapping in breast cancer: a multicenter experience

    Science.gov (United States)

    Verbeek, Floris P.R.; Troyan, Susan L.; Mieog, J. Sven D.; Liefers, Gerrit-Jan; Moffitt, Lorissa A.; Rosenberg, Mireille; Hirshfield-Bartek, Judith; Gioux, Sylvain; van de Velde, Cornelis J.H.; Vahrmeijer, Alexander L.; Frangioni, John V.

    2014-01-01

    NIR fluorescence imaging using indocyanine green (ICG) has the potential to improve the SLN procedure by facilitating percutaneous and intraoperative identification of lymphatic channels and SLNs. Previous studies suggested that a dose of 0.62 mg (1.6 ml of 0.5 mM) ICG is optimal for SLN mapping in breast cancer. The aim of this study was to evaluate the diagnostic accuracy of near-infrared (NIR) fluorescence for sentinel lymph node (SLN) mapping in breast cancer patients when used in conjunction with conventional techniques. Study subjects were 95 breast cancer patients planning to undergo SLN procedure at either the Dana-Farber/Harvard Cancer Center (Boston, MA, USA) or the Leiden University Medical Center (Leiden, the Netherlands) between July 2010 and January 2013. Subjects underwent the standard-of-care SLN procedure at each institution using 99Technetium-colloid in all subjects and patent blue in 27 (28%) of the subjects. NIR fluorescence-guided SLN detection was performed using the Mini-FLARE imaging system. SLN identification was successful in 94 of 95 subjects (99%) using NIR fluorescence imaging or a combination of both NIR fluorescence imaging and radioactive guidance. In 2 of 95 subjects, radioactive guidance was necessary for initial in vivo identification of SLNs. In 1 of 95 subjects, NIR fluorescence was necessary for initial in vivo identification of SLNs. A total of 177 SLNs (mean = 1.9, range = 1–5) were resected: 100% NIR fluorescent, 88% radioactive, and 78% (of 40 nodes) blue. In 2 of 95 subjects (2.1%), SLNs containing macrometastases were found only by NIR fluorescence, and in 1 patient this led to upstaging to N1. This study demonstrates the safe and accurate application of NIR fluorescence imaging for the identification of SLNs in breast cancer patients, but calls into question what technique should be used as the gold standard in future studies. PMID:24337507

  4. Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students

    Science.gov (United States)

    Ault, Andrew P.; Pomeroy, Robert

    2012-01-01

    Biodiesel has gained attention in recent years as a renewable fuel source due to its reduced greenhouse gas and particulate emissions, and it can be produced within the United States. A laboratory experiment designed for students in an upper-division undergraduate laboratory is described to study biodiesel production and biodiesel mixing with…

  5. Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students

    Science.gov (United States)

    Ault, Andrew P.; Pomeroy, Robert

    2012-01-01

    Biodiesel has gained attention in recent years as a renewable fuel source due to its reduced greenhouse gas and particulate emissions, and it can be produced within the United States. A laboratory experiment designed for students in an upper-division undergraduate laboratory is described to study biodiesel production and biodiesel mixing with…

  6. Background sources at PEP

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, ..gamma..-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs.

  7. Near-infrared fluorescence sentinel lymph node mapping in breast cancer: a multicenter experience.

    Science.gov (United States)

    Verbeek, Floris P R; Troyan, Susan L; Mieog, J Sven D; Liefers, Gerrit-Jan; Moffitt, Lorissa A; Rosenberg, Mireille; Hirshfield-Bartek, Judith; Gioux, Sylvain; van de Velde, Cornelis J H; Vahrmeijer, Alexander L; Frangioni, John V

    2014-01-01

    Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has the potential to improve the sentinel lymph node (SLN) procedure by facilitating percutaneous and intraoperative identification of lymphatic channels and SLNs. Previous studies suggested that a dose of 0.62 mg (1.6 mL of 0.5 mM) ICG is optimal for SLN mapping in breast cancer. The aim of this study was to evaluate the diagnostic accuracy of NIR fluorescence for SLN mapping in breast cancer patients when used in conjunction with conventional techniques. Study subjects were 95 breast cancer patients planning to undergo SLN procedure at either the Dana-Farber/Harvard Cancer Center (Boston, MA, USA) or the Leiden University Medical Center (Leiden, the Netherlands) between July 2010 and January 2013. Subjects underwent the standard-of-care SLN procedure at each institution using (99)Technetium-colloid in all subjects and patent blue in 27 (28 %) of the subjects. NIR fluorescence-guided SLN detection was performed using the Mini-FLARE imaging system. SLN identification was successful in 94 of 95 subjects (99 %) using NIR fluorescence imaging or a combination of both NIR fluorescence imaging and radioactive guidance. In 2 of 95 subjects, radioactive guidance was necessary for initial in vivo identification of SLNs. In 1 of 95 subjects, NIR fluorescence was necessary for initial in vivo identification of SLNs. A total of 177 SLNs (mean 1.9, range 1-5) were resected: 100 % NIR fluorescent, 88 % radioactive, and 78 % (of 40 nodes) blue. In 2 of 95 subjects (2.1 %), SLNs-containing macrometastases were found only by NIR fluorescence, and in one patient this led to upstaging to N1. This study demonstrates the safe and accurate application of NIR fluorescence imaging for the identification of SLNs in breast cancer patients, but calls into question what technique should be used as the gold standard in future studies.

  8. First background-free limit from a directional dark matter experiment: results from a fully fiducialised DRIFT detector

    CERN Document Server

    Battat, J B R; Daw, E; Dorofeev, A; Ezeribe, A C; Gauvreau, J -L; Gold, M; Harton, J L; Landers, J M; Law, E; Lee, E R; Loomba, D; Lumnah, A; Matthews, J A J; Miller, E H; Monte, A; Mouton, F; Murphy, A StJ; Paling, S M; Phan, N; Robinson, M; Sadler, S W; Scarff, A; Schuckman, F; Snowden-Ifft, D P; Spooner, N J C; Telfer, S; Vahsen, S E; Walker, D; Warner, D; Yuriev, L

    2014-01-01

    The addition of O2 to gas mixtures in time projection chambers containing CS2 has recently been shown to produce multiple negative ions that travel at slightly different velocities. This allows a measurement of the absolute position of ionising events in the z (drift) direction. In this work, we apply the z-fiducialisation technique to a directional dark matter search. In particular, we present results from a 46.3 live-day source-free exposure of the DRIFT-IId detector run in this completely new mode. With full-volume fiducialisation, we have achieved the first background-free operation of a directional detector. The resulting exclusion curve for spin-dependent WIMP-proton interactions reaches 0.9 pb at 100 GeV/c2, a factor of 2 better than our previous work. We describe the automated analysis used here, and argue that detector upgrades, implemented after the acquisition of these data, will bring an additional factor of >3 improvement in the near future.

  9. "It comes down to just how human someone can be": A qualitative study with young people from refugee backgrounds about their experiences of Australian mental health services.

    Science.gov (United States)

    Valibhoy, Madeleine C; Kaplan, Ida; Szwarc, Josef

    2017-02-01

    While much literature documents the mental health needs of young people from refugee backgrounds, and the barriers they face in accessing mental health services, researchers have yet to document the perspectives of service users from this population about their contacts with clinicians and services. We therefore individually interviewed 16 young people (aged 18-25 years) who were refugees about their experiences of seeing mental health professionals. Participants were born in 9 different countries and had lived in Australia for an average of 5.2 years. They placed most emphasis on in-session factors, and particularly on interpersonal considerations. Among the main themes identified via thematic analysis were the practitioner's sensitivity to the young person's cultural background and to the stressors affecting him or her, including traumatic refugee experiences, and the therapeutic relationship-especially the qualities of trust, understanding, respect, and a caring connection. The participants had diverse reactions to treatment strategies. They emphasised the role of their preconceptions around mental health services, and called for systematic mental health awareness-raising for young people from refugee backgrounds. Implications for research, policy, and practice are discussed with a focus on findings that may guide efforts to improve service acceptability, accessibility, and effectiveness. In particular, there is a need for practitioners to attend to their clients' experiences of sessions, to adopt an attuned, contextualised, systemic approach, and especially to take a nuanced approach to cultural sensitivity.

  10. Liquid argon as active shielding and coolant for bare germanium detectors. A novel background suppression method for the GERDA 0{nu}{beta}{beta} experiment

    Energy Technology Data Exchange (ETDEWEB)

    Peiffer, J.P.

    2007-07-25

    Two of the most important open questions in particle physics are whether neutrinos are their own anti-particles (Majorana particles) as required by most extensions of the StandardModel and the absolute values of the neutrino masses. The neutrinoless double beta (0{nu}{beta}{beta}) decay, which can be investigated using {sup 76}Ge (a double beta isotope), is the most sensitive probe for these properties. There is a claim for an evidence for the 0{nu}{beta}{beta} decay in the Heidelberg-Moscow (HdM) {sup 76}Ge experiment by a part of the HdM collaboration. The new {sup 76}Ge experiment Gerda aims to check this claim within one year with 15 kg.y of statistics in Phase I at a background level of {<=}10{sup -2} events/(kg.keV.y) and to go to higher sensitivity with 100 kg.y of statistics in Phase II at a background level of {<=}10{sup -3} events/(kg.keV.y). In Gerda bare germanium semiconductor detectors (enriched in {sup 76}Ge) will be operated in liquid argon (LAr). LAr serves as cryogenic coolant and as high purity shielding against external background. To reach the background level for Phase II, new methods are required to suppress the cosmogenic background of the diodes. The background from cosmogenically produced {sup 60}Co is expected to be {proportional_to}2.5.10{sup -3} events/(kg.keV.y). LAr scintillates in UV ({lambda}=128 nm) and a novel concept is to use this scintillation light as anti-coincidence signal for background suppression. In this work the efficiency of such a LAr scintillation veto was investigated for the first time. In a setup with 19 kg active LAr mass a suppression of a factor 3 has been achieved for {sup 60}Co and a factor 17 for {sup 232}Th around Q{sub {beta}}{sub {beta}} = 2039 keV. This suppression will further increase for a one ton active volume (factor O(100) for {sup 232}Th and {sup 60}Co). LAr scintillation can also be used as a powerful tool for background diagnostics. For this purpose a new, very stable and robust wavelength

  11. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  12. Understanding internal backgrounds in NaI(Tl) crystals toward a 200 kg array for the KIMS-NaI experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adhikari, P.; Adhikari, G.; Oh, S.Y. [Sejong University, Department of Physics, Seoul (Korea, Republic of); Choi, S.; Joo, H.W.; Kim, K.W.; Kim, S.K. [Seoul National University, Department of Physics and Astronomy, Seoul (Korea, Republic of); Ha, C.; Jeon, E.J.; Kang, W.G.; Kim, H.O.; Kim, N.Y.; Lee, H.S.; Lee, J.H.; Lee, M.H.; Leonard, D.S.; Li, J.; Olsen, S.L.; Park, H.K.; Park, K.S.; So, J.H.; Yoon, Y.S. [Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Hahn, I.S. [Ewha Womans University, Department of Science Education, Seoul (Korea, Republic of); Kim, H.J. [Kyungpook National University, Department of Physics, Daegu (Korea, Republic of); Kim, Y.D. [Sejong University, Department of Physics, Seoul (Korea, Republic of); Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Kim, Y.H. [Institute for Basic Science, Center for Underground Physics, Daejeon (Korea, Republic of); Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Park, H.S. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-04-15

    The Korea Invisible Mass Search (KIMS) collaboration has developed low-background NaI(Tl) crystals that are suitable for the direct detection of WIMP dark matter. Building on experience accumulated during the KIMS-CsI programs, the KIMS-NaI experiment will consist of a 200 kg NaI(Tl) crystal array surrounded by layers of shielding structures and will be operated at the Yangyang underground laboratory. The goal is to provide an unambiguous test of the DAMA/LIBRA annual modulation signature. Measurements of six prototype crystals show progress in the reduction of internal contamination from radioisotopes. Based on our understanding of these measurements, we expect to achieve a background level in the final detector configuration that is less than 1 count/day/keV/kg for recoil energies around 2 keV. The annual modulation sensitivity for the KIMS-NaI experiment shows that an unambiguous 7σ test of the DAMA/LIBRA signature would be possible with a 600 kg year exposure with this system. (orig.)

  13. Understanding internal backgrounds of NaI(Tl) crystals toward a 200~kg array for the KIMS-NaI experiment

    CERN Document Server

    Adhikari, P; Choi, S; Ha, C; Hahn, I S; Jeon, E J; Joo, H W; Kang, W G; Kim, H J; Kim, H O; Kim, K W; Kim, N Y; Kim, S K; Kim, Y D; Kim, Y H; Lee, H S; Lee, J H; Lee, M H; Leonard, D S; Li, J; Oh, S Y; Olsen, S L; Park, H K; Park, H S; Park, K S; So, J H; Yoon, Y S

    2015-01-01

    The Korea Invisible Mass Search (KIMS) collaboration has developed low-background NaI(Tl) crystals that are suitable for the direct detection of WIMP dark matter. With experience built on the KIMS-CsI programs, the KIMS-NaI experiment will consist of a 200~kg NaI(Tl) crystal array surrounded by layers of shielding structures and will be operated at the Yangyang underground laboratory. The goal is to provide an unambiguous test of the DAMA/LIBRA's annual modulation signature. Measurements of six prototype crystals show progress in the reduction of internal contaminations of radioisotopes. Based on our understanding of these measurements, we expect to achieve a background level in the final detector configuration that is less than 1~count/day/keV/kg for recoil energies around 2~keV. The annual modulation sensitivity for the KIMS-NaI experiment shows that an unambiguous 7$\\sigma$ test of the DAMA/LIBRA signature would be possible with a 600~kg$\\cdot$year exposure with this system.

  14. Combining computer game-based behavioural experiments with high-density EEG and infrared gaze tracking.

    Science.gov (United States)

    Yoder, Keith J; Belmonte, Matthew K

    2010-12-16

    Experimental paradigms are valuable insofar as the timing and other parameters of their stimuli are well specified and controlled, and insofar as they yield data relevant to the cognitive processing that occurs under ecologically valid conditions. These two goals often are at odds, since well controlled stimuli often are too repetitive to sustain subjects' motivation. Studies employing electroencephalography (EEG) are often especially sensitive to this dilemma between ecological validity and experimental control: attaining sufficient signal-to-noise in physiological averages demands large numbers of repeated trials within lengthy recording sessions, limiting the subject pool to individuals with the ability and patience to perform a set task over and over again. This constraint severely limits researchers' ability to investigate younger populations as well as clinical populations associated with heightened anxiety or attentional abnormalities. Even adult, non-clinical subjects may not be able to achieve their typical levels of performance or cognitive engagement: an unmotivated subject for whom an experimental task is little more than a chore is not the same, behaviourally, cognitively, or neurally, as a subject who is intrinsically motivated and engaged with the task. A growing body of literature demonstrates that embedding experiments within video games may provide a way between the horns of this dilemma between experimental control and ecological validity. The narrative of a game provides a more realistic context in which tasks occur, enhancing their ecological validity (Chaytor & Schmitter-Edgecombe, 2003). Moreover, this context provides motivation to complete tasks. In our game, subjects perform various missions to collect resources, fend off pirates, intercept communications or facilitate diplomatic relations. In so doing, they also perform an array of cognitive tasks, including a Posner attention-shifting paradigm (Posner, 1980), a go/no-go test of motor

  15. The Apache Point Observatory Galactic Evolution Experiment (APOGEE) high-resolution near-infrared multi-object fiber spectrograph

    Science.gov (United States)

    Wilson, John C.; Hearty, Fred; Skrutskie, Michael F.; Majewski, Steven; Schiavon, Ricardo; Eisenstein, Daniel; Gunn, Jim; Blank, Basil; Henderson, Chuck; Smee, Stephen; Barkhouser, Robert; Harding, Al; Fitzgerald, Greg; Stolberg, Todd; Arns, Jim; Nelson, Matt; Brunner, Sophia; Burton, Adam; Walker, Eric; Lam, Charles; Maseman, Paul; Barr, Jim; Leger, French; Carey, Larry; MacDonald, Nick; Horne, Todd; Young, Erick; Rieke, George; Rieke, Marcia; O'Brien, Tom; Hope, Steve; Krakula, John; Crane, Jeff; Zhao, Bo; Carr, Mike; Harrison, Craig; Stoll, Robert; Vernieri, Mary A.; Holtzman, Jon; Shetrone, Matt; Allende-Prieto, Carlos; Johnson, Jennifer; Frinchaboy, Peter; Zasowski, Gail; Bizyaev, Dmitry; Gillespie, Bruce; Weinberg, David

    2010-07-01

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) will use a dedicated 300-fiber, narrow-band (1.5-1.7 micron), high resolution (R~30,000), near-infrared spectrograph to survey approximately 100,000 giant stars across the Milky Way. This survey, conducted as part of the Sloan Digital Sky Survey III (SDSS III), will revolutionize our understanding of kinematical and chemical enrichment histories of all Galactic stellar populations. The instrument, currently in fabrication, will be housed in a separate building adjacent to the 2.5 m SDSS telescope and fed light via approximately 45-meter fiber runs from the telescope. The instrument design includes numerous technological challenges and innovations including a gang connector that allows simultaneous connection of all fibers with a single plug to a telescope cartridge that positions the fibers on the sky, numerous places in the fiber train in which focal ratio degradation must be minimized, a large (290 mm x 475 mm elliptically-shaped recorded area) mosaic-VPH, an f/1.4 sixelement refractive camera featuring silicon and fused silica elements with diameters as large as 393 mm, three near-within a custom, LN2-cooled, stainless steel vacuum cryostat with dimensions 1.4 m x 2.3 m x 1.3 m.

