WorldWideScience

Sample records for wide-field infrared explorer

  1. HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Adam C.; Cushing, Michael C. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N.; Wright, Edward L. [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Eisenhardt, Peter R. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Skrutskie, M. F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Griffith, Roger L. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Marsh, Kenneth A., E-mail: Adam.Schneider@Utoledo.edu [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)

    2015-05-10

    We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.

  2. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Padgett, D. L. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Rebull, L. M. [Spitzer Science Center (SSC), California Institute of Technology, M/S 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Assef, R. J. [Jet Propulsion Laboratory, MS 169-530, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2012-01-10

    We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the 'fireworks hypothesis' since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  3. Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

    Science.gov (United States)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Asslef, R. J.

    2012-01-01

    We present the results of a mid-infrared survey of II outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  4. A search for a distant companion to the sun with the wide-field infrared survey explorer

    Energy Technology Data Exchange (ETDEWEB)

    Luhman, K. L., E-mail: kluhman@astro.psu.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-01-20

    I have used multi-epoch astrometry from the Wide-field Infrared Survey Explorer to perform a search for a distant companion to the Sun via its parallactic motion. I have not found an object of this kind down to W2 = 14.5. This limit corresponds to analogs of Saturn and Jupiter at 28,000 and 82,000 AU, respectively, according to models of the Jovian planets by Fortney and coworkers. Models of brown dwarfs by Burrows and coworkers predict fainter fluxes at a given mass for the age of the solar system, producing a closer distance limit of 26,000 AU for a Jupiter-mass brown dwarf. These constraints exclude most combinations of mass and separation at which a solar companion has been suggested to exist by various studies over the years.

  5. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wilson M.; McCollum, Bruce; Fajardo-Acosta, Sergio [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Padgett, Deborah L. [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Terebey, Susan; Angione, John [Department of Physics and Astronomy, California State University, Los Angeles, CA 90032 (United States); Rebull, Luisa M. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Leisawitz, David, E-mail: wliu@ipac.caltech.edu [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 605, Greenbelt, MD 20771 (United States)

    2014-06-01

    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 μm, 4.6 μm, 12 μm, and 22 μm, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

  6. Wide-Field Infrared Survey Telescope (WFIRST) Integrated Modeling

    Science.gov (United States)

    Liu, Kuo-Chia; Blaurock, Carl

    2017-01-01

    Contents: introduction to WFIRST (Wide-Field Infrared Survey Telescope) and integrated modeling; WFIRST stability requirement summary; instability mitigation strategies; dynamic jitter results; STOP (structural-thermal-optical performance) (thermal distortion) results; STOP and jitter capability limitations; model validation philosophy.

  7. Star Formation Rate Indicators in Wide-Field Infrared Survey ...

    Indian Academy of Sciences (India)

    2016-01-27

    field Infrared Survey Explorer (WISE) traces the SFR, we analyse 3.4, 4.6, 12 and 22 m data in a sample of ∼ 140,000 star-forming galaxies or star-forming regions covering a wide range in metallicity 7.66 < 12 + \\log (O/H) ...

  8. A Classification Scheme for Young Stellar Objects Using the WIDE-FIELD INFRARED SURVEY EXPLORER ALLWISE Catalog: Revealing Low-Density Star Formation in the Outer Galaxy

    Science.gov (United States)

    Koening, X. P.; Leisawitz, D. T.

    2014-01-01

    We present an assessment of the performance of WISE and the AllWISE data release in a section of the Galactic Plane. We lay out an approach to increasing the reliability of point source photometry extracted from the AllWISE catalog in Galactic Plane regions using parameters provided in the catalog. We use the resulting catalog to construct a new, revised young star detection and classification scheme combining WISE and 2MASS near and mid-infrared colors and magnitudes and test it in a section of the Outer Milky Way. The clustering properties of the candidate Class I and II stars using a nearest neighbor density calculation and the two-point correlation function suggest that the majority of stars do form in massive star forming regions, and any isolated mode of star formation is at most a small fraction of the total star forming output of the Galaxy. We also show that the isolated component may be very small and could represent the tail end of a single mechanism of star formation in line with models of molecular cloud collapse with supersonic turbulence and not a separate mode all to itself.

  9. Three New Cool Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer (WISE) and an Improved Spectrum of the Y0 Dwarf WISE J041022.71+150248.4

    Science.gov (United States)

    Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Skrutskie, Michael F.; Gould, Andrew

    2014-05-01

    As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope, we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to 17. In addition, we present an improved spectrum (i.e., higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to directly measure the mass of a brown dwarf via astrometric microlensing.

  10. Three new cool brown dwarfs discovered with the wide-field infrared survey explorer (WISE) and an improved spectrum of the Y0 dwarf wise J041022.71+150248.4

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, Michael C. [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Skrutskie, Michael F. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Gould, Andrew, E-mail: michael.cushing@utoledo.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2014-05-01

    As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope, we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to 17. In addition, we present an improved spectrum (i.e., higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to directly measure the mass of a brown dwarf via astrometric microlensing.

  11. Infrared Testing of the Wide-field Infrared Survey Telescope Grism Using Computer Generated Holograms

    Science.gov (United States)

    Dominguez, Margaret Z.; Content, David A.; Gong, Qian; Griesmann, Ulf; Hagopian, John G.; Marx, Catherine T; Whipple, Arthur L.

    2017-01-01

    Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey Telescope (WFIRST) will allow the surveying of a large section of the sky to find bright galaxies.

  12. Spatially Resolved Two-Dimensional Infrared Spectroscopy via Wide-Field Microscopy.

    Science.gov (United States)

    Ostrander, Joshua S; Serrano, Arnaldo L; Ghosh, Ayanjeet; Zanni, Martin T

    2016-07-20

    We report the first wide-field microscope for measuring two-dimensional infrared (2D IR) spectroscopic images. We concurrently collect more than 16 000 2D IR spectra, made possible by a new focal plane array detector and mid-IR pulse shaping, to generate hyperspectral images with multiple frequency dimensions and diffraction-limited spatial resolution. Both frequency axes of the spectra are collected in the time domain by scanning two pairs of femtosecond pulses using a dual acousto-optic modulator pulse shaper. The technique is demonstrated by imaging a mixture of metal carbonyl absorbed polystyrene beads. The differences in image formation between FTIR and 2D IR microscopy are also explored by imaging a patterned USAF test target. We find that our 2D IR microscope has diffraction-limited spatial resolution and enhanced contrast compared to FTIR microscopy because of the nonlinear scaling of the 2D IR signal to the absorptivity coefficient for the vibrational modes. Images generated using off-diagonal peaks, created from vibrational anharmonicities, improve the molecular discrimination and eliminate noise. Two-dimensional wide-field IR microscopy provides information on vibrational lifetimes, molecular couplings, transition dipole orientations, and many other quantities that can be used for creating image contrast to help disentangle and interpret complex and heterogeneous samples. Such experiments made possible could include the study of amyloid proteins in tissues, protein folding in heterogeneous environments, and structural dynamics in devices employing mid-IR materials.

  13. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera

    OpenAIRE

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-01-01

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photog...

  14. Design status of WFCAM: a wide field camera for the UK infrared telescope

    Science.gov (United States)

    Henry, David M.; Casali, Mark M.; Montgomery, David; Burch, Keith; Laidlaw, Ken; Ives, Derek J.; Vick, Andrew J. A.; Bridger, Alan; Lunney, David; Adamson, Andrew J.; Rees, Nicholas P.; Chylek, Tomas; Chuter, Timothy C.

    2003-03-01

    An update on the design status of the UKIRT Wide Field Camera (WFCAM) is presented. WFCAM is a wide field infrared camera for the UK Infrared Telescope, designed to produce large scale infrared surveys. The complete system consists of a new IR camera with integral autoguider and a new tip/tilt secondary mirror unit. WFCAM is being designed and built by a team at the UK Astronomy Technology Centre in Edinburgh, supported by the Joint Astronomy Centre in Hawaii. The camera uses a novel quasi-Schmidt camera type design, with the camera mounted above the UKIRT primary mirror. The optical system operates over 0.7 - 2.4 μm and has a large corrected field of view of 0.9° diameter. The focal plane is sparsely populated with 4 2K x 2K Rockwell HAWAII-2 MCT array detectors, giving a pixel scale of 0.4 arcsec/pixel. A separate autoguider CCD is integrated into the focal plane unit. Parallel detector controllers are used, one for each of the four IR arrays and a fifth for the autoguider CCD.

  15. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera.

    Science.gov (United States)

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-09-29

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photography. The measurement wavelength range, obtained spectrum's wavenumber resolution, and measurement time was 8-14 μm, about 9 cm-1, and about 30 s, respectively. Using conventional methods, adhesives could not be distinguished from the others. By using this method, we found that adhesives could be precisely distinguished by setting an appropriate threshold value for the correlation coefficient. Thus, our approach can accurately measure the spatial distribution of different types of adhesive that cannot be discriminated by conventional methods.

  16. Precision Pointing for the Wide-Field Infrared Survey Telescope(WFIRST)

    Science.gov (United States)

    Stoneking, Eric T.; Hsu, Oscar C.; Welter, Gary

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to address the critical science requirements, the WFIRST mission will conduct large-scale surveys of the infrared sky, requiring both agility and precision pointing (11.6 milli-arcsec stability, 14 milli-arcsec jitter). This paper describes some of the challenges this mission profile presents to the Guidance, Navigation, and Control (GNC) subsystem, and some of the design elements chosen to accommodate those challenges. The high-galactic-latitude survey is characterized by 3-minute observations separated by slews ranging from 0.025 deg to 0.8 deg. The need for observation efficiency drives the slew and settle process to be as rapid as possible. A description of the shaped slew profile chosen to minimize excitation of structural oscillation, and the handoff from star tracker-gyro control to fine guidance sensor control is detailed. Also presented is the fine guidance sensor (FGS), which is integral with the primary instrument (WFI). The FGS is capable of tracking up to 18 guide stars, enabling robust FGS acquisition and precision pointing. To avoid excitation of observatory structural jitter, reaction wheel speeds are operationally maintained within set limits. In addition, the wheel balance law is designed to maintain 1-Hz separation between the wheel speeds to avoid reinforcing jitter excitation at any particular frequency. The wheel balance law and operational implications are described. Finally, the candidate GNC hardware suite needed to meet the requirements of the mission is presented.

  17. Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

    Science.gov (United States)

    Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; hide

    2016-01-01

    The slitless spectrometer plays an important role in the Wide-Field InfraRed Survey Telescope (WFIRST) mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  18. Application of a wide-field electromagnetic method to shale gas exploration in South China

    Science.gov (United States)

    Yang, Xue-Li; Li, Bo; Peng, Chuan-Sheng; Yang, Yang

    2017-09-01

    In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method (WFEM), because of its strong anti-interference capability, high resolution, ability to conduct exploration at large depths, and high efficiency, to the Bayan Syncline in the South Huayuan block, Hunan Province. We collected rock samples and analyzed their resistivity and induced polarization (IP) and built A series of two-dimensional models for geological conditions to investigate the applicability of WFEM to different geological structures. We also analyzed the correlation between TOC of shale and the resistivity and IP ratio to determine the threshold for identifying target formations. We used WFEM to identify the underground structures and determine the distribution, depth, and thickness of the target strata. Resistivity, IP, and total organic carbon were used to evaluate the shale gas prospects and select favorable areas (sweet spots) for exploration and development. Subsequently, drilling in these areas proved the applicability of WFEM in shale gas exploration.

  19. Preliminary Analysis of Ground-based Orbit Determination Accuracy for the Wide Field Infrared Survey Telescope (WFIRST)

    Science.gov (United States)

    Sease, Brad

    2017-01-01

    The Wide Field Infrared Survey Telescope is a 2.4-meter telescope planned for launch to the Sun-Earth L2 point in 2026. This paper details a preliminary study of the achievable accuracy for WFIRST from ground-based orbit determination routines. The analysis here is divided into two segments. First, a linear covariance analysis of early mission and routine operations provides an estimate of the tracking schedule required to meet mission requirements. Second, a simulated operations scenario gives insight into the expected behavior of a daily Extended Kalman Filter orbit estimate over the first mission year given a variety of potential momentum unloading schemes.

  20. Deep wide-field near-infrared survey of the Carina Nebula

    Science.gov (United States)

    Preibisch, T.; Ratzka, T.; Kuderna, B.; Ohlendorf, H.; King, R. R.; Hodgkin, S.; Irwin, M.; Lewis, J. R.; McCaughrean, M. J.; Zinnecker, H.

    2011-06-01

    Context. The Great Nebula in Carina is a giant H ii region and a superb location in which to study the physics of violent massive star formation, but the population of the young low-mass stars remained very poorly studied until recently. Aims: Our aim was to produce a near-infrared survey that is deep enough to detect the full low-mass stellar population (i.e. down to ≈0.1 M⊙ and for extinctions up to AV ≈ 15 mag) and wide enough to cover all important parts of the Carina Nebula complex (CNC), including the clusters Tr 14, 15, and 16 as well as the South Pillars region. Methods: We used HAWK-I at the ESO VLT to survey the central ≈0.36 deg2 area of the Carina Nebula. These data reveal more than 600 000 individual infrared sources down to magnitudes as faint as J ≈ 23, H ≈ 22, and Ks ≈ 21. The results of a recent deep X-ray survey (which is complete down to stellar masses of ~0.5-1 M⊙) are used to distinguish between young stars in Carina and background contaminants. We analyze color - magnitude diagrams (CMDs) to derive information about the ages and masses of the low-mass stars. Results: The ages of the low-mass stars agree with previous age estimates for the massive stars. The CMD suggests that ≈3200 of the X-ray selected stars have masses of M∗ ≥ 1 M⊙; this number is in good agreement with extrapolations of the field IMF based on the number of high-mass (M∗ ≥ 20 M⊙) stars and shows that there is no deficit of low-mass stars in the CNC. The HAWK-I images confirm that about 50% of all young stars in Carina are in a widely distributed, non-clustered spatial configuration. Narrow-band images reveal six molecular hydrogen emission objects (MHOs) that trace jets from embedded protostars. However, none of the optical HH objects shows molecular hydrogen emission, suggesting that the jet-driving protostars are located very close to the edges of the globules in which they are embedded. Conclusions: The near-infrared excess fractions for the

  1. Wide-Field InfraRed Survey Telescope (WFIRST) Mission and Synergies with LISA and LIGO-Virgo

    Science.gov (United States)

    Gehrels, N.; Spergel, D.

    2015-01-01

    The Wide-Field InfraRed Survey Telescope (WFIRST) is a NASA space mission in study for launch in 2024. It has a 2.4 m telescope, wide-field IR instrument operating in the 0.7 - 2.0 micron range and an exoplanet imaging coronagraph instrument operating in the 400 - 1000 nm range. The observatory will perform galaxy surveys over thousands of square degrees to J=27 AB for dark energy weak lensing and baryon acoustic oscillation measurements and will monitor a few square degrees for dark energy SN Ia studies. It will perform microlensing observations of the galactic bulge for an exoplanet census and direct imaging observations of nearby exoplanets with a pathfinder coronagraph. The mission will have a robust and wellfunded guest observer program for 25% of the observing time. WFIRST will be a powerful tool for time domain astronomy and for coordinated observations with gravitational wave experiments. Gravitational wave events produced by mergers of nearby binary neutron stars (LIGO-Virgo) or extragalactic supermassive black hole binaries (LISA) will produce electromagnetic radiation that WFIRST can observe.

  2. Detector Control and Data Acquisition for the Wide-Field Infrared Survey Telescope (WFIRST) with a Custom ASIC

    Science.gov (United States)

    Smith, Brian S.; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; hide

    2016-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally approx.300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  3. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    Science.gov (United States)

    Tamura, Naoyuki

    This short article is about Prime Focus Spectrograph (PFS), a very wide-field, massively-multiplexed, and optical & near-infrared (NIR) spectrograph as a next generation facility instrument on Subaru Telescope. More details and updates are available on the PFS official website (http://pfs.ipmu.jp), blog (http://pfs.ipmu.jp/blog/), and references therein. The project, instrument, & timeline PFS will position 2400 fibers to science targets or blank sky in the 1.3 degree field on the Subaru prime focus. These fibers will be quickly (~60sec) reconfigurable and feed the photons during exposures to the Spectrograph System (SpS). SpS consists of 4 modules each of which accommodate ~600 fibers and deliver spectral images ranging from 380nm to 1260nm simultaneously at one exposure via the 3 arms of blue, red, and NIR cameras. The instrument development has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky engineering observations in 2017-2018, and science operation in 2019. The survey design has also been under development envisioning a survey spanning ~300 nights over ~5 years in the framework of Subaru Strategic Program (SSP). The key science areas are: Cosmology, galaxy/AGN evolution, and Galactic Archaeology (GA) (Takada et al. 2014). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of 10 Gpc3 at z=0.8-2.4. In the galaxy/AGN program, the wide wavelength coverage of PFS as well as the large field of view will be exploited to characterize the galaxy populations and its clustering properties over a wide redshift range. A survey of color-selected galaxies/AGN at z = 1-2 will be conducted over 20 square degrees yielding a fair sample of galaxies with stellar masses down to ~1010 M ⊙. In the GA program, radial velocities and chemical abundances of stars in the Milky

  4. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source

    OpenAIRE

    Gioux, Sylvain; Lomnes, Stephen J.; Choi, Hak Soo; Frangioni, John V.

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequenc...

  5. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source.

    Science.gov (United States)

    Gioux, Sylvain; Lomnes, Stephen J; Choi, Hak Soo; Frangioni, John V

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequencies up to 35 MHz. Lifetime imaging of indocyanine green (ICG), IRDye 800-CW, and 3,3(')-diethylthiatricarbocyanine iodide (DTTCI) was performed over a large field of view (10 cm by 7.5 cm) using the LED light source. For comparison, a laser diode light source was employed as a gold standard. Experiments were performed both on the bench by diluting the fluorescent dyes in various chemical environments in Eppendorf tubes, and in vivo by injecting the fluorescent dyes mixed in Matrigel subcutaneously into CD-1 mice. Last, measured fluorescence lifetimes obtained using the LED and the laser diode sources were compared with those obtained using a state-of-the-art time-domain imaging system and with those previously described in the literature. On average, lifetime values obtained using the LED and the laser diode light sources were consistent, exhibiting a mean difference of 3% from the expected values and a coefficient of variation of 12%. Taken together, our study offers an alternative to laser diodes for clinical translation of FLi and explores the use of relatively low frequency modulation for in vivo imaging.

  6. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Ryan, R. E.; Koekemoer, A. M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Schneider, G.; Fan, X. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hathi, N. P. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Keel, W. C. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Roettgering, H. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Strauss, M. A. [Princeton University Observatory, Princeton, NJ 08544 (United States); Yan, H. J. [Department of Physics and Astronomy, The University of Missouri, 701 South College Ave, Columbia, MO 65211 (United States)

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  7. Addressing Thermal Model Run Time Concerns of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA)

    Science.gov (United States)

    Peabody, Hume; Guerrero, Sergio; Hawk, John; Rodriguez, Juan; McDonald, Carson; Jackson, Cliff

    2016-01-01

    The Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) utilizes an existing 2.4 m diameter Hubble sized telescope donated from elsewhere in the federal government for near-infrared sky surveys and Exoplanet searches to answer crucial questions about the universe and dark energy. The WFIRST design continues to increase in maturity, detail, and complexity with each design cycle leading to a Mission Concept Review and entrance to the Mission Formulation Phase. Each cycle has required a Structural-Thermal-Optical-Performance (STOP) analysis to ensure the design can meet the stringent pointing and stability requirements. As such, the models have also grown in size and complexity leading to increased model run time. This paper addresses efforts to reduce the run time while still maintaining sufficient accuracy for STOP analyses. A technique was developed to identify slews between observing orientations that were sufficiently different to warrant recalculation of the environmental fluxes to reduce the total number of radiation calculation points. The inclusion of a cryocooler fluid loop in the model also forced smaller time-steps than desired, which greatly increases the overall run time. The analysis of this fluid model required mitigation to drive the run time down by solving portions of the model at different time scales. Lastly, investigations were made into the impact of the removal of small radiation couplings on run time and accuracy. Use of these techniques allowed the models to produce meaningful results within reasonable run times to meet project schedule deadlines.

  8. INFRARED TRANSMISSION SPECTROSCOPY OF THE EXOPLANETS HD 209458b AND XO-1b USING THE WIDE FIELD CAMERA-3 ON THE HUBBLE SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Deming, Drake; Wilkins, Ashlee [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); McCullough, Peter; Crouzet, Nicolas [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Agol, Eric; Dobbs-Dixon, Ian [NASA Astrobiology Institute' s Virtual Planetary Laboratory (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06511 (United States); Desert, Jean-Michel; Knutson, Heather A.; Line, Michael [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Haynes, Korey [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030 (United States); Magic, Zazralt [Max-Planck-Institut fuer Astrophysik, D-85741 Garching (Germany); Mandell, Avi M.; Clampin, Mark [NASA' s Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ranjan, Sukrit; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Seager, Sara, E-mail: ddeming@astro.umd.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); and others

    2013-09-10

    Exoplanetary transmission spectroscopy in the near-infrared using the Hubble Space Telescope (HST) NICMOS is currently ambiguous because different observational groups claim different results from the same data, depending on their analysis methodologies. Spatial scanning with HST/WFC3 provides an opportunity to resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets HD 209458b and XO-1b in transit, using spatial scanning mode for maximum photon-collecting efficiency. We introduce an analysis technique that derives the exoplanetary transmission spectrum without the necessity of explicitly decorrelating instrumental effects, and achieves nearly photon-limited precision even at the high flux levels collected in spatial scan mode. Our errors are within 6% (XO-1) and 26% (HD 209458b) of the photon-limit at a resolving power of {lambda}/{delta}{lambda} {approx} 70, and are better than 0.01% per spectral channel. Both planets exhibit water absorption of approximately 200 ppm at the water peak near 1.38 {mu}m. Our result for XO-1b contradicts the much larger absorption derived from NICMOS spectroscopy. The weak water absorption we measure for HD 209458b is reminiscent of the weakness of sodium absorption in the first transmission spectroscopy of an exoplanet atmosphere by Charbonneau et al. Model atmospheres having uniformly distributed extra opacity of 0.012 cm{sup 2} g{sup -1} account approximately for both our water measurement and the sodium absorption. Our results for HD 209458b support the picture advocated by Pont et al. in which weak molecular absorptions are superposed on a transmission spectrum that is dominated by continuous opacity due to haze and/or dust. However, the extra opacity needed for HD 209458b is grayer than for HD 189733b, with a weaker Rayleigh component.

  9. Wide-Field Plate Database

    Science.gov (United States)

    Tsvetkov, M. K.; Stavrev, K. Y.; Tsvetkova, K. P.; Semkov, E. H.; Mutatov, A. S.

    The Wide-Field Plate Database (WFPDB) and the possibilities for its application as a research tool in observational astronomy are presented. Currently the WFPDB comprises the descriptive data for 400 000 archival wide field photographic plates obtained with 77 instruments, from a total of 1 850 000 photographs stored in 269 astronomical archives all over the world since the end of last century. The WFPDB is already accessible for the astronomical community, now only in batch mode through user requests sent by e-mail. We are working on on-line interactive access to the data via INTERNET from Sofia and parallel from the Centre de Donnees Astronomiques de Strasbourg. (Initial information can be found on World Wide Web homepage URL http://www.wfpa.acad.bg.) The WFPDB may be useful in studies of a variety of astronomical objects and phenomena, andespecially for long-term investigations of variable objects and for multi-wavelength research. We have analysed the data in the WFPDB in order to derive the overall characteristics of the totality of wide-field observations, such as the sky coverage, the distributions by observation time and date, by spectral band, and by object type. We have also examined the totality of wide-field observations from point of view of their quality, availability and digitisation. The usefulness of the WFPDB is demonstrated by the results of identification and investigation of the photometrical behaviour of optical analogues of gamma-ray bursts.

  10. The Ooty Wide Field Array

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 1. The Ooty Wide Field Array. C. R. Subrahmanya P. K. Manoharan Jayaram N. Chengalur. Review Article Volume 38 Issue 1 March 2017 Article ID ... Keywords. Cosmology: large scale structure of Universe; intergalactic medium; diffuse radiation.

  11. The LOFT wide field monitor

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2012-01-01

    be able to address fundamental questions about strong gravity in the vicinity of black holes and the equation of state of nuclear matter in neutron stars. The prime goal of the WFM will be to detect transient sources to be observed by the LAD. However, with its wide field of view and good energy...... to the community of ~100 gamma ray burst positions per year with a ~1 arcmin location accuracy within 30 s of the burst. This paper provides an overview of the design, configuration, and capabilities of the LOFT WFM instrument....

  12. Wide Field Imager for Athena

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Rau, Arne; Plattner, Markus; WFI proto-Consortium

    2015-09-01

    The Wide Field Imager focal plane instrument on ATHENA will combine unprecedented survey power through its large field of view of 40 arcmin with a high count-rate capability (> 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.1 keV to 15 keV. At energy of 6 keV for example, the full width at half maximum of the line shall be not worse than 150 eV until the end of the mission. The performance is accomplished by a set of DEPFET active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system.Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 micron thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single gateable DEPFET sensor matrix optimized for the high count rate capability of the instrument. An overview will be given about the presently developed instrument concept and design, the status of the technology development, and the expected performance. An outline of the project organization, the model philosophy as well as the schedule will complete the presentation about the Wide Field Imager for Athena.

  13. Athena Wide Field Imager key science drivers

    Science.gov (United States)

    Rau, Arne; Nandra, Kirpal; Aird, James; Comastri, Andrea; Dauser, Thomas; Merloni, Andrea; Pratt, Gabriel W.; Reiprich, Thomas H.; Fabian, Andy C.; Georgakakis, Antonis; Güdel, Manuel; RóŻańska, Agata; Sanders, Jeremy S.; Sasaki, Manami; Vaughan, Simon; Wilms, Jörn; Meidinger, Norbert

    2016-07-01

    The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI { the formation and growth of supermassive black holes, non-gravitational heating in clusters of galaxies, and spin measurements of stellar mass black holes { and describe their translation into the science requirements and ultimately instrument requirements. The WFI will be designed to provide excellent point source sensitivity and grasp for performing wide area surveys, surface brightness sensitivity, survey power, and absolute temperature and density calibration for in-depth studies of the outskirts of nearby clusters of galaxies and very good high-count rate capability, throughput, and low pile-up, paired with very good spectral resolution, for detailed explorations of bright Galactic compact objects.

  14. Michelson wide-field stellar interferometry

    NARCIS (Netherlands)

    Montilla, I.

    2004-01-01

    The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

  15. Wide-Field Imaging Using Nitrogen Vacancies

    Science.gov (United States)

    Englund, Dirk Robert (Inventor); Trusheim, Matthew Edwin (Inventor)

    2017-01-01

    Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

  16. IOT Overview: Wide-Field Imaging

    Science.gov (United States)

    Selman, F. J.

    The Wide Field Imager (WFI) instrument at La Silla has been the workhorse of wide-field imaging instruments at ESO for several years. In this contribution I will summarize the issues relating to its productivity for the community both in terms of the quality and quantity of data that has come out of it. Although only surveys of limited scope have been completed using WFI, it is ESO's stepping-stone to the new generation of survey telescopes.

  17. The LOFT wide field monitor simulator

    DEFF Research Database (Denmark)

    Donnarumma, I.; Evangelista, Y.; Campana, R.

    2012-01-01

    We present the simulator we developed for the Wide Field Monitor (WFM) aboard the Large Observatory For Xray Timing (LOFT) mission, one of the four ESA M3 candidate missions considered for launch in the 2022–2024 timeframe. The WFM is designed to cover a large FoV in the same bandpass as the Larg...

  18. Wide field focal plane arrays for UKIRT and VISTA

    Science.gov (United States)

    Ives, D.; Laidlaw, K.; Bezawada, N. N.

    This paper briefly describes the focal plane arrays of the UKIRT Wide Field Camera and the IR camera for the Visible and Infrared Survey Telescope for Astronomy (VISTA). Laboratory test results on the HAWAII-2 engineering grade detector are summarised. The interference problems resulting from the on-axis wavefront/autoguider sensors and their controllers (autoguider, wavefront sensor, etc.) are anticipated and possible options to eliminate or attenuate these effects are presented. Laboratory tests on the Electromagnetic Interference (EMI) issues are also reported.

  19. Wide field imaging problems in radio astronomy

    Science.gov (United States)

    Cornwell, T. J.; Golap, K.; Bhatnagar, S.

    2005-03-01

    The new generation of synthesis radio telescopes now being proposed, designed, and constructed face substantial problems in making images over wide fields of view. Such observations are required either to achieve the full sensitivity limit in crowded fields or for surveys. The Square Kilometre Array (SKA Consortium, Tech. Rep., 2004), now being developed by an international consortium of 15 countries, will require advances well beyond the current state of the art. We review the theory of synthesis radio telescopes for large fields of view. We describe a new algorithm, W projection, for correcting the non-coplanar baselines aberration. This algorithm has improved performance over those previously used (typically an order of magnitude in speed). Despite the advent of W projection, the computing hardware required for SKA wide field imaging is estimated to cost up to $500M (2015 dollars). This is about half the target cost of the SKA. Reconfigurable computing is one way in which the costs can be decreased dramatically.

  20. The Wide Field Imager for Athena

    Science.gov (United States)

    Rau, A.; Nandra, K.; Meidinger, N.; Plattner, M.

    2017-10-01

    The Wide Field Imager (WFI) is one of the two scientific instruments of Athena, ESA's next large X-ray Observatory with launch in 2028. The instrument will provide two defining capabilities to the mission sensitive wide-field imaging spectroscopy and excellent high-count rate performance. It will do so with the use of two separate detectors systems, the Large Detector Array (LDA) optimized for its field of view (40'×40') with a 100 fold survey speed increase compared to existing X-ray missions, and the Fast Detector (FD) tweaked for high throughput and low pile-up for point sources as bright as the Crab. In my talk I will present the key performance parameters of the instrument and their links to the scientific goals of Athena and summarize the status of the ongoing development activities.

  1. The Wide Field Imager Instrument for Athena

    OpenAIRE

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2017-01-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (larger than 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be better than 17...

  2. WFIRST: Simulating the Wide-Field Sky

    Science.gov (United States)

    Peeples, Molly; WFIRST Wide Field Imager Simulations Working Group

    2018-01-01

    As astronomy’s first high-resolution wide-field multi-mode instrument, simulated data will play a vital role in the planning for and analysis of data from WFIRST’s WFI (Wide Field Imager) instrument. Part of the key to WFIRST’s scientific success lies in our ability to push the systematics limit, but in order to do so, the WFI pipeline will need to be able to measure and take out said systematics. The efficacy of this pipeline can only be verified with large suites of synthetic data; these data must include both the range of astrophysical sky scenes (from crowded starfields to high-latitude grism data observations) and the systematics from the detector and telescope optics the WFI pipeline aims to mitigate. We summarize here(1) the status of current and planned astrophysical simulations in support of the WFI,(2) the status of current WFI instrument simulators and requirements on future generations thereof, and(3) plans, methods, and requirements on interfacing astrophysical simulations and WFI instrument simulators.

  3. Optical Design of the WFIRST Phase-A Wide Field Instrument

    Science.gov (United States)

    Pasquale, Bert A.; Marx, Catherine T.; Gao, Guangjun; Armani, Nerses; Casey, Thomas

    2017-01-01

    The WFIRST Wide-Field Infrared Survey Telescope TMA optical design provides 0.28-sq degrees FOV at 0.11” pixel scale to the Wide Field Instrument, operating between 0.48-2.0 micrometers, including a spectrograph mode (1.0-2.0 micrometers). An Integral Field Channel provides 2-D discrete spectroscopy at 0.15” & 0.3” sampling.

  4. WFIRST: Astrometry with the Wide-Field Imager

    Science.gov (United States)

    Bellini, Andrea; WFIRST Astrometry Working Group

    2018-01-01

    The wide field of view and stable, sharp images delivered by WFIRST's Wide-Field Imager make it an excellent instrument for astrometry, one of five major discovery areas identified in the 2010 Decadal Survey. Compared to the Hubble Space Telescope, WFIRST's wider field of view with similar image quality will provide hundreds more astrometric targets per image as well as background galaxies and stars with precise positions in the Gaia catalog. In addition, WFIRST will operate in the infrared, a wavelength regime where the most precise astrometry has so far been achieved with adaptive optics images from large ground-based telescopes. WFIRST will provide at least a factor of three improvement in astrometry over the current state of the art in this wavelength range, while spanning a field of view thousands of times larger. WFIRST is thus poised to make major contributions to multiple science topics in which astrometry plays an important role, without major alterations to the planned mission or instrument. We summarize a few of the most compelling science cases where WFIRST astrometry could prove transformational.

  5. A wide field of view plasma spectrometer

    Science.gov (United States)

    Skoug, R. M.; Funsten, H. O.; Möbius, E.; Harper, R. W.; Kihara, K. H.; Bower, J. S.