  16. Robot-assisted nerve-sparing radical prostatectomy using near-infrared fluorescence technology and indocyanine green: initial experience.

    Science.gov (United States)

    Mangano, Mario S; De Gobbi, Alberto; Beniamin, Francesco; Lamon, Claudio; Ciaccia, Matteo; Maccatrozzo, Luigino

    2017-05-23

    Indocyanine green (ICG) is a fluorescent molecule that provokes detectable photon emission. The use of ICG with near-infrared (NIR) imaging system (Akorn, Lake Forest, IL) has been described during robotic partial nephrectomy (RAPN) as an adjunctive means of identifying renal artery and parenchymal perfusion.We propose the use of the ICG with NIR fluorescence during laparoscopic robot-assisted radical prostatectomy (RARP), to identify the benchmark artery improving the preservation of neurovascular bundle and to improve the visualization of the vascularization and then the hemostasis. From April 2015 to February 2016, 62 patients underwent to RARP in our Urology Unit. In 26 consecutive patients, in the attempt to have a better visualization of neurovascular bundles, we used to inject ICG during the procedure. We evaluated the percentage of identification of neurovascular bundles using NIR fluorescence. Then, we evaluated complications related to injection of ICG and operative time differences between RARP with and without ICG injection performed by the same surgeons. We identified prostatic arteries and neurovascular bundles using NIR fluorescence technology in all patients (100%). There was not any increase in the operative time compared with RARP without ICG injection performed by the same surgeons. Complications related to injection of ICG did not occurred. In our experience, even if on a limited number of patients, the application of ICG with NIR fluorescence during RARP is helpful to identify the benchmark artery of neurovascular bundle.

  17. The SCUBA-2 Cosmology Legacy Survey: The EGS deep field I - Deep number counts and the redshift distribution of the recovered Cosmic Infrared Background at 450 and 850 um

    CERN Document Server

    Zavala, J A; Geach, J E; Hughes, D H; Birkinshaw, M; Chapin, E; Chapman, S; Chen, Chian-Chou; Clements, D L; Dunlop, J S; Farrah, D; Ivison, R J; Jenness, T; Michałowski, M J; Robson, E I; Scott, Douglas; Simpson, J; Spaans, M; van der Werf, P

    2016-01-01

    We present deep observations at 450 um and 850 um in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of $\\sigma_{450}=1.2$ mJy/beam and $\\sigma_{850}=0.2$ mJy/beam. We detect 57 sources at 450 um and 90 at 850 um with S/N > 3.5 over ~70 sq. arcmin. From these detections we derive the number counts at flux densities $S_{450}>4.0$ mJy and $S_{850}>0.9$ mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 um-selected galaxies through a stacking technique, which ...

  18. aiNet背景抑制的单帧红外弱小目标检测%Infrared dim target detection in single image based on background suppression by aiNet

    Institute of Scientific and Technical Information of China (English)

    陈炳文; 王文伟; 秦前清

    2012-01-01

    In order to solve the problem that the current approaches cannot suppress the background clutters effectively, which results in a poor detection performance, a new infrared dim target detection approach is presented, which is based on background suppression by artificial immune network ( aiNet) and threshold segmentation by k-means cluster of rows and columns. First, the aiNet is combined with Robinson guard to build the adaptive local spatial background models as fuzzy topological memory antibody bank. In the process of antibody bank modeling, a series of antibody evolution strategies are designed based on self-organizing maps ( SOM). With these models, background clutters are suppressed according to the degree of fuzzy match between pixels and models. Then, the proposed adaptive segmentation algorithm based on k-means cluster of rows and columns is used to detect the true targets. Experimental results show that the Fl measurement of the proposed approach is up to 99% . The proposed approach is able to build the spatial background models adaptively according to the local change of image, and suppress the background clutters and highlight the targets effectively. It is capable of improving the signal-to-noise ratio of images and detecting targets effectively.%针对现有背景抑制算法未能有效抑制背景而导致目标检测率低的问题,提出了一种基于人工免疫网络(aiNet)进行背景抑制、基于行列k均值聚类实现阈值分割的单帧红外弱小目标检测算法.首先采用aiNet结合Robinson警戒环技术,融入自组织特征映射(SOM)拓扑思想,设计一系列抗体进化策略,建立自适应局部空间背景模型—模糊拓扑记忆抗体库,并以此分析各像素点的背景模糊隶属度来抑制背景杂波;接着提出基于行列k均值聚类的阈值分割算法来检测真实目标.实验结果表明,该算法的F1指标高达99%,其能随背景的局部变化来自适应建立空间背景模型,从而

  19. Cardiotocography interpretation skills and the association with size of maternity unit, years of obstetric work experience and healthcare professional background: a national cross-sectional study.

    Science.gov (United States)

    Thellesen, Line; Sorensen, Jette L; Hedegaard, Morten; Rosthoej, Susanne; Colov, Nina P; Andersen, Kristine S; Bergholt, Thomas

    2017-09-01

    We aimed to examine whether cardiotocography (CTG) knowledge, interpretation skills and decision-making measured by a written assessment were associated with size of maternity unit, years of obstetric work experience and healthcare professional background. A national cross-sectional study in the setting of a CTG teaching intervention involving all 24 maternity units in Denmark. Participants were midwives (n = 1260) and specialists (n = 269) and residents (n = 142) in obstetrics and gynecology who attended a 1-day CTG course and answered a 30-item multiple-choice question test. Associations between mean test score and work conditions were analyzed using multivariable robust regression, in which the three variables were mutually adjusted. Participants from units with > 3000 deliveries/year scored higher on the test than participants from units with 4000 deliveries/year: mean difference 0.5, p = 0.006). Participants with 15 years of experience (15-20 years of experience: mean difference - 0.6, p = 0.007; > 20 years experience: mean difference - 0.9, p skills and decision-making measured by a written assessment were positively associated with working in large maternity units and having skills in small units and among experienced staff but could also reflect different levels of motivation, test familiarity and learning culture. Whether the findings are transferable to the clinical setting was not examined. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  20. The barriers and facilitators people with diabetes from a nonEnglish speaking background experience when managing their medications: a qualitative study.

    Science.gov (United States)

    Claydon-Platt, Kate; Manias, Elizabeth; Dunning, Trisha

    2014-08-01

    To explore the barriers to and facilitators of effective medication management from the perspectives of people with diabetes from a nonEnglish speaking background, carers and health professionals. The barriers that people with diabetes experience managing their medications can adversely impact on health outcomes. People from nonEnglish speaking backgrounds are at risk of medication-related problems, although there is a paucity of research in this area. A qualitative research design using a purposive sampling approach. People with type 1 or type 2 diabetes from a nonEnglish speaking background, their carers, and health professionals who assisted these people and their carers to manage their medications were recruited from the diabetes outpatient clinic at an adult teaching public hospital in Melbourne, Australia. Participants were interviewed using a semi-structured interview guide. All interviews were audio-recorded, transcribed verbatim and analysed using a thematic framework method. Eleven people with diabetes, 10 carers and 10 health professionals were interviewed, and four key issues were identified: diabetes knowledge, diabetes impact, medication knowledge and medication management. The cost of medications, language barriers that hinder communication, forgetfulness, and poor knowledge and understanding emerged as barriers to effective medication management. Facilitators included the use of dose administration aids to manage medications, but current medication lists were not used. Findings revealed people with diabetes experienced a multitude of barriers when managing their medications, and, despite the problems people experienced, there appeared to be poor use of support aids to assist people to effectively manage their medications. The findings can be used to develop strategies aiming at improving how people from nonEnglish speaking backgrounds manage their medicines. © 2013 John Wiley & Sons Ltd.

  1. Study of the neutron background noise generated by muons in the Edelweiss-2 experiment; Etude du bruit de fond neutron induit par les muons dans l'experience EDELWEISS-2

    Energy Technology Data Exchange (ETDEWEB)

    Chabert, L

    2004-07-01

    This thesis contributes to the Edelweiss experiment whose aim is to detect interactions between neutralinos and target nuclei. Bolometers used in Edelweiss combine the detection of phonons with the detection of electric charges generated by the energy deposition. This double detection enables us to discard background signals due to electronic interactions and soon detection sensitivity of the experiment will be limited by the neutron background noise due to residual cosmic muons. This work is dedicated to a detailed study of muon inelastic interactions and the consequent production of neutrons. Simulations show that the expected neutron flux is so high that the direct detection of muons is required in order to link it to the neutron signal issued by the bolometer. Results from simulations show that plastic scintillators might be the main components of the muon detector.

  2. The SCUBA-2 Cosmology Legacy Survey: the EGS deep field - I. Deep number counts and the redshift distribution of the recovered cosmic infrared background at 450 and 850 μ m

    Science.gov (United States)

    Zavala, J. A.; Aretxaga, I.; Geach, J. E.; Hughes, D. H.; Birkinshaw, M.; Chapin, E.; Chapman, S.; Chen, Chian-Chou; Clements, D. L.; Dunlop, J. S.; Farrah, D.; Ivison, R. J.; Jenness, T.; Michałowski, M. J.; Robson, E. I.; Scott, Douglas; Simpson, J.; Spaans, M.; van der Werf, P.

    2017-01-01

    We present deep observations at 450 and 850 μm in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of σ450 = 1.2 mJy beam-1 and σ850 = 0.2 mJy beam-1. We detect 57 sources at 450 μm and 90 at 850 μm with signal-to-noise ratio >3.5 over ˜70 arcmin2. From these detections, we derive the number counts at flux densities S450 > 4.0 mJy and S850 > 0.9 mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 μm-selected galaxies through a stacking technique, which add a total of 0.26 ± 0.03 and 0.07 ± 0.01 MJy sr-1, at 450 and 850 μm, respectively. These surface brightnesses correspond to 60 ± 20 and 50 ± 20 per cent of the total CIB measurements, where the errors are dominated by those of the total CIB. Using the photometric redshifts of the 24 μm-selected sample and the redshift distributions of the submillimetre galaxies, we find that the redshift distribution of the recovered CIB is different at each wavelength, with a peak at z ˜ 1 for 450 μm and at z ˜ 2 for 850 μm, consistent with previous observations and theoretical models.

  3. Evaluating the Charged Background Rejection Requirement in an Experiment to Measure BR(K L → π0 νν -) at the CERN SPS

    Science.gov (United States)

    Bradley, A.

    2016-11-01

    Measuring the rate at which the long-lived, neutral kaon decays into a neutral pion, neutrino, and anti-neutrino allows physicists an opportunity to test precise predictions made by the Standard Model. Differences between theoretical predictions and experimental measurements may point to new physics. Not only does the Standard Model predict a very low probability at approximately 3 KL→ π0 νν -) decay in 100 billion KL decays, but many of the common decays leave false signals in the detector that look the same as the true signal. Charged decays have been studied to determine the required detection efficiency necessary to eliminate them. The conclusion of these studies is that a reduction by a factor of 1/(3 × 109) will be required to achieve the 10:1 signal to charged background ratio necessary for the experiment.

  4. The extragalactic IR background

    CERN Document Server

    De Zotti, G; Mazzei, P; Toffolatti, L; Danese, L; De Zotti, G; Franceschini, A; Mazzei, P; Toffolatti, L; Danese, L

    1994-01-01

    Current limits on the intensity of the extragalactic infrared background are consistent with the expected contribution from evolving galaxies. Depending on the behaviour of the star formation rate and of the initial mass function, we can expect that dust extinction during early evolutionary phases ranges from moderate to strong. An example of the latter case may be the ultraluminous galaxy IRAS F10214 + 4724. The remarkable lack of high redshift galaxies in faint optically selected samples may be indirect evidence that strong extinction is common during early phases. Testable implications of different scenarios are discussed; ISO can play a key role in this context. Estimates of possible contributions of galaxies to the background under different assumptions are presented. The COBE/FIRAS limits on deviations from a blackbody spectrum at sub-mm wavelengths already set important constraints on the evolution of the far-IR emission of galaxies and on the density of obscured (``Type 2'') AGNs. A major progress in ...

  5. Background Music and Background Feelings

    DEFF Research Database (Denmark)

    Have, Iben

    2008-01-01

    With a focus on underscore music in film and television this report discusses the relations between music and emotions. The report will present and discuss an interdisciplinary theoretical framework connecting the experience of musical structures with emotional structures. Subsequently it discuss...... how music in the attachment to the audiovisual context contributes to the generation of different kinds of emotional experiences. The Danish television documentary Ballets droning (“The Queen of the Ball”) portraying the leader of the Danish right wing party The Danish Peoples’ Party...

  6. Cosmogenic Backgrounds to 0{\

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retière, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01

    As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood and eliminated. With this in mind, cosmogenic backgrounds have been studied with the EXO-200 experiment. Using the EXO-200 TPC, the muon flux (through a flat horizontal surface) underground at the Waste Isolation Pilot Plant (WIPP) has been measured to be {\\Phi} = 4.07 $\\pm$ 0.14 (sys) $\\pm$ 0.03 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$, with a vertical intensity of $I_{v}$ = 2.97$^{+0.14}_{-0.13}$ (sys) $\\pm$ 0.02 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$ sr$^{-1}$. Simulations of muon-induced backgrounds identified several potential cosmogenic radionuclides, though only 137Xe is a significant background for the 136Xe 0{\

  7. Study of rare neutron induced processes and coincidence analyses to identify and reduce background contributions in the COBRA experiment; Studien seltener neutroneninduzierter Prozesse und Koinzidenzanalysen zur Bestimmung und Reduktion von Untergrundbeitraegen im COBRA-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Timm, Jan Horst Karl

    2015-11-15

    The aim of the COBRA experiment is the observation of neutrinoless double-beta decay, primarily of the isotope {sup 116}Cd. The applied semiconductor detectors of cadmium zinc telluride that are 90% to be enriched enable both the detection and the source of this decay. The half-lives of decays of this kind are expected in the range of more than 10{sup 26} years. Therefore, the reduction of contributions to the background is of decisive importance. The main subjects of this work are, on the one hand, the time synchronization of the data, which provides the basis for coincidence analysis. This analysis method has access not only to identification of contributions to the background, but also to observe decays involving positron annihilation and decays into excited states. In this study, the intrinsic detector contamination of some decay products of {sup 238}U and {sup 232}Th was measured and sensitivities to the half-lives of the decays like {sup 120}Te and {sup 128}Te in each case to the first excited state of daughter products are given. On the other hand, qualitative studies on the importance of neutrons in the COBRA experiment were conducted. These have shown that fast neutrons, thus with energies greater than 10 keV, only result in an insignificant contribution to the background for the detection of neutrinoless double-beta decay of the {sup 116}Cd. Previous studies have also shown that the thermal neutron flux can be in situ determined by coincidence analysis.

  8. Spotlight on equality of employment opportunities: A qualitative study of job seeking experiences of graduating nurses and physiotherapists from black and minority ethnic backgrounds.

    Science.gov (United States)

    Hammond, John; Marshall-Lucette, Sylvie; Davies, Nigel; Ross, Fiona; Harris, Ruth

    2017-08-01

    There is growing attention in the UK and internationally to the representation of black and minority ethnic groups in healthcare education and the workplace. Although the NHS workforce is very diverse, ethnic minorities are unevenly spread across occupations, and considerably underrepresented in senior positions. Previous research has highlighted that this inequality also exists at junior levels with newly qualified nurses from non-White/British ethnic groups being less likely to get a job at graduation than their White/British colleagues. Although there is better national data on the scale of inequalities in the healthcare workforce, there is a gap in our understanding about the experience of job seeking, and the factors that influence disadvantage in nursing and other professions such as physiotherapy. This qualitative study seeks to fill that gap and explores the experience of student nurses (n=12) and physiotherapists (n=6) throughout their education and during the first 6-months post qualification to identify key experiences and milestones relating to successful employment particularly focusing on the perspectives from different ethnic groups. Participants were purposively sampled from one university to ensure diversity in ethnic group, age and gender. Using a phenomenological approach, in-depth semi-structured interviews were conducted at course completion and 6 months later. Two main themes were identified. The 'proactive self' ('It's up to me') theme included perceptions of employment success being due to student proactivity and resilience; qualities valued by employers. The second theme described the need to 'fit in' with organisational culture. Graduates described accommodating strategies where they modified aspects of their identity (clothing, cultural markers) to fit in. At one extreme, rather than fitting in, participants from minority ethnic backgrounds avoided applying to certain hospitals due to perceptions of discriminatory cultures, 'I wouldn

  9. Exploration of University Experiment Works Under the Background of MOOCs%MOOCs 背景下的高校实验室工作探讨

    Institute of Scientific and Technical Information of China (English)

    张惠芹

    2015-01-01

    MOOCs(大规模开放在线课程)作为一种全新的教育模式,正以迅猛的速度给全球带来一场全新的教育革命,对正处于社会急剧转型背景下的我国高校的实验教学与管理具有十分重要的意义。为适应时代发展的要求,高校的实验教学与管理工作必须与时俱进,通过树立新型的人才培养理念、建设一支素质过硬的实验教学队伍、转变实验教学和管理模式,在MOOCs 背景下探索出一条新的具有中国特色的实验教学和管理新模式。%MOOCs (massive open online courses)as a new education mode,which has brought the world a brand -new education rev-olution.It is great significant to the colleges and universityies lab teaching and management under the social transformation back-ground.In order to adapt to the requirement of times development,management of lab teaching work must keep pace with the times.Through setting up the new concept of talent training,building a good team of experiment teaching,changing experiment teaching and management mode,we are going to explore the new Chinese characteristics mode of experiment teaching and management under the background of MOOCs.