    2016-07-01

    We present a fundamentally new type of space plasma spectrometer, the wide field of view plasma spectrometer, whose field of view is > 1.25π ster using fewer resources than traditional methods. The enabling component is analogous to a pinhole camera with an electrostatic energy-angle filter at the image plane. Particle energy-per-charge is selected with a tunable bias voltage applied to the filter plate relative to the pinhole aperture plate. For a given bias voltage, charged particles from different directions are focused by different angles to different locations. Particles with appropriate locations and angles can transit the filter plate and are measured using a microchannel plate detector with a position-sensitive anode. Full energy and angle coverage are obtained using a single high-voltage power supply, resulting in considerable resource savings and allowing measurements at fast timescales. We present laboratory prototype measurements and simulations demonstrating the instrument concept and discuss optimizations of the instrument design for application to space measurements.

  6. The Wide Field Imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Barbera, Marco; Emberger, Valentin; Fürmetz, Maria; Manhart, Markus; Müller-Seidlitz, Johannes; Nandra, Kirpal; Plattner, Markus; Rau, Arne; Treberspurg, Wolfgang

    2017-08-01

    ESA's next large X-ray mission ATHENA is designed to address the Cosmic Vision science theme 'The Hot and Energetic Universe'. It will provide answers to the two key astrophysical questions how does ordinary matter assemble into the large-scale structures we see today and how do black holes grow and shape the Universe. The ATHENA spacecraft will be equipped with two focal plane cameras, a Wide Field Imager (WFI) and an X-ray Integral Field Unit (X-IFU). The WFI instrument is optimized for state-of-the-art resolution spectroscopy over a large field of view of 40 amin x 40 amin and high count rates up to and beyond 1 Crab source intensity. The cryogenic X-IFU camera is designed for high-spectral resolution imaging. Both cameras share alternately a mirror system based on silicon pore optics with a focal length of 12 m and large effective area of about 2 m2 at an energy of 1 keV. Although the mission is still in phase A, i.e. studying the feasibility and developing the necessary technology, the definition and development of the instrumentation made already significant progress. The herein described WFI focal plane camera covers the energy band from 0.2 keV to 15 keV with 450 μm thick fully depleted back-illuminated silicon active pixel sensors of DEPFET type. The spatial resolution will be provided by one million pixels, each with a size of 130 μm x 130 μm. The time resolution requirement for the WFI large detector array is 5 ms and for the WFI fast detector 80 μs. The large effective area of the mirror system will be completed by a high quantum efficiency above 90% for medium and higher energies. The status of the various WFI subsystems to achieve this performance will be described and recent changes will be explained here.

  7. The wide field imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea E.; Tenzer, Chris; Wilms, Jörn

    2014-07-01

    The "Hot and Energetic Universe" has been selected as the science theme for ESA's L2 mission, scheduled for launch in 2028. The proposed Athena X-ray observatory provides the necessary capabilities to achieve the ambitious goals of the science theme. The X-ray mirrors are based on silicon pore optics technology and will have a 12 m focal length. Two complementary camera systems are foreseen which can be moved in and out of the focal plane by an interchange mechanism. These instruments are the actively shielded micro-calorimeter spectrometer X-IFU and the Wide Field Imager (WFI). The WFI will combine an unprecedented survey power through its large field of view of 40 arcmin with a high countrate capability (approx. 1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 keV to 15 keV during the entire mission lifetime (e.g. FWHM serial analog output. The architecture of sensor and readout ASIC allows readout in full frame mode and window mode as well by addressing selectively arbitrary sub-areas of the sensor allowing time resolution in the order of 10 μs. The further detector electronics has mainly the following tasks: digitization, pre-processing and telemetry of event data as well as supply and control of the detector system. Although the sensor will already be equipped with an on-chip light blocking filter, a filter wheel is necessary to provide an additional external filter, an on-board calibration source, an open position for outgassing, and a closed position for protection of the sensor. The sensor concept provides high quantum efficiency over the entire energy band and we intend to keep the instrumental background as low as possible by designing a graded Z-shield around the sensor. All these properties make the WFI a very powerful survey instrument, significantly surpassing currently existing observatories and in addition allow high-time resolution of the brightest X-ray sources with low pile-up and high efficiency. This

  8. The wide field imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2016-07-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two detectors are planned for the WFI instrument: A large-area detector comprising four sensors with a total of 1024 x 1024 pixels and a fast detector optimized for high count rate observations. This high count rate capable detector permits for bright point sources with an intensity of 1 Crab a throughput of more than 80% and a pile-up of less than 1%. The fast readout of the DEPFET pixel matrices is facilitated by an ASIC development, called VERITAS-2. Together with the Switcher-A, a control ASIC that allows for operation of the DEPFET in rolling shutter mode, these elements form the key components of the WFI detectors. The detectors are surrounded by a graded-Z shield, which has in particular the purpose to avoid fluorescence lines that would contribute to the instrument background. Together with ultra-thin coating of the sensor and particle identification by the detector itself, the particle induced background shall be minimized in order to achieve the scientific requirement of a total instrumental background value smaller than 5 x 10-3 cts/cm2/s/keV. Each detector has its dedicated detector electronics (DE) for supply and data acquisition. Due to the high frame rate in combination with the large pixel array, signal correction and event filtering have to be done on-board and in real-time as the raw data rate would by far exceed the feasible telemetry rate. The data streams are merged and compressed in the Instrument Control and

  9. Infrared exploration of the architectural heritage: from passive infrared thermography to hybrid infrared thermography (HIRT approach

    Directory of Open Access Journals (Sweden)

    Sfarra, S.

    2016-09-01

    Full Text Available Up to now, infrared thermographic approaches have been considered either passive or active. In the latter case, the heat flux is historically attributed to a non-natural heat source. The use of the sun has recently been incorporated into the active approach thanks to multi-temporal inspections. In this paper, an innovative hybrid thermographic (HIRT approach is illustrated. It combines both the time component and the solar source to obtain quantitative information such as the defect depth. Thermograms were obtained by inspecting the facade of the Santa Maria Collemaggio church (L’Aquila, Italy, whereas quantitative results related to the sub-superficial discontinuities were obtained thanks to the use of advanced techniques. Experimental results linked to passive approach (i.e., the mosaicking procedure of the thermograms performed by selecting a set of historic churches are also included in order to explain, when and where, the hybrid procedure should be used.Hasta la fecha, los enfoques sobre la termografía infrarroja han sido considerados, o pasivos, o activos. En este último caso, el flujo de calor se obtiene a través de una fuente de calor no natural. El uso de energía solar ha sido recientemente incorporado al enfoque activo gracias a los estudios multitemporales. En este trabajo, se ilustra un enfoque innovador de la termografía híbrida (HIRT. Se combina tanto el componente de tiempo y la fuente de energía solar para recuperar la información cuantitativa así como la profundidad del defecto. Las imágenes térmicas se obtuvieron mediante el análisis de la fachada de la Iglesia de Santa María Collemaggio (L’Aquila, Italia, mientras que los resultados cuantitativos inherentes a las discontinuidades sub-superficiales se obtuvieron gracias al uso de otras técnicas avanzadas. Los resultados experimentales vinculados al enfoque pasivo (es decir, el proceso de mosaico de las imágenes térmicas derivan de un conjunto de Iglesias

  10. Wide-Field Slitless Spectroscopy with JWST/NIRISS

    Science.gov (United States)

    Dixon, William V.

    2013-01-01

    The Near Infrared Imager and Slitless Spectrograph (NIRISS) is one of four scientific instruments that will fly aboard the James Webb Space Telescope (JWST) later in this decade. Among its capabilities, NIRISS offers wide-field slitless spectroscopy (WFSS) with a resolving power R = 150 over the wavelength range 1.0 to 2.25 microns using a pair of grisms that disperse light in orthogonal directions. Employing the software packages aXe and Source Extractor, we have developed the configuration files needed to model WFSS observations with NIRISS and to extract and calibrate the resulting spectra. These files, together with a cookbook detailing their use, are available on the JWST/NIRISS web site at STScI. Using these tools, we construct synthetic images of the near-IR sky, identify and extract the spectra of individual sources, and demonstrate that NIRISS can observe galaxies with redshifts up to z = 17. NIRISS is provided to the JWST project by the Canadian Space Agency under the leadership of René Doyon of the Université de Montréal. The prime contractor is COM DEV Canada.

  11. DMD-based programmable wide field spectrograph for Earth observation

    Science.gov (United States)

    Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

    2015-03-01

    In Earth Observation, Universe Observation and Planet Exploration, scientific return could be optimized in future missions using MOEMS devices. In Earth Observation, we propose an innovative reconfigurable instrument, a programmable wide-field spectrograph where both the FOV and the spectrum could be tailored thanks to a 2D micromirror array (MMA). For a linear 1D field of view (FOV), the principle is to use a MMA to select the wavelengths by acting on intensity. This component is placed in the focal plane of a first grating. On the MMA surface, the spatial dimension is along one side of the device and for each spatial point, its spectrum is displayed along the perpendicular direction: each spatial and spectral feature of the 1D FOV is then fully adjustable dynamically and/or programmable. A second stage with an identical grating recomposes the beam after wavelengths selection, leading to an output tailored 1D image. A mock-up has been designed, fabricated and tested. The micromirror array is the largest DMD in 2048 x 1080 mirrors format, with a pitch of 13.68μm. A synthetic linear FOV is generated and typical images have been recorded o at the output focal plane of the instrument. By tailoring the DMD, we could modify successfully each pixel of the input image: for example, it is possible to remove bright objects or, for each spatial pixel, modify the spectral signature. The very promising results obtained on the mock-up of the programmable wide-field spectrograph reveal the efficiency of this new instrument concept for Earth Observation.

  12. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

    Montilla, I.; Pereira, S.F.; Braat, J.J.M.

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  13. Wide-Field, Deep UV Raman Hyperspectral Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ChemImage Sensor Systems (CISS), teaming with the University of South Carolina, proposes a revolutionary wide-field Raman hyperspectral imaging system capable of...

  14. A Simple, Student-Built Spectrometer to Explore Infrared Radiation and Greenhouse Gases

    Science.gov (United States)

    Bruce, Mitchell R. M.; Wilson, Tiffany A.; Bruce, Alice E.; Bessey, S. Max; Flood, Virginia J.

    2016-01-01

    In this experiment, students build a spectrometer to explore infrared radiation and greenhouse gases in an inquiry-based investigation to introduce climate science in a general chemistry lab course. The lab is based on the exploration of the thermal effects of molecular absorption of infrared radiation by greenhouse and non-greenhouse gases. A…

  15. The UKIRT wide-field camera (WFCAM): commissioning and performance on the telescope

    Science.gov (United States)

    Hirst, Paul; Casali, Mark; Adamson, Andy; Ives, Derek; Kerr, Tom

    2006-06-01

    The UKIRT Wide-Field Camera (WFCAM) was commissioned in two phases between October and December 2004, and March and April 2005. It has been carrying out full-scale sky survey operations since May 2005. This paper describes the commissioning process and compares actual performance on the telescope with specifications in four key areas: optical image quality including delivered FWHM and ghosting etc., noise and sensitivity in the infrared and on the visible autoguider, array artifacts such as crosstalk and persistent images, and observing efficiency. A comprehensive program of science verification was carried out before commencing the UKIRT Infrared Deep Sky Survey (UKIDSS).

  16. Ultra-wide-field imaging in diabetic retinopathy.

    Science.gov (United States)

    Ghasemi Falavarjani, Khalil; Tsui, Irena; Sadda, Srinivas R

    2017-10-01

    Since 1991, 7-field images captured with 30-50 degree cameras in the Early Treatment Diabetic Retinopathy Study were the gold standard for fundus imaging to study diabetic retinopathy. Ultra-wide-field images cover significantly more area (up to 82%) of the fundus and with ocular steering can in many cases image 100% of the fundus ("panretinal"). Recent advances in image analysis of ultra-wide-field imaging allow for precise measurements of the peripheral retinal lesions. There is a growing consensus in the literature that ultra-wide-field imaging improves detection of peripheral lesions in diabetic retinopathy and leads to more accurate classification of the disease. There is discordance among studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema and optimal management strategies to treat diabetic retinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Near-infrared Spectroscopy Of NEOs: Characterization Of Targets Of The ExploreNEOs (Spitzer) Program

    NARCIS (Netherlands)

    Emery, Joshua P.; Thomas, C. A.; Trilling, D. E.; Dave, R.; Delbo, M.; Mueller, M.

    2010-01-01

    In order to complement the ExploreNEOs program, we are characterizing surface compositions of near-Earth objects (NEOs) with near-infrared (NIR) spectroscopy (0.7 to 2.5 microns). The core ExploreNEOs program is an ambitious exploration of the history of near-Earth space using NASA's Spitzer space

  18. 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

  19. Thermal infrared exploration in the Carlin trend, northern Nevada

    Science.gov (United States)

    Watson, K.; Kruse, F.A.; Hummer-Miller, S.

    1990-01-01

    Experimental Thermal Infrared Multispectral Scanner (TIMS) aircraft data have been acquired for the Rodeo Creek NE 7 1/2 minute quadrangle, Eureka County, northern Nevada, covering the Carlin gold mine. A simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties of geologic materials. Emissivity-ratio images were prepared that allow generalized lithologic discrimination, identification of areas with high silica content, and the first reported detection of the carbonate secondary rest-strahlen feature. -from Authors

  20. Advanced MOKE magnetometry in wide-field Kerr-microscopy

    Science.gov (United States)

    Soldatov, I. V.; Schäfer, R.

    2017-10-01

    The measurement of MOKE (Magneto-Optical Kerr Effect) magnetization loops in a wide-field Kerr microscope offers the advantage that the relevant domain images along the loop can be readily recorded. As the microscope's objective lens is exposed to the magnetic field, the loops are usually strongly distorted by non-linear Faraday rotations of the polarized light that occur in the objective lens and that are superimposed to the MOKE signal. In this paper, an experimental method, based on a motorized analyzer, is introduced which allows to compensate the Faraday contributions, thus leading to pure MOKE loops. A wide field Kerr microscope, equipped with this technology, works well as a laser-based MOKE magnetometer, additionally offering domain images and thus providing the basis for loop interpretation.

  1. DCC Case Study: Wide Field Astronomy Unit (WFAU)

    OpenAIRE

    Donnelly, Martin

    2005-01-01

    Case study on the Wide Field Astronomy Unit (WFAU), Edinburgh. Outlines data curation issues with which WFAU is involved, with an emphasis on interoperability. Particular regard is given to the transfer and reuse of data collected from disparate sources. The case study also covers other factors influencing data curation, including methodological development, standards and legal issues, evaluation, and human factors. A technical appendix outlines the technologies used i...

  2. Exploring infrared neural stimulation with multimodal nonlinear imaging (Conference Presentation)

    Science.gov (United States)

    Adams, Wilson R.; Mahadevan-Jansen, Anita

    2017-02-01

    Infrared neural stimulation (INS) provides optical control of neural excitability using near to mid-infrared (mid-IR) light, which allows for spatially selective, artifact-free excitation without the introduction of exogenous agents or genetic modification. Although neural excitability is mediated by a transient temperature increase due to water absorption of IR energy, the molecular nature of IR excitability in neural tissue remains unknown. Current research suggests that transient changes in local tissue temperature give rise to a myriad of cellular responses that have been individually attributed to IR mediated excitability. To further elucidate the underlying biophysical mechanisms, we have begun work towards employing a novel multimodal nonlinear imaging platform to probe the molecular underpinnings of INS. Our imaging system performs coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS), two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG) and thermal imaging into a single platform that allows for unprecedented co-registration of thermal and biochemical information in real-time. Here, we present our work leveraging CARS and SRS in acute thalamocortical brain slice preparations. We observe the evolution of lipid and protein-specific Raman bands during INS and electrically evoked activity in real-time. Combined with two-photon fluorescence and second harmonic generation, we offer insight to cellular metabolism and membrane dynamics during INS. Thermal imaging allows for the coregistration of acquired biochemical information with temperature information. Our work previews the versatility and capabilities of coherent Raman imaging combined with multiphoton imaging to observe biophysical phenomena for neuroscience applications.

  3. Vestibular rehabilitation using a wide field of view virtual environment.

    Science.gov (United States)

    Sparto, P J; Furman, J M; Whitney, S L; Hodges, L F; Redfern, M S

    2004-01-01

    This paper presents a theoretical justification for using a wide field of view (FOV) virtual reality display system for use in vestibular rehabilitation. A wide FOV environment offers some unique features that may be beneficial to vestibular rehabilitation. Primarily, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. If this hypothesis is correct, then wide FOV systems will have an advantage over narrow field of view input devices such as head mounted or desktop displays. Devices that we have incorporated into our system that are critical for monitoring improvement in this clinical population will also be described.

  4. WISE Infrared Properties of Fermi AGNs JJ Qiu1, JS Zhang1,∗ & Q ...

    Indian Academy of Sciences (India)

    Abstract. The infrared properties of Fermi AGNs were investigated using the survey data of the Wide-field Infrared Survey Explorer (WISE). The results showed: (1) BL Lacs tend to be brighter than FSRQs at. 3.4μm. However, with increase of wavelength, FSRQs tend to be brighter than BL Lacs. (2) FSRQs colours are redder ...

  5. PERSPECTIVE: Toward a wide-field retinal prosthesis

    Science.gov (United States)

    Ameri, Hossein; Ratanapakorn, Tanapat; Ufer, Stefan; Eckhardt, Helmut; Humayun, Mark S.; Weiland, James D.

    2009-06-01

    The purpose of this paper is to present a wide field electrode array that may increase the field of vision in patients implanted with a retinal prosthesis. Mobility is often impaired in patients with low vision, particularly in those with peripheral visual loss. Studies on low vision patients as well as simulation studies on normally sighted individuals have indicated a strong correlation between the visual field and mobility. In addition, it has been shown that an increased visual field is associated with a significant improvement in visual acuity and object discrimination. Current electrode arrays implanted in animals or human vary in size; however, the retinal area covered by the electrodes has a maximum projected visual field of about 10°. We have designed wide field electrode arrays that could potentially provide a visual field of 34°, which may significantly improve the mobility. Tests performed on a mechanical eye model showed that it was possible to fix 10 mm wide flexible polyimide dummy electrode arrays onto the retina using a single retinal tack. They also showed that the arrays could conform to the inner curvature of the eye. Surgeries on an enucleated porcine eye model demonstrated feasibility of implantation of 10 mm wide arrays through a 5 mm eye wall incision.

  6. Visibility retrieval in Michelson wide-field stellar interferometry

    Science.gov (United States)

    Montilla, I.; Sellos, J.; Pereira, S. F.; Braat, J. J. M.

    2006-04-01

    Wide-field interferometry has become a subject of increasing interest in recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide-field method (homothetic mapping), which is not applicable when the aperture is highly diluted; for this reason, imaging with non-homothetic arrays is being extensively studied (E. Pedretti, et al., Astron. Astrophys. Suppl. Ser. 147 285 (2000); S. Gillet, et al., Astron. Astrophys. 400 393 (2003)). The field of view of a pupil-plane interferometer or a densified array consists of only a few resolution elements; in order to improve these systems, we have developed a new method consisting of a Michelson pupil-plane combination scheme where a wide field of view can be achieved in one shot. This technique, called the ‘staircase mirror’ approach, has been described in a previous paper (I. Montilla, S.F. Pereira and J.J.M. Braat, Appl. Optics 44 328 (2005)) and uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction of the differential delay for both the on- and off-axis image positions. Experimental results have been obtained showing the simultaneous recovery of the fringes of off-axis stars with an appreciable angular separation, and with a contrast similar to that of the on-axis reference star. With this example we demonstrate an increase of the field of view by a factor of 5, with no need for extra observation time. In this article, we present a further analysis of the method. We investigate how to retrieve the visibility when a star is focused on the edge of a step of the stair-shaped mirror. Even though the optical pathlength difference correction is discontinuous, we show both numerically and analytically that the visibility can be completely recovered, so that no information is lost. Our experimental results demonstrate that the visibility can be retrieved to within a 1% error.

  7. Wide-field subdiffraction RESOLFT microscopy using fluorescent protein photoswitching.

    Science.gov (United States)

    Schwentker, Miriam A; Bock, Hannes; Hofmann, Michael; Jakobs, Stefan; Bewersdorf, Jörg; Eggeling, Christian; Hell, Stefan W

    2007-03-01

    Subdiffraction fluorescence imaging is presented in a parallelized wide-field arrangement exploiting the principle of reversible saturable/switchable optical transitions (RESOLFT). The diffraction barrier is overcome by photoswitching ensembles of the label protein asFP595 between a nonfluorescent off- and a fluorescent on-state. Relying on ultralow continuous-wave intensities, reversible protein switching facilitates parallelized fast image acquisition. The RESOLFT principle is implemented by illuminating with intensity distributions featuring zero intensity lines that are further apart than the conventional Abbe resolution limit. The subdiffraction resolution is verified by recording live Escherichia coli bacteria labeled with asFP595. The obtained resolution of 50 nm ( approximately lambda/12) is limited only by the spectroscopic properties of the proteins and the imperfections of the optical implementation, but not on principle grounds. (c) 2007 Wiley-Liss, Inc.

  8. Thermal design of the Wide Field/Planetary Camera

    Science.gov (United States)

    Garcia, R. D.; Jones, J. A.; Stultz, J. W.

    1989-01-01

    The Wide Field/Planetary Camera is an imaging system developed by the Jet Propulsion Laboratory for the NASA Hubble Space Telescope currently scheduled to be launched in December 1989 aboard the space shuttle. The temperature control design of the instrument utilizes multilayered insulation, electric resistance heaters, aluminum/ammonia heat pipes, thermoelectric coolers, temperature control coatings, and space radiators. A feedback control system maintains stable sensor temperatures. Thermal capacitance maintains stable optics and electronics temperatures during transient conditions. Schedule slips and launch delays have allowed extensive thermal testing of the instrument. Six instrument thermal vacuum tests and a spacecraft thermal vacuum test were performed. Several modifications have been made to the instrument to correct icing and contamination problems that have been discovered during thermal vacuum testing. This paper describes the thermal design, last instrument thermal vacuum test, results, and thermal model correlation.

  9. The design of the wide field monitor for LOFT

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2014-01-01

    is designed to carry on-board two instruments with sensitivity in the 2-50 keV range: a 10 m 2 class Large Area Detector (LAD) with a ... will be to detect transient sources to be observed by the LAD. However, thanks to its unique combination of a wide field of view (FoV) and energy resolution (better than 500 eV), the WFM will be also an excellent monitoring instrument to study the long term variability of many classes of X-ray sources. The WFM...... consists of 10 independent and identical coded mask cameras arranged in 5 pairs to provide the desired sky coverage. We provide here an overview of the instrument design, configuration, and capabilities of the LOFT WFM. The compact and modular design of the WFM could easily make the instrument concept...

  10. Wide-Field Ultraviolet Spectrometer for Planetary Exospheres and Thermospheres

    Science.gov (United States)

    Fillingim, M. O.; Wishnow, E. H.; Miller, T.; Edelstein, J.; Lillis, R. J.; Korpela, E.; England, S.; Shourt, W. V.; Siegmund, O.; McPhate, J.; Courtade, S.; Curtis, D. W.; Deighan, J.; Chaffin, M.; Harmoul, A.; Almatroushi, H. R.

    2016-12-01

    Understanding the composition, structure, and variability of a planet's upper atmosphere - the exosphere and thermosphere - is essential for understanding how the upper atmosphere is coupled to the lower atmosphere, magnetosphere and near-space environment, and the Sun. Ultraviolet spectroscopy can directly observe emissions from constituents in the exosphere and thermosphere. From such observations, the structure, composition, and variability can be determined.We will present the preliminary design for a wide field ultraviolet imaging spectrometer for remote sensing of planetary atmospheres. The imaging spectrometer achieves an extremely large instantaneous 110 degree field of view with no moving scanning mirror. The imaging resolution is very appropriate for extended atmospheric emission studies, with a resolution of better than 0.3 degrees at the center to 0.4 degrees at the edges of the field. The spectral range covers 120 - 170 nm, encompassing emissions from H, O, C, N, CO, and N2, with an average spectral resolution of 1.5 nm. The instrument is composed of a 2-element wide-field telescope, a 3-element Offner spectrometer, and a sealed MCP detector system contained within a compact volume of about 40 x 25 x 20 cm. We will present the optical and mechanical design as well as the predicted optical performance.The wide instantaneous FOV simplifies instrument and spacecraft operations by removing the need for multiple scans (either from a scan mirror or spacecraft slews) to cover the regions of interest. This instrumentation can allow for two-dimensional spectral information to be built up with simple spacecraft operation or just using spacecraft motion. Applications to the terrestrial geocorona and thermosphere will be addressed as well as applications to the upper atmospheres of other planetary objects.

  11. Calibration and testing of wide-field UV instruments

    Science.gov (United States)

    Frey, H. U.; Mende, S. B.; Loicq, J.; Habraken, S.

    2017-06-01

    As with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. In theory a ray tracing and characterization of each individual component of the optical system (mirrors, windows, and grating) should provide the transmission efficiency of the combined system. However, potentially unknown effects (contamination, misalignment, and measurement errors) can make the final error too large and unacceptable for most applications. Therefore, it is desirable to test and measure the optical properties of the whole system in vacuum and compare the overall response to the response of a calibrated photon detector. A proper comparison then allows the quantification of individual sources of uncertainty and ensures that the whole instrument performance is within acceptable tolerances or pinpoints which parts fail to meet requirements. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera, and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and passband calibration, spot size, imaging distortions, flatfield, and field of view determination.Plain Language SummaryAs with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera (WIC), and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and pass-band calibration

  12. Extreme multiplex spectroscopy at wide-field 4-m telescopes

    Science.gov (United States)

    Content, Robert; Shanks, Tom

    2008-07-01

    We describe the design and science case for a spectrograph for the prime focus of classical 4-m wide-field telescopes that can deliver at least 4000 MOS slits over a 1° field. This extreme multiplex capability means that 25000 galaxy redshifts can be measured in a single night, opening up the possibilities for large galaxy redshift surveys out to z~0.7 and beyond for the purpose of measuring the Baryon Acoustic Oscillation (BAO) scale and for many other science goals. The design features four cloned spectrographs and exploits the exclusive possibility of tiling the focal plane of wide-field 4-m telescopes with CCDs for multi-object spectroscopic purposes. In ~200 night projects, such spectrographs have the potential to make galaxy redshift surveys of ~6×106 galaxies over a wide redshift range and thus may provide a low-cost alternative to other survey routes such as WFMOS and SKA. Two of these extreme multiplex spectrographs are currently being designed for the AAT (NG1dF) and Calar Alto (XMS) 4-m class telescopes. NG2dF, a larger version for the AAT 2° field, would have 12 clones and at least 12000 slits. The clones use a transparent design including a grism in which all optics are smaller than the clone square subfield so that the clones can be tightly packed with little gaps between the contiguous fields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing one or two of the lenses adjacent to the grism. The total weight and length is smaller with a few clones than a unique spectrograph which makes it feasible to place the spectrograph at the prime focus.

  13. The cryo-testing of infrared filters and beamsplitters for the cosmic background explorer's instruments

    Science.gov (United States)

    Heaney, James B.; Stewart, Kenneth P.; Boucarut, Rene A.; Alley, Phillip W.; Korb, Andrew R.

    1986-01-01

    The cryooptical methods used to measure the spectral transmittances of filters and beamsplitters for the Cosmic Background Explorer's instruments are described. Measured results demonstrate the temperature sensitivity, or insensitivity, of various infrared filter designs within the wavelength range from 1 to 1000 microns.

  14. Microlensing Surveys of M31 in the Wide Field Imaging ERA

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, E.

    2004-10-27

    The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the studies of the Milky Way halo using the Large and Small Magellanic Clouds. We consider the possibilities for microlensing surveys of M31 using the next generation of wide field imaging telescopes with fields of view in the square degree range. We consider proposals for such imagers both on the ground and in space. For concreteness, we specialize to the SNAP proposal for a space telescope and the LSST proposal for a ground based telescope. We find that a modest space-based survey of 50 visits of one hour each is considerably better than current ground based surveys covering 5 years. Crucially, systematic effects can be considerably better controlled with a space telescope because of both the infrared sensitivity and the angular resolution. To be competitive, 8 meter class wide-field ground based imagers must take exposures of several hundred seconds with several day cadence.

  15. A variable mid-infrared synchrotron break associated with the compact jet in GX 339-4

    NARCIS (Netherlands)

    Gandhi, P.; Blain, A.W.; Russell, D.M.; Casella, P.; Malzac, J.; Corbel, S.; D'Avanzo, P.; Lewis, F.W.; Markoff, S.; Cadolle Bel, M.; Goldoni, P.; Wachter, S.; Khangulyan, D.; Mainzer, A.

    2011-01-01

    Many X-ray binaries remain undetected in the mid-infrared, a regime where emission from their compact jets is likely to dominate. Here, we report the detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey Explorer (WISE) during a very bright, hard accretion state in 2010.

  16. San Pedro meeting on Wide Field Variability Surveys: Some concluding comments

    Directory of Open Access Journals (Sweden)

    Feast Michael W.

    2017-01-01

    Full Text Available This is a written version of the closing talk at the 22nd Los Alamos Stellar pulsation conference on wide field variability surveys. It comments on some of the issues which arise from the meeting. These include the need for attention to photometric standardization (especially in the infrared and the somewhat controversial problem of statistical bias in the use of parallaxes (and other methods of distance determination. Some major advances in the use of pulsating variables to study Galactic structure are mentioned. The paper includes a clarification of apparently conflicting results from classical Cepheids and RR Lyrae stars in the inner Galaxy and bulge. The importance of understanding non-periodic phenomena in variable stars, particularly asymptotic giant branch variables and R Coronae Borealis stars, is stressed, especially for its relevance to mass-loss in which pulsation may only play a minor role.

  17. Selected aspects of wide-field stellar interferometry

    Science.gov (United States)

    D'Arcio, Luigi Arsenio

    1999-11-01

    In Michelson stellar interferometry, the high-resolution information about the source structure is detected by performing observations with widely separated telescopes, interconnected to form an interferometer. At optical wavelengths, this method provides a technically viable approach for achieving angular resolutions in the milliarcsecond range, comparable to those of a 100 m diameter telescope, whose realization is beyond the immediate engineering capabilities. Considerable efforts are currently devoted to the definition of dedicated interferometric instruments, which will allow to address ambitious astronomical tasks such as high-resolution imaging, astrometry at microarcsecond level, and the direct detection of exoplanets. Astrometry and related techniques employ the so-called wide field-of-view interferometric mode, where phase measurements are performed simultaneously at two (or more) sources; often, the actual observable is the instantaneous phase difference of the two object signals. The future success of wide-field interferometry critically depends on the development of techniques for the accurate control of field-dependent (anisoplanatic) phase errors. In this thesis, we address two aspects of this problem in detail. The first one is theoretical in nature. For ground-based measurements, atmospheric turbulence is the largest source of random phase fluctuations between the on- and the off-axis fringes. We developed a model of the temporal power spectrum of this disturbance, whose validity is not limited to low frequencies only, as it is the case with earlier models. This extension opens the possibility of the analysis of dynamic issues, such as the determination of the allowable coherent integration time T for the off-axis fringes. The spectrum turns out to be well approximated by a sequences of four power-law branches. In first instance, its overall form is determined by the values of the baseline length, telescope diameter, and average beam separation in

  18. Wide Field-of-View Fluorescence Imaging of Coral Reefs

    Science.gov (United States)

    Treibitz, Tali; Neal, Benjamin P.; Kline, David I.; Beijbom, Oscar; Roberts, Paul L. D.; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys. PMID:25582836

  19. New Subarray Readout Patterns for the ACS Wide Field Channel

    Science.gov (United States)

    Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.

    2017-04-01

    At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.

  20. Development of the wide field imager for Athena

    Science.gov (United States)

    Meidinger, Norbert; Eder, Josef; Fürmetz, Maria; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Reiffers, Jonas; Strecker, Rafael; Barbera, Marco; Brand, Thorsten; Wilms, Jörn

    2015-08-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 arcmin x 40 arcmin together with excellent count-rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 6 keV will be MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of four large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single smaller gateable DEPFET sensor matrix optimized for high count-rate observations. Here we present the conceptual design of the instrument with focus on the critical subsystems and describe the instrument performance expectations. An outline of the model philosophy and the project organization completes the presentation.

  1. Pixel History for Advanced Camera for Surveys Wide Field Channel

    Science.gov (United States)

    Borncamp, D.; Grogin, N.; Bourque, M.; Ogaz, S.

    2017-06-01

    Excess thermal energy present in a Charged Coupled Device (CCD) can result in additional electrical current. This excess charge is trapped within the silicon lattice structure of the CCD electronics. It can persist through multiple exposures and have an adverse effect on science performance of the detectors unless properly flagged and corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as "dark" images, allow for the measurement of the thermal-electron contamination present in each pixel of the CCD lattice. This so-called "dark current" can then be subtracted from the science images by re-scaling the dark to the corresponding exposure times. Pixels that have signal above a certain threshold are traditionally marked as "hot" and flagged in the data quality array. Many users will discard these because of the extra current. However, these pixels may not be unusable because of an unreliable dark subtraction; if we find these pixels to be stable over an anneal period, we can properly subtract the charge and the extra Poisson noise from this dark current will be propagated into the error arrays. Here we present the results of a pixel history study that analyzes every individual pixel of the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs over time and allows pixels that were previously flagged as unusable to be brought back into the science image as a reliable pixel.