  10. Estimation of soil and vegetation temperatures with multiangular thermal infrared observations: IMGRASS, HEIFE, and SGP 1997 experiments

    NARCIS (Netherlands)

    Menenti, M.; Jia, L.; Li, Z.L.; Djepa, V.; Wang, J.; Stoll, M.P.; Su, Z.; Rast, M.

    2001-01-01

    The potential of directional observations in the thermal infrared region for land surface studies is a largely uncharted area of research. The availability of the dual-view Along Track Scanning Radiometer (ATSR) observations led to explore new opportunities in this direction. In the context of studi

  11. New approach to optimize near-infrared spectra with design of experiments and determination of milk compounds as influence factors for changing milk over time.

    Science.gov (United States)

    De Benedictis, Lorenzo; Huck, Christian

    2016-12-01

    The optimization of near-infrared spectroscopic parameters was realized via design of experiments. With this new approach objectivity can be integrated into conventional, rather subjective approaches. The investigated factors are layer thickness, number of scans and temperature during measurement. Response variables in the full factorial design consisted of absorption intensity, signal-to-noise ratio and reproducibility of the spectra. Optimized factorial combinations have been found to be 0.5mm layer thickness, 64 scans and 25°C ambient temperature for liquid milk measurements. Qualitative analysis of milk indicated a strong correlation of environmental factors, as well as the feeding of cattle with respect to the change in milk composition. This was illustrated with the aid of near-infrared spectroscopy and the previously optimized parameters by detection of altered fatty acids in milk, especially by the fatty acid content (number of carboxylic functions) and the fatty acid length.

  12. Infrared and Raman spectroscopy: principles and spectral interpretation

    National Research Council Canada - National Science Library

    Larkin, Peter

    2011-01-01

    "Infrared and Raman Spectroscopy: Principles and Spectral Interpretation explains the background, core principles and tests the readers understanding of the important techniques of Infrared and Raman Spectroscopy...

  13. Development of a stabilized low temperature infrared absorption cell for use in low temperature and collisional cooling experiments.

    Science.gov (United States)

    Valentin, A; Henry, A; Claveau, C; Camy-Peyret, C; Hurtmans, D; Mantz, A W

    2004-12-01

    We have constructed a stabilized low temperature infrared absorption cell cooled by an open cycle refrigerator, which can run with liquid nitrogen from 250 to 80K or with liquid helium from 80K to a few kelvin. Several CO infrared spectra were recorded at low temperature using a tunable diode laser spectrometer. These spectra were analyzed taking into account the detailed effects of collisions on the line profile when the pressure increases. We also recorded spectra at very low pressure to accurately model the diode laser emission. Spectra of the R(2) line in the fundamental band of 13CO cooled by collisions with helium buffer gas at 10.5K and at pressures near 1 Torr have been recorded. The He-pressure broadening parameter (gamma(0) = 0.3 cm(-1) atm(-1)) has been derived from the simultaneous analysis of four spectra at different pressures.

  14. Design of athermal phonon light detector for reducing alpha recoil background of next-gen CUORE 0 νββ experiment

    Science.gov (United States)

    Camilleri, Joseph; Pyle, Matt; Kolomensky, Yury; Cuore Collaboration; Cdms Collaboration

    2017-01-01

    The current generation of bolometric 0 νββ experiments, including CUORE, expect degraded alpha recoils to be the dominant background restricting experimental sensitivity. The CUPID project will aim to improve the sensitivity of CUORE by over an order of magnitude, and search for 0 νββ in the entire region of parameter space consistent with the inverted neutrino mass hierarchy. Surface contamination of Cu support structures for CUORE's 130Te crystal bolometers is primarily responsible for these unwanted alpha recoils. Electronic signals produced near Qββ (2.53 MeV) have been shown to produce Cherenkov radiation on the order of 100 eV in 130Te crystals. The heavier and slower alpha particles of comparable energy in the region of interest do not produce a Cherenkov signal, allowing for discrimination via a high-resolution cryogenic light detector. A photon detector with energy resolution <10 eV is necessary. We will discuss how athermal phonon collection calorimeter technology developed by the CDMS collaboration over the past decade can be scaled to produce such a sensitive detector, while also satisfying requirements for scintillating crystal alternatives. We will also present the current status of the detector development. NSF: NSF PHY-1314881.

  15. Judges in the Formation of the Nation- State: Professional Experiences, Academic Background and Geographic Circulation of Members of the Supreme Courts of Brazil and the United States

    Directory of Open Access Journals (Sweden)

    Luciano Da Ros

    2010-06-01

    Full Text Available This article compares the career profiles of judges from the highest bodies of the Judiciary in Brazil and the United States of America, examining the biographies of all the ministros of the Supreme Court of Justice (Empire and of the Supreme Federal Tribunal (Republic in Brazil, and of all the justices of the Supreme Court of the United States, appointed until 2008 in both cases. Based on the sociology of political elites perspective, the article examines data concerning academic background, geographic circulation and the different professional experiences — legal, political and linked to the administration of the State’s coercive activity (police or military — lived through by future members of the Supreme Courts of Brazil and the United States so as to identify the types of individuals recommended to join the top bodies of the Judiciary in the two countries. In this sense, different State-building processes are identified on the basis of the examination of Brazilian and US judicial elites, suggesting a more fragmented and diverse trajectory in the case of US justices, and greater homogeneity and centralization in the case of their Brazilian counterparts.

  16. Development of practical thermal infrared hyperspectral imaging system

    Science.gov (United States)

    Wang, Jianyu; Li, Chunlai; Lv, Gang; Yuan, Liyin; Liu, Enguang; Jin, Jian; Ji, Hongzhen

    2014-11-01

    As an optical remote sensing equipment, the thermal infrared hyperspectral imager operates in the thermal infrared spectral band and acquires about 180 wavebands in range of 8.0~12.5μm. The field of view of this imager is 13° and the spatial resolution is better than 1mrad. Its noise equivalent temperature difference (NETD) is less than 0.2K@300K(average). 1 The influence of background radiation of the thermal infrared hyperspectral imager,and a simulation model of simplified background radiation is builded. 2 The design and implementationof the Cryogenic Optics. 3 Thermal infrared focal plane array (FPA) and special dewar component for the thermal infrared hyperspectral imager. 4 Parts of test results of the thermal infrared hyperspectral imager.The hyperspectral imaging system is China's first success in developing this type of instrument, whose flight validation experiments have already been embarked on. The thermal infrared hyperspectral data acquired will play an important role in fields such as geological exploration and air pollutant identification.

  17. Bridging the gap between public health and primary care in prevention of cardiometabolic diseases; background of and experiences with the Prevention Consultation in The Netherlands

    Science.gov (United States)

    Assendelft, Willem J J; Nielen, Markus M J; Hettinga, Dries M; van der Meer, Victor; van Vliet, Mieke; Drenthen, Antonius J M; Schellevis, Francois G; van Oosterhout, Marianne J W

    2012-01-01

    Background. There is an increasing need for programmatic prevention of cardiometabolic diseases (cardiovascular disease, type 2 diabetes and chronic kidney disease). Therefore, in the Netherlands, a prevention programme linked to primary care has been developed. This initiative was supported by the national professional organizations of GPs and occupational physicians as well as three large health foundations. Objectives. To describe and discuss the content, structure of and first experiences with this initiative. Methods. Description of context, risk assessment tool, guideline, content of the Prevention Consultation and pilot studies. Results. Preceding surveys revealed a need for proactive disease prevention, linked to primary care. An evidence-based guideline was developed using a validated eight-question screening list. According to the guideline, high-risk participants were advised to attend two consultations at the general practice, for completing the risk assessment and for tailored advice. Three pilot studies revealed that the programme was feasible and that (sufficient) participants with a condition requiring treatment were detected. We learned that with a ‘passive’ recruitment (with only posters and brochures), screening uptake is limited. A more active approach with a personal invitation from the GP is more effective. Both an Internet as written questionnaire should be available and reminders are necessary. The need for a consultation with the GP practice after a high-risk test result should be emphasized. The first consultation can be performed by a practice nurse. Conclusions. A national systematic screening programme for cardiometabolic diseases linked to primary care is feasible. The cost-effectiveness still has to be established. PMID:22399541

  18. Overview of the Brooklyn traffic real-time ambient pollutant penetration and environmental dispersion (B-TRAPPED) study: theoretical background and model for design of field experiments.

    Science.gov (United States)

    Hahn, Intaek; Wiener, Russell W; Richmond-Bryant, Jennifer; Brixey, Laurie A; Henkle, Stacy W

    2009-12-01

    The Brooklyn traffic real-time ambient pollutant penetration and environmental dispersion (B-TRAPPED) study was a multidisciplinary field research project that investigated the transport, dispersion, and infiltration processes of traffic emission particulate matter (PM) pollutants in a near-highway urban residential area. The urban PM transport, dispersion, and infiltration processes were described mathematically in a theoretical model that was constructed to develop the experimental objectives of the B-TRAPPED study. In the study, simultaneous and continuous time-series PM concentration and meteorological data collected at multiple outdoor and indoor monitoring locations were used to characterize both temporal and spatial patterns of the PM concentration movements within microscale distances (dispersion of PM; (3) studying the influence of meteorological variables on the transport, dispersion, and infiltration processes; (4) characterizing the relationships between the building parameters and the infiltration mechanisms; (5) establishing a cause-and-effect relationship between outdoor-released PM and indoor PM concentrations and identifying the dominant mechanisms involved in the infiltration process; (6) evaluating the effectiveness of a shelter-in-place area for protection against outdoor-released PM pollutants; and (7) understanding the predominant airflow and pollutant dispersion patterns within the neighborhood using wind tunnel and CFD simulations. The 10 papers in this first set of papers presenting the results from the B-TRAPPED study address these objectives. This paper describes the theoretical background and models representing the interrelated processes of transport, dispersion, and infiltration. The theoretical solution for the relationship between the time-dependent indoor PM concentration and the initial PM concentration at the outdoor source was obtained. The theoretical models and solutions helped us to identify important parameters in the

  19. Background reduction in cryogenic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Daniel A.; /Fermilab

    2005-04-01

    This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.

  20. Are Schools Promoting Social and Economic Integration of Migrant and Ethnic Minorities? The Experiences of Some Young People of Ecuadorian Background in Spain

    Science.gov (United States)

    Ron-Balsera, Maria

    2015-01-01

    Although school is usually considered the most promising institution for the social and economic integration of young people of migration background, the educational outcomes of young people of Ecuadorian background signal a broken promise. Their families, peers, and teachers mediate the effect of the intersections of age, gender, class and…

  1. Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines

    Energy Technology Data Exchange (ETDEWEB)

    Soukhanovskii, V A; Johnson, D W; Kaita, R; Roquemore, A L

    2007-04-27

    Spatially resolved measurements of deuterium Balmer and Paschen line emission have been performed in the divertor region of the National Spherical Torus Experiment using a commercial 0.5 m Czerny-Turner spectrometer. While the Balmer emission lines, Balmer and Paschen continua in the ultraviolet and visible regions have been extensively used for tokamak divertor plasma temperature and density measurements, the diagnostic potential of infrared Paschen lines has been largely overlooked. We analyze Stark broadening of the lines corresponding to 2-n and 3-m transitions with principle quantum numbers n = 7-12 and m = 10-12 using recent Model Microfield Method calculations (C. Stehle and R. Hutcheon, Astron. Astrophys. Supl. Ser. 140, 93 (1999)). Densities in the range (5-50) x 10{sup 19} m{sup -3} are obtained in the recombining inner divertor plasma in 2-6 MW NBI H-mode discharges. The measured Paschen line profiles show good sensitivity to Stark effects, and low sensitivity to instrumental and Doppler broadening. The lines are situated in the near-infrared wavelength domain, where optical signal extraction schemes for harsh nuclear environments are practically realizable, and where a recombining divertor plasma is optically thin. These properties make them an attractive recombining divertor density diagnostic for a burning plasma experiment.

  2. Utilization of FADC for reconstruction and analysis of the background data in the Chooz neutrino experiment; Utilisation des FADC pour la reconstruction et l`analyse des donnees de bruit de fond dans l`experience neutrino de Chooz

    Energy Technology Data Exchange (ETDEWEB)

    Veron, Didier [Universite Claude Bernard, 69 - Lyon (France)

    1997-03-25

    This thesis describes a particular contribution to the Chooz experiment. The latter looks for the oscillations, over a distance of 1 km, of antineutrons emitted by two nuclear reactors. The electron-type antineutrinos are detected through their inverse beta interaction with a target`s proton. The neutron is detected through its capture by a gadolinium nucleus revealed by an 8 MeV gamma emission. In the first part we describe the reconstruction of events as simulated by the GIANT software. We show that the positron`s and neutron`s stopping point can actually be reconstructed with an accuracy of 10 and 20 cm respectively. In the second part, we proceed to the analysis of the calibration`s data as recorded with Fast Wave Form Digitizers. This confirms the reliability of the Monte-Carlo results and allows measurement of both the neutrons` capture probability and time by the target gadolinium. The last part deals with the background (reactor turned off) data analysis and the pin-pointing of its various sources. In order to reduce their contribution, we define spatial cuts. These cuts` reliability is validated by analysis of data obtained not only with a neutron source, but also with neutrons issued from cosmic rays. We end up with a background contribution of two to three events per day, about ten times less than the expected neutrino rate at full reactor power. (author) 81 refs., 152 figs.,43 tabs.

  3. On the time response of background obtained in γ-ray spectroscopy experiments using LaBr3(Ce) detectors with different shielding

    Science.gov (United States)

    Régis, J.-M.; Dannhoff, M.; Jolie, J.; Müller-Gatermann, C.; Saed-Samii, N.

    2016-03-01

    Employing the γ-γ fast-timing technique with LaBr3(Ce) scintillator detectors allows the direct determination of lifetimes of nuclear excited states with a lower limit of about 5 ps. This limit is increased as soon as background is present in the coincidence spectra underneath the full-energy peaks of the γ-γ cascade. Our aim was to identify the components of the γ-ray background by systematic γ-γ fast-timing measurements using different types of γ shielding within a large γ-ray spectrometer. The energy dependent physical zero-time response was measured using background-free full-energy peak events from the 152Eu γ-ray source. This is compared with the time response of the (Compton-) background distribution as obtained using the prompt 60Co γ-ray source. The time response of the typical Compton background is about 15 ps faster than the time response of background-free full-energy peak events. Below about 500 keV, a second type of background contributes by the detection of Compton-scattered γ rays generated in the materials of the spectrometer around the detector. Due to the additional time-of-flight of the Compton-scattered γ rays, this low-energy background is largely delayed. Compared with a bare cylindrical 1.5 in . × 1.5 in . LaBr3(Ce) detector, the BGO-shielded detector in the Compton-suppression mode improves the peak-to-total ratio by a factor of 1.66(5), while the Pb-shielded detector only slightly reduces the low-energy background.

  4. First results and future plans for the Canarias Infrared Camera Experiment (CIRCE) for the Gran Telescopio Canarias

    Science.gov (United States)

    Garner, Alan; Eikenberry, Stephen S.; Charcos, Miguel; Dallilar, Yigit; Edwards, Michelle; Lasso-Cabrera, Nestor; Stelter, Richard D.; Marin-Franch, Antonio; Raines, S. Nicholas; Ackley, Kendall; Bennett, John G.; Cenarro, Javier A.; Chinn, Brian; Donoso, Veronica H.; Frommeyer, Raymond; Hanna, Kevin; Herlevich, Michael D.; Julian, Jeff; Miller, Paola; Mullin, Scott; Murphey, Charles H.; Packham, Christopher; Varosi, Frank; Vega, Claudia; Warner, Craig; Ramaprakash, Anamparambu N.; Burse, Mahesh; Punnadi, Sujit; Chordia, Pravinkumar; Gerarts, Andreas; Martín, Héctor de Paz; Calero, María. Martín.; Scarpa, Riccardo; Fernandez Acosta, Sergio; Hernández Sánchez, William Miguel; Siegel, Benjamin; Pérez, Francisco Francisco; Viera Martín, Himar D.; Rodríguez Losada, José A.; Nuñez, Agustín.; Tejero, Álvaro; Martín González, Carlos E.; Rodríguez, César Cabrera; Molgó Sendra, Jordi; Rodriguez, J. Esteban; Fernádez Cáceres, J. Israel; Rodríguez García, Luis A.; Lopez, Manuel Huertas; Dominguez, Raul; Gaggstatter, Tim; Cabrera-Lavers, Antonio; Geier, Stefan; Pessev, Peter; Sarajedini, Ata; Castro-Tirado, A. J.