  2. Wide-Field Optic for Autonomous Acquisition of Laser Link

    Science.gov (United States)

    Page, Norman A.; Charles, Jeffrey R.; Biswas, Abhijit

    2011-01-01

    An innovation reported in Two-Camera Acquisition and Tracking of a Flying Target, NASA Tech Briefs, Vol. 32, No. 8 (August 2008), p. 20, used a commercial fish-eye lens and an electronic imaging camera for initially locating objects with subsequent handover to an actuated narrow-field camera. But this operated against a dark-sky background. An improved solution involves an optical design based on custom optical components for the wide-field optical system that directly addresses the key limitations in acquiring a laser signal from a moving source such as an aircraft or a spacecraft. The first challenge was to increase the light collection entrance aperture diameter, which was approximately 1 mm in the first prototype. The new design presented here increases this entrance aperture diameter to 4.2 mm, which is equivalent to a more than 16 times larger collection area. One of the trades made in realizing this improvement was to restrict the field-of-view to +80 deg. elevation and 360 azimuth. This trade stems from practical considerations where laser beam propagation over the excessively high air mass, which is in the line of sight (LOS) at low elevation angles, results in vulnerability to severe atmospheric turbulence and attenuation. An additional benefit of the new design is that the large entrance aperture is maintained even at large off-axis angles when the optic is pointed at zenith. The second critical limitation for implementing spectral filtering in the design was tackled by collimating the light prior to focusing it onto the focal plane. This allows the placement of the narrow spectral filter in the collimated portion of the beam. For the narrow band spectral filter to function properly, it is necessary to adequately control the range of incident angles at which received light intercepts the filter. When this angle is restricted via collimation, narrower spectral filtering can be implemented. The collimated beam (and the filter) must be relatively large to

  3. Understanding sub-stellar populations using wide-field infrared surveys

    Directory of Open Access Journals (Sweden)

    Hewett P.C.

    2011-07-01

    Full Text Available This paper discusses benchmark brown dwarfs in various environments, and focuses on those in wide binary systems. We present a summary of the recently discovered T dwarf population from the UKIDSS Large Area Survey, and describe the constraints that it places on our knowledge of the sub-stellar initial mass function. We also present some exciting results from our ongoing search for wide companions to this sample, that has so far revealed an M4-T8.5 binary system at ∼12 parsecs and also the first ever Tdwarf-white dwarf binary system. The T dwarfs in these binaries have their properties constrained by the primary object and are thus benchmark objects that are already testing the predictions of theoretical model atmospheres.

  4. WIDE-FIELD INFRARED POLARIMETRY OF THE ρ OPHIUCHI CLOUD CORE

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jungmi; Tamura, Motohide; Kusakabe, Nobuhiko [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Hough, James H. [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Nakajima, Yasushi [Center of Information and Communication Technology, Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601 (Japan); Nishiyama, Shogo [Miyagi University of Education, Sendai 980-0845 (Japan); Nagata, Tetsuya [Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Kandori, Ryo, E-mail: jungmi.kwon@astron.s.u-tokyo.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2015-09-15

    We conducted wide and deep simultaneous JHK{sub s}-band imaging polarimetry of the ρ Ophiuchi cloud complex. Aperture polarimetry in the JHK{sub s} band was conducted for 2136 sources in all three bands, of which 322 sources have significant polarizations in all the JHK{sub s} bands and have been used for a discussion of the core magnetic fields. There is a positive correlation between degrees of polarization and H − K{sub s} color up to H − K{sub s} ≈ 3.5. The magnetic field structures in the core region are revealed up to at least A{sub V} ≈ 47 mag and are unambiguously defined in each sub-region (core) of Oph-A, Oph-B, Oph-C, Oph-E, Oph-F, and Oph-AC. Their directions, degrees of polarization, and polarization efficiencies differ but their changes are gradual; thus, the magnetic fields appear to be connected from core to core, rather than as a simple overlap of the different cloud core components. Comparing our results with the large-scale field structures obtained from previous optical polarimetric studies, we suggest that the magnetic field structures in the core were distorted by the cluster formation in this region, which may have been induced by shock compression due to wind/radiation from the Scorpius–Centaurus association.

  5. Parfocal wide field near infrared grism design and fabrication for WFIRST Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The original objective was to ensure that the grism assembly can be designed and fabricated to meet the WFIRST spectrometer requirements. The current grism design...

  6. Optical System and Desing Of The New 1.6 Meter Wide-Field Telescope With Active Optics

    Science.gov (United States)

    Papushev, Pavel; Denisenko, Sergey; Kamus, Sergey; Pimenov, Yury; Tergoev, Vladim

    2006-08-01

    In this report we present and discuss the design, construction and capabilities of the two meters class wide field survey telescope. The designs based on modified R-C system with two or three lens correctors in visible and near infrared (2,2 mkm) spectral range. The optical systems of the 1.6 meters telescope with up to 3 degrees field of view and less than 15% obscuration area are considered in detail. Optical performance of system, its mount and separate element of the active optics system are examined.

  7. Exploration of in vivo Effect Assessment Factor Monitoring by Near-infrared Spectroscopy during LITT

    Energy Technology Data Exchange (ETDEWEB)

    Qian Aiping; Hua Guoran; Zhang Hua [Department of Biomedical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Qian Zhiyu, E-mail: huagr@ntu.edu.cn

    2011-02-01

    By studying the variation trends of the absorption coefficient ({mu}{sub a}) and the reduced scattering coefficient ({mu}'{sub s}), which were monitored in vivo by functional near infrared spectroscopy (fNIRS) system in real time during laser induced interstitial thermotherapy (LITT), the optimized near infrared effect assessment factor would be explored. In vivo measurements of the absorption coefficient (u{sub a}) and the reduced scattering coefficient (u'{sub s}) were performed with a functional near infrared spectroscopy system during LITT. Fresh porcine liver tissue samples in vitro and the subcutaneous implanted rat liver cancers were examined in different laser doses and define heating times. The absorption coefficient obtained by the fNIRS increased in the pork liver experiments, but decreased in the rat liver cancer experiments. The reduced scattering coefficient increased in the pork liver experiments and the rat liver cancer experiments, it increased quickly at beginning, and gradually reached the stable state. Therefore, the reduced scattering coefficient is more suitable for reflecting the progress of damage during different biological tissues' LITT than the absorption coefficient. This conclusion will effectively guide the study of suitable therapy effect assessment system during LITT in real time.

  8. Exploration of in vivo Effect Assessment Factor Monitoring by Near-infrared Spectroscopy during LITT

    Science.gov (United States)

    Qian, Ai-ping; Hua, Guo-ran; Zhang, Hua; Qian, Zhi-yu

    2011-02-01

    By studying the variation trends of the absorption coefficient (μa) and the reduced scattering coefficient (μ's), which were monitored in vivo by functional near infrared spectroscopy (fNIRS) system in real time during laser induced interstitial thermotherapy (LITT), the optimized near infrared effect assessment factor would be explored. In vivo measurements of the absorption coefficient (ua) and the reduced scattering coefficient (u's) were performed with a functional near infrared spectroscopy system during LITT. Fresh porcine liver tissue samples in vitro and the subcutaneous implanted rat liver cancers were examined in different laser doses and define heating times. The absorption coefficient obtained by the fNIRS increased in the pork liver experiments, but decreased in the rat liver cancer experiments. The reduced scattering coefficient increased in the pork liver experiments and the rat liver cancer experiments, it increased quickly at beginning, and gradually reached the stable state. Therefore, the reduced scattering coefficient is more suitable for reflecting the progress of damage during different biological tissues' LITT than the absorption coefficient. This conclusion will effectively guide the study of suitable therapy effect assessment system during LITT in real time.

  9. Advances on Hubble Wide Field Camera 3 Grism Calibration and Slitless Spectroscopy Analysis

    Science.gov (United States)

    Fowler, Julia; Brammer, Gabriel; Ryan, Russell; Deustua, Susana; Pirzkal, Nor

    2018-01-01

    Grisms are spectral elements combining a grating and prism to conduct slitless spectroscopy; presently they make up approximately 13% of all Wide Field Camera 3 (WFC3) observations on the Hubble Space Telescope (HST). WFC3 contains three grisms, two for the infrared (IR) channel and one for the ultraviolet-visible (UVIS). Here we summarize recent results from an ongoing effort to improve the analysis tools, characterization, and calibration of WFC3 slitless spectroscopic observations. This includes (1) calibrating the IR wavelength solutions with respect to compact zeroth order images, (2) improved IR throughput curves from modelling grism flux by extending the pixel range of effective point spread functions, (3) IR linear-reconstruction solving methods that solve for optimal, non-parametric spectra, (4) calibrating the UVIS +1 and -1 order over the entire field of view of both chips (allowing for spectral extraction from the entire UVIS detector.) With these efforts we continue to improve and advance the science possible with WFC3 grism observations.

  10. The Infrared and Radio Fluxes Densities of Galactic HII Regions

    OpenAIRE

    Makai, Z.; Anderson, L. D.; Mascoop, J. L.; Johnstone, B.

    2017-01-01

    We derive infrared and radio flux densities of all ~1000 known Galactic HII regions in the Galactic longitude range 17.5 < l < 65 degree. Our sample comes from the Wide-Field Infrared Survey Explorer (WISE) catalog of Galactic \\hii regions \\citep{anderson2014}. We compute flux densities at six wavelengths in the infrared (GLIMPSE 8 microns, WISE 12 microns and 22 microns, MIPSGAL 24 microns, and Hi-GAL 70 microns and 160 microns) and two in the radio (MAGPIS 20 cm and VGPS 21 cm). All HII reg...

  11. Structured illumination for wide-field Raman imaging of cell membranes

    Science.gov (United States)

    Chen, Houkai; Wang, Siqi; Zhang, Yuquan; Yang, Yong; Fang, Hui; Zhu, Siwei; Yuan, Xiaocong

    2017-11-01

    Although the diffraction limit still restricts their lateral resolution, conventional wide-field Raman imaging techniques offer fast imaging speeds compared with scanning schemes. To extend the lateral resolution of wide-field Raman microscopy using filters, standing-wave illumination technique is used, and an improvement of lateral resolution by a factor of more than two is achieved. Specifically, functionalized surface enhanced Raman scattering nanoparticles are employed to strengthen the desired scattering signals to label cell membranes. This wide-field Raman imaging technique affords various significant opportunities in the biological applications.

  12. Exploration of the Saturn System by the Cassini Mission: Observations with the Cassini Infrared Spectrometer

    Science.gov (United States)

    Abbas, Mian M.

    2014-01-01

    Outline: Introduction to the Cassini mission, and Cassini mission Objectives; Cassini spacecraft, instruments, launch, and orbit insertion; Saturn, Rings, and Satellite, Titan; Composite Infrared Spectrometer (CIRS); and Infrared observations of Saturn and titan.

  13. Wide Field-of-View (FOV) Soft X-Ray Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wide Field-of-View (FOV) Soft X-Ray Imager proposes to be a state-of-art instrument with applications for numerous heliospheric and planetary...

  14. The Far Infrared Spectroscopic Explorer (FIRSPEX): probing the lifecycle of the ISM in the universe

    Science.gov (United States)

    Rigopoulou, D.; Caldwell, M.; Ellison, B.; Pearson, C.; Caux, E.; Cooray, A.; Gallego, J. D.; Gerin, M.; Goicoechea, J. R.; Goldsmith, P.; Kramer, C.; Lis, D. C.; Molinari, S.; Ossenkopf-Okada, V.; Savini, G.; Tan, B. K.; Tielens, X.; Viti, S.; Wiedner, M.; Yassin, G.

    2016-07-01

    The Far Infrared Spectroscopic Explorer (FIRSPEX) is a novel European-led astronomy mission concept developed to enable large area ultra high spectroscopic resolution surveys in the THz regime. FIRSPEX opens up a relatively unexplored spectral and spatial parameter space that will produce an enormously significant scientific legacy by focusing on the properties of the multi-phase ISM, the assembly of molecular clouds in our Galaxy and the onset of star formation; topics which are fundamental to our understanding of galaxy evolution. The mission uses a heterodyne instrument and a ~1.2 m primary antenna to scan large areas of the sky in a number of discreet spectroscopic channels from L2. The FIRSPEX bands centered at [CI] 809 GHz, [NII]1460 GHz, [CII]1900 GHz and [OI]4700 GHz have been carefully selected to target key atomic and ionic fine structure transitions difficult or impossible to access from the ground but fundamental to the study of the multi-phase ISM in the Universe. The need for state-of-the-art sensitivity dictates the use of superconducting mixers configured either as tunnel junctions or hot electron bolometers. This technology requires cooling to low temperatures, approaching 4K, in order to operate. The receivers will operate in double sideband configuration providing a total of 7 pixels on the sky. FIRSPEX will operate from L2 in both survey and pointed mode enabling velocity resolved spectroscopy of large areas of sky as well as targeted observations.

  15. Exploring effective multiplicity in multichannel functional near-infrared spectroscopy using eigenvalues of correlation matrices.

    Science.gov (United States)

    Uga, Minako; Dan, Ippeita; Dan, Haruka; Kyutoku, Yasushi; Taguchi, Y-H; Watanabe, Eiju

    2015-01-01

    Recent advances in multichannel functional near-infrared spectroscopy (fNIRS) allow wide coverage of cortical areas while entailing the necessity to control family-wise errors (FWEs) due to increased multiplicity. Conventionally, the Bonferroni method has been used to control FWE. While Type I errors (false positives) can be strictly controlled, the application of a large number of channel settings may inflate the chance of Type II errors (false negatives). The Bonferroni-based methods are especially stringent in controlling Type I errors of the most activated channel with the smallest [Formula: see text] value. To maintain a balance between Types I and II errors, effective multiplicity ([Formula: see text]) derived from the eigenvalues of correlation matrices is a method that has been introduced in genetic studies. Thus, we explored its feasibility in multichannel fNIRS studies. Applying the [Formula: see text] method to three kinds of experimental data with different activation profiles, we performed resampling simulations and found that [Formula: see text] was controlled at 10 to 15 in a 44-channel setting. Consequently, the number of significantly activated channels remained almost constant regardless of the number of measured channels. We demonstrated that the [Formula: see text] approach can be an effective alternative to Bonferroni-based methods for multichannel fNIRS studies.

  16. Firearm Projectile in the Maxillary Tuberosity Located by Adjunctive Examination of Wide-Field Optical Fluorescence.

    Science.gov (United States)

    Andrade, Sérgio Araújo; Varotti, Fernando de Pilla; Bagnato, Vanderlei Salvador; Pratavieira, Sebastião

    2017-10-10

    Demonstrate the use of wide-field optical fluorescence as an adjunctive examination in a clinical routine to oral diagnosis. Use of wide-field optical fluorescence in the oral cavity has been restricted to topics related to the detection and diagnosis of oral cancer. In a regular medical appointment, a 58-year-old female patient, without any complaint or oral symptom, underwent the complementary examination by wide-field optical fluorescence. A device with high-power light-emitting diode emitting light centered at a wavelength of (400 ± 10) nm and maximum irradiance of (0.040 ± 0.008) W/cm(2) was used for fluorescence visualization. We report the location of a firearm projectile, intraosseous, in the maxillary tuberosity using wide-field optical fluorescence. It is evidenced that wide-field optical fluorescence, within a clinical routine, can provide relevant images and data, with an immediate result, without the use of ionizing radiation, enabling an efficient oral diagnosis.

  17. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Energy Technology Data Exchange (ETDEWEB)

    Zanda, Gianmarco, E-mail: gianmarco.zanda@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Sergent, Nicolas; Green, Mark; Levitt, James A. [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Petrasek, Zdenek [Biotechnologisches Zentrum, Technische Universitaet Dresden, Tatzberg 47/49, 01307 Dresden (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom)

    2012-12-11

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  18. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Science.gov (United States)

    Zanda, Gianmarco; Sergent, Nicolas; Green, Mark; Levitt, James A.; Petrášek, Zdeněk; Suhling, Klaus

    2012-12-01

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  19. SixPak: a wide-field IFU for the William Herschel Telescope

    NARCIS (Netherlands)

    Venema, Lars B.; Schoenmaker, Ton; Verheijen, Marc; Trager, Scott; Rutten, René; Bershady, Matthew; Larsen, Søren; Peletier, Reynier; Spaans, Marco

    2008-01-01

    We intend to construct SixPak, a wide-field fibre-based IFU for the 4.2-meter William Herschel Telescope on La Palma. The fibre bundle will consist of 238 fibres, each 3.0 arcsec in diameter, piping light from the Nasmyth focal plane of the WHT to the existing WYFFOS bench spectrograph. A total of

  20. Scalable wide-field optical coherence tomography-based angiography for in vivo imaging applications.

    Science.gov (United States)

    Xu, Jingjiang; Wei, Wei; Song, Shaozhen; Qi, Xiaoli; Wang, Ruikang K

    2016-05-01

    Recent advances in optical coherence tomography (OCT)-based angiography have demonstrated a variety of biomedical applications in the diagnosis and therapeutic monitoring of diseases with vascular involvement. While promising, its imaging field of view (FOV) is however still limited (typically less than 9 mm(2)), which somehow slows down its clinical acceptance. In this paper, we report a high-speed spectral-domain OCT operating at 1310 nm to enable wide FOV up to 750 mm(2). Using optical microangiography (OMAG) algorithm, we are able to map vascular networks within living biological tissues. Thanks to 2,048 pixel-array line scan InGaAs camera operating at 147 kHz scan rate, the system delivers a ranging depth of ~7.5 mm and provides wide-field OCT-based angiography at a single data acquisition. We implement two imaging modes (i.e., wide-field mode and high-resolution mode) in the OCT system, which gives highly scalable FOV with flexible lateral resolution. We demonstrate scalable wide-field vascular imaging for multiple finger nail beds in human and whole brain in mice with skull left intact at a single 3D scan, promising new opportunities for wide-field OCT-based angiography for many clinical applications.

  1. Astro-WISE Processing of Wide-field Images and Other Data

    NARCIS (Netherlands)

    Buddelmeijer, H.; Williams, O.R.; McFarland, J. P.; Belikov, A.; Ballester, P.; Egret, D.; Lorente, N.P.F.

    Astro-WISE (Vriend et al. 2012) is the Astronomical Wide-field Imaging System for Europe (Valentijn et al. 2007). It is a scientific information system which consists of hardware and software federated over about a dozen institutes throughout Europe. It has been developed to exploit the ever

  2. Wide-field interferometric phase microscopy with molecular specificity using plasmonic nanoparticles.

    Science.gov (United States)

    Turko, Nir A; Peled, Anna; Shaked, Natan T

    2013-11-01

    We present a method for adding molecular specificity to wide-field interferometric phase microscopy (IPM) by recording the phase signatures of gold nanoparticles (AuNPs) labeling targets of interest in biological cells. The AuNPs are excited by time-modulated light at a wavelength corresponding to their absorption spectral peak, evoking a photothermal (PT) effect due to their plasmonic resonance. This effect induces a local temperature rise, resulting in local refractive index and phase changes that can be detected optically. Using a wide-field interferometric phase microscope, we acquired an image sequence of the AuNP sample phase profile without requiring lateral scanning, and analyzed the time-dependent profile of the entire field of view using a Fourier analysis, creating a map of the locations of AuNPs in the sample. The system can image a wide-field PT phase signal from a cluster containing down to 16 isolated AuNPs. AuNPs are then conjugated to epidermal growth factor receptor (EGFR) antibodies and inserted to an EGFR-overexpressing cancer cell culture, which is imaged using IPM and verified by confocal microscopy. To the best of our knowledge, this is the first time wide-field interferometric PT imaging is performed at the subcellular level without the need for total internal reflection effects or scanning.

  3. Multi-feature combined cloud and cloud shadow detection in GaoFen-1 wide field of view imagery

    Science.gov (United States)

    Li, Zhiwei; Shen, Huanfeng; Li, Huifang; Xia, Guisong; Gamba, Paolo; Zhang, Liangpei

    2017-03-01

    The wide field of view (WFV) imaging system onboard the Chinese GaoFen-1 (GF-1) optical satellite has a 16-m resolution and four-day revisit cycle for large-scale Earth observation. The advantages of the high temporal-spatial resolution and the wide field of view make the GF-1 WFV imagery very popular. However, cloud cover is an inevitable problem in GF-1 WFV imagery, which influences its precise application. Accurate cloud and cloud shadow detection in GF-1 WFV imagery is quite difficult due to the fact that there are only three visible bands and one near-infrared band. In this paper, an automatic multi-feature combined (MFC) method is proposed for cloud and cloud shadow detection in GF-1 WFV imagery. The MFC algorithm first implements threshold segmentation based on the spectral features and mask refinement based on guided filtering to generate a preliminary cloud mask. The geometric features are then used in combination with the texture features to improve the cloud detection results and produce the final cloud mask. Finally, the cloud shadow mask can be acquired by means of the cloud and shadow matching and follow-up correction process. The method was validated using 108 globally distributed scenes. The results indicate that MFC performs well under most conditions, and the average overall accuracy of MFC cloud detection is as high as 96.8%. In the contrastive analysis with the official provided cloud fractions, MFC shows a significant improvement in cloud fraction estimation, and achieves a high accuracy for the cloud and cloud shadow detection in the GF-1 WFV imagery with fewer spectral bands. The proposed method could be used as a preprocessing step in the future to monitor land-cover change, and it could also be easily extended to other optical satellite imagery which has a similar spectral setting.

  4. Development of a lightweight near-zero CTE optical bench for the Wide-Field Camera 3 instrument

    Science.gov (United States)

    Holz, Jill M.; Kunt, Cengiz; Lashley, Chris; McGuffey, Douglas B.

    2003-02-01

    The design and development of an optical bench (OB) for Wide Field Camera 3 (WFC3), a next generation science instrument for the Hubble Space Telescope (HST) has proven a challenging task. WFC3 will replace Wide Field Planetary Camera 2 (WF/PC 2) during the next servicing mission of the HST in 2004. The WFC3 program is re-using much of the hardware from WF/PC 1, returned from the First Servicing Mission, which has added complexity to the program. This posed some significant packaging challenges, further complicated by WFC3 utilizing two, separate optical channels. The WF/PC 1 optical bench could not house the additional optical components, so a new bench was developed. The new bench had to be designed to accommodate the sometimes-conflicting requirements of the two channels, which operate over a wavelength range of 200nm to 1800nm, from Near Ultraviolet to Near Infrared. In addition, the bench had to interface to the reused WF/PC 1 hardware, which was not optimized for this mission. To aid in the design of the bench, the team used software tools to merge structural, thermal and optical models to obtain performance (STOP) of the optical systems in operation. Several iterations of this performance analysis were needed during the design process to verify the bench would meet requirements. The fabrication effort included a rigorous material characterization program and significant tooling. After assembly, the optical bench underwent an extensive qualification program to prove the design and manufacturing processes. This paper provides the details of the design and development process of this highly optimized optical bench.

  5. Concerning the Development of the Wide-Field Optics for WFXT Including Methods of Optimizing X-Ray Optical Prescriptions for Wide-Field Applications

    Science.gov (United States)

    Weisskopf, M. C.; Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.

    2010-01-01

    We present a progress report on the various endeavors we are undertaking at MSFC in support of the Wide Field X-Ray Telescope development. In particular we discuss assembly and alignment techniques, in-situ polishing corrections, and the results of our efforts to optimize mirror prescriptions including polynomial coefficients, relative shell displacements, detector placements and tilts. This optimization does not require a blind search through the multi-dimensional parameter space. Under the assumption that the parameters are small enough so that second order expansions are valid, we show that the performance at the detector can be expressed as a quadratic function with numerical coefficients derived from a ray trace through the underlying Wolter I optic. The optimal values for the parameters are found by solving the linear system of equations creating by setting derivatives of this function with respect to each parameter to zero.

  6. Hubble Space Telescope Wide Field Planetary Camera 2 Observations of Neptune

    Science.gov (United States)

    1995-01-01

    Two groups have recently used the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC 2) to acquire new high-resolution images of the planet Neptune. Members of the WFPC-2 Science Team, lead by John Trauger, acquired the first series of images on 27 through 29 June 1994. These were the highest resolution images of Neptune taken since the Voyager-2 flyby in August of 1989. A more comprehensive program is currently being conducted by Heidi Hammel and Wes Lockwood. These two sets of observations are providing a wealth of new information about the structure, composition, and meteorology of this distant planet's atmosphere.Neptune is currently the most distant planet from the sun, with an orbital radius of 4.5 billion kilometers (2.8 billion miles, or 30 Astronomical Units). Even though its diameter is about four times that of the Earth (49,420 vs. 12,742 km), ground-based telescopes reveal a tiny blue disk that subtends less than 1/1200 of a degree (2.3 arc-seconds). Neptune has therefore been a particularly challenging object to study from the ground because its disk is badly blurred by the Earth's atmosphere. In spite of this, ground-based astronomers had learned a great deal about this planet since its position was first predicted by John C. Adams and Urbain Leverrier in 1845. For example, they had determined that Neptune was composed primarily of hydrogen and helium gas, and that its blue color caused by the presence of trace amounts of the gas methane, which absorbs red light. They had also detected bright cloud features whose brightness changed with time, and tracked these clouds to infer a rotation period between 17 and 22 hours.When the Voyager-2 spacecraft flew past the Neptune in 1989, its instruments revealed a surprising array of meteorological phenomena, including strong winds, bright, high-altitude clouds, and two large dark spots attributed to long-lived giant storm systems. These bright clouds and dark spots were tracked as they moved

  7. Combining wide-field super-resolution microscopy and electron tomography: rendering nanoscopic correlative arrays on subcellular architecture.

    Science.gov (United States)

    Braet, Filip; Cheng, Delfine; Huynh, Minh; Henriquez, Jeffrey; Shami, Gerry; Lampe, Marko

    2014-01-01

    In this chapter, the authors outline in full detail, an uncomplicated approach that enables the combination of wide-field fluorescence super-resolution microscopy with electron tomography, thereby providing an approach that affords the best possible confidence in the structures investigated. The methodical steps to obtain these high-throughput correlative nanoscopic arrays will be visually explored and outlined in detail. The authors will demonstrate the feasibility of the method on cultured Caco-2 colorectal cancer cells that are labeled for filamentous actin. The presented images, morphometric data, and generated models illustrate the strengths of our correlative approach for future advanced structural-biology-oriented questions. Correlative nanoscopy applications can be readily found in which there is a need to reveal biomolecular information at unprecedented resolution on subcellular behavior in various biological and pathobiological processes. © 2014 Elsevier Inc. All rights reserved.

  8. Wide field monitoring of the X-ray sky using Rotation Modulation Collimators

    DEFF Research Database (Denmark)

    Lund, Niels; Brandt, Søren

    1995-01-01

    Wide field monitoring is of particular interest in X-ray astronomy due to the strong time-variability of most X-ray sources. Not only does the time-profiles of the persistent sources contain characteristic signatures of the underlying physical systems, but, additionally, some of the most intriguing...... sources have long periods of quiesense in which they are almost undetectable as X-ray sources, interspersed with relatively brief periods of intense outbursts, where we have unique opportunities of studying dynamical effects, in, for instance, the evolution of accretion discs. Another question for which...... wide field monitors may provide key information, is the origin and nature of the cosmic gamma ray bursts.Rotation Modulation Collimators (RMC's) were originally introduced in X-ray astronomy to provide accurate source localizations over extended fields. This role has since been taken over...

  9. The biocytin wide-field bipolar cell in the rabbit retina selectively contacts blue cones

    Science.gov (United States)

    MacNeil, Margaret A.; Gaul, Paulette A.

    2010-01-01

    The biocytin wide-field bipolar cell in rabbit retina is a sparsely populated ON cone bipolar cell with a broad dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the cone types that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-labeled cells selectively contacted cones whose outer segments stained for blue cone opsin and avoided cones that did not. We conclude that the biocytin wide-field bipolar cell is an ON blue cone bipolar cell in the rabbit retina and is homologous to the blue cone bipolar cells that have been previously described in primate, mouse, and ground squirrel retinas. PMID:17990268

  10. Biocytin wide-field bipolar cells in rabbit retina selectively contact blue cones.

    Science.gov (United States)

    MacNeil, Margaret A; Gaul, Paulette A

    2008-01-01

    The biocytin wide-field bipolar cell in rabbit retina has a broad axonal arbor in layer 5 of the inner plexiform layer and a wide dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the types of cones that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin, and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-labeled cells selectively contacted cones whose outer segments stained for blue cone opsin and avoided cones that did not. We conclude that the biocytin wide-field bipolar cell is an ON blue cone bipolar cell in the rabbit retina and is homologous to the blue cone bipolar cells that have been previously described in primate, mouse, and ground squirrel retinas. Copyright 2007 Wiley-Liss, Inc.

  11. Ground-based complex for detection and investigation of fast optical transients in wide field

    Science.gov (United States)

    Molinari, Emilio; Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Plokhotnichenko, Vladimir; de-Bur, Vjacheslav; Greco, Guiseppe; Bartolini, Corrado; Guarnieri, Adriano; Piccioni, Adalberto

    2008-07-01

    To study short stochastic optical flares of different objects (GRBs, SNs, etc) of unknown localizations as well as NEOs it is necessary to monitor large regions of sky with high time resolution. We developed a system which consists of wide-field camera (FOW is 400-600 sq.deg.) using TV-CCD with time resolution of 0.13 s to record and classify optical transients, and a fast robotic telescope aimed to perform their spectroscopic and photometric investigation just after detection. Such two telescope complex TORTOREM combining wide-field camera TORTORA and robotic telescope REM operated from May 2006 at La Silla ESO observatory. Some results of its operation, including first fast time resolution study of optical transient accompanying GRB and discovery of its fine time structure, are presented. Prospects for improving the complex efficiency are given.

  12. Prime focus wide-field corrector designs with lossless atmospheric dispersion correction

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Will [Australian Astron. Observ.; Gillingham, Peter [Australian Astron. Observ.; Smith, Greg [Australian Astron. Observ.; Kent, Steve [Fermilab; Doel, Peter [University Coll. London

    2014-07-18

    Wide-Field Corrector designs are presented for the Blanco and Mayall telescopes, the CFHT and the AAT. The designs are Terezibh-style, with 5 or 6 lenses, and modest negative optical power. They have 2.2-3 degree fields of view, with curved and telecentric focal surfaces suitable for fiber spectroscopy. Some variants also allow wide-field imaging, by changing the last WFC element. Apart from the adaptation of the Terebizh design for spectroscopy, the key feature is a new concept for a 'Compensating Lateral Atmospheric Dispersion Corrector', with two of the lenses being movable laterally by small amounts. This provides excellent atmospheric dispersion correction, without any additional surfaces or absorption. A novel and simple mechanism for providing the required lens motions is proposed, which requires just 3 linear actuators for each of the two moving lenses.

  13. Wide-field surface-enhanced CARS microscopy of cells (Conference Presentation)

    Science.gov (United States)

    Fast, Alexander; Kenison, John T.; Potma, Eric O.

    2017-02-01

    We have previously demonstrated a total internal reflection, wide-field CARS microscope, where the signal is enhanced with the aid of a thin gold layer that supports surface plasmon polariton resonances. This surface-enhanced CARS microscope is capable of generating images of lipid structures in close proximity (visualizing lipids in aqueous media, including imaging of cells, with a unique surface-sensitive contrast that cannot be obtained with conventional CARS microscopy.

  14. Laser light-field fusion for wide-field lensfree on-chip phase contrast nanoscopy

    OpenAIRE

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-01-01

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast nanoscopy, where interferometric laser light-field encodings acquired using an on-chip setup with laser pulsations at different wav...

  15. Wide-field monitoring strategy for the study of fast optical transients

    Science.gov (United States)

    Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Guarnieri, Adriano; Bartolini, Corrado; Greco, Giuseppe; Piccioni, Adalberto

    2010-10-01

    We discuss the strategy of search for fast optical transients accompanying gamma-ray bursts by means of continuous monitoring of wide sky fields with high temporal resolution. We describe the design, performance and results of our cameras, FAVOR and TORTORA. Also we discuss the perspectives of this strategy and possible design of next-generation equipment for wide-field monitoring which will be able to detect optical transients and to study their color and polarization properties with high time resolution.

  16. Wide-Field Fundus Autofluorescence for Retinitis Pigmentosa and Cone/Cone-Rod Dystrophy.

    Science.gov (United States)

    Oishi, Akio; Oishi, Maho; Ogino, Ken; Morooka, Satoshi; Yoshimura, Nagahisa

    2016-01-01

    Retinitis pigmentosa and cone/cone-rod dystrophy are inherited retinal diseases characterized by the progressive loss of rod and/or cone photoreceptors. To evaluate the status of rod/cone photoreceptors and visual function, visual acuity and visual field tests, electroretinogram, and optical coherence tomography are typically used. In addition to these examinations, fundus autofluorescence (FAF) has recently garnered attention. FAF visualizes the intrinsic fluorescent material in the retina, which is mainly lipofuscin contained within the retinal pigment epithelium. While conventional devices offer limited viewing angles in FAF, the recently developed Optos machine enables recording of wide-field FAF. With wide-field analysis, an association between abnormal FAF areas and visual function was demonstrated in retinitis pigmentosa and cone-rod dystrophy. In addition, the presence of "patchy" hypoautofluorescent areas was found to be correlated with symptom duration. Although physicians should be cautious when interpreting wide-field FAF results because the peripheral parts of the image are magnified significantly, this examination method provides previously unavailable information.