    2016-08-01

    CIRCE is a near-infrared (1-2.5 micron) imager (including low-resolution spectroscopy and polarimetery) in operation as a visitor instrument on the Gran Telescopio Canarias 10.-4m tele scope. It was built largely by graduate students and postdocs, with help from the UF Astronomy engineering group, and is funded by the University of Florida and the U.S. National Science Foundation. CIRCE is helping to fill the gap in time between GTC first light and the arrival of EMIR, and will also provide the following scientific capabilities to compliment EMIR after its arrival: high-resolution imaging, narrowband imaging, high-time-resolution photometry, polarimetry, and low-resolution spectroscopy. There are already scientific results from CIRCE, some of which we will review. Additionally, we will go over the observing modes of CIRCE, including the two additional modes that were added during a service and upgrading run in March 2016.

  5. Lead-chalcogenide mid-infrared vertical external cavity surface emitting lasers with improved threshold: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fill, Matthias [ETH Zurich, Laser Spectroscopy and Sensing Lab, 8093 Zurich (Switzerland); Phocone AG, 8005 Zurich (Switzerland); Debernardi, Pierluigi [IEIIT-CNR, Torino 10129 (Italy); Felder, Ferdinand [Phocone AG, 8005 Zurich (Switzerland); Zogg, Hans [ETH Zurich (Switzerland)

    2013-11-11

    Mid-infrared Vertical External Cavity Surface Emitting Lasers (VECSEL) based on narrow gap lead-chalcogenide (IV-VI) semiconductors exhibit strongly reduced threshold powers if the active layers are structured laterally for improved optical confinement. This is predicted by 3-d optical calculations; they show that lateral optical confinement is needed to counteract the anti-guiding features of IV-VIs due to their negative temperature dependence of the refractive index. An experimental proof is performed with PbSe quantum well based VECSEL grown on a Si-substrate by molecular beam epitaxy and emitting around 3.3 μm. With proper mesa-etching, the threshold intensity is about 8-times reduced.

  6. Detection of weak and small infrered targets under complicated background

    Science.gov (United States)

    Chen, Jinling; Zhang, Jiming; Deng, Linming; Niu, Xiaoming; Wei, Xueming; Xu, Jing; Wu, Jian

    2010-10-01

    The technique of weak small target detection and recognition has been the key technique of the electro-optical detecting system, many scholars are engaging the research of detection for weak and small targets. The effective detection for small targets in low SNR images is still a hot research field. Because infrared sensor is easily affected by atmosphere hot radiation, long distance and sensor noise, the detected targets in infrared images often present like small targets and drowned in noise. The basic problem inherent to extent the detection range is the detection of small, low observable, no obvious structural information in images and complicated background. In order to improve the detection ratio of weak small targets and decrease the false alarming ratio in the condition of complicated background, the paper presents the technology of pretreatment of infrared images and the technology of detection for weak small targets, mainly including the technology of Sobel edge algorithm and multi-degree and multi-orientation gradient. Based upon horizon-correlative characteristic of infrared images which were gotten by scanning, considering of the target properties in complicated background, an algorithm of weak and small target detection is presented. Because the images appear horizon-correlative characteristic, Sobel horizontal operator is adopted. By this algorithm, the background clutter was suppressed. Then an adaptive threshold was proposed to extract the precise location of small target. Incorporated with the two methods, a single frame weak and small target detection algorithm was built. Its high performance was then proved in a serial of experiments. In order to solve the detection problems of weak and small infrared targets under complicated background, a detection algorithm integrating with multi-degree and multi-orientation gradient fusion is proposed. Based on the principle of infrared radiation property of target, i.e., the gradient variations of pixel

  7. A thermal infrared instrument onboard a geostationary platform for CO and O3 measurements in the lowermost troposphere: observing system simulation experiments

    Directory of Open Access Journals (Sweden)

    M. Höpfner

    2011-02-01

    Full Text Available This paper presents observing system simulation experiments (OSSEs to compare the relative capabilities of two geostationary thermal infrared (TIR instruments to monitor ozone (O3 and carbon monoxide (CO for air quality (AQ purposes over Europe. The originality of this study is to use OSSEs to assess how these infrared instruments can constrain different errors affecting AQ hindcasts and forecasts (emissions, meteorology, initial condition and the 3 parameters together. The first instrument (GEO-TIR has a configuration optimized to monitor O3 and CO in the lowermost tr posphere (LmT; defined to be the atmosphere between the surface and 3 km, and the second instrument (GEO-TIR2 is designed to monitor temperature and humidity. Both instruments measure radiances in the same spectral TIR band. Results show that GEO-TIR could have a significant impact (GEO-TIR is closer to the reference atmosphere than GEO-TIR2 on the analyses of O3 and CO LmT column. The value of the measurements for both instruments is mainly over the Mediterranean Basin and some impact can be found over the Atlantic Ocean and Northern Europe. The impact of GEO-TIR is mainly above 1 km for O3 and CO but can also improve the surface analyses for CO. The analyses of GEO-TIR2 show low impact for O3 LmT column but a significant impact (but lower than for GEO-TIR for CO above 1 km. The results of this study indicate the beneficial impact from an infrared instrument (GEO-TIR dedicated to monitoring O3 and CO concentrations in the LmT, and quantify the value of this information for constraining AQ models.

  8. Using Gnuplot to process data of infrared temperature measurement experiment%利用Gnuplot处理红外测温实验数据

    Institute of Scientific and Technical Information of China (English)

    李艳; 王洪涛

    2012-01-01

    Data processing of experiments in modern physics is difficult for most of students, especially for the experiment which has mass data and needs curve fitting. Analyzing and plotting the data of infrared temperature measurement experiment use the open source software-Gnuplot. As an open source software, Gnuplotis more convenient and powerful than some other business software, so it is a meaningful thing to popularizethis tool in the teaching process of experiments in modern physics.%近代物理实验的数据处理是一个学生感觉比较困难的问题,特别是对于数据量比较大、又需要曲线拟合的实验项目.结合近代物理实验中的红外测温实验的数据处理问题,利用开源软件Gnuplot进行了数据的分析和绘图.相对于其他的数据处理工具,Gnuplot具有免费、小巧便捷、功能强大等特点,在近代物理实验教学中做适当推广具有一定的实际意义.

  9. Study of the reaction between ammonium thiocyanate and Fe (II or Fe (III using infrared spectroscopy: an experiment of prebiotic chemistry

    Directory of Open Access Journals (Sweden)

    Dimas Augusto Morozin Zaia

    2010-09-01

    Full Text Available The prebiotic chemistry studies the reactions that could be played an important role on origins of life on Earth. However, these reactions should be carried out under conditions that existed on the prebiotic Earth. The laboratory experiments of heating substances in solid state could be corresponding to the following prebiotic environments: cooling lava from volcanoes on the ground and impact of meteorites or comets on the earth. The present study examined the reaction in solid state between ammonium thiocyanate and Fe (II or Fe (III. The samples were heated at 220 ºC in several different times (6 hours, 24 hours, 7 days. The most important finding of this work is that a reaction of oxidation-reduction is occurring between Fe (II and ammonium thiocyanate, the infrared spectrum of the reaction product ammonium thiocyanate/Fe (II showed a band that it is characteristic of ferricyanate. The infrared spectra also showed bands that they are characteristics of guanidine thiocyanate. Thus, the heating of ammonium thiocyanate with Fe (II in solid state is synthesizing guanidine thiocyanate and at the same time oxidizing Fe (II to Fe (III. The product of reaction between Fe (III and ammonium thiocyanate is guanidine thiocyanate. Fe (II and Fe (III are reacting with ammonium thiocyanate in different way.

  10. The method of infrared image simulation based on the measured image

    Science.gov (United States)

    Lou, Shuli; Liu, Liang; Ren, Jiancun

    2015-10-01

    The development of infrared imaging guidance technology has promoted the research of infrared imaging simulation technology and the key of infrared imaging simulation is the generation of IR image. The generation of IR image is worthful in military and economy. In order to solve the problem of credibility and economy of infrared scene generation, a method of infrared scene generation based on the measured image is proposed. Through researching on optical properties of ship-target and sea background, ship-target images with various gestures are extracted from recorded images based on digital image processing technology. The ship-target image is zoomed in and out to simulate the relative motion between the viewpoint and the target according to field of view and the distance between the target and the sensor. The gray scale of ship-target image is adjusted to simulate the radiation change of the ship-target according to the distance between the viewpoint and the target and the atmospheric transmission. Frames of recorded infrared images without target are interpolated to simulate high frame rate of missile. Processed ship-target images and sea-background infrared images are synthetized to obtain infrared scenes according to different viewpoints. Experiments proved that this method is flexible and applicable, and the fidelity and the reliability of synthesis infrared images can be guaranteed.

  11. Improving the $t\\bar t+$jets background rejection in a search for supersymmetric particles in events with leptons and multiple jets at the ATLAS experiment

    CERN Document Server

    Guenther, Paul Andre

    2016-01-01

    In this report, an attempt to select $b$-quark pairs from $g\\rightarrow b\\bar b$ in the $t\\bar t+$jets background simulation of a search for supersymmetric particles in events with leptons and multiple jets is presented. $b$-tagged jets are paired and selected exploiting kinematic differences between these from gluon-splitting and mainly those from top quark decays. It is found that $(33\\pm3)\\%$ of the built pairs from the background in the signal region consist of two $b$-tagged jets from gluon-splitting. No large improvement of the signal-to-background ratio can be achieved from this. The fraction of built $b$-tagged jet pairs that originate from a gluon can be increased to above $60\\%$ with a cut on a discriminating variable.

  12. 3D-FEM electrical-thermal-mechanical analysis and experiment of Si-based MEMS infrared emitters

    Science.gov (United States)

    Wang, Xiang; Wang, Na; Chen, Ran-Bin; San, Hai-Sheng; Chen, Xu-Yuan

    2016-11-01

    Designs, simulations, and fabrications of silicon-based MEMS infrared (IR) emitters for gas sensing application are presented. A 3D finite element method (3D-FEM) was used to analyze the coupled electrical-thermal-mechanical properties of a bridge hotplate structure (BHS) IR emitter and closed hotplate structure (CHS) IR emitter using Joule heating and thermal expansion models of COMSOL™. The IR absorptions of n- and p-silicon were calculated for the design of self-heating structure. The BHS and CHS IR emitters were fabricated synchronously using micro-electromechanical systems technology for a direct performance comparison. Both types of IR emitters were characterized by electrical and optical measurements. The experimental results show that BHS IR emitters have higher radiation density, lower power consumption, and faster frequency-response than CHS IR emitters due to the use of a thermal isolation structure and self-heating structure. Meanwhile, the simulated results agree well with the corresponding measured results, which indicate that the 3D-FEM-model is effective and can be used in the optimal design of electro-thermal devices.

  13. Infrared Astronomy and Education: Linking Infrared Whole Sky Mapping with Teacher and Student Research

    Science.gov (United States)

    Borders, Kareen; Mendez, Bryan; Thaller, Michelle; Gorjian, Varoujan; Borders, Kyla; Pitman, Peter; Pereira, Vincent; Sepulveda, Babs; Stark, Ron; Knisely, Cindy; Dandrea, Amy; Winglee, Robert; Plecki, Marge; Goebel, Jeri; Condit, Matt; Kelly, Susan

    The Spitzer Space Telescope and the recently launched WISE (Wide Field Infrared Survey Explorer) observe the sky in infrared light. Among the objects WISE will study are asteroids, the coolest and dimmest stars, and the most luminous galaxies. Secondary students can do authentic research using infrared data. For example, students will use WISE data to mea-sure physical properties of asteroids. In order to prepare students and teachers at this level with a high level of rigor and scientific understanding, the WISE and the Spitzer Space Tele-scope Education programs provided an immersive teacher professional development workshop in infrared astronomy.The lessons learned from the Spitzer and WISE teacher and student pro-grams can be applied to other programs engaging them in authentic research experiences using data from space-borne observatories such as Herschel and Planck. Recently, WISE Educator Ambassadors and NASA Explorer School teachers developed and led an infrared astronomy workshop at Arecibo Observatory in PuertoRico. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance and age of objects in the Universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and the Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. We will outline specific steps for sec-ondary astronomy professional development, detail student involvement in infrared telescope data analysis, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional secondary professional development and student involvement in infrared astronomy. Funding was

  14. Extragalactic Background Light: Measurements and Applications

    CERN Document Server

    Cooray, Asantha

    2016-01-01

    This review covers the measurements related to the extragalactic background light (EBL) intensity from gamma-rays to radio in the electromagnetic spectrum over 20 decades in the wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centered at 1 microns, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar system. The best measurements of COB come from an indirect technique involving Gamma-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 microns established an energetically important background with an intensity comparable to the optical background. This discovery paved the path for large aperture far-infrared and sub-millimeter observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy for...

  15. Influence of a fat layer on the near infrared spectra of human muscle: quantitative analysis based on two-layered Monte Carlo simulations and phantom experiments

    Science.gov (United States)

    Yang, Ye; Soyemi, Olusola O.; Landry, Michelle R.; Soller, Babs R.

    2005-01-01

    The influence of fat thickness on the diffuse reflectance spectra of muscle in the near infrared (NIR) region is studied by Monte Carlo simulations of a two-layer structure and with phantom experiments. A polynomial relationship was established between the fat thickness and the detected diffuse reflectance. The influence of a range of optical coefficients (absorption and reduced scattering) for fat and muscle over the known range of human physiological values was also investigated. Subject-to-subject variation in the fat optical coefficients and thickness can be ignored if the fat thickness is less than 5 mm. A method was proposed to correct the fat thickness influence. c2005 Optical Society of America.

  16. Cryogenic performance of the space infrared optical payload

    Science.gov (United States)

    Wang, Dawei; Tan, Fanjiao; Zhang, Wei; Liu, Mingdong; Wang, Haipeng

    2016-10-01

    A model as well as the methodology is proposed to analyze the cryogenic performance of space infrared optical payload. And the model is established from two aspects: imaging quality and background radiation. On the basis of finite element analysis, the deformation of optical surface in cryogenic environment is characterized by Zernike polynomials, and then, the varying pattern of MTF of space cryogenic optical payload could be concluded accordingly. Then from the theory of thermal radiative transfer, the temperature distribution and the deformation of the optical payload under the action of inertial load and thermal load are analyzed based on the finite element method, and the spontaneous radiation and scattering properties of the optical surface and shielding factors between the opto-mechanical structure are considered to establish the radiation calculation model. Furthermore, the cryogenic radiation characteristics of the space infrared optical payload are obtained by the radiation calculation model. Finally, experiments are conducted using an actual off-axis TMA space infrared optical payload. And the results indicate that the background radiation of the space infrared optical payload is decreased by 79% while 33% for MTF at the thermal control temperature of 240K. In this circumstance, the system background radiation is effectively suppressed and the detection sensitivity of the optical payload is improved as well, while the imaging quality is acceptable. The model proposed in this paper can be applied to the analyzing cryogenic properties of space infrared optical payload, and providing theoretical guidance for the design and application of the space cryogenic optical payload.

  17. The Disposition of Silver Released from Soviet Oblako Rockets in Precipitation during the Hall Suppression Experiment Grossversuch IV. Part I: Measurements of Background and a Preliminary Seeding Test.

    Science.gov (United States)

    Lacaux, J.-P.; Warburton, J. A.

    1980-07-01

    In association with Grossversuch IV, a program designed to test the Soviet hail suppression method by seeding clouds with AgI from Oblako rockets, a complementary program was conducted by l'Observatoire du Puy-de-Dôme and the Desert Research Institute to study the diffusion of the seeding material (AgI) in the clouds, based on the analysis of silver in precipitation. This program covered the summers of 1977 and 1978, and this paper describes the results of measurements of natural background silver concentrations in unseeded precipitation. It also describes a new automatic precipitation collector, five of which were first tested in the field in 1977. A more extensive network of 15 collectors was deployed during two months of the 1978 summer.Based on the analysis of 118 unseeded precipitation samples collected in 1977, the natural background concentration of silver was estimated as 0.9 × 1011 g mL1( = 0.6 × 1011 g mL1). Although the standard deviations overlap, the 1978 season results appear to indicate a lower background of 0.5 × 1011 g mL1 ( = 0.3 × 1011 g mL1), based on the analysis of 414 rain samples. The average value for the two seasons was 0.6 × 1011 g mL1 with a standard deviation of 0.5 × 1011 g mL1. These background concentrations were found to be independent of both the length of sampling period and the precipitation intensity, averaged over the sampling periods of the collectors.The background is sufficiently low to permit the detection of the presence of silver iodide emitted from the Soviet rockets in the precipitation. The preliminary results from one case study are presented to support this conclusion.

  18. Probing ice clouds by broadband mid-infrared extinction spectroscopy: case studies from ice nucleation experiments in the AIDA aerosol and cloud chamber

    Directory of Open Access Journals (Sweden)

    R. Wagner

    2006-01-01

    Full Text Available Series of infrared extinction spectra of ice crystals were recorded in the 6000–800 cm−1 wavenumber regime during expansion cooling experiments in the large aerosol and cloud chamber AIDA of Forschungszentrum Karlsruhe. Either supercooled sulphuric acid solution droplets or dry mineral dust particles were added as seed aerosols to initiate ice formation after having established ice supersaturated conditions inside the chamber. The various ice nucleation runs were conducted at temperatures between 237 and 195 K, leading to median sizes of the nucleated ice particles of 1–15 µm. The measured infrared spectra were fitted with reference spectra from T-matrix calculations to retrieve the number concentration as well as the number size distribution of the generated ice clouds. The precise evaluation of the time-dependent ice particle number concentrations, i.e., the rates of new ice particle formation, is of particular importance to quantitatively analyse the ice nucleation experiments in terms of nucleation rates and ice activation spectra. The ice particles were modelled as finite circular cylinders with aspect ratios ranging from 0.5 to 3.0. Benefiting from the comprehensive diagnostic tools for the characterisation of ice clouds which are available at the AIDA facility, the infrared retrieval results with regard to the ice particle number concentration could be compared to independent measurements with various optical particle counters. This provided a unique chance to quantitatively assess potential errors or solution ambiguities in the retrieval procedure which mainly originate from the difficulty to find an appropriate shape representation for the aspherical particle habits of the ice crystals. Based on these inter-comparisons, we demonstrate that there is no standard retrieval approach which can be routinely applied to all different experimental scenarios. In particular, the concept to account for the asphericity of the ice crystals

  19. Design, Construction and Calibration of a Near-Infrared Four-Color Pyrometry System for Laser-Driven High Pressure Experiments

    Science.gov (United States)

    Ali, S. J.; Jeanloz, R.; Collins, G.; Spaulding, D. K.

    2010-12-01

    Current dynamic compression experiments, using both quasi-isentropic and shock-compression, allow access to pressure-temperature states both on and off the principle Hugoniot and over a wide range of conditions of direct relevance to planetary interiors. Such studies necessitate reliable temperature measurements below 4000-5000 K. Such relatively low temperature states are also of particular interest for materials such as methane and water that do not experience much heating under shock compression. In order to measure these temperatures as a function of time across the sample, a four-color, near-infrared pyrometry system is being developed for use at the Janus laser facility (LLNL) with channels at wavelengths of 932nm-1008nm, 1008nm-1108nm, 1108nm-1208nm, and 1208nm-1300nm. Each color band is fiber-coupled to an InGaAs PIN photodiode with a rise time of less than 60 ps, read using an 18 GHz oscilloscope in order to ensure time resolutions of under 200 ps. This will allow for high temporal resolution measurements of laser-driven shock compression experiments with total durations of 5-15 ns as well as correlation with simultaneous time-resolved velocity interferometry and visual-wavelength pyrometry. Calibration of the system is being accomplished using quartz targets, as the EOS for quartz is well known, along with a calibrated integrating sphere of known spectral radiance.

  20. Imaging the Spatial Fluctuations in Cosmic IR Background from Reionization with CIBER

    Science.gov (United States)

    Frazer, Chris; Bock, J.; Cooray, A.; Kawada, M.; Kim, M.; Lee, D.; Levenson, L.; Matsumoto, T.; Matsumuura, S.; Mitchell-Wynne, K.; Renbarger, T.; Smidt, J.; Sullivan, I.; Arai, T.; Tsumura, K.; Wada, T.; Zemcov, M.

    2011-01-01

    The Cosmic Infrared Background Experiment (CIBER) is a rocket-born absolute photometry imaging and spectroscopy experiment optimized to detect unresolved infrared signatures of first-light galaxies that were present during reionization. The signatures from reionization are theorized to be dominant at the wavelengths upon which CIBER surveys. CIBER consists of two wide field imagers to measure the extragalactic background fluctuations in the H and I-Bands (1.6 and 0.9 microns respectively) of the cosmic infrared background (CIB) as well as two spectrometers designed to take measurements of the foreground zodiacal light and the absolute Extragalactic Background Light (EBL) spectrum They imagers are capable of examining high-redshift (z 10-20) CIB fluctuations which will facilitate in the study of surface densities of sources associated with reionization. Studies of galaxies with similar redshift parameters (z > 6) are largely unaccounted for. The spectrometer configuration consists of one low resolution spectrometer and one narrow band spectrometer. They are respectively designed to take measurements of the absolute Extragalactic Background Light (EBL) spectrum, and foreground zodiacal light. In this poster we present the specifications for both CIBER imagers and detail how the fluctuations from galaxies during reionization will be measured.

  1. Background and introduction

    DEFF Research Database (Denmark)

    2012-01-01

    background information to understand the following chapters in this book. Research limitations: The chapter is mainly based on the experience and knowledge of the editors. It does not include original research but provides an introductory overview of the book. Originality/value: This chapter takes a look......Purpose: To explain the purpose and background of this book and introduce the three basic perspectives behind the research presented as well as the structure and editing process of the book. Methodology: The editors shared and discussed individual contributions to this chapter, based on their own...... expertise, the involvement in the process leading to this the book including a number of workshops, and a literature review of the development of their disciplinary fields: Facilities Management (FM), Corporate Real Estate Management (CREM) and Business to Business (B2B) Marketing. Findings: The difference...

  2. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  3. A 1.5k x 1.5k class photon counting HgCdTe linear avalanche photo-diode array for low background space astronomy in the 1-5micron infrared

    Science.gov (United States)

    Hall, Donald

    Under a current award, NASA NNX 13AC13G "EXTENDING THE ASTRONOMICAL APPLICATION OF PHOTON COUNTING HgCdTe LINEAR AVALANCHE PHOTODIODE ARRAYS TO LOW BACKGROUND SPACE OBSERVATIONS" UH has used Selex SAPHIRA 320 x 256 MOVPE L-APD HgCdTe arrays developed for Adaptive Optics (AO) wavefront (WF) sensing to investigate the potential of this technology for low background space astronomy applications. After suppressing readout integrated circuit (ROIC) glow, we have placed upper limits on gain normalized dark current of 0.01 e-/sec at up to 8 volts avalanche bias, corresponding to avalanche gain of 5, and have operated with avalanche gains of up to several hundred at higher bias. We have also demonstrated detection of individual photon events. The proposed investigation would scale the format to 1536 x 1536 at 12um (the largest achievable in a standard reticule without requiring stitching) while incorporating reference pixels required at these low dark current levels. The primary objective is to develop, produce and characterize a 1.5k x 1.5k at 12um pitch MOVPE HgCdTe L-APD array, with nearly 30 times the pixel count of the 320 x 256 SAPHIRA, optimized for low background space astronomy. This will involve: 1) Selex design of a 1.5k x 1.5k at 12um pitch ROIC optimized for low background operation, silicon wafer fabrication at the German XFab foundry in 0.35 um 3V3 process and dicing/test at Selex, 2) provision by GL Scientific of a 3-side close-buttable carrier building from the heritage of the HAWAII xRG family, 3) Selex development and fabrication of 1.5k x 1.5k at 12 um pitch MOVPE HgCdTe L-APD detector arrays optimized for low background applications, 4) hybridization, packaging into a sensor chip assembly (SCA) with initial characterization by Selex and, 5) comprehensive characterization of low background performance, both in the laboratory and at ground based telescopes, by UH. The ultimate goal is to produce and eventually market a large format array, the L

  4. Acupuncture or Low Frequency Infrared Treatment for Low Back Pain in Chinese Patients: A Discrete Choice Experiment

    OpenAIRE

    Li-Chia Chen; Li-Jen Cheng; Yan Zhang; Xin He; Knaggs, Roger D.

    2015-01-01

    Acupuncture is a popular but controversial treatment option for low back pain. In China, it is practised as traditional Chinese medicine; other treatment strategies for low back pain are commonly practised as Western medicine. Research on patient preference for low back-pain treatment options has been mainly conducted in Western countries and is limited to a willingness-to-pay approach. A stated-preference, discrete choice experiment was conducted to determine Chinese patient preferences and ...

  5. Performance of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) high-resolution near-infrared multi-object fiber spectrograph

    Science.gov (United States)

    Wilson, John C.; Hearty, F.; Skrutskie, M. F.; Majewski, S. R.; Schiavon, R.; Eisenstein, D.; Gunn, J.; Holtzman, J.; Nidever, D.; Gillespie, B.; Weinberg, D.; Blank, B.; Henderson, C.; Smee, S.; Barkhouser, R.; Harding, A.; Hope, S.; Fitzgerald, G.; Stolberg, T.; Arns, J.; Nelson, M.; Brunner, S.; Burton, A.; Walker, E.; Lam, C.; Maseman, P.; Barr, J.; Leger, F.; Carey, L.; MacDonald, N.; Ebelke, G.; Beland, S.; Horne, T.; Young, E.; Rieke, G.; Rieke, M.; O'Brien, T.; Crane, J.; Carr, M.; Harrison, C.; Stoll, R.; Vernieri, M.; Shetrone, M.; Allende-Prieto, C.; Johnson, J.; Frinchaboy, P.; Zasowski, G.; Garcia Perez, A.; Bizyaev, D.; Cunha, K.; Smith, V. V.; Meszaros, Sz.; Zhao, B.; Hayden, M.; Chojnowski, S. D.; Andrews, B.; Loomis, C.; Owen, R.; Klaene, M.; Brinkmann, J.; Stauffer, F.; Long, D.; Jordan, W.; Holder, D.; Cope, F.; Naugle, T.; Pfaffenberger, B.; Schlegel, D.; Blanton, M.; Muna, D.; Weaver, B.; Snedden, S.; Pan, K.; Brewington, H.; Malanushenko, E.; Malanushenko, V.; Simmons, A.; Oravetz, D.; Mahadevan, S.; Halverson, S.

    2012-09-01

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) uses a dedicated 300-fiber, narrow-band near-infrared (1.51-1.7 μm), high resolution (R~22,500) spectrograph to survey approximately 100,000 giant stars across the Milky Way. This three-year survey, in operation since late-summer 2011 as part of the Sloan Digital Sky Survey III (SDSS III), will revolutionize our understanding of the kinematical and chemical enrichment histories of all Galactic stellar populations. We present the performance of the instrument from its first year in operation. The instrument is housed in a separate building adjacent to the 2.5-m SDSS telescope and fed light via approximately 45-meter fiber runs from the telescope. The instrument design includes numerous innovations including a gang connector that allows simultaneous connection of all fibers with a single plug to a telescope cartridge that positions the fibers on the sky, numerous places in the fiber train in which focal ratio degradation had to be minimized, a large mosaic-VPH (290 mm x 475 mm elliptically-shaped recorded area), an f/1.4 six-element refractive camera featuring silicon and fused silica elements with diameters as large as 393 mm, three near-infrared detectors mounted in a 1 x 3 mosaic with sub-pixel translation capability, and all of these components housed within a custom, LN2-cooled, stainless steel vacuum cryostat with dimensions 1.4-m x 2.3-m x 1.3-m.

  6. Computational Chemistry Meets Experiments for Explaining the Behavior of Bibenzyl: A Thermochemical and Spectroscopic (Infrared, Raman, and NMR) Investigation.

    Science.gov (United States)

    Latouche, Camille; Barone, Vincenzo

    2014-12-09

    The structure, conformational behavior, and spectroscopic parameters of bibenzyl have been investigated by a computational protocol including proper treatment of anharmonic and hindered rotor contributions. Conventional hybrid functionals overstabilize the anti conformer while low-order post-Hartree-Fock (MP2) approaches strongly favor the gauche conformer. However, inclusion of semiempirical dispersion effects in density functionals or coupled cluster post-Hartree-Fock models agree in forecasting the simultaneous presence of both conformers in the gas phase with a slightly larger stability (0.7 kcal·mol(-1)) of the gauche conformer. Addition of thermal and entropic effects finally leads to very close Gibbs free energies for both conformers and, thus, to a slight preference for the gauche form due to statistical factors (2 vs 1). The situation remains essentially the same in solution. On these grounds, perturbative vibrational computations including both electrical and mechanical anharmonicities lead to IR and Raman spectra in remarkable agreement with experiment. Full assignment of the IR spectra explains the presence of peaks from gauche or anti conformers. Comparison between computed and experimental Raman spectra confirms that both conformers are present in liquid phase, whereas the anti conformer seems to be preponderant in the solid state. Also computed NMR parameters are in good agreement with experiment.

  7. submitter Study of possible Supersymmetric processes and Mini Black Hole production and comparison to background events with high transverse energy in the ATLAS experiment

    CERN Document Server

    Melamed-Katz, Arie

    2009-01-01

    The ATLAS detector, which was installed at one of the interaction points of the Large Hadron Collider (LHC), has the capability to discover 'new physics' beyond the Standard Model (SM) already during its first year of operation. In this work an assessment of ATLAS capabilities regarding the detection of some 'new physics' signals is performed. In the course of this research all relevant SM background sources were produced. These sources were studied with several simulation tools and the results are compared. In the scope of these background studies, a verification procedure that relies on expected SM production rates was developed. This procedure is able to distinguish between new physics and a faked one originating in malfunctioning detector. Supersymmetry (SUSY) is one of the best candidates for the theory 'beyond the Standard Model'. It predicts the existence of new symmetry between bosons and fermions, and assumes a new fermion partner for each SM boson and a new boson partner for each SM fermion. A maj...

  8. Infrared thermography

    CERN Document Server

    Meola, Carosena

    2012-01-01

    This e-book conveys information about basic IRT theory, infrared detectors, signal digitalization and applications of infrared thermography in many fields such as medicine, foodstuff conservation, fluid-dynamics, architecture, anthropology, condition monitoring, non destructive testing and evaluation of materials and structures.

  9. LHCb: Beam and Background Monitoring and the Upgrade of the Timing and Fast Control System of the LHCb experiment at CERN

    CERN Document Server

    Alessio, F

    2009-01-01

    The LHCb experiment at CERN is preparing for first real data taking, foreseen by the end of the year 2009 with the start-up of the LHC. A large amount of work of commissioning, tests and improvements of the full detector has been done in order to optimize its performance. During my first year as a Doctoral Student at CERN, I have been working on the timing and readout control of the LHCb experiment in the frame of the LHCb Online group. The group is responsible for the full data acquisition of the LHCb experiment, from the Front-End Electronics (FEE) to the storage of the data for offline analysis, as well as the Timing and Fast Control (TFC) system. The latter controls and distributes centrally timing and trigger information, as well as synchronous and asynchronous commands to the readout system. It is also responsible for receiving and adjusting the bunch and orbit clocks of the LHC machine and distributing it to the electronics of the whole experiment. It is of vital importance to assure that the timing o...

  10. The Cosmic Background Explorer Satellite

    Science.gov (United States)

    Mather, J.; Kelsall, T.

    1980-01-01

    The Cosmic Background Explorer (COBE) satellite, planned for launch in 1985, will measure the diffuse infrared and microwave radiation of the universe over the entire wavelength range from a few microns to 1.3 cm. It will include three instruments: a set of microwave isotropy radiometers at 23, 31, 53, and 90 GHz, an interferometer spectrometer from 1 to 100/cm, and a filter photometer from 1 to 300 microns. The COBE satellite is designed to reach the sensitivity limits set by foreground sources such as the interstellar and interplanetary dust, starlight, and galactic synchrotron radiation, so that a diffuse residual radiation may be interpreted unambiguously as extragalactic

  11. Global optimization of the infrared matrix-assisted laser desorption electrospray ionization (IR MALDESI) source for mass spectrometry using statistical design of experiments.

    Science.gov (United States)

    Barry, Jeremy A; Muddiman, David C

    2011-12-15

    Design of experiments (DOE) is a systematic and cost-effective approach to system optimization by which the effects of multiple parameters and parameter interactions on a given response can be measured in few experiments. Herein, we describe the use of statistical DOE to improve a few of the analytical figures of merit of the infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source for mass spectrometry. In a typical experiment, bovine cytochrome c was ionized via electrospray, and equine cytochrome c was desorbed and ionized by IR-MALDESI such that the ratio of equine:bovine was used as a measure of the ionization efficiency of IR-MALDESI. This response was used to rank the importance of seven source parameters including flow rate, laser fluence, laser repetition rate, ESI emitter to mass spectrometer inlet distance, sample stage height, sample plate voltage, and the sample to mass spectrometer inlet distance. A screening fractional factorial DOE was conducted to designate which of the seven parameters induced the greatest amount of change in the response. These important parameters (flow rate, stage height, sample to mass spectrometer inlet distance, and laser fluence) were then studied at higher resolution using a full factorial DOE to obtain the globally optimized combination of parameter settings. The optimum combination of settings was then compared with our previously determined settings to quantify the degree of improvement in detection limit. The limit of detection for the optimized conditions was approximately 10 attomoles compared with 100 femtomoles for the previous settings, which corresponds to a four orders of magnitude improvement in the detection limit of equine cytochrome c.

  12. Sentinel Node Mapping Using Indocyanine Green and Near-infrared Fluorescence Imaging Technology for Uterine Malignancies: Preliminary Experience With the Da Vinci Xi System.