  17. Monitoring with high temporal resolution to search for optical transients in the wide field

    Science.gov (United States)

    Beskin, Grigory; Bondar, Sergey; Ivanov, Evgeny; Karpov, Sergey; Katkova, Elena; Pozanenko, Alexei; Guarnieri, Adriano; Bartolini, Corrado; Piccioni, Adalberto; Greco, Giuseppe; Molinari, Emilio; Covino, Stefano

    2008-02-01

    In order to detect and investigate short stochastic optical flares from a number of variable astrophysical objects (GRBs, SNs, flare stars, CVs, X-Ray binaries) of unknown localizations as well as near-earth objects (NEOs), both natural and artificial, it is necessary to perform the systematic monitoring of large regions of the sky with high temporal resolution. Here we describe the design of a system able to perform such a task, which consists of a wide-field camera with high time resolution able to detect and classify the transient events on a subsecond time scale, and a fast robotic telescope aimed to perform their detailed investigation. In a last few years we've created the prototype FAVOR wide-field camera, placed at North Caucasus near Russian 6-m telescope, and a complete two-telescope complex TORTOREM, combining TORTORA wide-field camera with REM robotic telescope and placed at La Silla ESO observatory. Its technical parameters and first results of operation are described.

  18. Ground to on-orbit alignment study of the WFIRST wide-field channel and resulting changes in the telescope architecture

    Science.gov (United States)

    Hagopian, John; Armani, Nerses; Bartusek, Lisa; Casey, Tom; Content, Dave; Conturie, Yves; Gao, Guangjun; Jurling, Alden; Marx, Cathy; Marzouk, Joe; Pasquale, Bert; Smith, J. Scott; Tang, Hong; Whipple, Arthur

    2017-08-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission[1] is the top-ranked large space mission in the New Worlds, New Horizon (NWNH) Decadal Survey of Astronomy and Astrophysics. WFIRST will settle essential questions in both exoplanet and dark energy research and will advance topics ranging from galaxy evolution to the study of objects within the galaxy. The WFIRST mission uses a repurposed 2.4-m Forward Optical Telescope assembly (FOA), which, when completed with new aft optics will be an Integrated Optical Assembly (IOA). WFIRST is equipped with a Wide Field Instrument (WFI) and a Coronagraph Instrument (CGI). An Instrument Carrier (IC) meters these payload elements together and to the spacecraft bus (S/C). A distributed ground system receives the data, uploads commands and software updates, and processes the data. After transition from the study phase, Pre-Phase-A (a.k.a., "Cycle 6") design to NASA Phase A formulation, a significant change to the IOA was initiated; including moving the tertiary mirror from the instrument package to a unified three-mirror anastigmat (TMA) placement, that provides a wide 0.28-sq° instrumented field of view to the Wide Field Instrument (WFI). In addition, separate relays from the primary and secondary mirror feed the Wide Field Instrument (WFI) and Coronagraph Instrument (CGI). During commissioning the telescope is aligned using wavefront sensing with the WFI[2]. A parametric and Monte-Carlo analysis was performed, which determined that alignment compensation with the secondary mirror alone degraded performance in the other instruments. This led to the addition of a second compensator in the WFI optical train to alleviate this concern. This paper discusses the trades and analyses that were performed and resulting changes to the WFIRST telescope architecture.

  19. The HST/WFC3 Quicklook Project: A User Interface to Hubble Space Telescope Wide Field Camera 3 Data

    Science.gov (United States)

    Bourque, Matthew; Bajaj, Varun; Bowers, Ariel; Dulude, Michael; Durbin, Meredith; Gosmeyer, Catherine; Gunning, Heather; Khandrika, Harish; Martlin, Catherine; Sunnquist, Ben; Viana, Alex

    2017-06-01

    The Hubble Space Telescope's Wide Field Camera 3 (WFC3) instrument, comprised of two detectors, UVIS (Ultraviolet-Visible) and IR (Infrared), has been acquiring ~ 50-100 images daily since its installation in 2009. The WFC3 Quicklook project provides a means for instrument analysts to store, calibrate, monitor, and interact with these data through the various Quicklook systems: (1) a ~ 175 TB filesystem, which stores the entire WFC3 archive on disk, (2) a MySQL database, which stores image header data, (3) a Python-based automation platform, which currently executes 22 unique calibration/monitoring scripts, (4) a Python-based code library, which provides system functionality such as logging, downloading tools, database connection objects, and filesystem management, and (5) a Python/Flask-based web interface to the Quicklook system. The Quicklook project has enabled large-scale WFC3 analyses and calibrations, such as the monitoring of the health and stability of the WFC3 instrument, the measurement of ~ 20 million WFC3/UVIS Point Spread Functions (PSFs), the creation of WFC3/IR persistence calibration products, and many others.

  20. Cross-Comparative Analysis of GF-1 Wide Field View and Landsat-7 Enhanced Thematic Mapper Plus Data

    Science.gov (United States)

    Wei, X.-Q.; Gu, X.-F.; Meng, Q.-Y.; Yu, T.; Jia, K.; Zhan, Y.-L.; Wang, Ch.-M.

    2017-11-01

    The wide field view (WFV) sensor on-board GF-1 satellite can acquire multi-spectral data with moderate spatial resolution, which holds great potential for monitoring the Earth's surface. This study assesses WFV data through cross-comparison of spectral band reflectances and vegetation indices with Landsat-7 Enhanced Thematic Mapper plus (ETM+) data. The four vegetation indices considered in this study are the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), the ratio vegetation index (RVI), and the soil adjusted vegetation index (SAVI). The R2 between the WFV and ETM+ data were 0.82, 0.89, 0.92, and 0.80 for the blue, green, red, and near-infrared bands reflectance, and 0.90, 0.84, 0.83, and 0.91 for NDVI, EVI, RVI, and SAVI, respectively. The results displayed a high correlation between the spectral reflectances and vegetation indices of the two sensors' data, which indicated the reliability of the WFV data. Furthermore, the WFV data were better than the ETM+ data with regards to spatial and temporal resolutions.

  1. Exploring the Spatial Resolution of the Photothermal Beam Deflection Technique in the Infrared Region

    CERN Document Server

    Seidel, Wolfgang

    2004-01-01

    In photothermal beam deflection spectroscopy (PTBD) generating and detection of thermal waves occur generally in the sub-millimeter length scale. Therefore, PTBD provides spatial information about the surface of the sample and permits imaging and/or microspectrometry. Recent results of PTBD experiments are presented with a high spatial resolution which is near the diffraction limit of the infrared pump beam (CLIO-FEL). We investigated germanium substrates showing restricted O+-doped regions with an infrared absorption line at a wavelength around 11.6 microns. The spatial resolution was obtained by strongly focusing the probe beam (i.e. a HeNe laser) on a sufficiently small spot. The strong divergence makes it necessary to refocus the probe beam in front of the position detector. The influence of the focusing elements on spatial resolution and signal-to-noise ratio is discussed. In future studies we expect an enhanced spatial resolution due to an extreme focusing of the probe beam leading to a highly sensitive...

  2. A Wide Field Auroral Imager (WFAI for low Earth orbit missions

    Directory of Open Access Journals (Sweden)

    N. P. Bannister

    2007-03-01

    Full Text Available A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI.

  3. Wide-field Imaging of the Environments of LITTLE THINGS Dwarf Irregular Galaxies

    Science.gov (United States)

    Hunter, Deidre A.; Melton, Casey; Leshin, Stephen; Wong, Alson; Clark, Maurice; Kamienski, Jerald; Moriya, Netzer; Packwood, Burley; Birket, Bob; Edwards, William; Millward, Mervyn; Wheelband, Ian

    2018-01-01

    We have obtained wide-field images of 36 of the 41 LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The H I Nearby Galaxy Survey) nearby (limiting magnitudes of the images range from 19.7 to 28.3 mag arcsec‑2, with a median value of 25.9 mag arcsec‑2. We did not find any unknown companions. Two of the LITTLE THINGS galaxies, NGC 4163 and NGC 4214, and the fainter dwarf, UGCA 276, lie potentially within 100 kpc of each other, but our imaging does not reveal any stellar bridge between the galaxies. This project was part of the Lowell Amateur Research Initiative.

  4. Wide-Field Plates Observations of Stars from Earth Orientation Catalogs (EOC)

    Science.gov (United States)

    Chapanov, Y.; Tsvetkova, K.; Tsvetkov, M.; Vondrak, J.; Ron, C.; Stefka, V.

    2012-01-01

    The Earth Orientation Catalogues (EOCs) are primarily meant to provide stable celestial reference frame in optical wavelengths for deriving Earth Orientation Parameters (EOP) from astrometric observations. The EOCs combine catalogues ARIHIP and TYCHO-2 with the rich observation material (variations of Latitude/Universal Time), obtained during the 20th century in programs of monitoring Earth orientation. Other possible source of information for improving the EOCs is the WFPDB (Wide-Field Plate Database). The number of plates, containing EOCs stars and their distribution in time are determined by means of the search engine of the WFPDB.

  5. Sherlock: An Automated Follow-Up Telescope for Wide-Field Transit Searches

    Science.gov (United States)

    Kotredes, Lewis; Charbonneau, David; Looper, Dagny L.; O'Donovan, Francis T.

    2004-06-01

    The most significant challenge currently facing photometric surveys for transiting gas-giant planets is that of confusion with eclipsing binary systems that mimic the photometric signature. A simple way to reject most forms of these false positives is high-precision, rapid-cadence monitoring of the suspected transit at higher angular resolution and in several filters. We are currently building a system that will perform higher-angular-resolution, multi-color follow-up observations of candidate systems identified by Sleuth (our wide-field transit survey instrument at Palomar), and its two twin system instruments in Tenerife and northern Arizona.

  6. Wide-field TCSPC-based fluorescence lifetime imaging (FLIM) microscopy

    Science.gov (United States)

    Suhling, Klaus; Hirvonen, Liisa M.; Becker, Wolfgang; Smietana, Stefan; Netz, Holger; Milnes, James; Conneely, Thomas; Le Marois, Alix; Jagutzki, Ottmar

    2016-05-01

    Time-correlated single photon counting (TCSPC) is a widely used, sensitive, precise, robust and mature technique to measure photon arrival times in applications such as fluorescence spectroscopy and microscopy, light detection and ranging (lidar) and optical tomography. Wide-field TCSPC detection techniques, where the position and the arrival time of the photons are recorded simultaneously, have seen several advances in the last few years, from the microsecond to the picosecond time scale. Here, we summarise some of our recent work in this field with emphasis on microsecond resolution phosphorescence lifetime imaging (PLIM) and nanosecond fluorescence lifetime imaging (FLIM) microscopy.

  7. Developments of wide field submillimeter optics and lens antenna-coupled MKID cameras

    Science.gov (United States)

    Sekimoto, Y.; Nitta, T.; Karatsu, K.; Sekine, M.; Sekiguchi, S.; Okada, T.; Shu, S.; Noguchi, T.; Naruse, M.; Mitsui, K.; Okada, N.; Tsuzuki, T.; Dominjon, A.; Matsuo, H.

    2014-07-01

    Wide field cryogenic optics and millimeter-wave Microwave Kinetic Inductance Detector (MKID) cameras with Si lens array have been developed. MKID is a Cooper-pair breaking photon detector and consists of supercon- ducting resonators which enable microwave (~GHz) frequency multiplexing. Antenna-coupled Aluminum CPW resonators are put in a line on a Si substrate to be read by a pair of coaxial cables. A 220 GHz - 600 pixels MKID camera with anti-reflection (AR) coated Si lens has been demonstrated in an 0.1 K cryostat. A compact cryogenic system with high refractive index materials has been developed for the MKID camera.

  8. The biocytin wide-field bipolar cell in the rabbit retina selectively contacts blue cones

    OpenAIRE

    MacNeil, Margaret A.; Gaul, Paulette A.

    2008-01-01

    The biocytin wide-field bipolar cell in rabbit retina is a sparsely populated ON cone bipolar cell with a broad dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the cone types that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-...

  9. The High-Speed and Wide-Field TORTORA Camera: description & results .

    Science.gov (United States)

    Greco, G.; Beskin, G.; Karpov, S.; Guarnieri, A.; Bartolini, C.; Bondar, S.; Piccioni, A.; Molinari, E.

    We present the description and the most significant results of the wide-field and ultra-fast TORTORA camera devoted to the investigation of rapid changes in light intensity in a phenomenon occurring within an extremely short period of time and randomly distributed over the sky. In particular, the ground-based TORTORA observations synchronized with the gamma -ray BAT telescope on board of the Swift satellite has permitted to trace the optical burst time-structure of the Naked-Eye GRB 080319B with an unprecedented level of accuracy.

  10. Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Larger Particles

    Science.gov (United States)

    Kearsley, A. T.; Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V.; Colaux, J. L.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; hide

    2014-01-01

    The Wide Field and Planetary Camera 2 (WFPC2) was returned from the Hubble Space Telescope (HST) by shuttle mission STS-125 in 2009. In space for 16 years, the surface accumulated hundreds of impact features on the zinc orthotitanate paint, some penetrating through into underlying metal. Larger impacts were seen in photographs taken from within the shuttle orbiter during service missions, with spallation of paint in areas reaching 1.6 cm across, exposing alloy beneath. Here we describe larger impact shapes, the analysis of impactor composition, and the micrometeoroid (MM) types responsible.

  11. 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

  12. Blind deconvolution with principal components analysis for wide-field and small-aperture telescopes

    Science.gov (United States)

    Jia, Peng; Sun, Rongyu; Wang, Weinan; Cai, Dongmei; Liu, Huigen

    2017-09-01

    Telescopes with a wide field of view (greater than 1°) and small apertures (less than 2 m) are workhorses for observations such as sky surveys and fast-moving object detection, and play an important role in time-domain astronomy. However, images captured by these telescopes are contaminated by optical system aberrations, atmospheric turbulence, tracking errors and wind shear. To increase the quality of images and maximize their scientific output, we propose a new blind deconvolution algorithm based on statistical properties of the point spread functions (PSFs) of these telescopes. In this new algorithm, we first construct the PSF feature space through principal component analysis, and then classify PSFs from a different position and time using a self-organizing map. According to the classification results, we divide images of the same PSF types and select these PSFs to construct a prior PSF. The prior PSF is then used to restore these images. To investigate the improvement that this algorithm provides for data reduction, we process images of space debris captured by our small-aperture wide-field telescopes. Comparing the reduced results of the original images and the images processed with the standard Richardson-Lucy method, our method shows a promising improvement in astrometry accuracy.

  13. Wide-field and high-resolution optical imaging for early detection of oral neoplasia

    Science.gov (United States)

    Pierce, Mark C.; Schwarz, Richard A.; Rosbach, Kelsey; Roblyer, Darren; Muldoon, Tim; Williams, Michelle D.; El-Naggar, Adel K.; Gillenwater, Ann M.; Richards-Kortum, Rebecca

    2010-02-01

    Current procedures for oral cancer screening typically involve visual inspection of the entire tissue surface at risk under white light illumination. However, pre-cancerous lesions can be difficult to distinguish from many benign conditions when viewed under these conditions. We have developed wide-field (macroscopic) imaging system which additionally images in cross-polarized white light, narrowband reflectance, and fluorescence imaging modes to reduce specular glare, enhance vascular contrast, and detect disease-related alterations in tissue autofluorescence. We have also developed a portable system to enable high-resolution (microscopic) evaluation of cellular features within the oral mucosa in situ. This system is a wide-field epi-fluorescence microscope coupled to a 1 mm diameter, flexible fiber-optic imaging bundle. Proflavine solution was used to specifically label cell nuclei, enabling the characteristic differences in N/C ratio and nuclear distribution between normal, dysplastic, and cancerous oral mucosa to be quantified. This paper discusses the technical design and performance characteristics of these complementary imaging systems. We will also present data from ongoing clinical studies aimed at evaluating diagnostic performance of these systems for detection of oral neoplasia.

  14. A wide-field suprachoroidal retinal prosthesis is stable and well tolerated following chronic implantation.

    Science.gov (United States)

    Villalobos, Joel; Nayagam, David A X; Allen, Penelope J; McKelvie, Penelope; Luu, Chi D; Ayton, Lauren N; Freemantle, Alexia L; McPhedran, Michelle; Basa, Meri; McGowan, Ceara C; Shepherd, Robert K; Williams, Chris E

    2013-05-01

    The safety of chronic implantation of a retinal prosthesis in the suprachoroidal space has not been established. This study aimed to determine the safety of a wide-field suprachoroidal electrode array following chronic implantation using histopathologic techniques and electroretinography. A platinum electrode array in a wide silicone substrate was implanted unilaterally in the suprachoroidal space in adult cats (n = 7). The lead and connector were tunneled out of the orbit and positioned subcutaneously. Postsurgical recovery was assessed using fundus photography and electroretinography (ERG). Following 3 months of passive implantation, the animals were terminated and the eyes assessed for the pathologic response to implantation. The implant was mechanically stable in the suprachoroidal space during the course of the study. The implanted eye showed a transient increase in ERG response amplitude at 2 weeks, which returned to normal by 3 months. Pigmentary changes were observed at the distal end of the implant, near the optic disc. Histopathologic assessment revealed a largely intact retina and a thin fibrous capsule around the suprachoroidal implant cavity. The foreign body response was minimal, with sporadic presence of macrophages and no active inflammation. All implanted eyes were negative for bacterial or fungal infections. A midgrade granuloma and thick fibrous buildup surrounded the extraocular cable. Scleral closure was maintained in six of seven eyes. There were no staphylomas or choroidal incarceration. A wide-field retinal prosthesis was stable and well tolerated during long-term suprachoroidal implantation in a cat model. The surgical approach was reproducible and overall safe.

  15. Stray-field-induced Faraday contributions in wide-field Kerr microscopy and -magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Markó, D.; Soldatov, I. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany); Tekielak, M. [Institute of Experimental Physics, University of Bialystok, Lipowa 41, Bialystok 15-424 Poland (Poland); Schäfer, R., E-mail: r.schaefer@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany)

    2015-12-15

    The magnetic domain contrast in wide-field Kerr microscopy on bulk specimens can be substantially distorted by non-linear, field-dependent Faraday rotations in the objective lens that are caused by stray-field components emerging from the specimen. These Faraday contributions, which were detected by Kerr-magnetometry on grain-oriented iron–silicon steel samples, are thoroughly elaborated and characterized. They express themselves as a field-dependent gray-scale offset to the domain contrast and in highly distorted surface magnetization curves if optically measured in a wide field Kerr microscope. An experimental method to avoid such distortions is suggested. In the course of these studies, a low-permeability part in the surface magnetization loop of slightly misoriented (110)-surfaces in iron–silicon sheets was discovered that is attributed to demagnetization effects in direction perpendicular to the sheet surface. - Highlights: • Magnetizing a finite sample in a Kerr microscope leads to sample-generated stray-fields. • They cause non-linear, field- and position-dependent Faraday rotations in the objective. • This leads to a modulation of the Kerr contrast and to distorted MOKE loops. • A method to compensate these Faraday rotations is presented.

  16. Wide-Field Imaging Telescope-0 (WIT0) with automatic observing system

    Science.gov (United States)

    Ji, Tae-Geun; Byeon, Seoyeon; Lee, Hye-In; Park, Woojin; Lee, Sang-Yun; Hwang, Sungyong; Choi, Changsu; Gibson, Coyne Andrew; Kuehne, John W.; Prochaska, Travis; Marshall, Jennifer L.; Im, Myungshin; Pak, Soojong

    2018-01-01

    We introduce Wide-Field Imaging Telescope-0 (WIT0), with an automatic observing system. It is developed for monitoring the variabilities of many sources at a time, e.g. young stellar objects and active galactic nuclei. It can also find the locations of transient sources such as a supernova or gamma-ray bursts. In 2017 February, we installed the wide-field 10-inch telescope (Takahashi CCA-250) as a piggyback system on the 30-inch telescope at the McDonald Observatory in Texas, US. The 10-inch telescope has a 2.35 × 2.35 deg field-of-view with a 4k × 4k CCD Camera (FLI ML16803). To improve the observational efficiency of the system, we developed a new automatic observing software, KAOS30 (KHU Automatic Observing Software for McDonald 30-inch telescope), which was developed by Visual C++ on the basis of a windows operating system. The software consists of four control packages: the Telescope Control Package (TCP), the Data Acquisition Package (DAP), the Auto Focus Package (AFP), and the Script Mode Package (SMP). Since it also supports the instruments that are using the ASCOM driver, the additional hardware installations become quite simplified. We commissioned KAOS30 in 2017 August and are in the process of testing. Based on the WIT0 experiences, we will extend KAOS30 to control multiple telescopes in future projects.

  17. Optically sectioned wide-field fluorescence lifetime imaging endoscopy enabled by structured illumination (Conference Presentation)

    Science.gov (United States)

    Hinsdale, Taylor; Malik, Bilal H.; Rico-Jimenez, Jose J.; Jo, Javier A.; Maitland, Kristen C.

    2016-03-01

    We present a wide-field fluorescence lifetime imaging (FLIM) system with optical sectioning by structured illumination microscopy (SIM). FLIM measurements were made using a time gated ICCD camera in conjunction with a pulsed nitrogen dye laser operating at 450 nm. Intensity images were acquired at multiple time delays from a trigger initiated by a laser pulse to create a wide-field FLIM image, which was then combined with three phase SIM to provide optical sectioning. Such a mechanism has the potential to increase the reliability and accuracy of the FLIM measurements by rejecting background intensity. SIM also provides the opportunity to create volumetric FLIM images with the incorporation of scanning mechanisms for the sample plane. We present multiple embodiments of such a system: one as a free space endoscope and the other as a fiber microendoscope enabled by the introduction of a fiber bundle. Finally, we demonstrate the efficacy of such an imaging system by imaging dyes embedded in a tissue phantom.

  18. Simple concept for a wide-field lensless digital holographic microscope using a laser diode

    Directory of Open Access Journals (Sweden)

    Adinda-Ougba A.

    2015-09-01

    Full Text Available Wide-field, lensless digital holographic microscopy is a new microscopic imaging technique for telemedicine and for resource limited setting [1]. In this contribution we propose a very simple wide-field lensless digital holographic microscope using a laser diode. It is based on in-line digital holography which is capable to provide amplitude and phase images of a sample resulting from numerical reconstruction. The numerical reconstruction consists of the angular spectrum propagation method together with a phase retrieval algorithm. Amplitude and phase images of the sample with a resolution of ∽2 µm and with ∽24 mm2 field of view are obtained. We evaluate our setup by imaging first the 1951 USAF resolution test chart to verify the resolution. Second, we record holograms of blood smear and diatoms. The individual specimen can be easily identified after the numerical reconstruction. Our system is a very simple, compact and low-cost possibility of realizing a microscope capable of imaging biological samples. The availability of the phase provide topographic information of the sample extending the application of this system to be not only for biological sample but also for transparent microstructure. It is suitable for fault detection, shape and roughness measurements of these structures.

  19. SHOK—The First Russian Wide-Field Optical Camera in Space

    Science.gov (United States)

    Lipunov, V. M.; Gorbovskoy, E. S.; Kornilov, V. G.; Panasyuk, M. I.; Amelushkin, A. M.; Petrov, V. L.; Yashin, I. V.; Svertilov, S. I.; Vedenkin, N. N.

    2018-02-01

    Onboard the spacecraft Lomonosov is established two fast, fixed, very wide-field cameras SHOK. The main goal of this experiment is the observation of GRB optical emission before, synchronously, and after the gamma-ray emission. The field of view of each of the cameras is placed in the gamma-ray burst detection area of other devices located onboard the "Lomonosov" spacecraft. SHOK provides measurements of optical emissions with a magnitude limit of ˜ 9-10m on a single frame with an exposure of 0.2 seconds. The device is designed for continuous sky monitoring at optical wavelengths in the very wide field of view (1000 square degrees each camera), detection and localization of fast time-varying (transient) optical sources on the celestial sphere, including provisional and synchronous time recording of optical emissions from the gamma-ray burst error boxes, detected by the BDRG device and implemented by a control signal (alert trigger) from the BDRG. The Lomonosov spacecraft has two identical devices, SHOK1 and SHOK2. The core of each SHOK device is a fast-speed 11-Megapixel CCD. Each of the SHOK devices represents a monoblock, consisting of a node observations of optical emission, the electronics node, elements of the mechanical construction, and the body.

  20. Exploring new bands in modified multichannel regression SST algorithms for the next-generation infrared sensors at NOAA

    Science.gov (United States)

    Petrenko, B.; Ignatov, A.; Kramar, M.; Kihai, Y.

    2016-05-01

    Multichannel regression algorithms are widely used to retrieve sea surface temperature (SST) from infrared observations with satellite radiometers. Their theoretical foundations were laid in the 1980s-1990s, during the era of the Advanced Very High Resolution Radiometers which have been flown onboard NOAA satellites since 1981. Consequently, the multi-channel and non-linear SST algorithms employ the bands centered at 3.7, 11 and 12 μm, similar to available in AVHRR. More recent radiometers carry new bands located in the windows near 4 μm, 8.5 μm and 10 μm, which may also be used for SST. Involving these bands in SST retrieval requires modifications to the regression SST equations. The paper describes a general approach to constructing SST regression equations for an arbitrary number of radiometric bands and explores the benefits of using extended sets of bands available with the Visible Infrared Imager Radiometer Suite (VIIRS) flown onboard the Suomi National Polar-orbiting Partnership (SNPP) and to be flown onboard the follow-on Joint Polar Satellite System (JPSS) satellites, J1-J4, to be launched from 2017-2031; Moderate Resolution Imaging Spectroradiometers (MODIS) flown onboard Aqua and Terra satellites; and the Advanced Himawari Imager (AHI) flown onboard the Japanese Himawari-8 satellite (which in turn is a close proxy of the Advanced Baseline Imager (ABI) to be flown onboard the future Geostationary Operational Environmental Satellites - R Series (GOES-R) planned for launch in October 2016.

  1. Radiometric calibration of wide-field camera system with an application in astronomy

    Science.gov (United States)

    Vítek, Stanislav; Nasyrova, Maria; Stehlíková, Veronika

    2017-09-01

    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

  2. Plastic optical fiber for wide field-of-view optical wireless receiver

    Science.gov (United States)

    Fallah, Hoorieh; Sterckx, Karel; Saengudomlert, Poompat; Mohammed, Waleed S.

    2016-10-01

    This paper demonstrates a working indoor optical wireless link for smart environment applications. The system utilizes a wide field-of-view (FOV) optical wireless receiver through cleaving the tip of large core plastic optical fibers (POFs) attached to the detector. The quality of the optical link is quantified through bit error rate (BER) measurements. The experimental results show a wide FOV with the uncoded BER in the order of 10-3 for transmission distances up to 35 cm when using two POFs for signal collection. The distance can be improved further by increasing the number of fibers. The transmitted signal format and how the BER measurement is achieved are discussed at length. In addition, details are provided for the design of the electronics to establish the optical wireless link.

  3. Programmable LED-based integrating sphere light source for wide-field fluorescence microscopy.

    Science.gov (United States)

    Rehman, Aziz Ul; Anwer, Ayad G; Goldys, Ewa M

    2017-12-01

    Wide-field fluorescence microscopy commonly uses a mercury lamp, which has limited spectral capabilities. We designed and built a programmable integrating sphere light (PISL) source which consists of nine LEDs, light-collecting optics, a commercially available integrating sphere and a baffle. The PISL source is tuneable in the range 365-490nm with a uniform spatial profile and a sufficient power at the objective to carry out spectral imaging. We retrofitted a standard fluorescence inverted microscope DM IRB (Leica) with a PISL source by mounting it together with a highly sensitive low- noise CMOS camera. The capabilities of the setup have been demonstrated by carrying out multispectral autofluorescence imaging of live BV2 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. I - Theory

    Science.gov (United States)

    Smith, G. L.; Green, R. N.

    1981-01-01

    The theory of deconvolution of wide field-of-view (WFOV) radiometer measurements of earth-emitted radiation provides a technique by which the resolution of such measurements can be enhanced to provide radiant exitance at the top of the atmosphere with a finer resolution than the field of view. An analytical solution for the earth-emitted radiant exitance in terms of WFOV radiometer measurements is derived for the nonaxisymmetric (or regional) case, in which the measurements and radiant exitance are considered to be functions of both latitude and longitude. This solution makes it possible to deconvolve a set of WFOV radiometer measurements of earth-emitted radiation and obtain information with a finer resolution than the instantaneous field of view of the instrument. It is shown that there are tradeoffs involved in the selection between WFOV and scanning radiometers.

  5. Miniaturized high-resolution wide-field contact lens for panretinal photocoagulation

    Directory of Open Access Journals (Sweden)

    Koushan K

    2014-04-01

    Full Text Available Keyvan Koushan, KV Chalam Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USA Background and objective: We describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina. Instrument design: The miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165° visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization. Conclusion: This new lens (50% lighter and 89% smaller improves upon earlier contact lenses for visualization of the peripheral retina. Keywords: contact lens, panretinal photocoagulation, retinal examination, peripheral retina, high resolution view, wide-angle lens, lens

  6. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    Science.gov (United States)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

  7. Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Smaller Particle Impacts

    Science.gov (United States)

    Ross, D. K.; Anz-Meador, P.; Liou, J.C.; Opiela, J.; Kearsley, A. T.; Grime, G.; Webb, R.; Jeynes, C.; Palitsin, V.; Colaux, J.; hide

    2014-01-01

    The radiator shield on the Wide Field and Planetary Camera 2 (WFPC2) was subject to optical inspection following return from the Hubble Space Telescope (HST) in 2009. The survey revealed over 600 impact features of > 300 micrometers diameter, from exposure in space for 16 years. Subsequently, an international collaborative programme of analysis was organized to determine the origin of hypervelocity particles responsible for the damage. Here we describe examples of the numerous smaller micrometeoroid (MM) impact features (< 700 micrometers diameter) which excavated zinc orthotitanate (ZOT) paint from the radiator surface, but did not incorporate material from underlying Al alloy; larger impacts are described by [3]. We discuss recognition and interpretation of impactor remains, and MM compositions found on WFPC2.

  8. Wide-field microscopic FRET imaging using simultaneous spectral unmixing of excitation and emission spectra.

    Science.gov (United States)

    Du, Mengyan; Zhang, Lili; Xie, Shusen; Chen, Tongsheng

    2016-07-11

    Simultaneous spectral unmixing of excitation and emission spectra (ExEm unmixing) has the inherent ability to resolve donor emission, fluorescence resonance energy transfer (FRET)-sensitized acceptor emission and directly excited acceptor emission. We here develop an ExEm unmixing-based quantitative FRET measurement method (EES-FRET) independent of excitation intensity and detector parameter setting. The ratio factor (rK), predetermined using a donor-acceptor tandem construct, of total acceptor absorption to total donor absorption in excitation wavelengths used is introduced for determining the concentration ratio of acceptor to donor. We implemented EES-FRET method on a wide-field microscope to image living cells expressing tandem FRET constructs with different donor-acceptor stoichiometry.

  9. Meteor observations with Mini-Mega-TORTORA wide-field monitoring system

    Science.gov (United States)

    Karpov, S.; Orekhova, N.; Beskin, G.; Biryukov, A.; Bondar, S.; Ivanov, E.; Katkova, E.; Perkov, A.; Sasyuk, V.

    2016-12-01

    Here we report on the results of meteor observations with 9-channel Mini-Mega-TORTORA (MMT-9) optical monitoring system with the wide field and high temporal resolution. During the first 1.5 years of operation more than 90 thousands of meteors have been detected, at a rate of 300-350 per night, with durations from 0.1 to 2.5 seconds and angular velocities up to 38 degrees per second. The faintest detected meteors have peak brightnesses about 10 mag, while the majority have them ranging from 4 to 8 mag. Some of the meteors have been observed in BVR filters simultaneously. Color variations along the trail for them have been determined. The parameters of the detected meteors have been published online. The database also includes data from 10 thousands of meteors detected by our previous FAVOR camera during 2006-2009.

  10. Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Yilmaz, Hasan

    2016-03-01

    Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

  11. Stellar photometry in the inner bulge of M31 using the Hubble Space Telescope wide field camera

    Science.gov (United States)

    Rich, R. M.; Mighell, K. J.

    1995-01-01

    We present photometry of two fields in the M31 bulge imaged with the Hubble Space Telescope (HST) Wide-Field Camara (WFC). The nuclear field (r less than 40 arcsecs = 150 pc) giant branch extends to I = 19.5, M(sub I) = -5 (Cousins system), a full 0.9 mag brighter than the giant-branch tips of metal-poor Galactic globular clusters and M31 halo fields. This is also approximately = 1.5 mag brighter than the giant branches of metal-rich Galactic globular clusters, but is no brighter than Mould's (1986) M31 bulge field 1 kpc from the nucleus. The data also suggest that the brighter stars may be preferentially concentrated to the center. The 648 luminous stars detected in 2 x 10(exp 9) solar luminosity is approximately = 25% that expected from a hypothetical population of evolved asymptotic giant branch (AGB) stars with lifetimes approximately = 10(exp 5) yr, with the cautionary note that we are near the detection limit. The number of bright stars is also consistent with the progeny of blue stragglers, if one uses a lifetime for the thermal-pulsing AGB of 2 x 10(exp 6) yr. We strongly caution that incompleteness becomes severe below I = 19.9 mag and that future surveys are likely to find numbers of bright stars too large to accomodate the blue straggler progeny hypothesis. We have imaged an additional field 2 arcmin = 500 pc south of the nucleus. The brightest stars in this field are also I = 19.5, but bright stars appear less numerous than in the nuclear field. If the population resembles that of the Galactic bulge, then M(sub bol) = -4.5 is a lower limit to the giant-branch tip luminosity; infrared studies should reveal stars 0.5 mag or more brighter. Either high-metallicity or (more likely) age approximately = 10 Gyr may be responsible for the presence of these luminous AGB stars. These observations confirm that previous ground-based infrared studies (e.g., Rich & Mould 1991) very likely detect an extended giant branch and not spurious luminous stars caused by

  12. Detailed faecal fat analysis using Fourier transform infrared spectroscopy: Exploring the possibilities.

    Science.gov (United States)

    De Koninck, Anne-Sophie; Nys, Karen; Vandenheede, Brent; Van Biervliet, Stephanie; Speeckaert, Marijn M; Delanghe, Joris R

    2016-11-01

    Fourier transform infrared (FTIR) spectroscopic determination of faecal fat is a simple and elegant alternative for the classical Van De Kamer approach. Besides quantification of the total amount of fat, analysis of the lipase hydrolysis efficiency (fatty acid/triglyceride ratio), fatty acid chain length and trans-unsaturated fatty acids could provide a better monitoring of dietary treatment. Stool samples (26 routine samples and 36 cystic fibrosis patients) were analysed with the Perkin Elmer Spectrum Two® spectrometer (3500-450cm(-1)). Fatty acid/triglyceride ratio was calculated using the absorbance ratio at 2855:1746cm(-1). To estimate lipase hydrolysis efficiency, sample ratios were compared with the ratio of butter and pure free fatty acids. Mean fatty acid chain length was calculated using the absorbance ratio at 2855:1709cm(-1). The absorbance at 966cm(-1) was used to trace the presence of trans-type unsaturated fatty acids. Butter showed a low fatty acid/triglyceride ratio (1.21) and pure free fatty acids a high fatty acid/triglyceride ratio (6.76). Mean fatty acid/triglyceride ratio of routine stool samples was 4.16±1.01. The applicability of fatty acid/triglyceride ratios was also tested in cystic fibrosis patients under treatment with a mean of 4.92±0.98. Relative absorbance contribution per carbon atom was 0.06 (ratio 1.06 for C18 standard, 0.91 for C16 standard). The mean ratio of the stool samples was 1.12 (mean acyl chain length of C19), with values ranging from 0.73 (C12) to 1.68 (C28). The presence of traceable amounts of trans-unsaturated fatty acids was also demonstrated. For the analysis of faecal material, FTIR provides unique information, difficult to obtain using other techniques. These findings offer perspectives for diet monitoring in patients with (non-)pancreatic malabsorption. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  13. Mid-infrared Variability of Changing-look AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo [CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Sciences and Technology of China, Hefei, Anhui 230026 (China); Yan, Lin [Caltech Optical Observatories, Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dou, Liming, E-mail: shengzf@mail.ustc.edu.cn, E-mail: twang@ustc.edu.cn [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)

    2017-09-01

    It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

  14. Cost-effective and compact wide-field fluorescent imaging on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

    2011-01-21

    We demonstrate wide-field fluorescent and darkfield imaging on a cell-phone with compact, light-weight and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. For this purpose, we used battery powered light-emitting diodes (LEDs) to pump the sample of interest from the side using butt-coupling, where the pump light was guided within the sample cuvette to uniformly excite the specimen. The fluorescent emission from the sample was then imaged using an additional lens that was positioned right in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to our detection path, an inexpensive plastic colour filter was sufficient to create the dark-field background required for fluorescent imaging, without the need for a thin-film interference filter. We validate the performance of this platform by imaging various fluorescent micro-objects in 2 colours (i.e., red and green) over a large field-of-view (FOV) of ∼81 mm(2) with a raw spatial resolution of ∼20 μm. With additional digital processing of the captured cell-phone images, through the use of compressive sampling theory, we demonstrate ∼2 fold improvement in our resolving power, achieving ∼10 μm resolution without a trade-off in our FOV. Further, we also demonstrate darkfield imaging of non-fluorescent specimen using the same interface, where this time the scattered light from the objects is detected without the use of any filters. The capability of imaging a wide FOV would be exceedingly important to probe large sample volumes (e.g., >0.1 mL) of e.g., blood, urine, sputum or water, and for this end we also demonstrate fluorescent imaging of labeled white-blood cells from whole blood samples, as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts. Weighing only ∼28 g (∼1 ounce), this compact and cost-effective fluorescent imaging platform

  15. VizieR Online Data Catalog: Wide field imagers ground-based astrometry. V. (Libralato+, 2014)

    Science.gov (United States)

    Libralato, M.; Bellini, A.; Bedin, L. R.; Piotto, G.; Platais, I.; Kissler-Patig, M.; Milone, A. P.

    2014-01-01

    Astro-photometric catalogs of 7 different fields. For each field we provide equatorial and pixel coordinates, infrared wide-band photometry. For NGC 6656 and NGC 6121 we also provide proper motions and an estimate of the membership probability. (11 data files).

  16. Wide-field imaging through scattering media by scattered light fluorescence microscopy

    Science.gov (United States)

    Zhou, Yulan; Li, Xun

    2017-08-01

    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

  17. Development of a Data Reduction algorithm for Optical Wide Field Patrol

    Directory of Open Access Journals (Sweden)

    Sun-youp Park

    2013-09-01

    Full Text Available The detector subsystem of the Optical Wide-field Patrol (OWL network efficiently acquires the position and time information of moving objects such as artificial satellites through its chopper system, which consists of 4 blades in front of the CCD camera. Using this system, it is possible to get more position data with the same exposure time by changing the streaks of the moving objects into many pieces with the fast rotating blades during sidereal tracking. At the same time, the time data from the rotating chopper can be acquired by the time tagger connected to the photo diode. To analyze the orbits of the targets detected in the image data of such a system, a sequential procedure of determining the positions of separated streak lines was developed that involved calculating the World Coordinate System (WCS solution to transform the positions into equatorial coordinate systems, and finally combining the time log records from the time tagger with the transformed position data. We introduce this procedure and the preliminary results of the application of this procedure to the test observation images.

  18. Automated segmentation of oral mucosa from wide-field OCT images (Conference Presentation)

    Science.gov (United States)

    Goldan, Ryan N.; Lee, Anthony M. D.; Cahill, Lucas; Liu, Kelly; MacAulay, Calum; Poh, Catherine F.; Lane, Pierre

    2016-03-01

    Optical Coherence Tomography (OCT) can discriminate morphological tissue features important for oral cancer detection such as the presence or absence of basement membrane and epithelial thickness. We previously reported an OCT system employing a rotary-pullback catheter capable of in vivo, rapid, wide-field (up to 90 x 2.5mm2) imaging in the oral cavity. Due to the size and complexity of these OCT data sets, rapid automated image processing software that immediately displays important tissue features is required to facilitate prompt bed-side clinical decisions. We present an automated segmentation algorithm capable of detecting the epithelial surface and basement membrane in 3D OCT images of the oral cavity. The algorithm was trained using volumetric OCT data acquired in vivo from a variety of tissue types and histology-confirmed pathologies spanning normal through cancer (8 sites, 21 patients). The algorithm was validated using a second dataset of similar size and tissue diversity. We demonstrate application of the algorithm to an entire OCT volume to map epithelial thickness, and detection of the basement membrane, over the tissue surface. These maps may be clinically useful for delineating pre-surgical tumor margins, or for biopsy site guidance.

  19. Wide field imaging spectrometer for ESA's future X-ray mission: XEUS

    CERN Document Server

    Strüder, L

    1999-01-01

    An active pixel sensor (APS) based on the DEpleted P-channel junction Field Effect Transistor (DEPFET) concept will be described as a potential wide field imager for ESA's high resolution, high throughput mission: 'X-ray Evolving Universe Spectroscopy' (XEUS). It comprises a parallel multichannel readout, low noise at high speed readout, backside illumination and a fill factor of 100% over the whole field of view. The depleted thickness will be 500 microns. These design parameters match the scientific requirements of the mission. The fabrication techniques of the DEPFET arrays are related to the high resistivity process of the X-ray pn-CCDs. Potential extensions of the already realized DEPFET structures are a non-destructive repetitive readout of the signal charges. This concept will be presented. As an alternative solution, frame store pn-CCDs are considered having the same format and pixel sizes as the proposed DEPFET arrays. Their development is a low risk, straightforward continuation of the XMM devices. ...

  20. Water-Immersible MEMS scanning mirror designed for wide-field fast-scanning photoacoustic microscopy

    Science.gov (United States)

    Yao, Junjie; Huang, Chih-Hsien; Martel, Catherine; Maslov, Konstantin I.; Wang, Lidai; Yang, Joon-Mo; Gao, Liang; Randolph, Gwendalyn; Zou, Jun; Wang, Lihong V.

    2013-03-01

    By offering images with high spatial resolution and unique optical absorption contrast, optical-resolution photoacoustic microscopy (OR-PAM) has gained increasing attention in biomedical research. Recent developments in OR-PAM have improved its imaging speed, but have sacrificed either the detection sensitivity or field of view or both. We have developed a wide-field fast-scanning OR-PAM by using a water-immersible MEMS scanning mirror (MEMS-ORPAM). Made of silicon with a gold coating, the MEMS mirror plate can reflect both optical and acoustic beams. Because it uses an electromagnetic driving force, the whole MEMS scanning system can be submerged in water. In MEMS-ORPAM, the optical and acoustic beams are confocally configured and simultaneously steered, which ensures uniform detection sensitivity. A B-scan imaging speed as high as 400 Hz can be achieved over a 3 mm scanning range. A diffraction-limited lateral resolution of 2.4 μm in water and a maximum imaging depth of 1.1 mm in soft tissue have been experimentally determined. Using the system, we imaged the flow dynamics of both red blood cells and carbon particles in a mouse ear in vivo. By using Evans blue dye as the contrast agent, we also imaged the flow dynamics of lymphatic vessels in a mouse tail in vivo. The results show that MEMS-OR-PAM could be a powerful tool for studying highly dynamic and time-sensitive biological phenomena.

  1. Wide-field OCT imaging of oral lesions in vivo: quantification and classification (Conference Presentation)

    Science.gov (United States)

    Raizada, Rashika; Lee, Anthony M. D.; Liu, Kelly Y.; MacAulay, Calum E.; Ng, Samson; Poh, Catherine F.; Lane, Pierre M.

    2017-02-01

    Worldwide, there are over 450,000 new cases of oral cancer reported each year. Late-stage diagnosis remains a significant factor responsible for its high mortality rate (>50%). In-vivo non-invasive rapid imaging techniques, that can visualise clinically significant changes in the oral mucosa, may improve the management of oral cancer. We present an analysis of features extracted from oral images obtained using our hand- held wide-field Optical Coherence Tomography (OCT) instrument. The images were analyzed for epithelial scattering, overall tissue scattering, and 3D basement membrane topology. The associations between these three features and disease state (benign, pre-cancer, or cancer), as measured by clinical assessment or pathology, were determined. While scattering coefficient has previously been shown to be sensitive to cancer and dysplasia, likely due to changes in nuclear and cellular density, the addition of basement membrane topology may increase diagnostic ability- as it is known that the presence of bulbous rete pegs in the basement membrane are characteristic of dysplasia. The resolution and field-of-view of our oral OCT system allowed analysis of these features over large areas of up to 2.5mm x 90mm, in a timely fashion, which allow for application in clinical settings.

  2. Studies of prototype DEPFET sensors for the Wide Field Imager of Athena

    Science.gov (United States)

    Treberspurg, Wolfgang; Andritschke, Robert; Bähr, Alexander; Behrens, Annika; Hauser, Günter; Lechner, Peter; Meidinger, Norbert; Müller-Seidlitz, Johannes; Treis, Johannes

    2017-08-01

    The Wide Field Imager (WFI) of ESA's next X-ray observatory Athena will combine a high count rate capability with a large field of view, both with state-of-the-art spectroscopic performance. To meet these demands, specific DEPFET active pixel detectors have been developed and operated. Due to the intrinsic amplification of detected signals they are best suited to achieve a high speed and low noise performance. Different fabrication technologies and transistor geometries have been implemented on a dedicated prototype production in the course of the development of the DEPFET sensors. The main modifications between the sensors concern the shape of the transistor gate - regarding the layout - and the thickness of the gate oxide - regarding the technology. To facilitate the fabrication and testing of the resulting variety of sensors the presented studies were carried out with 64×64 pixel detectors. The detector comprises a control ASIC (Switcher-A), a readout ASIC (VERITAS- 2) and the sensor. In this paper we give an overview on the evaluation of different prototype sensors. The most important results, which have been decisive for the identification of the optimal fabrication technology and transistor layout for subsequent sensor productions are summarized. It will be shown that the developments result in an excellent performance of spectroscopic X-ray DEPFETs with typical noise values below 2.5 ENC at 2.5 μs/row.

  3. WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, S.; Rau, U.; Golap, K., E-mail: sbhatnag@nrao.edu, E-mail: rurvashi@nrao.edu, E-mail: kgolap@nrao.edu [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

    2013-06-20

    Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.

  4. FAINT TIDAL FEATURES IN GALAXIES WITHIN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY WIDE FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, Adam M.; Abraham, Roberto G. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Ferguson, Annette M. N. [Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    2013-03-01

    We present an analysis of the detectability of faint tidal features in galaxies from the wide-field component of the Canada-France-Hawaii Telescope Legacy Survey. Our sample consists of 1781 luminous (M{sub r{sup '}}<-19.3 mag) galaxies in the magnitude range 15.5 mag < r' < 17 mag and in the redshift range 0.04 < z < 0.2. Although we have classified tidal features according to their morphology (e.g., streams, shells, and tails), we do not attempt to interpret them in terms of their physical origin (e.g., major versus minor merger debris). Instead, we provide a catalog that is intended to provide raw material for future investigations which will probe the nature of low surface brightness substructure around galaxies. We find that around 12% of the galaxies in our sample show clear tidal features at the highest confidence level. This fraction rises to about 18% if we include systems with convincing, albeit weaker tidal features, and to 26% if we include systems with more marginal features that may or may not be tidal in origin. These proportions are a strong function of rest-frame color and of stellar mass. Linear features, shells, and fans are much more likely to occur in massive galaxies with stellar masses >10{sup 10.5} M {sub Sun }, and red galaxies are twice as likely to show tidal features than are blue galaxies.

  5. Calibration of BVRI Photometry for the Wide Field Channel of the HST Advanced Camera for Surveys

    Science.gov (United States)

    Saha, Abhijit; Shaw, Richard A.; Claver, Jennifer A.; Dolphin, Andrew E.

    2011-04-01

    We present new observations of two Galactic globular clusters, PAL4 and PAL14, using the Wide Field Channel of the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST) and reanalyze archival data from a third, NGC2419. We matched our photometry of hundreds of stars in these fields from the ACS images to existing ground-based photometry of faint sequences that were calibrated on the standard BVRI system of Landolt. These stars are significantly fainter than those generally used for HST calibration purposes and therefore are much better matched to supporting precision photometry of ACS science targets. We were able to derive more accurate photometric transformation coefficients for the commonly used ACS broadband filters, compared with those published by Sirianni et al., due to the use of a factor of several more calibration stars that span a greater range of color. We find that the inferred transformations from each cluster individually do not vary significantly from the average, except for a small offset of the photometric zero point in the F850LP filter. Our results suggest that the published prescriptions for the time-dependent correction of CCD charge transfer efficiency appear to work very well over the ˜3.5 yr interval that spans our observations of PAL4 and PAL14 and the archived images of NGC2419.

  6. The ARGO-YBJ legacy to next generation wide field-of-view experiments

    Directory of Open Access Journals (Sweden)

    Di Sciascio Giuseppe

    2017-01-01

    Full Text Available The ARGO-YBJ experiment has been in stable data taking for more than 5 years at the YangBaJing Cosmic Ray Observatory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm2. With a duty-cycle greater than 86% the detector collected about 5×1011 events in a wide energy range, from few hundreds GeV up to about 10 PeV. High altitude location and detector features make ARGO-YBJ capable of investigating a wide range of important issues in Cosmic Ray and Astroparticle Physics by imaging the front of atmospheric showers with unprecedented resolution and detail. In this contribution some of the latest physics results obtained by ARGO-YBJ in gamma-ray astronomy and in cosmic ray physics are summarized. The prospects of TeV gamma-ray observations with new ground-based wide field-of-view detectors are presented.

  7. Mapping absolute tissue endogenous fluorophore concentrations with chemometric wide-field fluorescence microscopy

    Science.gov (United States)

    Xu, Zhang; Reilley, Michael; Li, Run; Xu, Min

    2017-06-01

    We report chemometric wide-field fluorescence microscopy for imaging the spatial distribution and concentration of endogenous fluorophores in thin tissue sections. Nonnegative factorization aided by spatial diversity is used to learn both the spectral signature and the spatial distribution of endogenous fluorophores from microscopic fluorescence color images obtained under broadband excitation and detection. The absolute concentration map of individual fluorophores is derived by comparing the fluorescence from "pure" fluorophores under the identical imaging condition following the identification of the fluorescence species by its spectral signature. This method is then demonstrated by characterizing the concentration map of endogenous fluorophores (including tryptophan, elastin, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide) for lung tissue specimens. The absolute concentrations of these fluorophores are all found to decrease significantly from normal, perilesional, to cancerous (squamous cell carcinoma) tissue. Discriminating tissue types using the absolute fluorophore concentration is found to be significantly more accurate than that achievable with the relative fluorescence strength. Quantification of fluorophores in terms of the absolute concentration map is also advantageous in eliminating the uncertainties due to system responses or measurement details, yielding more biologically relevant data, and simplifying the assessment of competing imaging approaches.

  8. Exploring the NRO Opportunity for a Hubble-Sized Wide-Field Near-IR Space Telescope - New WFIRST

    Science.gov (United States)

    Dressler, Alan; Spergel, David; Mountain, Matt; Postman, Mark; Elliott, Erin; Bendek, Eduardo; Bennett, David; Dalcanton, Julianne; Gaudi, Scott; Gehrels, Neil; hide

    2013-01-01

    We discuss scientific, technical, and programmatic issues related to the use of an NRO 2.4m telescope for the WFIRST initiative of the 2010 Decadal Survey. We show that this implementation of WFIRST, which we call "NEW WFIRST," would achieve the goals of the NWNH Decadal Survey for the WFIRST core programs of Dark Energy and Microlensing Planet Finding, with the crucial benefit of deeper and/or wider near-IR surveys for GO science and a potentially Hubble-like Guest Observer program. NEW WFIRST could also include a coronagraphic imager for direct detection of dust disks and planets around neighboring stars, a high-priority science and technology precursor for future ambitious programs to image Earth-like planets around neighboring stars.

  9. SAAO's new robotic telescope and WiNCam (Wide-field Nasmyth Camera)

    Science.gov (United States)

    Worters, Hannah L.; O'Connor, James E.; Carter, David B.; Loubser, Egan; Fourie, Pieter A.; Sickafoose, Amanda; Swanevelder, Pieter

    2016-08-01

    The South African Astronomical Observatory (SAAO) is designing and manufacturing a wide-field camera for use on two of its telescopes. The initial concept was of a Prime focus camera for the 74" telescope, an equatorial design made by Grubb Parsons, where it would employ a 61mmx61mm detector to cover a 23 arcmin diameter field of view. However, while in the design phase, SAAO embarked on the process of acquiring a bespoke 1-metre robotic alt-az telescope with a 43 arcmin field of view, which needs a homegrown instrument suite. The Prime focus camera design was thus adapted for use on either telescope, increasing the detector size to 92mmx92mm. Since the camera will be mounted on the Nasmyth port of the new telescope, it was dubbed WiNCam (Wide-field Nasmyth Camera). This paper describes both WiNCam and the new telescope. Producing an instrument that can be swapped between two very different telescopes poses some unique challenges. At the Nasmyth port of the alt-az telescope there is ample circumferential space, while on the 74 inch the available envelope is constrained by the optical footprint of the secondary, if further obscuration is to be avoided. This forces the design into a cylindrical volume of 600mm diameter x 250mm height. The back focal distance is tightly constrained on the new telescope, shoehorning the shutter, filter unit, guider mechanism, a 10mm thick window and a tip/tilt mechanism for the detector into 100mm depth. The iris shutter and filter wheel planned for prime focus could no longer be accommodated. Instead, a compact shutter with a thickness of less than 20mm has been designed in-house, using a sliding curtain mechanism to cover an aperture of 125mmx125mm, while the filter wheel has been replaced with 2 peripheral filter cartridges (6 filters each) and a gripper to move a filter into the beam. We intend using through-vacuum wall PCB technology across the cryostat vacuum interface, instead of traditional hermetic connector-based wiring. This

  10. A small animal time-resolved optical tomography platform using wide-field excitation

    Science.gov (United States)

    Venugopal, Vivek

    Small animal imaging plays a critical role in present day biomedical research by filling an important gap in the translation of research from the bench to the bedside. Optical techniques constitute an emerging imaging modality which have tremendous potential in preclinical applications. Optical imaging methods are capable of non-invasive assessment of the functional and molecular characteristics of biological tissue. The three-dimensional optical imaging technique, referred to as diffuse optical tomography, provides an approach for the whole-body imaging of small animal models and can provide volumetric maps of tissue functional parameters (e.g. blood volume, oxygen saturation etc.) and/or provide 3D localization and quantification of fluorescence-based molecular markers in vivo. However, the complex mathematical reconstruction problem associated with optical tomography and the cumbersome instrumental designs limits its adoption as a high-throughput quantitative whole-body imaging modality in current biomedical research. The development of new optical imaging paradigms is thus necessary for a wide-acceptance of this new technology. In this thesis, the design, development, characterization and optimization of a small animal optical tomography system is discussed. Specifically, the platform combines a highly sensitive time-resolved imaging paradigm with multi-spectral excitation capability and CCD-based detection to provide a system capable of generating spatially, spectrally and temporally dense measurement datasets. The acquisition of such data sets however can take long and translate to often unrealistic acquisition times when using the classical point source based excitation scheme. The novel approach in the design of this platform is the adoption of a wide-field excitation scheme which employs extended excitation sources and in the process allows an estimated ten-fold reduction in the acquisition time. The work described herein details the design of the imaging

  11. Wide-field fluorescent microscopy and fluorescent imaging flow cytometry on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Ozcan, Aydogan

    2013-04-11

    Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. - 10 μm over a very large field-of-view of - 81 mm(2). This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

  12. WIDE-FIELD PRECISION KINEMATICS OF THE M87 GLOBULAR CLUSTER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Strader, Jay [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Romanowsky, Aaron J.; Brodie, Jean P.; Beasley, Michael A.; Arnold, Jacob A. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Spitler, Lee R. [Center for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Tamura, Naoyuki [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Sharples, Ray M. [Department of Physics, University of Durham, South Road, Durham (United Kingdom); Arimoto, Nobuo, E-mail: jstrader@cfa.harvard.edu [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)

    2011-12-01

    We present the most extensive combined photometric and spectroscopic study to date of the enormous globular cluster (GC) system around M87, the central giant elliptical galaxy in the nearby Virgo Cluster. Using observations from DEIMOS and the Low Resolution Imaging Spectrometer at Keck, and Hectospec on the Multiple Mirror Telescope, we derive new, precise radial velocities for 451 GCs around M87, with projected radii from {approx}5 to 185 kpc. We combine these measurements with literature data for a total sample of 737 objects, which we use for a re-examination of the kinematics of the GC system of M87. The velocities are analyzed in the context of archival wide-field photometry and a novel Hubble Space Telescope catalog of half-light radii, which includes sizes for 344 spectroscopically confirmed clusters. We use this unique catalog to identify 18 new candidate ultracompact dwarfs and to help clarify the relationship between these objects and true GCs. We find much lower values for the outer velocity dispersion and rotation of the GC system than in earlier papers and also differ from previous work in seeing no evidence for a transition in the inner halo to a potential dominated by the Virgo Cluster, nor for a truncation of the stellar halo. We find little kinematical evidence for an intergalactic GC population. Aided by the precision of the new velocity measurements, we see significant evidence for kinematical substructure over a wide range of radii, indicating that M87 is in active assembly. A simple, scale-free analysis finds less dark matter within {approx}85 kpc than in other recent work, reducing the tension between X-ray and optical results. In general, out to a projected radius of {approx}150 kpc, our data are consistent with the notion that M87 is not dynamically coupled to the Virgo Cluster; the core of Virgo may be in the earliest stages of assembly.

  13. Performance Improvement of Near Earth Space Survey (NESS Wide-Field Telescope (NESS-2 Optics

    Directory of Open Access Journals (Sweden)

    Sung-Yeol Yu

    2010-06-01

    Full Text Available We modified the optical system of 500 mm wide-field telescope of which point spread function showed an irregularity. The telescope has been operated for Near Earth Space Survey (NESS located at Siding Spring Observatory (SSO in Australia, and the optical system was brought back to Korea in January 2008. After performing a numerical simulation with the tested value of surface figure error of the primary mirror using optical design program, we found that the surface figure error of the mirror should be fabricated less than root mean square (RMS λ/10 in order to obtain a stellar full width at half maximum (FWHM below 28 μm. However, we started to figure the mirror for the target value of RMS λ/20, because system surface figure error would be increased by the error induced by the optical axis adjustment, mirror cell installation, and others. The radius of curvature of the primary mirror was 1,946 mm after the correction. Its measured surface figure error was less than RMS λ/20 on the table of polishing machine, and RMS λ/15 after installation in the primary mirror cell. A test observation performed at Daeduk Observatory at Korea Astronomy and Space Science Institute by utilizing the exiting mount, and resulted in 39.8 μm of stellar FWHM. It was larger than the value from numerical simulation, and showed wing-shaped stellar image. It turned out that the measured-curvature of the secondary mirror, 1,820 mm, was not the same as the designed one, 1,795.977 mm. We fabricated the secondary mirror to the designed value, and finally obtained a stellar FWHM of 27 μm after re-installation of the optical system into SSO NESS Observatory in Australia.

  14. Anisoplanatic error evaluation and wide-field adaptive optics performance at Dome C, Antarctica

    Science.gov (United States)

    Carbillet, M.; Aristidi, É.; Giordano, C.; Vernin, J.

    2017-11-01

    The aim of this paper is twofold: (i) to deduce the most representative C_N^2 profile(s) for Dome C (DC), Antarctica, from the latest measurements, and (ii) to evaluate the performance of a wide-field adaptive optics (AO) system equipping a 2-3 m telescope. Two models of the C_N^2 profile, corresponding to the bimodal distribution of seeing (a poor seeing mode and a good seeing mode), are composed from both Single Star Scidar data and balloon radio soundings. The anisoplanatic error is first evaluated for a standard AO system from Monte Carlo simulations. DC is shown to outperform Mauna Kea for both seeing modes. A simple ground-layer AO (GLAO) system is then considered. This provides an anisoplanatic error of less than 150 nm over a field of 30 arcmin for the good seeing mode, corresponding to a basic performance Strehl ratio (considering also the fitting and the servo-lag errors) of more than ˜80 per cent in K and ˜50 per cent in J. The poor seeing model shows performance comparable to the Mauna Kea model. We also studied the influence of telescope elevation, showing that a telescope at 40 m would perform, in the poor seeing mode, like a telescope observing 8 m above the ground in the good seeing mode. Finally, we show that while tip-tilt-only correction permits high levels of correction in the good seeing mode at 40 m, it is not as efficient as the GLAO system, even at an altitude of 8 m, and it is not sufficient for high levels of correction for poor seeing, even at a height of 40 m.

  15. Evaluation of illumination system uniformity for wide-field biomedical hyperspectral imaging

    Science.gov (United States)

    Sawyer, Travis W.; Siri Luthman, A.; E Bohndiek, Sarah

    2017-04-01

    Hyperspectral imaging (HSI) systems collect both spatial (morphological) and spectral (chemical) information from a sample. HSI can provide sensitive analysis for biological and medical applications, for example, simultaneously measuring reflectance and fluorescence properties of a tissue, which together with structural information could improve early cancer detection and tumour characterisation. Illumination uniformity is a critical pre-condition for quantitative data extraction from an HSI system. Non-uniformity can cause glare, specular reflection and unwanted shading, which negatively impact statistical analysis procedures used to extract abundance of different chemical species. Here, we model and evaluate several illumination systems frequently used in wide-field biomedical imaging to test their potential for HSI. We use the software LightTools and FRED. The analysed systems include: a fibre ring light; a light emitting diode (LED) ring; and a diffuse scattering dome. Each system is characterised for spectral, spatial, and angular uniformity, as well as transfer efficiency. Furthermore, an approach to measure uniformity using the Kullback-Leibler divergence (KLD) is introduced. The KLD is generalisable to arbitrary illumination shapes, making it an attractive approach for characterising illumination distributions. Although the systems are quite comparable in their spatial and spectral uniformity, the most uniform angular distribution is achieved using a diffuse scattering dome, yielding a contrast of 0.503 and average deviation of 0.303 over a ±60° field of view with a 3.9% model error in the angular domain. Our results suggest that conventional illumination sources can be applied in HSI, but in the case of low light levels, bespoke illumination sources may offer improved performance.

  16. Automatic detection of diabetic retinopathy features in ultra-wide field retinal images

    Science.gov (United States)

    Levenkova, Anastasia; Sowmya, Arcot; Kalloniatis, Michael; Ly, Angelica; Ho, Arthur

    2017-03-01

    Diabetic retinopathy (DR) is a major cause of irreversible vision loss. DR screening relies on retinal clinical signs (features). Opportunities for computer-aided DR feature detection have emerged with the development of Ultra-WideField (UWF) digital scanning laser technology. UWF imaging covers 82% greater retinal area (200°), against 45° in conventional cameras3 , allowing more clinically relevant retinopathy to be detected4 . UWF images also provide a high resolution of 3078 x 2702 pixels. Currently DR screening uses 7 overlapping conventional fundus images, and the UWF images provide similar results1,4. However, in 40% of cases, more retinopathy was found outside the 7-field ETDRS) fields by UWF and in 10% of cases, retinopathy was reclassified as more severe4 . This is because UWF imaging allows examination of both the central retina and more peripheral regions, with the latter implicated in DR6 . We have developed an algorithm for automatic recognition of DR features, including bright (cotton wool spots and exudates) and dark lesions (microaneurysms and blot, dot and flame haemorrhages) in UWF images. The algorithm extracts features from grayscale (green "red-free" laser light) and colour-composite UWF images, including intensity, Histogram-of-Gradient and Local binary patterns. Pixel-based classification is performed with three different classifiers. The main contribution is the automatic detection of DR features in the peripheral retina. The method is evaluated by leave-one-out cross-validation on 25 UWF retinal images with 167 bright lesions, and 61 other images with 1089 dark lesions. The SVM classifier performs best with AUC of 94.4% / 95.31% for bright / dark lesions.

  17. Wide field imager instrument for the Advanced Telescope for High Energy Astrophysics

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea; Tenzer, Chris; Wilms, Jörn

    2015-01-01

    The Advanced Telescope for High Energy Astrophysics (Athena) has been selected for ESA's L2 mission, scheduled for launch in 2028. It will provide the necessary capabilities to achieve the ambitious goals of the science theme "The Hot and Energetic Universe." Athena's x-ray mirrors will be based on silicon pore optics technology with a 12-m focal length. Two complementary focal plane camera systems are foreseen, which can be moved interchangeably to the focus of the mirror system: the actively shielded micro-calorimeter spectrometer X-IFU and the wide field imager (WFI). The WFI camera will provide an unprecedented survey power through its large field of view of 40 arc min with a high count-rate capability (˜1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 to 15 keV during the entire mission lifetime (e.g., full width at half maximum ≤150 eV at 6 keV). This performance is accomplished by a set of depleted P-channel field effect transistor (DEPFET) active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450-μm-thick silicon bulk. This manuscript will summarize the current instrument concept and design, the status of the technology development, and the envisaged baseline performance.