    Science.gov (United States)

    Siesto, Gabriele; Romano, Fabrizio; Fiamengo, Barbara; Vitobello, Domenico

    2016-01-01

    Sentinel lymph node (SLN) mapping has emerged as the new frontier for the surgical staging of apparently early-stage cervical and endometrial cancer. Different colorimetric and radioactive tracers, alone and in combination, have been proposed with encouraging results. Fluorometric mapping using indocyanine green (ICG) appears to be a suitable and attractive alternative to provide reliable staging [1-4]. In this video, we present the technique of SLN mapping in 2 cases (1 endometrial and 1 cervical cancer, respectively) using ICG and the near-infrared technology provided by the newest Da Vinci Xi robotic system (Intuitive Surgical Inc., Sunnyvale, CA). Together we report the results of our preliminary experience on the first 20 cases performed. The new robotic Da Vinci Xi system was available at our institution since May 2015. Upon institutional review board/ethical committee approval, all consecutive patients with early-stage endometrial and cervical cancer who were judged suitable for robotic surgery have been enrolled for SLN mapping with ICG. We adopted the Memorial Sloan Kettering Cancer Center SLN algorithm; the tracer was delivered into the cervix in all cases. Four milliliters (1.25 mg/mL) of ICG was injected divided into the 3- and 9-o'clock positions of the cervix alone, with 1 mL deep into the stroma and 1 mL submucosally at the skin incision. Sentinel lymph nodes were examined with a protocol including both ultrastaging with immunohistochemistry [3] and 1-step nucleic acid amplification assay [5,6] under a parallel protocol of study. During the study period, 20 cases were managed; 14 and 6 patients had endometrial and cervical cancer, respectively. SLN was detected in all cases (20/20, 100%). Bilateral SLNs were detected in 17 of 20 (85.0%) cases. Based on preoperative and intraoperative findings, 13 (65.0%) patients received systematic pelvic lymphadenectomy after SLN mapping. Three (15.0%) patients had microscopic nodal metastases on SLN. No

  13. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    Science.gov (United States)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  14. High-sensitive spectrometer of fast neutrons and the results of fast neutron background flux measurements at the Gallium-Germanium Solar Neutrino Experiment

    CERN Document Server

    Abdurashitov, J N; Kalikhov, A V; Matushko, V L; Shikhin, A A; Yants, V E; Zaborskaia, O S

    2002-01-01

    The principle of operation, design, registration system and main characteristics of a fast neutron spectrometer are described. The spectrometer is intended for direct measurements of ultra low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10 sup - sup 7 cm sup - sup 2 s sup - sup 1 and lower. The detection efficiency of fast neutrons with simultaneous energy measurement was determined from Monte-Carlo simulation to be equal to 0.11+-0.01. The background counting rate in the detector corresponds to a neutron flux of (6.5+-2.1)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The natural neutron flux from the surrounding mine rock at the depth of 4600 m of water equivalent was measured to be (7.3+-2.4)x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in the range 1.0-11.0 MeV. The flux of fast neutrons in the SAGE main room was measured to be <2.3x10 sup - sup 7 cm sup - sup 2 s sup - sup 1 in 1.0-11.0 MeV energy range.

  15. A Cherenkov-based Beam Loss Scintillator system for beam, background and online luminosity monitoring at the LHCb experiment at CERN

    CERN Document Server

    Alessio, F; Jacobsson, R

    2013-01-01

    The installation of a scintillator-based system in the LHCb cavern was initially proposed in order to observe injection problems around the LHCb interaction region. Thanks to the fact that LHCb had already developed a custom-made electronics board (BPIM) for the LHCb beam pickups and global LHCb timing monitoring, a complete, inexpensive but flexible and robust system was quickly developed and installed few cm from the beam pipe just in front of the LHCb VELO detector in time for the very first beams injected in the LHC. The current and final system – commonly referred to as Beam Loss Scintillator (BLS) system - ultimately played a central role in the fast beam, background and online luminosity monitoring at LHCb. In this paper, the features of the detector – based on quartz radiator and Cherenkov light - are described, including the functionalities that the system acquired during the proton-proton physics programmes in 2009- 2013 thanks to its flexibility, reliability and sensitivity to beam hal...

  16. An Unmanned Airship Thermal Infrared Remote Sensing System for Low-Altitude and High Spatial Resolution Monitoring of Urban Thermal Environments: Integration and an Experiment

    Directory of Open Access Journals (Sweden)

    Peng Ren

    2015-10-01

    Full Text Available Satellite remote sensing data that lacks spatial resolution and timeliness is of limited ability to access urban thermal environment on a micro scale. This paper presents an unmanned airship low-altitude thermal infrared remote sensing system (UALTIRSS, which is composed of an unmanned airship, an onboard control and navigation subsystem, a task subsystem, a communication subsystem, and a ground-base station. Furthermore, an experimental method and an airborne-field experiment for collecting land surface temperature (LST were designed and conducted. The LST pattern within 0.8-m spatial resolution and with root mean square error (RMSE value of 2.63 °C was achieved and analyzed in the study region. Finally, the effects of surface types on the surrounding thermal environment were analyzed by LST profiles. Results show that the high thermal resolution imagery obtained from UALTIRSS can provide more detailed thermal information, which are conducive to classify fine urban material and assess surface urban heat island (SUHI. There is a significant positive correlation between the average LST of profiles and the percent impervious surface area (ISA% with R2 around 0.917. Overall, UALTIRSS and the retrieval method were proved to be low-cost and feasible for studying micro urban thermal environments.

  17. Characterization of silicon micro-strip sensors with a pulsed infra-red laser system for the CBM experiment at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Pradeep [Goethe University, Frankfurt am Main (Germany); GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt (Germany); Eschke, Juergen [GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt (Germany); Facility for Anti-proton and Ion Research, GmbH, Darmstadt (Germany); Collaboration: CBM-Collaboration

    2015-07-01

    The Silicon Tracking System (STS) of the CBM experiment at FAIR is composed of 8 tracking stations comprising of 1292 double-sided silicon micro-strip sensors. A Laser Test System (LTS) has been developed for the quality assurance of prototype sensors. The aim is to scan sensors with a pulsed infra-red laser driven by step motor to determine the charge sharing in-between strips and to measure qualitative uniformity of the sensor response over the whole active area. Several prototype sensors with strip pitch of 50 and 58 μm have been tested, as well as a prototype module with realistic mechanical arrangement of sensor and read-out cables. The LTS is designed to measure sensor response in an automatized procedure across the sensor with focused laser beam (spot-size ∼ 12 μm, wavelength = 1060 nm). The pulse with duration (∼ 10 ns) and power (∼ 5 mW) of the laser pulses is selected such, that the absorption of the laser light in the 300 μm thick silicon sensors produces a number of about 24000 electrons, which is similar to the charge created by minimum ionizing particles (MIP) in these sensors. Results from laser scans of prototype sensors and detector module are reported.

  18. Validating an infrared thermal switch as a novel access technology

    Directory of Open Access Journals (Sweden)

    Memarian Negar

    2010-08-01

    Full Text Available Abstract Background Recently, a novel single-switch access technology based on infrared thermography was proposed. The technology exploits the temperature differences between the inside and surrounding areas of the mouth as a switch trigger, thereby allowing voluntary switch activation upon mouth opening. However, for this technology to be clinically viable, it must be validated against a gold standard switch, such as a chin switch, that taps into the same voluntary motion. Methods In this study, we report an experiment designed to gauge the concurrent validity of the infrared thermal switch. Ten able-bodied adults participated in a series of 3 test sessions where they simultaneously used both an infrared thermal and conventional chin switch to perform multiple trials of a number identification task with visual, auditory and audiovisual stimuli. Participants also provided qualitative feedback about switch use. User performance with the two switches was quantified using an efficiency measure based on mutual information. Results User performance (p = 0.16 and response time (p = 0.25 with the infrared thermal switch were comparable to those of the gold standard. Users reported preference for the infrared thermal switch given its non-contact nature and robustness to changes in user posture. Conclusions Thermal infrared access technology appears to be a valid single switch alternative for individuals with disabilities who retain voluntary mouth opening and closing.

  19. QCD background estimation for Supersymmetry searches with jets and missing transverse momentum with the ATLAS experiment at the Large Hadron Collider

    CERN Document Server

    Stoerig, Kathrin

    Some of the most interesting questions mankind might ask are closely related to the field of astro- and particle physics: What are the fundamental building blocks of our universe and how do they interact? Will there eventually be a theory that can describe everything? During the last decades, particle collision experiments unraveled various aspects of these mysteries - and a very successful theory emerged: the Standard Model (SM) of particle physics: As of today’s knowledge, matter consists of fermions, the quarks and the leptons. Among these, four fundamental interactions are known: the strong, the weak, the electromagnetic and the gravitational force. These interactions are mediated by bosons (force carriers). While the SM describes the first three interactions with high precision, various fundamental questions remain unanswered - such as the structure in the SM itself, the origin of dark matter/energy and the matter-/antimatter asymmetry. One aesthetically appealing solution is Supersymmetry (SUSY), whic...

  20. Infrared Imaging

    Science.gov (United States)

    Danchi, W.; Lawson, P.; Absil, O.; Akeson, R.; Bally, J.; Barry, R.; Beichman, C.; Belu, A.; Boyce, M.; Breckinridge, J.; Burrows, A.; Chen, C.; Cole, D.; Crisp, D.; Danner, R.; Deroo, P.; Coudé du Foresto, V.; Defrère, D.; Ebbets, D.; Falkowski, P.; Gappinger, R.; Haugabook, I.; Hanot, C.; Henning, T.; Hinz, P.; Hollis, J.; Hunyadi, S.; Hyland, D.; Johnston, K.; Kaltenegger, L.; Kasting, J.; Kenworthy, M.; Ksendzov, A.; Lane, B.; Laughlin, G.; Lay, O.; Liseau, R.; Lopez, B.; Millan-Gabet, R.; Martin, S.; Mawet, D.; Mennesson, B.; Monnier, J.; Murakami, N.; Noecker, C.; Nishikawa, J.; Pesesen, M.; Peters, R.; Quillen, A.; Ragland, S.; Rinehart, S.; Rottgering, H.; Scharf, D.; Serabyn, G.; Tamura, M.; Tehrani, M.; Traub, W.; Unwin, S.; Wilner, D.; Woilliez, J.; Woolf, N.; Zhao, M.

    2009-03-01

    A mid-infrared mission would enable the detection of biosignatures of Earth-like exoplanets around more than 150 nearby stars. The mid-infrared spectral region is attractive for characterizing exoplanets because contrast with the parent star brightness is more favorable than in the visible (10 million vs. 10 billion), and because mid-infrared light probes deep into a planet's troposphere. Furthermore, the mid-infrared offers access to several strong molecular features that are key signs of life, and also provides a measure of the effective temperature and size of a planet. Taken together, an infrared mission plus a visible one would provide a nearly full picture of a planet, including signs of life; with a measure of mass from an astrometric mission, we would have a virtually complete picture. A small infrared mission would have several telescopes that are rigidly connected, with a science return from the detection and characterization of super-Earth sized to larger planets near the HZ, plus a direct measure of the exozodi brightness in the HZ. In a large infrared mission, with formation-flying telescopes, planets from an Earth-twin and upwards in mass could be detected and characterized, as well as the exozodi. If proceeded by an astrometric mission, the detection phase could be skipped and the mission devoted to characterization, as in the visible case; lacking an astrometric mission, an infrared one could proceed alone, as was discussed for a visible coronograph, and with similar caveats. The technology needed for a large formation-flying mission is similar to that for a small connected-element one (e.g., cryogenics and detectors), with the addition of formationflying technology. The technology is now in hand to implement a probe-scale mission; starlight suppression has even been demonstrated to meet the requirements of a flagship mission. However, additional development of formation-flying technology is needed, particularly in-space testing of sensors and

  1. Background and introduction

    DEFF Research Database (Denmark)

    2012-01-01

    by their particular theories and conceptual analyses, data, tools, and best practices, with a focus on respectively costs and benefits of facilities and services, alignment of corporate and public real estate to organizational objectives and organisational performance, and relationship management in market...... background information to understand the following chapters in this book. Research limitations: The chapter is mainly based on the experience and knowledge of the editors. It does not include original research but provides an introductory overview of the book. Originality/value: This chapter takes a look...... behind the scenes of the making of this book and connects contributions from three different fields - FM, CREM, and B2B marketing - to shed more light on the concept of added value of FM. It serves as an introduction to the research presented in the other chapters in this book....

  2. 背景反思模式在密立根油滴实验中的应用%Application of background reflection mode in Millikan oil-drop experiment

    Institute of Scientific and Technical Information of China (English)

    解光亮; 董有尔; 陈宝明

    2011-01-01

    以密立根油滴实验为例,介绍了在物理实验教学中,如何应用背景反思模式,启迪学生对物理实验进行全方位多角度的反思,不仅拓展了学生的视野,对学生的科学思维进行全面训练,而且极大地调动了学生对物理实验的兴趣和积极性,有效培养了学生的实践能力和创新能力.%Taking Millikan oil-drop experiment as an example, this article introduces how to apply the background reflection mode to enlighten the students on a full range of physics experiments multi-angle reflection in physics experiment teaching. It can not only expand the horizons of students, scientific thinking for students' comprehensive training on the background reflection mode, but also greatly arouse the enthusiasm of students in physics experiments and enthusiasm to effectively train the students practical skills and innovative ability.

  3. Mid-infrared picosecond pump-dump-probe and pump-repump-probe experiments to resolve a ground-state intermediate in cyanobacterial phytochrome Cph1.

    Science.gov (United States)

    van Wilderen, Luuk J G W; Clark, Ian P; Towrie, Michael; van Thor, Jasper J

    2009-12-24

    Multipulse picosecond mid-infrared spectroscopy has been used to study photochemical reactions of the cyanobacterial phytochrome photoreceptor Cph1. Different photophysical schemes have been discussed in the literature to describe the pathways after photoexcitation, particularly, to identify reaction phases that are linked to photoisomerisation and electronic decay in the 1566-1772 cm(-1) region that probes C=C and C=O stretching modes of the tetrapyrrole chromophore. Here, multipulse spectroscopy is employed, where, compared to conventional visible pump-mid-infrared probe spectroscopy, an additional visible pulse is incorporated that interacts with populations that are evolving on the excited- and ground-state potential energy surfaces. The time delays between the pump and the dump pulse are chosen such that the dump pulse interacts with different phases in the reaction process. The pump and dump pulses are at the same wavelength, 640 nm, and are resonant with the Pr ground state as well as with the excited state and intermediates. Because the dump pulse additionally pumps the remaining, partially recovered, and partially oriented ground-state population, theory is developed for estimating the fraction of excited-state molecules. The calculations take into account the model-dependent ground-state recovery fraction, the angular dependence of the population transfer resulting from the finite bleach that occurs with linearly polarized intense femtosecond optical excitation, and the partially oriented population for the dump field. Distinct differences between the results from the experiments that use a 1 or a 14 ps dump time favor a branching evolution from S1 to an excited state or reconfigured chromophore and to a newly identified ground-state intermediate (GSI). Optical dumping at 1 ps shows the instantaneous induced absorption of a delocalized C=C stretching mode at 1608 cm(-1), where the increased cross section is associated with the electronic ground

  4. An Inexpensive Digital Infrared Camera

    Science.gov (United States)

    Mills, Allan

    2012-01-01

    Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)

  5. The Influence of Urban Emissions on Background Aerosols and Trace Gases in Amazonia as Seen in the GoAmazon2014/2015 Experiment.

    Science.gov (United States)

    Artaxo, P.; Martin, S. T.; Barbosa, H. M.; Brito, J.; Carbone, S.; Rizzo, L. V.; Andreae, M. O.; Pöhlker, C.; Souza, R. A. F. D.

    2015-12-01

    As part of the GoAmazon2014/2015 experiment, several aerosol and trace gas monitoring stations are being operated for two years before and after the Manaus urban plume in Central Amazonia. Three sites are being operated in pristine conditions, with atmospheric properties under natural biogenic conditions. These three sites named T0 are ATTO (Amazon Tall Tower Observatory), ZF2 and EMBRAPA. After the air masses are exposed to the Manaus plume, one site (called T2) is being operated under the direct influence of the Manaus plume at 5 Km downwind. Finally, at about 150 Km downwind of Manaus is the T3 Manacapuru site. Aerosol chemical composition is being analysed using filters for fine (PM2.5) and coarse mode aerosol as well as three Aerodyne ACSM (Aerosol Chemical Speciation Monitors) instruments. Optical properties were measured with several AE33 aethalometers and MAAP, and multi wavelengths nephelometers. Aerosol size distribution is determined using scanning mobility particle sizers. The aerosol column is measures using AERONET sunphotometers before and after the Manaus plume, as well as several Lidar systems. The three sites before the Manaus plume show remarkable similar variability in aerosol concentrations and optical properties. This pattern is very different at the T2 site, with large aerosol concentrations enhancing aerosol absorption and scattering significantly as a result of the Manaus pollution plume. The aerosol is very oxidized before being exposed to the Manaus plume, and this pattern changes significantly for T2 and T3 sites, with a much higher presence of less oxidized aerosol. Typical ozone concentrations at mid-day before Manaus plume is a low 10-12 ppb, value that changes to 50-70 ppb for air masses suffering the influence of Manaus plume. Aerosol size distribution also change significantly, with stronger presence of nucleation mode particles. A detailed comparison of aerosol characteristics and composition for the several sites will be

  6. Ultraviolet Background Radiation

    Science.gov (United States)

    Henry, R. C.; Murthy, J.