  18. Hyper Suprime-Camera Survey of the Akari NEP Wide Field

    Science.gov (United States)

    Goto, Tomotsugu; Toba, Yoshiki; Utsumi, Yousuke; Oi, Nagisa; Takagi, Toshinobu; Malkan, Matt; Ohayma, Youichi; Murata, Kazumi; Price, Paul; Karouzos, Marios; Matsuhara, Hideo; Nakagawa, Takao; Wada, Takehiko; Serjeant, Steve; Burgarella, Denis; Buat, Veronique; Takada, Masahiro; Miyazaki, Satoshi; Oguri, Masamune; Miyaji, Takamitsu; Oyabu, Shinki; White, Glenn; Takeuchi, Tsutomu; Inami, Hanae; Perason, Chris; Malek, Katarzyna; Marchetti, Lucia; Lee, Hyung Mok; Im, Myung; Kim, Seong Jin; Koptelova, Ekaterina; Chao, Dani; Wu, Yi-Han; AKARI NEP Survey Team; AKARI All Sky Survey Team

    2017-03-01

    The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z ∼1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field (5.4 deg^2), using ∼10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ∼25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute significantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1 Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate mid-IR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

  19. Quantitative analysis of wide field-of-view and broadband quarter-wave plate based on metasurface

    Science.gov (United States)

    Chen, Yanjun; Guo, Zhe; Liu, Ke; Liu, Lihui; Li, Yanqiu

    2018-01-01

    As the numerical aperture (NA) of the projection objective increases continually and the exposure pattern feature size decreases gradually, the polarization illumination is introduced into the lithography system. Therefore, it is necessary to design a wide field-of-view (FOV) wave plate to eliminate the effect of oblique incident light on the phase delay of the traditional zero order wave plate effectively. The quarter-wave plate with 20° FOV based on birefringent optical crystals has been designed in our laboratory by Dong et al. In order to obtain a wider FOV, we explore a previously reported Ag patch ultrathin quarter-wave plate whose performances were not analyzed by finite-difference time-domain (FDTD) method. In this paper, we mainly investigate three performances of the Ag patch quarter-wave plate consisting of FOV, achromatic band and achromatic band transmission. The simulation results indicate that when phase difference error is controlled at +/-2° (1) the range of FOV of the quarter-wave plate is +/-29° at 632nm; (2) the achromatic band ranges from 618nm to 658nm at normal incidence; (3) the achromatic band transmission ranges from 11% to 30%. Compared with the traditional wave plate made of birefringent crystals, the achromatic band and transmission is slightly lower but the FOV of this quarter-wave plate is much wider. Thus, this Ag patch nanoscale wide FOV quarter-wave plate can be effectively used in high NA lithography projection exposure systems to reduce the polarization aberration caused by oblique incidence of light.

  20. Systems, computer-implemented methods, and tangible computer-readable storage media for wide-field interferometry

    Science.gov (United States)

    Lyon, Richard G. (Inventor); Leisawitz, David T. (Inventor); Rinehart, Stephen A. (Inventor); Memarsadeghi, Nargess (Inventor)

    2012-01-01

    Disclosed herein are systems, computer-implemented methods, and tangible computer-readable storage media for wide field imaging interferometry. The method includes for each point in a two dimensional detector array over a field of view of an image: gathering a first interferogram from a first detector and a second interferogram from a second detector, modulating a path-length for a signal from an image associated with the first interferogram in the first detector, overlaying first data from the modulated first detector and second data from the second detector, and tracking the modulating at every point in a two dimensional detector array comprising the first detector and the second detector over a field of view for the image. The method then generates a wide-field data cube based on the overlaid first data and second data for each point. The method can generate an image from the wide-field data cube.

  1. Wide field imaging - I. Applications of neural networks to object detection and star/galaxy classification

    Science.gov (United States)

    Andreon, S.; Gargiulo, G.; Longo, G.; Tagliaferri, R.; Capuano, N.

    2000-12-01

    Astronomical wide-field imaging performed with new large-format CCD detectors poses data reduction problems of unprecedented scale, which are difficult to deal with using traditional interactive tools. We present here NExt (Neural Extractor), a new neural network (NN) based package capable of detecting objects and performing both deblending and star/galaxy classification in an automatic way. Traditionally, in astronomical images, objects are first distinguished from the noisy background by searching for sets of connected pixels having brightnesses above a given threshold; they are then classified as stars or as galaxies through diagnostic diagrams having variables chosen according to the astronomer's taste and experience. In the extraction step, assuming that images are well sampled, NExt requires only the simplest a priori definition of `what an object is' (i.e. it keeps all structures composed of more than one pixel) and performs the detection via an unsupervised NN, approaching detection as a clustering problem that has been thoroughly studied in the artificial intelligence literature. The first part of the NExt procedure consists of an optimal compression of the redundant information contained in the pixels via a mapping from pixel intensities to a subspace individualized through principal component analysis. At magnitudes fainter than the completeness limit, stars are usually almost indistinguishable from galaxies, and therefore the parameters characterizing the two classes do not lie in disconnected subspaces, thus preventing the use of unsupervised methods. We therefore adopted a supervised NN (i.e. a NN that first finds the rules to classify objects from examples and then applies them to the whole data set). In practice, each object is classified depending on its membership of the regions mapping the input feature space in the training set. In order to obtain an objective and reliable classification, instead of using an arbitrarily defined set of features

  2. Automatic Processing of Chinese GF-1 Wide Field of View Images

    Science.gov (United States)

    Zhang, Y.; Wan, Y.; Wang, B.; Kang, Y.; Xiong, J.

    2015-04-01

    The wide field of view (WFV) imaging instrument carried on the Chinese GF-1 satellite includes four cameras. Each camera has 200km swath-width that can acquire earth image at the same time and the observation can be repeated within only 4 days. This enables the applications of remote sensing imagery to advance from non-scheduled land-observation to periodically land-monitoring in the areas that use the images in such resolutions. This paper introduces an automatic data analysing and processing technique for the wide-swath images acquired by GF-1 satellite. Firstly, the images are validated by a self-adaptive Gaussian mixture model based cloud detection method to confirm whether they are qualified and suitable to be involved into the automatic processing workflow. Then the ground control points (GCPs) are quickly and automatically matched from the public geo-information products such as the rectified panchromatic images of Landsat-8. Before the geometric correction, the cloud detection results are also used to eliminate the invalid GCPs distributed in the cloud covered areas, which obviously reduces the ratio of blunders of GCPs. The geometric correction module not only rectifies the rational function models (RFMs), but also provides the self-calibration model and parameters for the non-linear distortion, and it is iteratively processed to detect blunders. The maximum geometric distortion in WFV image decreases from about 10-15 pixels to 1-2 pixels when compensated by self-calibration model. The processing experiments involve hundreds of WFV images of GF-1 satellite acquired from June to September 2013, which covers the whole mainland of China. All the processing work can be finished by one operator within 2 days on a desktop computer made up by a second-generation Intel Core-i7 CPU and a 4-solid-State-Disk array. The digital ortho maps (DOM) are automatically generated with 3 arc second Shuttle Radar Topography Mission (SRTM). The geometric accuracies of the

  3. Wide-Field Gamma-Spectrometer BDRG: GRB Monitor On-Board the Lomonosov Mission

    Science.gov (United States)

    Svertilov, S. I.; Panasyuk, M. I.; Bogomolov, V. V.; Amelushkin, A. M.; Barinova, V. O.; Galkin, V. I.; Iyudin, A. F.; Kuznetsova, E. A.; Prokhorov, A. V.; Petrov, V. L.; Rozhkov, G. V.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Jeong, S.; Kim, M. B.

    2018-02-01

    The study of GRB prompt emissions (PE) is one of the main goals of the Lomonosov space mission. The payloads of the GRB monitor (BDRG) with the wide-field optical cameras (SHOK) and the ultra-fast flash observatory (UFFO) onboard the Lomonosov satellite are intended for the observation of GRBs, and in particular, their prompt emissions. The BDRG gamma-ray spectrometer is designed to obtain the temporal and spectral information of GRBs in the energy range of 10-3000 keV as well as to provide GRB triggers on several time scales (10 ms, 1 s and 20 s) for ground and space telescopes, including the UFFO and SHOK. The BDRG instrument consists of three identical detector boxes with axes shifted by 90° from each other. This configuration allows us to localize a GRB source in the sky with an accuracy of ˜ 2°. Each BDRG box contains a phoswich NaI(Tl)/CsI(Tl) scintillator detector. A thick CsI(Tl) crystal in size of \\varnothing 130 × 17 mm is placed underneath the NaI(Tl) as an active shield in the soft energy range and as the main detector in the hard energy range. The ratio of the CsI(Tl) to NaI(Tl) event rates at varying energies can be employed as an independent metric to distinguish legitimate GRB signals from false positives originating from electrons in near-Earth vicinities. The data from three detectors are collected in a BA BDRG information unit, which generates a GRB trigger and a set of data frames in output format. The scientific data output is ˜ 500 Mb per day, including ˜ 180 Mb of continuous data for events with durations in excess of 100 ms for 16 channels in each detector, detailed energy spectra, and sets of frames with ˜ 5 Mb of detailed information for each burst-like event. A number of pre-flight tests including those for the trigger algorithm and calibration were carried out to confirm the reliability of the BDRG for operation in space.

  4. Herbig-Haro Objects and Mid-infrared Outflows in the Vela C Molecular Cloud

    Science.gov (United States)

    Zhang, Miaomiao; Wang, Hongchi; Henning, Thomas

    2014-08-01

    We have performed a deep [S II] λλ6717/6731 wide field Herbig-Haro (HH) object survey toward the Vela C molecular cloud with a sky coverage of about 2 deg2. In total, 18 new HH objects, HH 1090-1107, are discovered and the two previously known HH objects, HH 73-74, are also detected in our [S II] images. We also present an investigation of mid-infrared outflows in the Vela C molecular cloud using the Wide-field Infrared Survey Explorer images taken from AllWISE data release. Using the method suggested by Zhang & Wang, 11 extended green objects (EGOs) are identified to be the mid-infrared outflows, including 6 new mid-infrared outflows that have not been detected previously at other wavelengths and 5 mid-infrared counterparts of the HH objects detected in this work. Using the AllWISE Source Catalog and the source classification scheme suggested by Koenig et al., we have identified 56 young stellar object (YSO) candidates in the Vela C molecular cloud. The possible driving sources of the HH objects and EGOs are discussed based on the morphology of HH objects and EGOs and the locations of HH objects, EGOs and YSO candidates. Finally we associate 12 HH objects and 5 EGOs with 10 YSOs and YSO candidates. The median length of the outflows in Vela C is 0.35 pc and the outflows seem to be oriented randomly.

  5. Exploring methodological frameworks for a mental task-based near-infrared spectroscopy brain-computer interface.

    Science.gov (United States)

    Weyand, Sabine; Takehara-Nishiuchi, Kaori; Chau, Tom

    2015-10-30

    Near-infrared spectroscopy (NIRS) brain-computer interfaces (BCIs) enable users to interact with their environment using only cognitive activities. This paper presents the results of a comparison of four methodological frameworks used to select a pair of tasks to control a binary NIRS-BCI; specifically, three novel personalized task paradigms and the state-of-the-art prescribed task framework were explored. Three types of personalized task selection approaches were compared, including: user-selected mental tasks using weighted slope scores (WS-scores), user-selected mental tasks using pair-wise accuracy rankings (PWAR), and researcher-selected mental tasks using PWAR. These paradigms, along with the state-of-the-art prescribed mental task framework, where mental tasks are selected based on the most commonly used tasks in literature, were tested by ten able-bodied participants who took part in five NIRS-BCI sessions. The frameworks were compared in terms of their accuracy, perceived ease-of-use, computational time, user preference, and length of training. Most notably, researcher-selected personalized tasks resulted in significantly higher accuracies, while user-selected personalized tasks resulted in significantly higher perceived ease-of-use. It was also concluded that PWAR minimized the amount of data that needed to be collected; while, WS-scores maximized user satisfaction and minimized computational time. In comparison to the state-of-the-art prescribed mental tasks, our findings show that overall, personalized tasks appear to be superior to prescribed tasks with respect to accuracy and perceived ease-of-use. The deployment of personalized rather than prescribed mental tasks ought to be considered and further investigated in future NIRS-BCI studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Exploration

    Science.gov (United States)

    Wilburn, D.R.

    2001-01-01

    Part of an annual review of mines and mineral resources in the U.S. An overview of nonfuel-mineral exploration in 2000 is presented. Principal exploration target was gold exploration in Latin America, Australia, and the U.S. There was a decrease of 18 percent in the exploration budget for gold as compared with the budget for 1999. Statistical information on nonfuel-mineral exploration worldwide is presented, analyzed, and interpreted.

  7. The FLARE mission: deep and wide-field 1-5um imaging and spectroscopy for the early universe: a proposal for M5 cosmic vision call

    Science.gov (United States)

    Burgarella, D.; Levacher, P.; Vives, S.; Dohlen, K.; Pascal, S.

    2016-07-01

    FLARE (First Light And Reionization Explorer) is a space mission that will be submitted to ESA (M5 call). Its primary goal (~80% of lifetime) is to identify and study the universe before the end of the reionization at z > 6. A secondary objective (~20% of lifetime) is to survey star formation in the Milky Way. FLARE's strategy optimizes the science return: imaging and spectroscopic integral-field observations will be carried out simultaneously on two parallel focal planes and over very wide instantaneous fields of view. FLARE will help addressing two of ESA's Cosmic Vision themes: a) universe originate and what is it made of? » and b) « What are the conditions for planet formation and the emergence of life? >> and more specifically, >. FLARE will provide to the ESA community a leading position to statistically study the early universe after JWST's deep but pin-hole surveys. Moreover, the instrumental development of wide-field imaging and wide-field integral-field spectroscopy in space will be a major breakthrough after making them available on ground-based telescopes.

  8. Clinical assessment of human breast cancer margins with wide-field optical coherence micro-elastography (Conference Presentation)

    Science.gov (United States)

    Allen, Wes M.; Chin, Lixin; Wijesinghe, Philip; Kirk, Rodney W.; Latham, Bruce; Sampson, David D.; Saunders, Christobel M.; Kennedy, Brendan F.

    2017-02-01

    Breast cancer has the second highest mortality rate of all cancers in females. Surgical excision of malignant tissue forms a central component of breast-conserving surgery (BCS) procedures. Incomplete excision of malignant tissue is a major issue in BCS with typically 20 - 30% cases requiring a second surgical procedure due to postoperative detection of tumor in the margin. A major challenge for surgeons during BCS is the lack of effective tools to assess the surgical margin intraoperatively. Such tools would enable the surgeon to more effectively remove all tumor during the initial surgery, hence reducing re-excision rates. We report advances in the development of a new tool, optical coherence micro-elastography, which forms images, known as elastograms, based on mechanical contrast within the tissue. We demonstrate the potential of this technique to increase contrast between malignant tumor and healthy stroma in elastograms over OCT images. We demonstrate a key advance toward clinical translation by conducting wide-field imaging in intraoperative time frames with a wide-field scanning system, acquiring mosaicked elastograms with overall dimensions of 50 × 50 mm, large enough to image an entire face of most lumpectomy specimens. We describe this wide-field imaging system, and demonstrate its operation by presenting wide-field optical coherence tomography images and elastograms of a tissue mimicking silicone phantom and a number of representative freshly excised human breast specimens. Our results demonstrate the feasibility of scanning large areas of lumpectomies, which is an important step towards practical intraoperative margin assessment.

  9. Wide-Field Multi-Parameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells.

    NARCIS (Netherlands)

    Vitali, M.; Picazo, F.; Prokazov, Y.; Duci, A.; Turbin, E.; Götze, C.; Llopis, J.; Hartig, R.; Visser, A.J.W.G.; Zuschratter, W.

    2011-01-01

    Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity

  10. Initial evaluation of safety of wide-field irradiation in the treatment of hematopoietic neoplasia in the cat.

    Science.gov (United States)

    Husbands, Brian D; McNiel, Elizabeth A; Modiano, Jaime F

    2010-01-01

    Localized radiation therapy is well tolerated in cats with confined tumors; however, the use of wide-field radiation therapy to treat disseminated neoplasia has not been evaluated systematically in this species. Wide-field external beam radiation therapy, which we define as irradiation of cranial or caudal halves of the body either individually or sequentially, was undertaken as an experimental option to treat cats with either chemotherapy-refractory or naive hematopoietic neoplasia considered to have a poor prognosis. Fifteen cats with hematopoietic malignancies received wide-field external beam radiation therapy between 2003 and 2006. Cats received 8 Gy delivered in 4 Gy fractions with 60Co photons. Treatment-related toxicity was scored according to criteria established by the Veterinary Cooperative Oncology Group. Animals without preexisting abnormalities on hemograms exhibited no or mild (Grade 1 or 2) hematopoietic toxicity. Although most cats (14 of 15) had preexisting gastrointestinal (GI) signs, these signs were stable (29%) or improved (42%) following irradiation. Worsening GI signs following irradiation occurred transiently in two cats and in association with progressive disease in two others. No pulmonary, renal, hepatic, or dermatologic toxicities were detected. In summary, wide-field external beam radiation therapy can be administered safely to, and may provide therapeutic benefit for, cats with disseminated hematopoietic neoplasia.

  11. Narcissus analysis of cooled IR optical system with multi-magnification in wide field of view

    Science.gov (United States)

    Hong, Jinsuk; Kim, Youngsoo

    2012-10-01

    The designed Infra-red optical system with multi-magnification shows non-uniform thermal distribution only in Wide FOV and suspected to be narcissus effect. To analyze the system's artifacts more effectively, the optical system design was imported to analysis codes. Initial ray tracing was performed with a point source from the detector to identify main candidates of Narcissus effect by analyzing irradiance distribution and flux distribution. As a second step, a planer source was created at the detector and traced again. As a result, four major candidates were selected and the major contributor was identified among them. To confirm the result with experiment, replacement optical component was manufactured. We can confirm that the Narcissus effect was improved significantly by replacing the identified component.

  12. The science enabled by the Maunakea Spectroscopic Explorer

    Science.gov (United States)

    Martin, N. F.; Babusiaux, C.

    2017-12-01

    With its unique wide-field, multi-object, and dedicated spectroscopic capabilities, the Maunakea Spectroscopic Explorer (MSE) is a powerful facility to shed light on the faint Universe. Built around an upgrade of the Canada-France Hawaii Telescope (CFHT) to a 11.25-meter telescope with a dedicated ˜1.5 deg^2, 4,000-fiber wide-field spectrograph that covers the optical and near-infrared wavelengths at resolutions between 2,500 and 40,000, the MSE is the essential follow-up complement to the current and next generations of multi-wavelength imaging surveys, such as the LSST, Gaia, Euclid, eROSITA, SKA, and WFIRST, and is an ideal feeder facility for the extremely large telescopes that are currently being built (E-ELT, GMT, and TMT). The science enabled by the MSE is vast and would have an impact on almost all aspects of astronomy research.

  13. ProtoEXIST2: Advanced Wide-field Imaging CZT Detector Development For The HET On The Proposed EXIST Mission

    Science.gov (United States)

    Hong, JaeSub; Allen, B.; Grindlay, J.; Barthelmy, S.; Baker, R.; Gehrels, N.; Cook, W.; Kaye, S.; Harrison, F.

    2010-03-01

    We describe our development of ProtoEXIST2, the advanced CZT imaging detector and wide field telescope prototype for the High Energy Telescope (HET) on the proposed Energetic X-ray Imaging Survey Telescope (EXIST) mission. EXIST is a multi-wavelength Medium class mission which would explore the early Universe using high redshift Gamma-ray Bursts and survey black holes on all scales. ProtoEXIST2 will demonstrate the feasibility of a large scale imaging module (256 cm2) with a close-tiled array of fine pixel (0.6 mm) CZT with a balloon flight test in 2010 or 2011. This second generation close-tiled CZT imager follows ProtoEXIST1, which had a recent successful balloon flight (see Allen et al in this meeting) using the same area CZT detector module (256 cm2) but with larger pixel size (2.5mm). For signal readout and event processing, we use the Direct-Bond (DB) ASIC, developed for the NuSTAR mission to be used in a close-tiled 2 x 2 array of 2x2 cm2 CZT detectors, each with 32x32 pixels. The DB-ASIC is attractive for a large scale implementation of tiled imaging CZT detectors given its low noise and power consumption (70uW/pixel). We are developing readout for the DB-ASIC that incorporates our back-end FPGA readout architecture developed for ProtoEXIST1 in order to accomplish the 256 cm2 detector module area with totally vertical integration (i.e. no auxialliary boards to the sides of the module. This is required to tile large numbers of modules into the very large total area (4.5m^2) proposed for the HET on EXIST. We review the design of the EXIST/HET and its optimum shielding in light of our ProtoEXIST1 balloon flight and our plan for future development of ProtoEXIST3, a final EXIST/HET detector module that would incorporate a still lower power version of the DB ASIC.

  14. 3D-HST: A WIDE-FIELD GRISM SPECTROSCOPIC SURVEY WITH THE HUBBLE SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Brammer, Gabriel B. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Van Dokkum, Pieter G.; Skelton, Rosalind E.; Nelson, Erica; Bezanson, Rachel; Leja, Joel; Lundgren, Britt [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbe, Ivo [Leiden Observatory, Leiden University, Leiden (Netherlands); Rix, Hans-Walter; Schmidt, Kasper B.; Da Cunha, Elisabete [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, 69117 Heidelberg (Germany); Kriek, Mariska [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Erb, Dawn K. [Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201 (United States); Fan, Xiaohui [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Foerster Schreiber, Natascha [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Illingworth, Garth D.; Magee, Dan, E-mail: gbrammer@eso.org [Astronomy Department, University of California, Santa Cruz, CA 95064 (United States); and others

    2012-06-01

    We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of {approx}7000 galaxies at 1 < z < 3.5, the epoch when {approx}60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin{sup 2}) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of {approx}5 per resolution element at H{sub 140} {approx} 23.1 and a 5{sigma} emission-line sensitivity of {approx}5 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} for typical objects, improving by a factor of {approx}2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 {mu}m at a spatial resolution of {approx}0.''13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of {sigma}(z) = 0.0034(1 + z), or {sigma}(v) Almost-Equal-To 1000 km s{sup -1}. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z {approx} 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys

  15. Compressive hyperspectral time-resolved wide-field fluorescence lifetime imaging

    Science.gov (United States)

    Pian, Qi; Yao, Ruoyang; Sinsuebphon, Nattawut; Intes, Xavier

    2017-07-01

    Spectrally resolved fluorescence lifetime imaging and spatial multiplexing have offered information content and collection-efficiency boosts in microscopy, but efficient implementations for macroscopic applications are still lacking. An imaging platform based on time-resolved structured light and hyperspectral single-pixel detection has been developed to perform quantitative macroscopic fluorescence lifetime imaging (MFLI) over a large field of view (FOV) and multiple spectral bands simultaneously. The system makes use of three digital micromirror device (DMD)-based spatial light modulators (SLMs) to generate spatial optical bases and reconstruct N by N images over 16 spectral channels with a time-resolved capability (∼40 ps temporal resolution) using fewer than N2 optical measurements. We demonstrate the potential of this new imaging platform by quantitatively imaging near-infrared (NIR) Förster resonance energy transfer (FRET) both in vitro and in vivo. The technique is well suited for quantitative hyperspectral lifetime imaging with a high sensitivity and paves the way for many important biomedical applications.

  16. Picosecond wide-field time-correlated single photon counting fluorescence microscopy with a delay line anode detector

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Le Marois, Alix; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Becker, Wolfgang; Smietana, Stefan [Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin (Germany); Milnes, James; Conneely, Thomas [Photek Ltd., 26 Castleham Rd, Saint Leonards-on-Sea TN38 9NS (United Kingdom); Jagutzki, Ottmar [Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany)

    2016-08-15

    We perform wide-field time-correlated single photon counting-based fluorescence lifetime imaging (FLIM) with a crossed delay line anode image intensifier, where the pulse propagation time yields the photon position. This microchannel plate-based detector was read out with conventional fast timing electronics and mounted on a fluorescence microscope with total internal reflection (TIR) illumination. The picosecond time resolution of this detection system combines low illumination intensity of microwatts with wide-field data collection. This is ideal for fluorescence lifetime imaging of cell membranes using TIR. We show that fluorescence lifetime images of living HeLa cells stained with membrane dye di-4-ANEPPDHQ exhibit a reduced lifetime near the coverslip in TIR compared to epifluorescence FLIM.

  17. Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles.

    Science.gov (United States)

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-12-13

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm(2) without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.

  18. Wide-field time-resolved luminescence imaging and spectroscopy to decipher obliterated documents in forensic science

    Science.gov (United States)

    Suzuki, Mototsugu; Akiba, Norimitsu; Kurosawa, Kenji; Kuroki, Kenro; Akao, Yoshinori; Higashikawa, Yoshiyasu

    2016-01-01

    We applied a wide-field time-resolved luminescence (TRL) method with a pulsed laser and a gated intensified charge coupled device (ICCD) for deciphering obliterated documents for use in forensic science. The TRL method can nondestructively measure the dynamics of luminescence, including fluorescence and phosphorescence lifetimes, which prove to be useful parameters for image detection. First, we measured the TRL spectra of four brands of black porous-tip pen inks on paper to estimate their luminescence lifetimes. Next, we acquired the TRL images of 12 obliterated documents at various delay times and gate times of the ICCD. The obliterated contents were revealed in the TRL images because of the difference in the luminescence lifetimes of the inks. This method requires no pretreatment, is nondestructive, and has the advantage of wide-field imaging, which makes it is easy to control the gate timing. This demonstration proves that TRL imaging and spectroscopy are powerful tools for forensic document examination.

  19. Design of refocusing system for a high-resolution space TDICCD camera with wide-field of view

    Science.gov (United States)

    Lv, Shiliang; Liu, Jinguo

    2015-10-01

    This paper describes the design and realization of a refocusing system for a space TDICCD camera of 2.2-meter focal length, which, features a three mirror anastigmatic(TMA) optical system along with 8 TDICCDs assemble at the focal plane, is high resolution and wide field of view. TDICCDs assemble is a kind of major method of acquiring wide field of view for space camera. In this way, the swath width reach 60km. First, the design of TMA optical system and its advantage of this space TDICCD camera was introduced; Then, the refocusing system as well as the technique of mechanical interleaving assemble for TDICCDs focal plane of this space camera was discussed in detail, At last, the refocusing system was measured. Experimental results indicated that the precision of the refocusing system is +/- 3.12μm(3σ), which satisfy the refocusing control system requirements of higher precision and stabilization.

  20. Status and Perspectives of the Mini-MegaTORTORA Wide-field Monitoring System with High Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Sergey Karpov

    2013-01-01

    Full Text Available Here we briefly summarize our long-term experience of constructing and operating wide-field monitoring cameras with sub-second temporal resolution to look for optical components of GRBs, fast-moving satellites and meteors. The general hardware requirements for these systems are discussed, along with algorithms for real-time detection and classification of various kinds of short optical transients. We also give a status report on the next generation, the MegaTORTORA multi-objective and transforming monitoring system, whose 6-channel (Mini-MegaTORTORA-Spain and 9-channel prototypes (Mini-MegaTORTORA-Kazan we have been building at SAO RAS. This system combines a wide field of view with subsecond temporal resolution in monitoring regime, and is able, within fractions of a second, to reconfigure itself to follow-up mode, which has better sensitivity and simultaneously provides multi-color and polarimetric information on detected transients.

  1. Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles

    Science.gov (United States)

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-12-01

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm2 without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.

  2. Searching for fast optical transients by means of a wide-field monitoring observations with high temporal resolution

    Science.gov (United States)

    Beskin, G.; Karpov, S.; Plokhotnichenko, V.; Bondar, S.; Ivanov, E.; Perkov, A.; Greco, G.; Guarnieri, A.; Bartolini, C.

    We discuss the strategy of search for fast optical transients accompanying gamma-ray bursts by means of continuous monitoring of wide sky fields with high temporal resolution. We describe the design, performance and results of our cameras, FAVOR and TORTORA. Also we discuss the perspectives of this strategy and possible design of next-generation equipment for wide-field monitoring which will be able to detect optical transients and to study their color and polarization properties with high time resolution.

  3. Obtaining Sub-uas Astrometry on a Wide-field, Coronagraph Equipped, Space Telescope Using a Diffractive Pupil

    Science.gov (United States)

    Bendek, Eduardo; Belikov, R.; Guyon, O.

    2013-01-01

    Detection and mass measurement of earth-size exoplanets using the astrometric signal of the host star requires sub-uas measurement precision. One major challenge in achieving this precision using medium-size space telescopes is the calibration of dynamic distortions. To solve this problem, we propose a diffractive pupil approach in which an array of dots on the primary mirror generates polychromatic diffraction spikes in the focal plane used to calibrate the distortions in the optical system. According to our simulations, this technique enables 0.2microarcsecond or better single-visit precision astrometric measurements on a 2.4m wide-field (>0.1deg2) space telescope. We present the laboratory results of the diffractive pupil concept performed at the University of Arizona, showing that this approach can calibrate dynamic distortion errors even for wide field applications. Also, this technique can be used simultaneously with a high-performance coronagraph to determine/constrain the masses, composition, atmospheric properties, and planetary system architectures. Numerical simulations and experiments performed at the NASA Ames ACE test bed have shown that the diffractive pupil does not affect the coronagraph performance. Finally, we assess the compatibility of a diffractive pupil telescope with a general astrophysics mission, showing that the spikes are too faint to impact wide field observations.

  4. Multimodal wide-field two-photon excitation imaging: characterization of the technique for in vivo applications.

    Science.gov (United States)

    Hwang, Jae Youn; Wachsmann-Hogiu, Sebastian; Ramanujan, V Krishnan; Nowatzyk, Andreas G; Koronyo, Yosef; Medina-Kauwe, Lali K; Gross, Zeev; Gray, Harry B; Farkas, Daniel L

    2011-01-13

    We report fast, non-scanning, wide-field two-photon fluorescence excitation with spectral and lifetime detection for in vivo biomedical applications. We determined the optical characteristics of the technique, developed a Gaussian flat-field correction method to reduce artifacts resulting from non-uniform excitation such that contrast is enhanced, and showed that it can be used for ex vivo and in vivo cellular-level imaging. Two applications were demonstrated: (i) ex vivo measurements of beta-amyloid plaques in retinas of transgenic mice, and (ii) in vivo imaging of sulfonated gallium(III) corroles injected into tumors. We demonstrate that wide-field two photon fluorescence excitation with flat-field correction provides more penetration depth as well as better contrast and axial resolution than the corresponding one-photon wide field excitation for the same dye. Importantly, when this technique is used together with spectral and fluorescence lifetime detection modules, it offers improved discrimination between fluorescence from molecules of interest and autofluorescence, with higher sensitivity and specificity for in vivo applications.

  5. Nova-like cataclysmic variables in the infrared

    Energy Technology Data Exchange (ETDEWEB)

    Hoard, D. W. [Eureka Scientific, Inc., Oakland, CA (United States); Long, Knox S. [Space Telescope Science Institute, Baltimore, MD (United States); Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA (United States); Wachter, Stefanie [Max Planck Institut für Astronomie, D-69117 Heidelberg (Germany); Brinkworth, Carolyn S. [Spitzer Science Center, California Institute of Technology, Pasadena, CA (United States); Knigge, Christian [Physics and Astronomy, University of Southampton, Southampton (United Kingdom); Drew, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield (United Kingdom); Szkody, Paula [Department of Astronomy, University of Washington, Seattle, WA (United States); Kafka, S. [Carnegie Institution of Washington, Department of Terrestrial Magnetism, Washington, DC (United States); Belle, Kunegunda [Los Alamos National Laboratory, Los Alamos, NM (United States); Ciardi, David R. [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA (United States); Froning, Cynthia S. [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO (United States); Van Belle, Gerard T. [Lowell Observatory, Flagstaff, AZ (United States); Pretorius, M. L., E-mail: hoard@mpia.de [Department of Physics, University of Oxford, Oxford (United Kingdom)

    2014-05-01

    Nova-like (NL) cataclysmic variables have persistently high mass transfer rates and prominent steady state accretion disks. We present an analysis of infrared observations of 12 NLs obtained from the Two Micron All Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer All Sky Survey. The presence of an infrared excess at λ ≳ 3-5 μm over the expectation of a theoretical steady state accretion disk is ubiquitous in our sample. The strength of the infrared excess is not correlated with orbital period, but shows a statistically significant correlation (but shallow trend) with system inclination that might be partially (but not completely) linked to the increasing view of the cooler outer accretion disk and disk rim at higher inclinations. We discuss the possible origin of the infrared excess in terms of emission from bremsstrahlung or circumbinary dust, with either mechanism facilitated by the mass outflows (e.g., disk wind/corona, accretion stream overflow, and so on) present in NLs. Our comparison of the relative advantages and disadvantages of either mechanism for explaining the observations suggests that the situation is rather ambiguous, largely circumstantial, and in need of stricter observational constraints.

  6. Wide-field flexible endoscope for simultaneous color and NIR fluorescence image acquisition during surveillance colonoscopy

    Science.gov (United States)

    García-Allende, P. Beatriz; Nagengast, Wouter B.; Glatz, Jürgen; Ntziachristos, Vasilis

    2013-03-01

    Colorectal cancer (CRC) is the third most common form of cancer and, despite recent declines in both incidence and mortality, it still remains the second leading cause of cancer-related deaths in the western world. Colonoscopy is the standard for detection and removal of premalignant lesions to prevent CRC. The major challenges that physicians face during surveillance colonoscopy are the high adenoma miss-rates and the lack of functional information to facilitate decision-making concerning which lesions to remove. Targeted imaging with NIR fluorescence would address these limitations. Tissue penetration is increased in the NIR range while the combination with targeted NIR fluorescent agents provides molecularly specific detection of cancer cells, i.e. a red-flag detection strategy that allows tumor imaging with optimal sensitivity and specificity. The development of a flexible endoscopic fluorescence imaging method that can be integrated with standard medical endoscopes and facilitates the clinical use of this potential is described in this work. A semi-disposable coherent fiber optic imaging bundle that is traditionally employed in the exploration of biliary and pancreatic ducts is proposed, since it is long and thin enough to be guided through the working channel of a traditional video colonoscope allowing visualization of proximal lesions in the colon. A custom developed zoom system magnifies the image of the proximal end of the imaging bundle to fill the dimensions of two cameras operating in parallel providing the simultaneous color and fluorescence video acquisition.

  7. SkICAT: A cataloging and analysis tool for wide field imaging surveys

    Science.gov (United States)

    Weir, N.; Fayyad, U. M.; Djorgovski, S. G.; Roden, J.

    1992-01-01

    We describe an integrated system, SkICAT (Sky Image Cataloging and Analysis Tool), for the automated reduction and analysis of the Palomar Observatory-ST ScI Digitized Sky Survey. The Survey will consist of the complete digitization of the photographic Second Palomar Observatory Sky Survey (POSS-II) in three bands, comprising nearly three Terabytes of pixel data. SkICAT applies a combination of existing packages, including FOCAS for basic image detection and measurement and SAS for database management, as well as custom software, to the task of managing this wealth of data. One of the most novel aspects of the system is its method of object classification. Using state-of-theart machine learning classification techniques (GID3* and O-BTree), we have developed a powerful method for automatically distinguishing point sources from non-point sources and artifacts, achieving comparably accurate discrimination a full magnitude fainter than in previous Schmidt plate surveys. The learning algorithms produce decision trees for classification by examining instances of objects classified by eye on both plate and higher quality CCD data. The same techniques will be applied to perform higher-level object classification (e.g., of galaxy morphology) in the near future. Another key feature of the system is the facility to integrate the catalogs from multiple plates (and portions thereof) to construct a single catalog of uniform calibration and quality down to the faintest limits of the survey. SkICAT also provides a variety of data analysis and exploration tools for the scientific utilization of the resulting catalogs. We include initial results of applying this system to measure the counts and distribution of galaxies in two bands down to Bj is approximately 21 mag over an approximate 70 square degree multi-plate field from POSS-II. SkICAT is constructed in a modular and general fashion and should be readily adaptable to other large-scale imaging surveys.

  8. A simple and rapid infrared-assisted self enzymolysis extraction method for total flavonoid aglycones extraction from Scutellariae Radix and mechanism exploration.

    Science.gov (United States)

    Wang, Liping; Duan, Haotian; Jiang, Jiebing; Long, Jiakun; Yu, Yingjia; Chen, Guiliang; Duan, Gengli

    2017-09-01

    A new, simple, and fast infrared-assisted self enzymolysis extraction (IRASEE) approach for the extraction of total flavonoid aglycones (TFA) mainly including baicalein, wogonin, and oroxylin A from Scutellariae Radix is presented to enhance extraction yield. Extraction enzymolysis temperature, enzymolysis liquid-to-solid ratio, enzymolysis pH, enzymolysis time and infrared power, the factors affecting IRASEE procedure, were investigated in a newly designed, temperature-controlled infrared-assisted extraction (TC-IRAE) system to acquire the optimum analysis conditions. The results illustrated that IRASEE possessed great advantages in terms of efficiency and time compared with other conventional extraction techniques. Furthermore, the mechanism of IRASEE was preliminarily explored by observing the microscopic change of the samples surface structures, studying the main chemical compositions change of the samples before and after extraction and investigating the kinetics and thermodynamics at three temperature levels during the IRASEE process. These findings revealed that IRASEE can destroy the surface microstructures to accelerate the mass transfer and reduce the activation energy to intensify the chemical process. This integrative study presents a simple, rapid, efficient, and environmental IRASEE method for TFA extraction which has promising prospects for other similar herbal medicines. Graphical Abstract ᅟ.

  9. Lensfree Fluorescent On-Chip Imaging of Transgenic Caenorhabditis elegans Over an Ultra-Wide Field-of-View

    Science.gov (United States)

    Ozcan, Aydogan

    2011-01-01

    We demonstrate lensfree on-chip fluorescent imaging of transgenic Caenorhabditis elegans (C. elegans) over an ultra-wide field-of-view (FOV) of e.g., >2–8 cm2 with a spatial resolution of ∼10µm. This is the first time that a lensfree on-chip platform has successfully imaged fluorescent C. elegans samples. In our wide-field lensfree imaging platform, the transgenic samples are excited using a prism interface from the side, where the pump light is rejected through total internal reflection occurring at the bottom facet of the substrate. The emitted fluorescent signal from C. elegans samples is then recorded on a large area opto-electronic sensor-array over an FOV of e.g., >2–8 cm2, without the use of any lenses, thin-film interference filters or mechanical scanners. Because fluorescent emission rapidly diverges, such lensfree fluorescent images recorded on a chip look blurred due to broad point-spread-function of our platform. To combat this resolution challenge, we use a compressive sampling algorithm to uniquely decode the recorded lensfree fluorescent patterns into higher resolution images, demonstrating ∼10 µm resolution. We tested the efficacy of this compressive decoding approach with different types of opto-electronic sensors to achieve a similar resolution level, independent of the imaging chip. We further demonstrate that this wide FOV lensfree fluorescent imaging platform can also perform sequential bright-field imaging of the same samples using partially-coherent lensfree digital in-line holography that is coupled from the top facet of the same prism used in fluorescent excitation. This unique combination permits ultra-wide field dual-mode imaging of C. elegans on a chip which could especially provide a useful tool for high-throughput screening applications in biomedical research. PMID:21253611

  10. Rapid wide-field Mueller matrix polarimetry imaging based on four photoelastic modulators with no moving parts.

    Science.gov (United States)

    Alali, Sanaz; Gribble, Adam; Vitkin, I Alex

    2016-03-01

    A new polarimetry method is demonstrated to image the entire Mueller matrix of a turbid sample using four photoelastic modulators (PEMs) and a charge coupled device (CCD) camera, with no moving parts. Accurate wide-field imaging is enabled with a field-programmable gate array (FPGA) optical gating technique and an evolutionary algorithm (EA) that optimizes imaging times. This technique accurately and rapidly measured the Mueller matrices of air, polarization elements, and turbid phantoms. The system should prove advantageous for Mueller matrix analysis of turbid samples (e.g., biological tissues) over large fields of view, in less than a second.

  11. ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

    Science.gov (United States)

    Camp, Jordan

    2012-01-01

    The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

  12. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode

    OpenAIRE

    Becker, Wolfgang; Hirvonen, Liisa; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-01-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ∼190 to 230 ps full width at hal...

  13. All sky coordination initiative, simple service for wide-field monitoring systems to cooperate in searching for fast optical transients

    Science.gov (United States)

    Karpov, S.; Sokołowski, M.; Gorbovskoy, E.

    Here we stress the necessity of cooperation between different wide-field monitoring projects (FAVOR/TORTORA, Pi of the Sky, MASTER, etc), aimed for independent detection of fast optical transients, in order to maximize the area of the sky covered at any moment and to coordinate the monitoring of gamma-ray telescopes' field of view. We review current solutions available for it and propose a simple protocol with dedicated service (ASCI) for such systems to share their current status and pointing schedules.

  14. Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Experimental Simulation of Micrometeoroid Capture

    Science.gov (United States)

    Price, M. C.; Kearsley, A. T.; Wozniakiewicz, P. J.; Spratt, J.; Burchell, M. J.; Cole, M. J.; Anz-Meador, P.; Liou, J. C.; Ross, D. K.; Opiela, J.; hide

    2014-01-01

    Hypervelocity impact features have been recognized on painted surfaces returned from the Hubble Space Telescope (HST). Here we describe experiments that help us to understand their creation, and the preservation of micrometeoroid (MM) remnants. We simulated capture of silicate and sulfide minerals on the Zinc orthotitanate (ZOT) paint and Al alloy plate of the Wide Field and Planetary Camera 2 (WFPC2) radiator, which was returned from HST after 16 years in low Earth orbit (LEO). Our results also allow us to validate analytical methods for identification of MM (and orbital debris) impacts in LEO.

  15. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  16. Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year

    Science.gov (United States)

    Nowomiejska, Katarzyna; Haszcz, Dariusz; Forlini, Cesare; Forlini, Matteo; Moneta-Wielgos, Joanna; Maciejewski, Ryszard; Zarnowski, Tomasz; Juenemann, Anselm G.

    2015-01-01

    Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP) using a wide-field Landers intraoperative temporary keratoprosthesis (TKP) in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity) and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure) were assessed during the follow-up (mean 16 months). Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor. PMID:26617994

  17. Wide-field retinal optical coherence tomography with wavefront sensorless adaptive optics for enhanced imaging of targeted regions.

    Science.gov (United States)

    Polans, James; Keller, Brenton; Carrasco-Zevallos, Oscar M; LaRocca, Francesco; Cole, Elijah; Whitson, Heather E; Lad, Eleonora M; Farsiu, Sina; Izatt, Joseph A

    2017-01-01

    The peripheral retina of the human eye offers a unique opportunity for assessment and monitoring of ocular diseases. We have developed a novel wide-field (>70°) optical coherence tomography system (WF-OCT) equipped with wavefront sensorless adaptive optics (WSAO) for enhancing the visualization of smaller (23°) retina. We demonstrated the ability of our WF-OCT system to acquire non wavefront-corrected wide-field images rapidly, which could then be used to locate regions of interest, zoom into targeted features, and visualize the same region at different time points. A pilot clinical study was conducted on seven healthy volunteers and two subjects with prodromal Alzheimer's disease which illustrated the capability to image Drusen-like pathologies as far as 32.5° from the fovea in un-averaged volume scans. This work suggests that the proposed combination of WF-OCT and WSAO may find applications in the diagnosis and treatment of ocular, and potentially neurodegenerative, diseases of the peripheral retina, including diabetes and Alzheimer's disease.

  18. Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year

    Directory of Open Access Journals (Sweden)

    Katarzyna Nowomiejska

    2015-01-01

    Full Text Available Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV and penetrating keratoplasty (PKP using a wide-field Landers intraoperative temporary keratoprosthesis (TKP in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure were assessed during the follow-up (mean 16 months. Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor.

  19. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    Science.gov (United States)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  20. AWARE Wide Field View

    Science.gov (United States)

    2016-04-29

    RGB colors to the standard sRGB to allow spectrally consistent colors on monitors for viewing . Finally, the images from each sensor are corrected based ...on the exposure time used and the calibrated sensitivity of each image sensor, again based on the flat field calibration, to allow viewing of imagery...prediction is scaled based on available bandwidth and the computational resources of the cluster. In addition to the interface described in the

  1. Fourier transform infrared spectral detection of life in polar subsurface environments and its application to Mars exploration.

    Science.gov (United States)

    Preston, Louisa J; Johnson, Diane; Cockell, Charles S; Grady, Monica M

    2015-09-01

    Cryptoendolithic lichen communities of the Dry Valleys, Antarctica, survive in an extremely inhospitable environment, finding refuge in microscopic niches where conditions suitable for life exist. Such "within-rock" communities may have evolved on Mars when conditions for life on the surface deteriorated to such an extent that they could no longer survive. Fourier transform infrared spectroscopy of unprepared whole-rock Antarctic Beacon sandstones was used to vertically profile molecular vibrations of fatty acids, proteins, and carboxylic acids created by endolithic communities. Spectral biosignatures were found localized to lichen-rich areas and were absent in crustal regions and the bulk rock substrate. These cryptoendolithic profiles will aid similar spectroscopic investigations of organic biosignatures during future Martian subsurface studies and will help in the identification of similar communities in other localities across the Earth.

  2. Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

    Science.gov (United States)

    Borders, Kareen; Mendez, B. M.

    2010-01-01

    K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance 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 Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

  3. CALIPSO Wide Field Camera (WFC) L1B Science 125 m Native Science Data V3-01

    Data.gov (United States)

    National Aeronautics and Space Administration — Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) was launched on April 28, 2006 to study the impact of clouds and aerosols on the Earth’s...

  4. CALIPSO Wide Field Camera (WFC) L1B Science 1 km Native Science Data V1-10

    Data.gov (United States)

    National Aeronautics and Space Administration — Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) was launched on April 28, 2006 to study the impact of clouds and aerosols on the Earth’s...

  5. CALIPSO Wide Field Camera (WFC) L1B Science 1 km Registered Science Data V3-02

    Data.gov (United States)

    National Aeronautics and Space Administration — Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) was launched on April 28, 2006 to study the impact of clouds and aerosols on the Earth’s...

  6. CALIPSO Wide Field Camera (WFC) L1B Science 1 km Registered Science Data V1-10

    Data.gov (United States)

    National Aeronautics and Space Administration — Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) was launched on April 28, 2006 to study the impact of clouds and aerosols on the Earth’s...

  7. CALIPSO Wide Field Camera (WFC) L1B Science 1 km Native Science Data V3-02

    Data.gov (United States)

    National Aeronautics and Space Administration — Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) was launched on April 28, 2006 to study the impact of clouds and aerosols on the Earth’s...

  8. Wide-Field Multi-Parameter FLIM: long-term minimal invasive observation of proteins in living cells.

    Science.gov (United States)

    Vitali, Marco; Picazo, Fernando; Prokazov, Yury; Duci, Alessandro; Turbin, Evgeny; Götze, Christian; Llopis, Juan; Hartig, Roland; Visser, Antonie J W G; Zuschratter, Werner

    2011-02-02

    Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the estimation accuracy of physical parameters at very low fluorescence signal levels approaching the lower bound theoretical limit. We demonstrate the efficiency of WFMP-FLIM by presenting two independent and relevant long-term experiments in cell biology: 1) FRET analysis of simultaneously recorded donor and acceptor fluorescence in living HeLa cells and 2) tracking of mitochondrial transport combined with fluorescence lifetime analysis in neuronal processes.

  9. A flexible wide-field FLIM endoscope utilising blue excitation light for label-free contrast of tissue.

    Science.gov (United States)

    Sparks, Hugh; Warren, Sean; Guedes, Joana; Yoshida, Nagisa; Charn, Tze Choong; Guerra, Nadia; Tatla, Taranjit; Dunsby, Christopher; French, Paul

    2015-01-01

    Fluorescence lifetime imaging (FLIM) has previously been shown to provide contrast between normal and diseased tissue. Here we present progress towards clinical and preclinical FLIM endoscopy of tissue autofluorescence, demonstrating a flexible wide-field endoscope that utilised a low average power blue picosecond laser diode excitation source and was able to acquire ∼mm-scale spatial maps of autofluorescence lifetimes from fresh ex vivo diseased human larynx biopsies in ∼8 seconds using an average excitation power of ∼0.5 mW at the specimen. To illustrate its potential for FLIM at higher acquisition rates, a higher power mode-locked frequency doubled Ti:Sapphire laser was used to demonstrate FLIM of ex vivo mouse bowel at up to 2.5 Hz using 10 mW of average excitation power at the specimen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Wide-field time-correlated single photon counting (TCSPC) microscopy with time resolution below the frame exposure time

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M. [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Petrášek, Zdeněk [Max Planck Institute of Biochemistry, Department of Cellular and Molecular Biophysics, Am Klopferspitz 18, D-82152 Martinsried (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2015-07-01

    Fast frame rate CMOS cameras in combination with photon counting intensifiers can be used for fluorescence imaging with single photon sensitivity at kHz frame rates. We show here how the phosphor decay of the image intensifier can be exploited for accurate timing of photon arrival well below the camera exposure time. This is achieved by taking ratios of the intensity of the photon events in two subsequent frames, and effectively allows wide-field TCSPC. This technique was used for measuring decays of ruthenium compound Ru(dpp) with lifetimes as low as 1 μs with 18.5 μs frame exposure time, including in living HeLa cells, using around 0.1 μW excitation power. We speculate that by using an image intensifier with a faster phosphor decay to match a higher camera frame rate, photon arrival time measurements on the nanosecond time scale could well be possible.

  11. KOALA: a wide-field 1000 element integral-field unit for the Anglo-Australian Telescope

    Science.gov (United States)

    Ellis, S. C.; Ireland, M.; Lawrence, J. S.; Tims, J.; Staszak, N.; Brzeski, J.; Parker, Q. A.; Sharp, R.; Bland-Hawthorn, J.; Case, S.; Colless, M.; Croom, S.; Couch, W.; De Marco, O.; Glazebrook, K.; Saunders, W.; Webster, R.; Zucker, D. B.

    2012-09-01

    KOALA, the Kilofibre Optimised Astronomical Lenslet Array, is a wide-field, high efficiency integral field unit being designed for use with the bench mounted AAOmega spectrograph on the AAT. KOALA will have 1000 fibres in a rectangular array with a selectable field of view of either 1390 or 430 sq. arcseconds with a spatial sampling of 1.25" or 0.7" respectively. To achieve this KOALA will use a telecentric double lenslet array with interchangeable fore-optics. The IFU will feed AAOmega via a 31m fibre run. The efficiency of KOALA is expected to be ≍ 52% at 3700A and ≍ 66% at 6563°Å with a throughput of > 52% over the entire wavelength range.

  12. Mini-Mega-TORTORA wide-field monitoring system with sub-second temporal resolution: first year of operation

    Science.gov (United States)

    Karpov, S.; Beskin, G.; Biryukov, A.; Bondar, S.; Ivanov, E.; Katkova, E.; Perkov, A.; Sasyuk, V.

    2016-12-01

    Here we present the summary of first years of operation and the first results of a novel 9-channel wide-field optical monitoring system with sub-second temporal resolution, Mini-Mega-TORTORA (MMT-9), which is in operation now at Special Astrophysical Observatory on Russian Caucasus. The system is able to observe the sky simultaneously in either wide (˜900 square degrees) or narrow (˜100 square degrees) fields of view, either in clear light or with any combination of color (Johnson-Cousins B, V or R) and polarimetric filters installed, with exposure times ranging from 0.1 s to hundreds of seconds. The real-time system data analysis pipeline performs automatic detection of rapid transient events, both near-Earth and extragalactic. The objects routinely detected by MMT include faint meteors and artificial satellites. The pipeline for a longer time scales variability analysis is still in development.

  13. VizieR Online Data Catalog: Wide-field spectrosc. survey of GCs in Virgo cluster (Ko+, 2017)

    Science.gov (United States)

    Ko, Y.; Hwang, H. S.; Lee, M. G.; Park, H. S.; Lim, S.; Sohn, J.; Jang, I. S.; Hwang, N.; Park, B.-G.

    2017-08-01

    We selected globular cluster (GC) candidates using the Next Generation Virgo Cluster Survey (NGVS; Ferrarese+ 2012ApJS..200....4F) archival images covering the central region of the Virgo cluster. The NGVS is a wide-field imaging survey of the Virgo cluster using MegaCam with a field of view of 1°x1° attached at the Canada-French-Hawaii Telescope. We carried out spectroscopic observation of GC candidates in the Virgo using the Hectospec mounted on the 6.5m Multiple-Mirror Telescope in queue mode under program ID 2014A-UAO-G18 (PI: Myung Gyoon Lee) between 2014 February and March (wavelength range: 3650Å to 9200Å). (3 data files).

  14. Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Microanalysis and Recognition of Micrometeoroid Compositions

    Science.gov (United States)

    Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; hide

    2014-01-01

    Postflight surveys of the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope have located hundreds of features on the 2.2 by 0.8 m curved plate, evidence of hypervelocity impact by small particles during 16 years of exposure to space in low Earth orbit (LEO). The radiator has a 100 - 200 micron surface layer of white paint, overlying 4 mm thick Al alloy, which was not fully penetrated by any impact. Over 460 WFPC2 samples were extracted by coring at JSC. About half were sent to NHM in a collaborative program with NASA, ESA and IBC. The structural and compositional heterogeneity at micrometer scale required microanalysis by electron and ion beam microscopes to determine the nature of the impactors (artificial orbital debris, or natural micrometeoroids, MM). Examples of MM impacts are described elsewhere. Here we describe the development of novel electron beam analysis protocols, required to recognize the subtle traces of MM residues.

  15. Micrometeoroid Impacts on the Hubble Sace Telescope Wide Field and Planetary Camera 2: Ion Beam Analysis of Subtle Impactor Traces

    Science.gov (United States)

    Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; hide

    2014-01-01

    Recognition of origin for particles responsible for impact damage on spacecraft such as the Hubble Space Telescope (HST) relies upon postflight analysis of returned materials. A unique opportunity arose in 2009 with collection of the Wide Field and Planetary Camera 2 (WFPC2) from HST by shuttle mission STS-125. A preliminary optical survey confirmed that there were hundreds of impact features on the radiator surface. Following extensive discussion between NASA, ESA, NHM and IBC, a collaborative research program was initiated, employing scanning electron microscopy (SEM) and ion beam analysis (IBA) to determine the nature of the impacting grains. Even though some WFPC2 impact features are large, and easily seen without the use of a microscope, impactor remnants may be hard to find.

  16. Evaluation of thermal infrared hyperspectral imagery for the detection of onshore methane plumes: Significance for hydrocarbon exploration and monitoring

    Science.gov (United States)

    Scafutto, Rebecca DeĺPapa Moreira; de Souza Filho, Carlos Roberto; Riley, Dean N.; de Oliveira, Wilson Jose

    2018-02-01

    Methane (CH4) is the main constituent of natural gas. Fugitive CH4 emissions partially stem from geological reservoirs (seepages) and leaks in pipelines and petroleum production plants. Airborne hyperspectral sensors with enough spectral and spatial resolution and high signal-to-noise ratio can potentially detect these emissions. Here, a field experiment performed with controlled release CH4 sources was conducted in the Rocky Mountain Oilfield Testing Center (RMOTC), Casper, WY (USA). These sources were configured to deliver diverse emission types (surface and subsurface) and rates (20-1450 scf/hr), simulating natural (seepages) and anthropogenic (pipeline) CH4 leaks. The Aerospace Corporation's SEBASS (Spatially-Enhanced Broadband Array Spectrograph System) sensor acquired hyperspectral thermal infrared data over the experimental site with 128 bands spanning the 7.6 μm-13.5 μm range. The data was acquired with a spatial resolution of 0.5 m at 1500 ft and 0.84 m at 2500 ft above ground level. Radiance images were pre-processed with an adaptation of the In-Scene Atmospheric Compensation algorithm and converted to emissivity through the Emissivity Normalization algorithm. The data was processed with a Matched Filter. Results allowed the separation between endmembers related to the spectral signature of CH4 from the background. Pixels containing CH4 signatures (absorption bands at 7.69 μm and 7.88 μm) were highlighted and the gas plumes mapped with high definition in the imagery. The dispersion of the mapped plumes is consistent with the wind direction measured independently during the experiment. Variations in the dimension of mapped gas plumes were proportional to the emission rate of each CH4 source. Spectral analysis of the signatures within the plumes shows that CH4 spectral absorption features are sharper and deeper in pixels located near the emitting source, revealing regions with higher gas density and assisting in locating CH4 sources in the field

  17. Deep wide-field imaging down to the oldest main sequence turn-offs in the Sculptor dwarf spheroidal galaxy

    Science.gov (United States)

    de Boer, T. J. L.; Tolstoy, E.; Saha, A.; Olsen, K.; Irwin, M. J.; Battaglia, G.; Hill, V.; Shetrone, M. D.; Fiorentino, G.; Cole, A.

    2011-04-01

    We present wide-field photometry of resolved stars in the nearby Sculptor dwarf spheroidal galaxy using CTIO/MOSAIC, going down to the oldest main sequence turn-off. The accurately flux calibrated wide field colour-magnitude diagrams can be used to constrain the ages of different stellar populations, and also their spatial distribution. The Sculptor dSph contains a predominantly ancient stellar population (>10 Gyr old) which can be easily resolved into individual stars. A galaxy dominated by an old population provides a clear view of ancient processes of galaxy formation unimpeded by overlying younger populations. By using spectroscopic metallicities of RGB stars in combination with our deep main sequence turn-off photometry we can constrain the ages of different stellar populations with particular accuracy. We find that the known metallicity gradient in Sculptor is well matched to an age gradient. This is the first time that this link with age has been directly quantified. This gradient has been previously observed as a variation in horizontal branch properties and is now confirmed to exist for main sequence turn-offs as well. It is likely the Sculptor dSph first formed an extended metal-poor population at the oldest times, and subsequent more metal-rich, younger stars were formed more towards the centre until the gas was depleted or lost roughly 7 Gyr ago. The fact that these clear radial gradients have been preserved up to the present day is consistent with the apparent lack of signs of recent tidal interactions. Appendices are only available in electronic form at http://www.aanda.org

  18. The exploration of monochromatic near-infrared LED improved anoxygenic photosynthetic bacteria Rhodopseudomonas sp. for wastewater treatment.

    Science.gov (United States)

    Qi, Xiang; Ren, Yiwei; Tian, Enling; Wang, Xingzu

    2017-10-01

    The future wastewater treatment requires high-efficiency and energy-saving technology. Anoxygenic photosynthetic bacteria (APB) is deemed as an eco-friendly microorganism, which could be employed in wastewater treatment. Here, monochromatic near-infrared (MNIR) light emitting diode (LED) was used, and three key factors (light quality, light intensity and photoperiod) of it were analyzed by a response surface methodology (RSM) in APB wastewater treatment. The results showed that light quality was the biggest impact factor in APB wastewater treatment, and nearly 58.07% of NH4+-N and 70.62% of chemical oxygen demand (COD) could be removed based on 46.4% of that theoretically possible. The light quality's study revealed that APB had the highest NH4+-N and COD removal, biomass production, and bacteriochlorophyll a production with 850nm IR LED. Moreover, the application of optimal MNIR LED could not only save energy, but also avoid algae bloom of photo-bioreactors (PBR). Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Understanding the interface between silicon-based materials and water: Molecular-dynamics exploration of infrared spectra

    Directory of Open Access Journals (Sweden)

    José A. Martinez-Gonzalez

    2017-11-01

    Full Text Available Molecular-dynamics simulations for silicon, hydrogen- and hydroxyl-terminated silicon in contact with liquid water, at 220 and 300 K, display water-density ‘ordering’ along the laboratory z-axis, emphasising the hydrophobicity of the different systems and the position of this first adsorbed layer. Density of states (DOS of the oxygen and proton velocity correlation functions (VACFs and infrared (IR spectra of the first monolayer of adsorbed water, calculated via Fourier transformation, indicate similarities to more confined, ice-like dynamical behaviour (redolent of ice. It was observed that good qualitative agreement is obtained between the DOS for this first layer in all systems. The DOS for the lower-frequency zone indicates that for the interface studied (i.e., the first layer near the surface, the water molecules try to organise in a similar form, and that this form is intermediate between liquid water and ice. For IR spectra, scrutiny of the position of the highest-intensity peaks for the stretching and bending bands indicate that such water molecules in the first solvating layer are organised in an intermediate fashion between ice and liquid water.

  20. Exploring the capability of wireless near infrared spectroscopy as a portable seizure detection device for epilepsy patients.

    Science.gov (United States)

    Jeppesen, Jesper; Beniczky, Sándor; Johansen, Peter; Sidenius, Per; Fuglsang-Frederiksen, Anders

    2015-03-01

    Near infrared spectroscopy (NIRS) has proved useful in measuring significant hemodynamic changes in the brain during epileptic seizures. The advance of NIRS-technology into wireless and portable devices raises the possibility of using the NIRS-technology for portable seizure detection. This study used NIRS to measure changes in oxygenated (HbO), deoxygenated (HbR), and total hemoglobin (HbT) at left and right side of the frontal lobe in 33 patients with epilepsy undergoing long-term video-EEG monitoring. Fifteen patients had 34 focal seizures (20 temporal-, 11 frontal-, 2 parietal-lobe, one unspecific) recorded and analyzed with NIRS. Twelve parameters consisting of maximum increase and decrease changes of HbO, HbR and HbT during seizures (1 min before- to 3 min after seizure-onset) for left and right side, were compared with the patients' own non-seizure periods (a 2-h period and a 30-min exercise-period). In both non-seizure periods 4 min moving windows with maximum overlapping were applied to find non-seizure maxima of the 12 parameters. Detection was defined as positive when seizure maximum change exceeded non-seizure maximum change. When analyzing the 12 parameters separately the positive seizure detection was in the range of 6-24%. The increase in hemodynamics was in general better at detecting seizures (15-24%) than the decrease in hemodynamics (6-18%) (P=0.02). NIRS did not seem to be a suitable technology for generic seizure detection given the device, settings, and methods used in this study. There are still several challenges to overcome before the NIRS-technology can be used as a home-monitoring seizure detection device. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  1. Exploring the Role of the Spatial Characteristics of Visible and Near-Infrared Reflectance in Predicting Soil Organic Carbon Density

    Directory of Open Access Journals (Sweden)

    Long Guo

    2017-10-01

    Full Text Available Soil organic carbon stock plays a key role in the global carbon cycle and the precision agriculture. Visible and near-infrared reflectance spectroscopy (VNIRS can directly reflect the internal physical construction and chemical substances of soil. The partial least squares regression (PLSR is a classical and highly commonly used model in constructing soil spectral models and predicting soil properties. Nevertheless, using PLSR alone may not consider soil as characterized by strong spatial heterogeneity and dependence. However, considering the spatial characteristics of soil can offer valuable spatial information to guarantee the prediction accuracy of soil spectral models. Thus, this study aims to construct a rapid and accurate soil spectral model in predicting soil organic carbon density (SOCD with the aid of the spatial autocorrelation of soil spectral reflectance. A total of 231 topsoil samples (0–30 cm were collected from the Jianghan Plain, Wuhan, China. The spectral reflectance (350–2500 nm was used as auxiliary variable. A geographically-weighted regression (GWR model was used to evaluate the potential improvement of SOCD prediction when the spatial information of the spectral features was considered. Results showed that: (1 The principal components extracted from PLSR have a strong relationship with the regression coefficients at the average sampling distance (300 m based on the Moran’s I values. (2 The eigenvectors of the principal components exhibited strong relationships with the absorption spectral features, and the regression coefficients of GWR varied with the geographical locations. (3 GWR displayed a higher accuracy than that of PLSR in predicting the SOCD by VNIRS. This study aimed to help people realize the importance of the spatial characteristics of soil properties and their spectra. This work also introduced guidelines for the application of GWR in predicting soil properties by VNIRS.

  2. Portable lensless wide-field microscopy imaging platform based on digital inline holography and multi-frame pixel super-resolution

    National Research Council Canada - National Science Library

    Antonio C Sobieranski; Fatih Inci; H Cumhur Tekin; Mehmet Yuksekkaya; Eros Comunello; Daniel Cobra; Aldo Von Wangenheim; Utkan Demirci

    2015-01-01

      In this paper, an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing...

  3. The Geminga pulsar wind nebula in the mid-infrared and submillimetre

    Science.gov (United States)

    Greaves, J. S.; Holland, W. S.

    2017-10-01

    The nearby middle-aged Geminga pulsar has crossed the Galactic plane within the last ∼0.1 Myr. We present archival data from Wide-field Infrared Survey Explorer and from SCUBA and SCUBA-2 on the James Clerk Maxwell Telescope to assess whether any mid-infrared and submillimetre emission arises from interaction of the pulsar wind nebula with the interstellar medium. A candidate shell and bow shock are reported. Given the low pulsar velocity and local density, dust grains appear able to penetrate into the nebula. A compact source seen towards the pulsar is fitted with a dust spectrum. If confirmed as a real association at higher resolution, this could be a circum-pulsar disc of at least a few Earth-masses, in which future planets could form.

  4. Exploring the vascular smooth muscle receptor landscape in vivo: ultrasound Doppler versus near-infrared spectroscopy assessments.

    Science.gov (United States)

    Ives, Stephen J; Fadel, Paul J; Brothers, R Matthew; Sander, Mikael; Wray, D Walter

    2014-03-01

    Ultrasound Doppler and near-infrared spectroscopy (NIRS) are routinely used for noninvasive monitoring of peripheral hemodynamics in both clinical and experimental settings. However, the comparative ability of these methodologies to detect changes in microvascular and whole limb hemodynamics during pharmacological manipulation of vascular smooth muscle receptors located at varied locations within the arterial tree is unknown. Thus, in 10 healthy subjects (25 ± 2 yr), changes in resting leg blood flow (ultrasound Doppler; femoral artery) and muscle oxygenation (oxyhemoglobin + oxymyoglobin; vastus lateralis) were simultaneously evaluated in response to intra-arterial infusions of phenylephrine (PE, 0.025-0.8 μg·kg(-1)·min(-1)), BHT-933 (2.5-40 μg·kg(-1)·min(-1)), and angiotensin II (ANG II, 0.5-8 ng·kg(-1)·min(-1)). All drugs elicited significant dose-dependent reductions in leg blood flow and oxyhemoglobin + oxymyoglobin. Significant relationships were found between ultrasound Doppler and NIRS changes across doses of PE (r(2) = 0.37 ± 0.08), BHT-933 (r(2) = 0.74 ± 0.06), and ANG II (r(2) = 0.68 ± 0.13), with the strongest relationships evident with agonists for receptors located preferentially "downstream" in the leg microcirculation (BHT-933 and ANG II). Analyses of drug potency revealed similar EC50 between ultrasound Doppler and NIRS measurements for PE (0.06 ± 0.02 vs. 0.10 ± 0.01), BHT-933 (5.0 ± 0.9 vs. 4.5 ± 1.3), and ANG II (1.4 ± 0.8 vs. 1.3 ± 0.3). These data provide evidence that both ultrasound Doppler and NIRS track pharmacologically induced changes in peripheral hemodynamics and are equally capable of determining drug potency. However, considerable disparity was observed between agonist infusions targeting different levels of the arterial tree, suggesting that receptor landscape is an important consideration for proper interpretation of hemodynamic monitoring with these methodologies.