    1993-12-01

    The UVX experiment was carried on the Space Shuttle Columbia between 1986 January 12 and 19 (STS-61C). Several ultraviolet spectrometers were used to obtain measurements of the diffuse ultraviolet background at 8 locations in the sky. We have reanalysed the UVX measurements of the surface brightness of the diffuse ultraviolet background above b = 40 using the dust-scattering model of Onaka & Kodaira (1991), which explicitly takes into account the variation of the source function with galactic longitude. The range of allowed values of interstellar grain albedoJa, and scattering asymmetry parameter g, is considerably expanded over those of a previous analysis. The new chi square probability contours come close to, but do not include, the values of a and g found for the interstellar grains by Witt et al. (1992) using the Ultraviolet Imaging Telescope (UIT) on the Astro mission. If we hypothesize in additon to the dust-scattered light an extragalactic component, of 300 1 100 photons cm-2 s-1 sr-1 A-1, attenuated by a cosecant b law, the new reduction of the UVX data gives complete consistency with the Witt et al. determination of the optical parameters of the grains in the ultraviolet. This work was supported by United States Air Force Contract F19628-93-K-0004, and by National Aeronautics and Space Administration grant NASA NAG5-619. We are grateful for the encouragement of Dr. Stephan Price, and we thank Dr. L. Danly for information. Onaka, T., & Kodaira, K. 1991, ApJ, 379, 532 Witt, A. N., Petersohn, J. K., Bohlin, R. C., O'Connell, R. W., Roberts, M. S., Smith, A. M., & Stecher, T. P. 1992, ApJ, 395, L5

  7. Cosmic Microwave Background Mapping

    Science.gov (United States)

    Verkhodanov, O. V.; Doroshkevich, A. G.

    2012-03-01

    The last decade of research in cosmology was connected with the ambitious experiments including space and ground base observations. Among the most impressive results of these investigations are the measurements of the cosmic microwave background (CMB) radiation like WMAP* and Planck. Exactly from the CMB studies, we have started the epoch of the precision cosmology when generally the values of cosmological parameters have been known and present research is devoted to improvement of the precision. These achievements are connected with both the creation of the new facilities in millimeter and submillimeter astronomy (e.g., satellites, receivers, antennas, computers) and development of the methods for the CMB data analysis. Actually, the process of data analysis contains several technical stages including 1. Registration of time-ordered data (TOD) 2. Pixelization of the CMB data - map preparation 3. Component separation 4. Map statistics analysis 5. Map - spherical harmonics transformation 6. C(l)-spectrum calculation and spectrum statistics analysis 7. Cosmological parameters estimation Starting from the cosmic background explorer (COBE) experiment using the so-called Quadrilateralized Sky Cube Projection (see [1-3]), the problem of the whole sky CMB pixelization has attracted great interest and many such schemes were developed. Let us note however that accurate pixelization of the CMB data on the sphere is very important but not the final step of analysis. Usually, the next step implies the determination of the coefficients of the spherical harmonic decomposition of the CMB signal for both anisotropy and polarization. This means that some of the pixelization schemes provide a very accurate map but are inconvenient for further decomposition. This also means that the choice of suitable pixelization schemes depends upon the general goals of the investigation. In this review, we consider several of the most popular sky map pixelization schemes and link them with the

  8. Building Background Knowledge

    Science.gov (United States)

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley

    2014-01-01

    This article make a case for the importance of background knowledge in children's comprehension. It suggests that differences in background knowledge may account for differences in understanding text for low- and middle-income children. It then describes strategies for building background knowledge in the age of common core standards.

  9. Data-driven background predictions for a search of direct gluino pair production in the single-lepton final state using 13 TeV pp-collisions at the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lobanov, Artur; Seitz, Claudia; Melzer-Pellmann, Isabell [DESY, Hamburg (Germany)

    2016-07-01

    We present a search for direct gluino-pair production in events with a single lepton using 13 TeV pp-collisions at the CMS experiment. This final state is characterised by high multiplicities of jets and b-quark jets, as well as a large scalar sum of all jet transverse momenta, and a large scalar sum of the transverse missing momentum and the lepton transverse momentum, called L{sub T}. The dominating Standard Model backgrounds in this phase-space are tt+jets and W+jets production. A data-driven method is used to estimate the background in the search regions. All backgrounds except for QCD in the (high ΔΦ(W,l)) signal regions are predicted by from the number of events in the low ΔΦ(W,l) region, with transfer factors determined also from data, while for the multi-jet events a fake-lepton enriched side-band is used. We conclude by showing predictions and final results from data corresponding to 2.1 fb{sup -1} integrated luminosity recorded with the CMS detector during the LHC Run2 in 2015.

  10. Exploration on collaboration of conducting designing experiments by students in different levels of language and knowledge background%不同民族和年级的学生协作开展设计性实验的探讨

    Institute of Scientific and Technical Information of China (English)

    赵红琼; 夏利宁; 张晓红; 王金泉; 姚刚

    2013-01-01

    针对新疆少数民族学生的实际情况加强实践环节的教学,将不同年级不同民族的学生组织在一起共同完成了生理学的设计性实验.在此基础上,探讨了对不同年级和不同民族的学生开设综合性和设计性实验的体会:正确认识综合性和设计性实验;注意实验的可行性;编写翔实的实验教学大纲;合理搭配民、汉语言学生和高、低年级学生;注重对学生协作能力的培养等.这种方式既提高学生对专业知识的理解,也锻炼了他们取长补短、团结协作的能力.%Aiming at students who are in different levels of Han language and knowledge background may have the professional knowledge differently in depth and breadth,minority language-speaking students have more difficulties in understanding obscure theoretical knowledge than Han language-speaking students.Therefore the enhancement of the experimental and practical learning segments is very helpful for minority language speaking students.In order to develop the advantages of them and to train their ability of collaboration,some comprehensive and designing experiments of animal physiology were conducted by organizing students in different levels of Han language-speaking and knowledge background.The experience what the authors learned from these experiments is discussed as fallows:firstly,having all students involving in the experiments fully understanding the meaning of a comprehensive and designing experiment; secondly,preparing the experimental teaching protocol in detail; thirdly,matching students reasonably in groups by Han language and minority language speaking,different grades and genders; fourthly,laying emphasis on the cultivation of collaboration ability for all students in the experiment; finally,showing the procedure how to carry out the designing experiment,the effect of herbs from Xinjiang on animals by physiological methods.

  11. Cosmic Microwave Background Data Analysis

    Science.gov (United States)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    About 400,000 years after the Big Bang the temperature of the Universe fell to about a few thousand degrees. As a result, the previously free electrons and protons combined and the Universe became neutral. This released a radiation which we now observe as the cosmic microwave background (CMB). The tiny fluctuations* in the temperature and polarization of the CMB carry a wealth of cosmological information. These so-called temperature anisotropies were predicted as the imprints of the initial density perturbations which gave rise to the present large-scale structures such as galaxies and clusters of galaxies. This relation between the present-day Universe and its initial conditions has made the CMB radiation one of the most preferred tools to understand the history of the Universe. The CMB radiation was discovered by radio astronomers Arno Penzias and Robert Wilson in 1965 [72] and earned them the 1978 Nobel Prize. This discovery was in support of the Big Bang theory and ruled out the only other available theory at that time - the steady-state theory. The crucial observations of the CMB radiation were made by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite [86]- orbited in 1989-1996. COBE made the most accurate measurements of the CMB frequency spectrum and confirmed it as being a black-body to within experimental limits. This made the CMB spectrum the most precisely measured black-body spectrum in nature. The CMB has a thermal black-body spectrum at a temperature of 2.725 K: the spectrum peaks in the microwave range frequency of 160.2 GHz, corresponding to a 1.9mmwavelength. The results of COBE inspired a series of ground- and balloon-based experiments, which measured CMB anisotropies on smaller scales over the next decade. During the 1990s, the first acoustic peak of the CMB power spectrum (see Figure 5.1) was measured with increasing sensitivity and by 2000 the BOOMERanG experiment [26] reported

  12. Infrared small target tracking by discriminative classification based on Gaussian mixture model in compressive sensing domain

    Science.gov (United States)

    Wang, Chuanyun; Song, Fei; Qin, Shiyin

    2017-02-01

    Addressing the problems of infrared small target tracking in forward looking infrared (FLIR) system, a new infrared small target tracking method is presented, in which features binding of both target gray intensity and spatial relationship is implemented by compressive sensing so as to construct the Gaussian mixture model of compressive appearance distribution. Subsequently, naive Bayesian classification is carried out over testing samples acquired with non-uniform sampling probability to identify the most credible location of targets from background scene. A series of experiments are carried out over four infrared small target image sequences with more than 200 images for each sequence, the results demonstrate the effectiveness and advantages of the proposed method in both success rate and precision rate.

  13. COBE DIRBE near-infrared polarimetry of the zodiacal light: Initial results

    Science.gov (United States)

    Berriman, G. B.; Boggess, N. W.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    This Letter describes near-infrared polarimetry of the zodiacal light at 2.2 micrometers, measured with the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The polarization is due to scattering of sunlight. The polarization vector is perpendicular to the scattering plane, and its observed amplitude on the ecliptic equator at an elongation of 90 deg and ecliptic longitude of 10 deg declines from 12.0 +/- 0.4% at 1.25 micrometers to 8.0 +/- 0.6% at 3.5 micrometers (cf. 16% in the visible); the principal source of uncertainty is photometric noise due to stars. The observed near-infrared colors at this location are redder than Solar, but at 3.5 micrometers this is due at least in part to the thermal emission contribution from the interplanetary dust. Mie theory calculations show that both polarizations and colors are important in constraining models of interplanetary dust.

  14. Background music and cognitive performance.

    Science.gov (United States)

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance.

  15. Infrared retina

    Science.gov (United States)

    Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong

    2011-12-06

    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  16. Test and analysis of the infrared characteristic of the plume-smoke

    Science.gov (United States)

    Zhang, Xiaolong; Zhang, Guang; Chen, Dapeng; Dong, Yanbing

    2015-04-01

    The plume-smoke is one of the main infrared characteristic signal sources of the engine. In this paper, the infrared signal characteristic of a small test engine's plume-smoke is studied. We conduct a quantitative observation of some specific points in the movement path of the plume-smoke by the MW and LW infrared thermal imager. Through the analysis of the smokeless and smoke infrared sequential images, we can get the infrared radiation and the transmission characteristics of the plume-smoke and their variation law with time. Experiments show that there exists a critical temperature of the plume-smoke; the radiation of background can increase when the temperature of the plume-smoke is higher than the critical temperature. On the contrary, the radiation of background decreases when the temperature of the plume-smoke is lower than the critical temperature. In this paper, the research provides a reference for further study on the infrared characteristic of the plume-smoke.

  17. Gravitational Lensing of Cosmic Microwave Background Polarization

    CERN Document Server

    Ade, P A R; Anthony, A E; Arnold, K; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Schanning, I; Schenck, D E; Sherwin, B; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

    2013-01-01

    Primary fluctuations in both temperature and polarization of the Cosmic Microwave Background (CMB) reflect the properties of the Universe from the Big Bang until the photons decoupled from matter 380,000 years later. These primary fluctuations are then lensed by large-scale structures (such as clusters of galaxies and filaments of dark matter), with the result that the distribution and properties of dark matter, including the masses of neutrinos, can be determined more accurately by extracting the lensing information than through studying the primary fluctuations alone. Polarization lensing can give cleaner, higher resolution results than temperature lensing. The correlation of lensed CMB polarization with large-scale structure, traced through the Cosmic Infrared Background, was recently detected; however, this correlation does not trace all structure and depends on the relationship between the infrared flux from the galaxies and the underlying mass distribution. Here we report the detection of gravitational ...

  18. Extragalactic background light measurements and applications.

    Science.gov (United States)

    Cooray, Asantha

    2016-03-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

  19. Background simulations and shielding calculations

    Science.gov (United States)

    Kudryavtsev, Vitaly A.

    2011-04-01

    Key improvements in the sensitivity of the underground particle astrophysics experiments can only be achieved if the radiation causing background events in detectors is well understood and proper measures are taken to suppress it. The background radiation arising from radioactivity and cosmic-ray muons is discussed here together with the methods of its suppression. Different shielding designs are considered to attenuate gamma-rays and neutrons coming from radioactivity in rock and lab walls. Purity of materials used in detector construction is analysed and the background event rates due to the presence of radioactive isotopes in detector components are discussed. Event rates in detectors caused by muon-induced neutrons with and without active veto systems are presented leading to the requirements for the depth of an underground laboratory and the efficiency of the veto system.

  20. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  1. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2002-01-01

    This set of lectures provides an overview of the basic theory and phenomenology of the cosmic microwave background. Topics include a brief historical review; the physics of temperature and polarization fluctuations; acoustic oscillations of the primordial plasma; the space of inflationary cosmological models; current and potential constraints on these models from the microwave background; and constraints on inflation.

  2. Supersymmetric heterotic string backgrounds

    NARCIS (Netherlands)

    Gran, U.; Papadopoulos, G.; Roest, D.; Cvetič, M.

    2007-01-01

    We present the main features of the solution of the gravitino and dilatino Killing spinor equations derived in hep-th/0510176 and hep-th/0703143 which have led to the classification of geometric types of all type I backgrounds. We then apply these results to the supersymmetric backgrounds of the het

  3. The Athena Background

    Science.gov (United States)

    Piro, Luigi; Lotti, Simone; Macculi, Claudio; Molendi, Silvano; Eraerds, Tanja; Laurent, Philippe

    2015-09-01

    Estimating, reducing and controlling the residual particle background is fundamental for achieving the objectives of several science topics of Athena, in particular those connected with background dominated observations of faint and/or diffuse sources. This requires assessing the particle environment in L2, propagating the various particle components throughout the mirror, spacecraft, and instruments via proper modelling and simulations of various physical processes, implementing design and h/w measures at instrument and mission level to reduce the un-rejected background and identifying proper calibration methods to control the background variations. Likewise, an adequate knowledge of the XRB, made of components that may vary spatially or temporally, is required as well. Here we will review the present status of the background knowledge, and summarize the activities on-going within Athena at various levels.

  4. Target Detection over the Diurnal Cycle Using a Multispectral Infrared Sensor.

    Science.gov (United States)

    Zhao, Huijie; Ji, Zheng; Li, Na; Gu, Jianrong; Li, Yansong

    2016-12-29

    When detecting a target over the diurnal cycle, a conventional infrared thermal sensor might lose the target due to the thermal crossover, which could happen at any time throughout the day when the infrared image contrast between target and background in a scene is indistinguishable due to the temperature variation. In this paper, the benefits of using a multispectral-based infrared sensor over the diurnal cycle have been shown. Firstly, a brief theoretical analysis on how the thermal crossover influences a conventional thermal sensor, within the conditions where the thermal crossover would happen and why the mid-infrared (3~5 μm) multispectral technology is effective, is presented. Furthermore, the effectiveness of this technology is also described and we describe how the prototype design and multispectral technology is employed to help solve the thermal crossover detection problem. Thirdly, several targets are set up outside and imaged in the field experiment over a 24-h period. The experimental results show that the multispectral infrared imaging system can enhance the contrast of the detected images and effectively solve the failure of the conventional infrared sensor during the diurnal cycle, which is of great significance for infrared surveillance applications.

  5. Approach for moving small target detection in infrared image sequence based on reinforcement learning

    Science.gov (United States)

    Wang, Chuanyun; Qin, Shiyin

    2016-09-01

    Addressing the problems of moving small target detection in infrared image sequence caused by background clutter and target size variation with time, an approach for moving small target detection is proposed under a pipeline framework with an optimization strategy based on reinforcement learning. The pipeline framework is composed by pipeline establishment, target-background images separation, and target confirmation, in which the pipeline is established by designating several successive images with temporal sliding window, target-background images separation is dealt with low-rank and sparse matrix decomposition via robust principal component analysis, and target confirmation is achieved by employing a voting mechanism over more than one separated target images of the same input image. For unremitting optimization of target-background images separation, the weighting parameter of low-rank and sparse matrix decomposition is dynamically regulated by the way of reinforcement learning in consecutive detection, in which the complexity evaluation from sequential infrared images and results assessment of moving small target detection are integrated. The experiment results over four infrared small target image sequences with different cloudy sky backgrounds demonstrate the effectiveness and advantages of the proposed approach in both background clutter suppression and small target detection.

  6. Solar Tower Experiments for Radiometric Calibration and Validation of Infrared Imaging Assets and Analysis Tools for Entry Aero-Heating Measurements

    Science.gov (United States)

    Splinter, Scott C.; Daryabeigi, Kamran; Horvath, Thomas J.; Mercer, David C.; Ghanbari, Cheryl M.; Ross, Martin N.; Tietjen, Alan; Schwartz, Richard J.

    2008-01-01

    The NASA Engineering and Safety Center sponsored Hypersonic Thermodynamic Infrared Measurements assessment team has a task to perform radiometric calibration and validation of land-based and airborne infrared imaging assets and tools for remote thermographic imaging. The IR assets and tools will be used for thermographic imaging of the Space Shuttle Orbiter during entry aero-heating to provide flight boundary layer transition thermography data that could be utilized for calibration and validation of empirical and theoretical aero-heating tools. A series of tests at the Sandia National Laboratories National Solar Thermal Test Facility were designed for this task where reflected solar radiation from a field of heliostats was used to heat a 4 foot by 4 foot test panel consisting of LI 900 ceramic tiles located on top of the 200 foot tall Solar Tower. The test panel provided an Orbiter-like entry temperature for the purposes of radiometric calibration and validation. The Solar Tower provided an ideal test bed for this series of radiometric calibration and validation tests because it had the potential to rapidly heat the large test panel to spatially uniform and non-uniform elevated temperatures. Also, the unsheltered-open-air environment of the Solar Tower was conducive to obtaining unobstructed radiometric data by land-based and airborne IR imaging assets. Various thermocouples installed on the test panel and an infrared imager located in close proximity to the test panel were used to obtain surface temperature measurements for evaluation and calibration of the radiometric data from the infrared imaging assets. The overall test environment, test article, test approach, and typical test results are discussed.

  7. On Background Independence

    CERN Document Server

    Anderson, Edward

    2013-01-01

    This paper concerns what Background Independence itself is (as opposed to some particular physical theory that is background independent). The notions presented mostly arose from a layer-by-layer analysis of the facets of the Problem of Time in Quantum Gravity. Part of this coincides with two relational postulates which are thus identified as classical precursors of two of the facets of the Problem of Time. These are furthemore tied to the forms of each of the GR Hamiltonian and momentum constraints. Other aspects of Background Independence include the algebraic closure of these constraints, expressing physics in terms of beables, foliation independence as implemented by refoliation invariance, the reconstruction of spacetime from space. The final picture is that Background Independence - a philosophically desirable and physically implementable feature for a theory to have - has the facets of the Problem of Time among its consequences. Thus these arise naturally and are problems to be resolved, as opposed to ...

  8. Test method on infrared system range based on space compression

    Science.gov (United States)

    Chen, Zhen-xing; Shi, Sheng-bing; Han, Fu-li

    2016-09-01

    Infrared thermal imaging system generates image based on infrared radiation difference between object and background and is a passive work mode. Range is important performance and necessary appraised test item in appraisal test for infrared system. In this paper, aim is carrying out infrared system range test in laboratory , simulated test ground is designed based on object equivalent, background analog, object characteristic control, air attenuation characteristic, infrared jamming analog and so on, repeatable and controllable tests are finished, problem of traditional field test method is solved.

  9. Online RFC-PRM method for infrared target tracking

    Science.gov (United States)

    Zhou, Xiao; Hu, Ruolan; Xu, Yaming; Zhang, Guilin

    2009-10-01

    A novel online tracking method is proposed based on the response of feature combination (RFC) and relative position map (RPM). First, large numbers of features around the target are achieved after some designed filtering, then a suboptimal feature combination obtained by a given feature selection criteria can be used for next frame. The distinction between the target and background is maximized in the result image. Based on this distinction the target can be segmented out easily. While around the target there always exists some similar regions and will be residue left after filtering. To depress these clutters, the position relationship of local maximal response points cased by the similar regions is recorded as RPM and compared to the last frame. At last, the new feature combination is updated based on the new background around the target. The experiment using small infrared target sequence with different background texture conditions demonstrates the robustness of the new method.

  10. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  11. Passive infrared bullet detection and tracking

    Energy Technology Data Exchange (ETDEWEB)

    Karr, T.J.

    1994-12-31

    An apparatus and method for passively detecting a projectile such as, for example, a bullet using a passive infrared detector. A passive infrared detector is focused onto a region in which a projectile is expected to be located. Successive images of infrared radiation in the region are recorded. Background infrared radiation present in the region is suppressed such that second successive images of infrared radiation generated by the projectile as the projectile passes through the region are produced. A projectile path calculator determines the path and other aspects of the projectile by using the second successive images of infrared radiation generated by the projectile. The present invention, in certain embodiments, also determines the origin of the path of the projectile and takes a photograph of the area surrounding the origin and/or fires at least one projectile at the area surrounding the origin of the path of the projectile.

  12. Gravitational lensing effect and polarization of the cosmic microwave background in the PLANCK Experiment and post-planckian projects; Effet de lentilles gravitationnelles et polarisation du fond diffus cosmologique dans le cadre de l'experience PLANCK et de projets post-planckiens

    Energy Technology Data Exchange (ETDEWEB)

    Perotto, Laurence [Universite Paris 7 - Denis Diderot, UFR de Physique, 75205 Paris Cedex 13 (France)

    2006-01-15

    This thesis is motivated by the upcoming high-resolution, high-sensitivity microwave background experiments, which should be sensitive to the CMB polarization and lensing. The first chapter provides a review of the CMB polarization with emphasis on future related experiments. The PLANCK experiment is described in a second chapter, where I develop a fast simulation code of PLANCK time-ordered data optimized to ease elaboration and test of data analysis methods. The two last chapters deal with gravitational lensing of the cosmic background radiation. First, I evaluate the capability of the upcoming experiments mentioned above to measure the power spectrum of Large Scale Structure by means of the extraction of weak lensing. Then I derive their sensitivity to the total neutrino mass, using the suppression of power due to free-streaming of massive neutrinos. Finally, I develop a method to estimate the foreground effects in the gravitational lensing extraction process. This method uses the best linear estimator available in the literature and is validated by numerical simulations that include non-Gaussian CMB lensed maps and extra-galactic radio sources maps. I find that sources emission reduces the sensitivity of future experiments to the weak lensing and leads to an overestimate of the convergence power spectrum. (author)

  13. 空间低温光学试验深低温背景环境的实现%ACHIEVING THE DEEP CRYOGENIC BACKGROUND ENVIRONMENT OF SPACE CRYOGENIC OPTICAL EXPERIMENT

    Institute of Scientific and Technical Information of China (English)

    徐冰; 马龙

    2012-01-01

    In order to get the deep cryogenic background conditions of space cryogenic optical test, it discussed achieving deep cryogenic environment simulation technology and helium cooling system. It's analysed that 20K stable deep cryogenic cold and black background established by helium circulating is the most suitable cryogenic optical test Environment. The system is a closed circulatory system, which is composed of the helium liquefaction system with corresponding cold helium assigned device and the terminal cold cabin. Helium liquefaction system is based on the Claude cycle, that is composed of Brayton cycle and Joule-Thomson effect. It can continuously provide the liquid helium with a certain flow and pressure or cold helium as cycle refrigerant, and supply a stable deep cryogenic environment for the experiment.%为了实现空间低温光学试验的深低温背景条件,对实现深低温环模技术以及氦冷却系统进行了探讨.通过分析得到以氦循环方式建立的20 K稳定深低温冷黑背景是最为合适的低温光学试验背景环境.该系统是由氦液化系统配合相应冷氦分配装置以及终端冷舱组成密闭循环系统.氦液化系统是基于由布雷顿循环和焦耳-汤姆逊作用组合而成的克劳德循环,它能持续提供一定流量和压力的液氦或冷氦气作为循环系统中制冷工质,从而为试验提供稳定的深低温环境.

  14. Infrared heating

    Science.gov (United States)

    1983-11-01

    The transfer of energy by radiation whose limits lie between 1 mm and 400 mm is indicated. The radiation used lies practically completely in the infrared region. Its use therefore depends on the thermal radiation laws (black body or integral receiver laws). These laws were derived mathematically in accordance with the properties of an ideal body, the so-called ""integral receiver'' (formerly black body). According to definition this integral receiver has the property of absorbing completely all incident electromagnetic radiation. From these the following laws were deduced: (1) All bodies with a temperature above absolute zero emit a radiation. (2) The energy emitted by the integral receiver is proportional to the 4th power of the absolute temperature. (3) The emission theoretically comprizes the whole radiation. (4) The radiation comprizing the emission spectrum does not transport the same amount of energy at every wavelength.

  15. Polarization of Cosmic Microwave Background

    CERN Document Server

    Buzzelli, Alessandro; de Gasperis, Giancarlo; Vittorio, Nicola

    2016-01-01

    In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross-correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales.

  16. Exploring String Theory Backgrounds

    CERN Document Server

    Williams, B P

    2004-01-01

    This thesis examines phenomenological and theoretical questions by exploring string theoretic backgrounds. Part I focuses on cosmology. First we propose that the induced metric along a brane moving through a curved bulk may be interpreted as the cosmology of the brane universe, providing a resolution to the apparent cosmological singularity on the brane. We then look at various decay channels of the certain meta-stable de Sitter vacua and show that there exist NS5-brane meditated decays which are much faster than decays to decompactification. Part II discusses a new class of nongeometric vacua in string theory. These backgrounds may be described locally as T2 fibrations. By enlarging the monodromy group of the fiber to include perturbative stringy duality symmetries we are able to explicitly construct nongeometric backgrounds.

  17. Beam-gas Background Observations at LHC

    CERN Document Server

    Gibson, Stephen; The ATLAS collaboration; Lazic, Dragoslav-Laza; Alemany Fernandez, Reyes

    2017-01-01

    Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

  18. Cosmic Tachyon Background Radiation

    CERN Document Server

    Tomaschitz, R

    1999-01-01

    The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson-Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh-Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

  19. Infrared small target detection technology based on OpenCV

    Science.gov (United States)

    Liu, Lei; Huang, Zhijian

    2013-09-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detection are described. These algorithms are traditional two-frame difference method, improved three-frame difference method, background estimate and frame difference fusion method, and building background with neighborhood mean method. On the foundation of above works, an infrared target detection software platform which is developed by OpenCV and MFC is introduced. Three kinds of tracking algorithms are integrated in this software. In order to explain the software clearly, the framework and the function are described in this paper. At last, the experiments are performed for some real-life IR images. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  20. Texture orientation-based algorithm for detecting infrared maritime targets.

    Science.gov (United States)

    Wang, Bin; Dong, Lili; Zhao, Ming; Wu, Houde; Xu, Wenhai

    2015-05-20

    Infrared maritime target detection is a key technology for maritime target searching systems. However, in infrared maritime images (IMIs) taken under complicated sea conditions, background clutters, such as ocean waves, clouds or sea fog, usually have high intensity that can easily overwhelm the brightness of real targets, which is difficult for traditional target detection algorithms to deal with. To mitigate this problem, this paper proposes a novel target detection algorithm based on texture orientation. This algorithm first extracts suspected targets by analyzing the intersubband correlation between horizontal and vertical wavelet subbands of the original IMI on the first scale. Then the self-adaptive wavelet threshold denoising and local singularity analysis of the original IMI is combined to remove false alarms further. Experiments show that compared with traditional algorithms, this algorithm can suppress background clutter much better and realize better single-frame detection for infrared maritime targets. Besides, in order to guarantee accurate target extraction further, the pipeline-filtering algorithm is adopted to eliminate residual false alarms. The high practical value and applicability of this proposed strategy is backed strongly by experimental data acquired under different environmental conditions.

  1. China: Background Notes Series.

    Science.gov (United States)

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  2. Reseach on Comparison of Detecting Method of Protective Experiments Using Infrared Gas Analyser%红外气体分析仪比对防护试验检测方法的探究

    Institute of Scientific and Technical Information of China (English)

    周晓东; 宋振超; 温维丽; 黄嘉琳

    2012-01-01

    Chemical method and instrument protective experiments. Infrared gas analyzer is The result showed that with high automation, method were based on comparing detecting method of ammonia the two methods' accuracy was 2.77%, and were well coincident. rapid and convenient. It is suitable for protective experiments.%本文通过比对检测方法,即化学法检测氨气防护试验的浓度和仪器法进行比对试验,得出两种方法准确度为2.77%,一致性良好,并且红外气体分析仪自动化程度高,测定简便、迅速,适用于防护试验。

  3. Early results from the Cosmic Background Explorer (COBE)

    Energy Technology Data Exchange (ETDEWEB)

    Mather, J.C.; Hauser, M.G.; Bennett, C.L.; Boggess, N.W.; Cheng, E.S.; Eplee, R.E. Jr.; Freudenreich, H.T.; Isaacman, R.B.; Kelsall, T.; Lisse, C.M.; Moseley, S.H. Jr.; Shafer, R.A.; Silverberg, R.F.; Spiesman, W.J.; Toller, G.N.; Weiland, J.L. (Laboratory for Astronomy and Solar Physics, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)); Gulkis, S.; Jansssen, M. (Jet Propulsion Laboratory, MS 169-506, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)); Lubin, P.M. (UCSB Department of Physics, Goleta, California 93106 (United States)); Meyer, S.S.; Weiss, R. (Room 20F-001, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)); Murdock, T.L. (General Research Corporation, 5 Cherry Hill Drive, Suite 220, Danvers, Massachusetts 01923 (United States)); Smoot, G.F. (Lawrence Berkeley Laboratory, 50-232, University of California, Berkeley, California 94720 (United States)); Wilkinson, D.T. (Dep

    1992-01-10

    The Cosmic Background Explorer, launched November 18, 1989, has nearly completed its first full mapping of the sky with all three of its instruments: a Far Infrared Absolute Spectrophotometer (FIRAS) covering 0.1 to 10 mm, a set of Differential Microwave Radiometers (DMR) operating at 3.3, 5.7, and 9.6 mm, and a Diffuse Infrared Background Experiment (DIRBE) spanning 1 to 300 {mu}m in ten bands. A preliminary map of the sky derived from DIRBE data is presented. Initial cosmological implications include: a limit on the Comptonization {ital y} parameter of 10{sup {minus}3}, on the chemical potential {mu} parameter of 10{sup {minus}2}, a strong limit on the existence of a hot smooth intergalactic medium, and a confirmation that the dipole anisotropy has the spectrum expected from a Doppler shift of a blackbody. There are no significant anisotropies in the microwave sky detected, other than from our own galaxy and a cos {theta} dipole anisotropy whose amplitude and direction agree with previous data. At shorter wavelengths, the sky spectrum and anisotropies are dominated by emission from local' sources of emission within our Galaxy and Solar System. Preliminary comparison of {ital IRAS} and {ital DIRBE} sky brightnesses toward the ecliptic poles shows the {ital IRAS} values to be significantly higher than found by {ital DIRBE} at 100 {mu}m. We suggest the presence of gain and zero-point errors in the {ital IRAS} total brightness data. The spacecraft, instrument designs, and data reduction methods are described.

  4. CIBER : a near-infrared probe of the epoch of reionization

    Science.gov (United States)

    Sullivan, Ian Sorensen

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed to study the near-Infrared background by measuring fluctuations and the absolute spectrum. The platform of a sounding rocket enables observations of the near-Infrared background outside of narrow atmospheric windows that are uncontaminated by airglow. CIBER uses two spectrometers to measure the absolute brightness spectrum of the extragalactic near-Infrared background. One, a high-resolution Fabry-Perot spectometer, is tuned to the 854.5 nm CaII line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the near-Infrared background spectrum. The second spectrometer measures the near-Infrared background spectrum from 700 nm to 1800 nm, spanning the wavelength range where a Lyman limit cutoff feature from reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2 x 2 degree field of views with 7 arcsecond pixels, but have different band defining filters. The first imager has a wide band centered at 1600 nm, and images the background at the expected peak of the spectrum. The imagers?~@~Y wide field of view allows them to measure the distinctive power spectrum of first-light galaxy fluctuations peaking at 10 arcminutes. The second imager has a wide band centered at 1000 nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600 nm / 1000 nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or moderate-redshift galaxies. This work describes the design and

  5. Background Extraction Using Random Walk Image Fusion.

    Science.gov (United States)

    Hua, Kai-Lung; Wang, Hong-Cyuan; Yeh, Chih-Hsiang; Cheng, Wen-Huang; Lai, Yu-Chi

    2016-12-23

    It is important to extract a clear background for computer vision and augmented reality. Generally, background extraction assumes the existence of a clean background shot through the input sequence, but realistically, situations may violate this assumption such as highway traffic videos. Therefore, our probabilistic model-based method formulates fusion of candidate background patches of the input sequence as a random walk problem and seeks a globally optimal solution based on their temporal and spatial relationship. Furthermore, we also design two quality measures to consider spatial and temporal coherence and contrast distinctness among pixels as background selection basis. A static background should have high temporal coherence among frames, and thus, we improve our fusion precision with a temporal contrast filter and an optical-flow-based motionless patch extractor. Experiments demonstrate that our algorithm can successfully extract artifact-free background images with low computational cost while comparing to state-of-the-art algorithms.

  6. Simulation and Experiment Research on Emissivity of Infrared Stealth Coating%红外隐身涂层发射率的仿真计算

    Institute of Scientific and Technical Information of China (English)

    刘姜伟; 时家明; 党可征; 陈宗胜; 冯玥玥

    2012-01-01

    A simulating model of emissivity of infrared stealth coating based on Kubelka-Munk theory is put forward. Taking aluminum particles as pigments, using Maxwell-Garnett effective medium theory, the relationship between equivalent refractive index of coating and wavelength is calculated and analyzed. Based on the mutual interaction of the electromagnetic wave and pigments, adopting geometrical optical theory, scattering and absorption coefficients of the coating are calculated. Effects of aluminum particles' parameters, such as size and volume, to the emissivity of coating are analyzed quantitatively. The result shows that the proposed model could be used to guide the preparation of infrared stealth coating.%建立了基于Kubelka-Munk理论的红外隐身涂层发射率仿真计算模型.以Al粉颗粒作为颜料粒子,采用Maxwell-Garnett有效介质理论计算分析了涂层的等效折射率与波长的关系.从电磁波与颜料相互作用的机理出发,采用几何光学理论计算得到了涂层的吸收系数和散射系数.定量分析了铝粉颗粒粒径以及体积分数对涂层发射率的影响.结果表明,该模型对红外隐身涂层的制备具有一定的指导意义.

  7. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  8. Visualizing Chemistry with Infrared Imaging

    Science.gov (United States)

    Xie, Charles

    2011-01-01

    Almost all chemical processes release or absorb heat. The heat flow in a chemical system reflects the process it is undergoing. By showing the temperature distribution dynamically, infrared (IR) imaging provides a salient visualization of the process. This paper presents a set of simple experiments based on IR imaging to demonstrate its enormous…