  5. Use of thermal infrared remote sensing data for fisheries, environmental monitoring, oil and gas exploration, and ship routing.

    Science.gov (United States)

    Roffer, M. A.; Gawlikowski, G.; Muller-Karger, F.; Schaudt, K.; Upton, M.; Wall, C.; Westhaver, D.

    2006-12-01

    Thermal infrared (TIR) and ocean color remote sensing data (1.1 - 4.0 km) are being used as the primary data source in decision making systems for fisheries management, commercial and recreational fishing advisory services, fisheries research, environmental monitoring, oil and gas operations, and ship routing. Experience over the last 30 years suggests that while ocean color and other remote sensing data (e.g. altimetry) are important data sources, TIR presently yields the most useful data for studying ocean surface circulation synoptically on a daily basis. This is due primarily to the greater temporal resolution, but also due to one's better understanding of the dynamics of sea surface temperature compared with variations in ocean color and the spatial limitations of altimeter data. Information derived from commercial operations and research is being used to improve the operational efficiency of fishing vessels (e.g. reduce search time and increase catch rate) and to improve our understanding of the variations in catch distribution and rate needed to properly manage fisheries. This information is also being used by the oil and gas industry to minimize transit time and thus, save costs (e.g., tug charter, insurance), to increase production and revenue up to 500K dollars a day. The data are also be used to reduce the risk of equipment loss, loss of time and revenue to sudden and unexpected currents such as eddies. Sequential image analysis integrating TIR and ocean color provided near-real time, synoptic visualization of the rapid and wide dispersal of coastal waters from the northern Gulf of Mexico following Hurricanes Katrina and Rita in September 2005. The satellite data and analysis techniques have also been used to monitor the effects and movement of other potential environmentally damaging substances, such as dispersing nutrient enriched waste water offshore. A review of our experience in several commercial applications and research efforts will reinforce the

  6. Possible Influences on the Interpretation of Functional Domain (FD) Near-Infrared Spectroscopy (NIRS): An Explorative Study.

    Science.gov (United States)

    Celie, Bert M; Boone, Jan; Dumortier, Jasmien; Derave, Wim; De Backer, Tine; Bourgois, Jan G

    2016-02-01

    The influence of subcutaneous adipose tissue (ATT) and oxygen (O2) delivery has been poorly defined in frequency domain (FD) near-infrared spectroscopy (NIRS). Therefore, the aim of this study was to investigate the possible influence of these variables on all FD NIRS responses using a reliable protocol. Moreover, these influences were also investigated when using relative oxy- and deoxyhemoglobin and -myoglobin (oxy[Hb + Mb] and deoxy[Hb + Mb]) values (in %). A regression analysis was carried out for ATT and maximal-minimum oxy[Hb + Mb], deoxy[Hb + Mb], oxygen saturation (SmO2), and total hemoglobin (totHb) amplitudes during an incremental cyclic contraction protocol (ICCP) in a group of 45 participants. Moreover, the same analysis was carried out between subcutaneous ATT and the relative oxy- and deoxy[Hb + Mb] values (in %). In the second part of this study, a regression analysis was performed for peak forearm blood flow (FBF) during ICCP and the absolute and relative NIRS values in a group of 37 participants. Significant exponential correlation coefficients were found between ATT and deoxy[Hb + Mb] (r = 0.53; P < 0.001), oxy[Hb + Mb] (r = 0.57; P < 0.001), and SmO2 amplitudes (r = 0.57; P < 0.001). No significant relations were found between ATT and relative oxy[Hb + Mb] (r = 0.37; P = 0.07) and deoxy[Hb + Mb] (r = 0.09; P = 0.82). Significant positive correlation coefficients were found between force at exhaustion and maximal FBF (r = 0.66; P < 0.001), maximal differences in deoxy[Hb + Mb] (r = 0.353; P = 0.032) and totHb (r = 0.512; P = 0.002) while no significant correlation coefficients were found between these maximal force values and maximal differences in oxy[Hb + Mb] (r = -0.267; P = 0.111) and SmO2 (r = -0.267; P = 0.111). Significant linear correlation coefficients were found between FBF and deoxy[Hb + Mb] (r = 0.51; P

  7. Development of a Data Reduction Algorithm for Optical Wide Field Patrol (OWL II: Improving Measurement of Lengths of Detected Streaks

    Directory of Open Access Journals (Sweden)

    Sun-Youp Park

    2016-09-01

    Full Text Available As described in the previous paper (Park et al. 2013, the detector subsystem of optical wide-field patrol (OWL provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.

  8. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    Science.gov (United States)

    Renkoski, Timothy E.; Hatch, Kenneth D.; Utzinger, Urs

    2012-03-01

    With no sufficient screening test for ovarian cancer, a method to evaluate the ovarian disease state quickly and nondestructively is needed. The authors have applied a wide-field spectral imager to freshly resected ovaries of 30 human patients in a study believed to be the first of its magnitude. Endogenous fluorescence was excited with 365-nm light and imaged in eight emission bands collectively covering the 400- to 640-nm range. Linear discriminant analysis was used to classify all image pixels and generate diagnostic maps of the ovaries. Training the classifier with previously collected single-point autofluorescence measurements of a spectroscopic probe enabled this novel classification. The process by which probe-collected spectra were transformed for comparison with imager spectra is described. Sensitivity of 100% and specificity of 51% were obtained in classifying normal and cancerous ovaries using autofluorescence data alone. Specificity increased to 69% when autofluorescence data were divided by green reflectance data to correct for spatial variation in tissue absorption properties. Benign neoplasm ovaries were also found to classify as nonmalignant using the same algorithm. Although applied ex vivo, the method described here appears useful for quick assessment of cancer presence in the human ovary.

  9. THE LOW-FREQUENCY CHARACTERISTICS OF PSR J0437–4715 OBSERVED WITH THE MURCHISON WIDE-FIELD ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, N. D. R.; Ord, S. M.; Tremblay, S. E.; Tingay, S. J.; Oronsaye, S.; Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Deshpande, A. A. [Raman Research Institute, Bangalore 560080 (India); Van Straten, W.; Briggs, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Curtin University, Bentley, WA 6102 (Australia); Bernardi, G. [Square Kilometre Array South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Goeke, R.; Hewitt, J. N. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Greenhill, L. J.; Kasper, J. C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hazelton, B. J. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Kaplan, D. L. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States); and others

    2014-08-20

    We report on the detection of the millisecond pulsar PSR J0437–4715 with the Murchison Wide-field Array (MWA) at a frequency of 192 MHz. Our observations show rapid modulations of pulse intensity in time and frequency that arise from diffractive scintillation effects in the interstellar medium (ISM), as well as prominent drifts of intensity maxima in the time-frequency plane that arise from refractive effects. Our analysis suggests that the scattering screen is located at a distance of ∼80-120 pc from the Sun, in disagreement with a recent claim that the screen is closer (∼10 pc). Comparisons with higher frequency data from Parkes reveal a dramatic evolution of the pulse profile with frequency, with the outer conal emission becoming comparable in strength to that from the core and inner conal regions. As well as demonstrating the high time resolution science capabilities currently possible with the MWA, our observations underscore the potential to conduct low-frequency investigations of timing-array millisecond pulsars, which may lead to increased sensitivity in the detection of nanoHertz gravitational waves via the accurate characterization of ISM effects.

  10. Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars

    Science.gov (United States)

    Garling, Christopher; Willman, Beth; Sand, David J.; Hargis, Jonathan; Crnojević, Denija; Bechtol, Keith; Carlin, Jeffrey L.; Strader, Jay; Zou, Hu; Zhou, Xu; Nie, Jundan; Zhang, Tianmeng; Zhou, Zhimin; Peng, Xiyan

    2018-01-01

    We investigate the hypothesized tidal disruption of the Hercules ultra-faint dwarf galaxy (UFD). Previous tidal disruption studies of the Hercules UFD have been hindered by the high degree of foreground contamination in the direction of the dwarf. We bypass this issue by using RR Lyrae stars, which are standard candles with a very low field-volume density at the distance of Hercules. We use wide-field imaging from the Dark Energy Camera on CTIO to identify candidate RR Lyrae stars, supplemented with observations taken in coordination with the Beijing–Arizona Sky Survey on the Bok Telescope. Combining color, magnitude, and light-curve information, we identify three new RR Lyrae stars associated with Hercules. All three of these new RR Lyrae stars lie outside its published tidal radius. When considered with the nine RR Lyrae stars already known within the tidal radius, these results suggest that a substantial fraction of Hercules’ stellar content has been stripped. With this degree of tidal disruption, Hercules is an interesting case between a visibly disrupted dwarf (such as the Sagittarius dwarf spheroidal galaxy) and one in dynamic equilibrium. The degree of disruption also shows that we must be more careful with the ways we determine object membership when estimating dwarf masses in the future. One of the three discovered RR Lyrae stars sits along the minor axis of Hercules, but over two tidal radii away. This type of debris is consistent with recent models that suggest Hercules’ orbit is aligned with its minor axis.

  11. An experiment in big data: storage, querying and visualisation of data taken from the Liverpool Telescope's wide field cameras

    Science.gov (United States)

    Barnsley, R. M.; Steele, Iain A.; Smith, R. J.; Mawson, Neil R.

    2014-07-01

    The Small Telescopes Installed at the Liverpool Telescope (STILT) project has been in operation since March 2009, collecting data with three wide field unfiltered cameras: SkycamA, SkycamT and SkycamZ. To process the data, a pipeline was developed to automate source extraction, catalogue cross-matching, photometric calibration and database storage. In this paper, modifications and further developments to this pipeline will be discussed, including a complete refactor of the pipeline's codebase into Python, migration of the back-end database technology from MySQL to PostgreSQL, and changing the catalogue used for source cross-matching from USNO-B1 to APASS. In addition to this, details will be given relating to the development of a preliminary front-end to the source extracted database which will allow a user to perform common queries such as cone searches and light curve comparisons of catalogue and non-catalogue matched objects. Some next steps and future ideas for the project will also be presented.

  12. Development of digital system for the wide-field x-ray imaging detector aboard Kanazawa-SAT3

    Science.gov (United States)

    Kagawa, Yasuaki; Yonetoku, Daisuke; Sawano, Tatsuya; Mihara, Tatehiro; Kyutoku, Koutarou; Ikeda, Hirokazu; Yoshida, Kazuki; Ina, Masao; Ota, Kaichi; Suzuki, Daichi; Miyao, Kouga; Watanabe, Syouta; Hatori, Satoshi; Kume, Kyo; Mizushima, Satoshi; Hasegawa, Takashi

    2017-08-01

    We are planning to launch a micro satellite, Kanazawa-SAT3 , at the end of FY2018 to localize X-ray transients associated with gravitational wave sources. Now we are testing a prototype model of wide-field Xray imaging detector named T-LEX (Transient Localization EXperiment). T-LEX is an orthogonally distributed two sets of 1-dimensional silicon strip detectors with coded aperture masks, and covers more than 1 steradian field of view in the energy range of 1 - 20 keV. Each dimension has 512 readout electrodes (totally 1,024 channels), and they are read out with application specific integrated circuits (ASICs) controlled by two onboard FPGAs. Moreover, each FPGA calculates the cross correlation between the X-ray intensity and mask patterns every 64 msec, makes a histogram of lightcurves and energy spectra, and also plays a role of telemetry/command interface to mission CPU. In this paper, we report an overview of digital electronics system. Especially, we focus on the high-speed imaging processor on FPGA and demonstrate its performance as an X-ray imaging system.

  13. Gradient Permittivity Meta-Structure model for Wide-field Super-resolution imaging with a sub-45 nm resolution.

    Science.gov (United States)

    Cao, Shun; Wang, Taisheng; Xu, Wenbin; Liu, Hua; Zhang, Hongxin; Hu, Bingliang; Yu, Weixing

    2016-03-21

    A gradient permittivity meta-structure (GPMS) model and its application in super-resolution imaging were proposed and discussed in this work. The proposed GPMS consists of alternate metallic and dielectric films with a gradient permittivity which can support surface plasmons (SPs) standing wave interference patterns with a super resolution. By employing the rigorous numerical FDTD simulation method, the GPMS was carefully simulated to find that the period of the SPs interference pattern is only 84 nm for a 532 nm incident light. Furthermore, the potential application of the GPMS for wide-field super-resolution imaging was also discussed and the simulation results show that an imaging resolution of sub-45 nm can be achieved based on the plasmonic structure illumination microscopic method, which means a 5.3-fold improvement on resolution has been achieved in comparison with conventional epifluorescence microscopy. Moreover, besides the super-resolution imaging application, the proposed GPMS model can also be applied for nanolithography and other areas where super resolution patterns are needed.

  14. Wide field of view tabletop light field display based on piece-wise tracking and off-axis pickup

    Science.gov (United States)

    Zhu, Yanhong; Sang, Xinzhu; Yu, Xunbo; Wang, Peng; Xing, Shujun; Chen, Duo; Yan, Binbin; Wang, Kuiru; Yu, Chongxiu

    2017-11-01

    A wide field of view (FOV) tabletop light field display (LFD) based on piece-wise tracking and off-axis pickup is presented to display the floating three-dimensional (3D) scene, which is 360°surrounding viewable. The demonstrated LFD is specially designed with an integral imaging display (IID) with 83 × 83 viewpoints and a full-parallax holographic functional screen (HFS). To improve the FOV, a piece-wise tracking based FOV enhancement method is proposed. The relationship between the viewing zone and the elemental images (EIs) is formulated. A ray-tracing based method using off-axis pickup instead of parallel pickup directly is adopted to render the 3D scene to EIs. Then the piece-wise tracking method of varying the viewing zone by placing the EIs according to the position of viewer is analyzed. The floating 3D scene with a FOV of 70° × 70°is experimentally demonstrated with a good 3D perception.

  15. ON THE BINARY FREQUENCY OF THE LOWEST MASS MEMBERS OF THE PLEIADES WITH HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, E. V. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff (United States); Dupuy, Trent J. [The University of Texas at Austin, Department of Astronomy, 2515 Speedway C1400, Austin, TX 78712 (United States); Allers, Katelyn N. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Liu, Michael C. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Deacon, Niall R., E-mail: eugenio.v.garcia@gmail.com [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, AL1 5TL (United Kingdom)

    2015-05-01

    We present the results of a Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging survey of 11 of the lowest mass brown dwarfs in the Pleiades known (25–40 M{sub Jup}). These objects represent the predecessors to T dwarfs in the field. Using a semi-empirical binary point-spread function (PSF)-fitting technique, we are able to probe to 0.″ 03 (0.75 pixel), better than 2x the WFC3/UVIS diffraction limit. We did not find any companions to our targets. From extensive testing of our PSF-fitting method on simulated binaries, we compute detection limits which rule out companions to our targets with mass ratios of ≳0.7 and separations ≳4 AU. Thus, our survey is the first to attain the high angular resolution needed to resolve brown dwarf binaries in the Pleiades at separations that are most common in the field population. We constrain the binary frequency over this range of separation and mass ratio of 25–40 M{sub Jup} Pleiades brown dwarfs to be <11% for 1σ (<26% at 2σ). This binary frequency is consistent with both younger and older brown dwarfs in this mass range.

  16. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode.

    Science.gov (United States)

    Becker, Wolfgang; Hirvonen, Liisa M; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-09-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ∼190 to 230 ps full width at half maximum depending on the position on the photocathode. The position of the photon event is obtained from the pulse propagation time along the two delay lines, one in x and one in y. One end of a delay line is fed into the "start" input of the corresponding TCSPC board, and the other end is delayed by 40 ns and fed into the "stop" input. The time between start and stop is directly converted into position, with a resolution of 200-250 μm. The data acquisition software builds up the distribution of the photons over their spatial coordinates, x and y, and their times after the excitation pulses, typically into 512 × 512 pixels and 1024 time channels per pixel. We apply the system to fluorescence lifetime imaging of cells labelled with Alexa 488 phalloidin in an epi-fluorescence microscope and discuss the application of our approach to other fluorescence microscopy methods.

  17. Measuring galaxy [O ii] emission line doublet with future ground-based wide-field spectroscopic surveys

    Science.gov (United States)

    Comparat, Johan; Kneib, Jean-Paul; Bacon, Roland; Mostek, Nick J.; Newman, Jeffrey A.; Schlegel, David J.; Yèche, Christophe

    2013-11-01

    The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7 ≤ z ≤ 2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [Oii] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [Oii] (λλ 3727, 3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies for the choice of the resolution for future spectrographs for BAO surveys. For bright [Oii] emitter surveys ([Oii] flux ~30 × 10-17 erg cm-2 s-1 like SDSS-IV/eBOSS), a resolution of R ~ 3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [Oii] emitter surveys ([Oii] flux ~10 × 10-17 erg cm-2 s-1 like DESi), the detection improves continuously with resolution, so we recommend the highest possible resolution, the limit being given by the number of pixels (4k by 4k) on the detector and the number of spectroscopic channels (2 or 3).

  18. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode

    Science.gov (United States)

    Becker, Wolfgang; Hirvonen, Liisa M.; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-09-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ˜190 to 230 ps full width at half maximum depending on the position on the photocathode. The position of the photon event is obtained from the pulse propagation time along the two delay lines, one in x and one in y. One end of a delay line is fed into the "start" input of the corresponding TCSPC board, and the other end is delayed by 40 ns and fed into the "stop" input. The time between start and stop is directly converted into position, with a resolution of 200-250 μm. The data acquisition software builds up the distribution of the photons over their spatial coordinates, x and y, and their times after the excitation pulses, typically into 512 × 512 pixels and 1024 time channels per pixel. We apply the system to fluorescence lifetime imaging of cells labelled with Alexa 488 phalloidin in an epi-fluorescence microscope and discuss the application of our approach to other fluorescence microscopy methods.

  19. Argus+: The Future of Wide-Field, Spectral-Line Imaging at 3-mm with the Green Bank Telescope

    Science.gov (United States)

    Maddalena, Ronald; Frayer, David; Lockman, Felix; O'Neil, Karen; White, Steven; Argus+ Collaboration

    2018-01-01

    The Robert C Byrd Green Bank Telescope has met its design goal of providing high-quality observations at 115 GHz. Observers also have access to the new, 16-pixel, 3-mm Argus receiver, which is providing high-dynamic range images over wide fields for the multitude of spectral lines between 85 and 115 GHz, including CO, 13CO, C18O, SiO, HCN, HCO+, HNC, N2H+, and CS. The small number of pixels in Argus limits its ability to map many of the most interesting objects whose extent exceeds many arc-minutes. The successful performance of Argus, and its modular design, demonstrates that receivers with many more pixels could be built for the GBT. A 12 x 12 array of the Argus design would have mapping speeds about nine times faster than Argus without suffering any degradation in performance for the outer pixels in the array. We present our plans to build the next-generation Argus instrument (Argus+) with 144-pixels, a footprint 5’x5’, and 7" resolution at 110 GHz. The project will be a collaboration between the Green Bank Observatory and university groups, who will supply key components. The key science drivers for Argus+ are studies of molecular filaments in the Milky Way, studies of molecular clouds in nearby galaxies, and the observations of rapidly evolving solar system objects.

  20. Wide Field-of-View Fluorescence Imaging with Optical-Quality Curved Microfluidic Chamber for Absolute Cell Counting

    Directory of Open Access Journals (Sweden)

    Mohiuddin Khan Shourav

    2016-07-01

    Full Text Available Field curvature and other aberrations are encountered inevitably when designing a compact fluorescence imaging system with a simple lens. Although multiple lens elements can be used to correct most such aberrations, doing so increases system cost and complexity. Herein, we propose a wide field-of-view (FOV fluorescence imaging method with an unconventional optical-quality curved sample chamber that corrects the field curvature caused by a simple lens. Our optics simulations and proof-of-concept experiments demonstrate that a curved substrate with lens-dependent curvature can reduce greatly the distortion in an image taken with a conventional planar detector. Following the validation study, we designed a curved sample chamber that can contain a known amount of sample volume and fabricated it at reasonable cost using plastic injection molding. At a magnification factor of approximately 0.6, the curved chamber provides a clear view of approximately 119 mm2, which is approximately two times larger than the aberration-free area of a planar chamber. Remarkably, a fluorescence image of microbeads in the curved chamber exhibits almost uniform intensity over the entire field even with a simple lens imaging system, whereas the distorted boundary region has much lower brightness than the central area in the planar chamber. The absolute count of white blood cells stained with a fluorescence dye was in good agreement with that obtained by a commercially available conventional microscopy system. Hence, a wide FOV imaging system with the proposed curved sample chamber would enable us to acquire an undistorted image of a large sample volume without requiring a time-consuming scanning process in point-of-care diagnostic applications.

  1. THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R. E. Jr. [Physics Department, University of California, Davis, CA 95616 (United States); McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Cohen, S. H.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Hathi, N. P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Koekemoer, A. M.; Bond, H. E.; Bushouse, H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); O' Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Crockett, R. M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Disney, M. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia); Frogel, J. A. [Galaxies Unlimited, Lutherville, MD 21093 (United States); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A., E-mail: rryan@physics.ucdavis.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); and others

    2012-04-10

    We present the size evolution of passively evolving galaxies at z {approx} 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z {approx}> 1.5. We identify 30 galaxies in {approx}40 arcmin{sup 2} to H < 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 {mu}m {approx}< {lambda}{sub obs} {approx}< 1.6 {mu}m with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of {approx}0.033(1 + z). We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M{sub *} {approx} 10{sup 11} M{sub Sun }) undergo the strongest evolution from z {approx} 2 to the present. Parameterizing the size evolution as (1 + z){sup -{alpha}}, we find a tentative scaling of {alpha} Almost-Equal-To (- 0.6 {+-} 0.7) + (0.9 {+-} 0.4)log (M{sub *}/10{sup 9} M{sub Sun }), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of high-redshift systems. We discuss the implications of this result for the redshift evolution of the M{sub *}-R{sub e} relation for red galaxies.

  2. Outcome of universal newborn eye screening with wide-field digital retinal image acquisition system: a pilot study.

    Science.gov (United States)

    Goyal, P; Padhi, T R; Das, T; Pradhan, L; Sutar, S; Butola, S; Behera, U C; Jain, L; Jalali, S

    2017-07-24

    PurposeTo evaluate the outcome of universal newborn eye screening with wide-field digital retinal imaging (WFDRI) system.MethodsIn this pilot study, we examined 1152 apparently healthy newborn infants in the obstetrics and gynecology ward of a civil hospital in Eastern India over 1.5 years. The examination included external eye examination, red reflex test and fundus imaging by WFDRI (RetCam II, Clarity medical system, Pleasanton, CA, USA) by a trained optometrist. The pathologies detected, net monetary gain and skilled manpower saved were documented. The results were compared with three similar studies thus far published in the literature.ResultsOcular abnormality of any kind was seen in 172 (14.93%) babies. Retinal hemorrhage in 153 babies (88.9% of all abnormal findings) was the most common abnormality; it was bilateral in 118 (77.12%) babies and 4 babies had foveal hemorrhage. Other abnormalities included vitreous hemorrhage (n=1), congenital glaucoma (n=2), uveal coloboma (n=2), retinopathy mimicking retinopathy of prematurity (n=2), and cystic fovea (n=3). The retinal hemorrhages resolved spontaneously in all eyes. One baby with congenital glaucoma received surgery and the other was treated medically. The benefits included savings in skilled manpower, a net monetary gain of INR 4.195 million (US$ 62,612) and skilled manpower saving by 319.4 h.ConclusionsThe universal neonatal eye screening using WFDRI detected pathologies that needed immediate care or regular follow up; saved skilled manpower with a net monetary gain. But compared to a red reflex test the benefits were marginal in terms of detecting treatment warranting ocular pathologies.Eye advance online publication, 24 July 2017; doi:10.1038/eye.2017.129.

  3. Wide-field human photoreceptor morphological analysis using phase-resolved sensorless adaptive optics swept-source OCT (Conference Presentation)

    Science.gov (United States)

    Ju, Myeong Jin; Heisler, Morgan; Zawadzki, Robert J.; Bonora, Stefano; Jian, Yifan; Sarunic, Marinko V.

    2017-02-01

    Adaptive optics optical coherence tomography (AO-OCT) systems capable of 3D high resolution imaging have been applied to posterior eye imaging in order to resolve the fine morphological features in the retina. Human cone photoreceptors have been extensively imaged and studied for the investigation of retinal degeneration resulting in photoreceptor cell death. However, there are still limitations of conventional approaches to AO in the clinic, such as relatively small field-of-view (FOV) and the complexities in system design and operation. In this research, a recently developed phase-resolved Sensorless AO Swept Source based OCT (SAO-SS-OCT) system which is compact in size and easy to operate is presented. Owing to its lens-based system design, wide-field imaging can be performed up to 6° on the retina. A phase stabilization unit was integrated with the OCT system. With the phase stabilized OCT signal, we constructed retinal micro-vasculature image using a phase variance technique. The retinal vasculature image was used to align and average multiple OCT volumes acquired sequentially. The contrast-enhanced photoreceptor projection image was then extracted from the averaged volume, and analyzed based on its morphological features through a novel photoreceptor structure evaluation algorithm. The retinas of twelve human research subjects (10 normal and 2 pathological cases) were measured in vivo. Quantitative parameters used for evaluating the cone photoreceptor mosaic such as cell density, cell area, and mosaic regularity are presented and discussed. The SAO-SS-OCT system and the proposed photoreceptor evaluation method has significant potential to reveal early stage retinal diseases associated with retinal degeneration.

  4. Active optics and modified-Rumsey wide-field telescopes: MINITRUST demonstrators with vase- and tulip-form mirrors

    Science.gov (United States)

    Lemaître, Gérard R.; Montiel, Pierre; Joulié, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2005-12-01

    Wide-field astronomy requires the development of larger aperture telescopes. The optical properties of a three-mirror modified-Rumsey design provide significant advantages when compared to other telescope designs: (i) at any wavelength, the design has a flat field and is anastigmatic; (ii) the system is extremely compact, i.e., it is almost four times shorter than a Schmidt. Compared to the equally compact flat-field Ritchey-Chrétien with a doublet-lens corrector, as developed for the Sloan digital sky survey - and which requires the polishing of six optical surfaces - the proposed modified-Rumsey design requires only a two-surface polishing and provides a better imaging quality. All the mirrors are spheroids of the hyperboloid type. Starting from the classical Rumsey design, it is shown that the use of all eight available free parameters allows the simultaneous aspherization of the primary and tertiary mirrors by active optics methods from a single deformable substrate. The continuity conditions between the primary and the tertiary hyperbolizations are achieved by an intermediate narrow ring of constant thickness that is not optically used. After the polishing of a double vase form in a spherical shape, the primary-tertiary hyperbolizations are achieved by in situ stressing. The tulip-form secondary is hyperbolized by stress polishing. Other active optics alternatives are possible for a space telescope. The modified-Rumsey design is of interest for developing large space- and ground-based survey telescopes in UV, visible, or IR ranges, such as currently demonstrated with the construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° field of view. Double-pass optical tests show diffraction-limited images.

  5. A deep, wide-field study of Holmberg II with Suprime-Cam: evidence for ram pressure stripping

    Science.gov (United States)

    Bernard, Edouard J.; Ferguson, Annette M. N.; Barker, Michael K.; Irwin, Michael J.; Jablonka, Pascale; Arimoto, Nobuo

    2012-11-01

    We present a deep, wide-field optical study of the M81 group dwarf galaxy Holmberg II (HoII) based on Subaru/Suprime-Cam imaging. Individual stars are resolved down to I ˜ 25.2, that is, about 1.5 mag below the tip of the red giant branch (RGB). We use resolved star counts in the outskirts of the galaxy to measure the radial surface brightness profile down to μV ˜ 32 mag arcsec-2, from which we determine a projected exponential scalelength of 0.70 ± 0.01 arcmin (i.e. 0.69 ± 0.01 kpc). The composite profile, ranging from the cored centre out to R = 7 arcmin, is best fitted by an Elson-Fall-Freeman profile which gives a half-light radius of 1.41 ± 0.04 arcmin (i.e. 1.39 ± 0.04 kpc), and an absolute magnitude MV = -16.3. The low surface brightness stellar component of HoII is regular and symmetric and has an extent much smaller than the vast H I cloud in which it is embedded. We compare the spatial distribution of the young, intermediate-age and old stellar populations, and find that the old RGB stars are significantly more centrally concentrated than the young stellar populations, contrary to what is observed in most dwarf galaxies of the local Universe. We discuss these properties in the context of the comet-like distribution of H I gas around HoII, and argue for the presence of a hot intragroup medium in the vicinity of HoII to explain the contrasting morphologies of gas and stars. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  6. THE HUBBLE WIDE FIELD CAMERA 3 TEST OF SURFACES IN THE OUTER SOLAR SYSTEM: SPECTRAL VARIATION ON KUIPER BELT OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, Wesley C. [Herzberg Institute of Astrophysics, 5071 West Saanich Road Victoria, BC V9E 2E7 (Canada); Brown, Michael E. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91101 (United States); Glass, Florian, E-mail: wesley.fraser@nrc.ca [Observatoire de Genve, Universit de Genve, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland)

    2015-05-01

    Here, we present additional photometry of targets observed as part of the Hubble Wide Field Camera 3 (WFC3) Test of Surfaces in the Outer Solar System. Twelve targets were re-observed with the WFC3 in the optical and NIR wavebands designed to complement those used during the first visit. Additionally, all of the observations originally presented by Fraser and Brown were reanalyzed through the same updated photometry pipeline. A re-analysis of the optical and NIR color distribution reveals a bifurcated optical color distribution and only two identifiable spectral classes, each of which occupies a broad range of colors and has correlated optical and NIR colors, in agreement with our previous findings. We report the detection of significant spectral variations on five targets which cannot be attributed to photometry errors, cosmic rays, point-spread function or sensitivity variations, or other image artifacts capable of explaining the magnitude of the variation. The spectrally variable objects are found to have a broad range of dynamical classes and absolute magnitudes, exhibit a broad range of apparent magnitude variations, and are found in both compositional classes. The spectrally variable objects with sufficiently accurate colors for spectral classification maintain their membership, belonging to the same class at both epochs. 2005 TV189 exhibits a sufficiently broad difference in color at the two epochs that span the full range of colors of the neutral class. This strongly argues that the neutral class is one single class with a broad range of colors, rather than the combination of multiple overlapping classes.

  7. Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan, Sukrit; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Désert, Jean-Michel [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06511 (United States); Deming, Drake; Wilkins, Ashlee [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Mandell, Avi M., E-mail: sranjan@cfa.harvard.edu [NASA' s Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-04-20

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 μm) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 μm, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1σ precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1σ precision per bin corresponds to a planet-to-star flux ratio of 1.5 × 10{sup –4} and 2.1 × 10{sup –4} for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  8. Atmospheric Characterization of Five Hot Jupiters with the Wide Field Camera 3 on the Hubble Space Telescope

    Science.gov (United States)

    Ranjan, Sukrit; Charbonneau, David; Desert, Jean-Michel; Madhusudhan, Nikku; Deming, Drake; Wilkins, Ashlee; Mandell, Avi M.

    2014-01-01

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 micrometers) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 micrometers, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1s precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1 sigma precision per bin corresponds to a planet-to-star flux ratio of 1.5 x 10(exp -4) and 2.1 x 10(exp -4) for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  9. Infrared properties of blazars: putting the GASP-WEBT sources into context

    Science.gov (United States)

    Raiteri, C. M.; Villata, M.; Carnerero, M. I.; Acosta-Pulido, J. A.; Larionov, V. M.; D'Ammando, F.; Arévalo, M. J.; Arkharov, A. A.; Bueno Bueno, A.; Di Paola, A.; Efimova, N. V.; González-Morales, P. A.; Gorshanov, D. L.; Grinon-Marin, A. B.; Lázaro, C.; Manilla-Robles, A.; Pastor Yabar, A.; Puerto Giménez, I.; Velasco, S.

    2014-07-01

    The infrared properties of blazars can be studied from the statistical point of view with the help of sky surveys, like that provided by the Wide-field Infrared Survey Explorer and the Two Micron All Sky Survey. However, these sources are known for their strong and unpredictable variability, which can be monitored for a handful of objects only. In this paper, we consider the 28 blazars (14 BL Lac objects and 14 flat-spectrum radio quasars, FSRQs) that are regularly monitored by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope since 2007. They show a variety of infrared colours, redshifts, and infrared-optical spectral energy distributions (SEDs), and thus represent an interesting mini-sample of bright blazars that can be investigated in more detail. We present near-IR light curves and colours obtained by the GASP from 2007 to 2013, and discuss the infrared-optical SEDs. These are analysed with the aim of understanding the interplay among different emission components. BL Lac SEDs are accounted for by synchrotron emission plus an important contribution from the host galaxy in the closest objects, and dust signatures in 3C 66A and Mrk 421. FSRQ SEDs require synchrotron emission with the addition of a quasar-like contribution, which includes radiation from a generally bright accretion disc (νLν up to ˜4 × 1046 erg s-1), broad-line region, and a relatively weak dust torus.

  10. An Atlas of Galaxy Spectral Energy Distributions from the Ultraviolet to the Mid-infrared

    Science.gov (United States)

    Brown, Michael J. I.; Moustakas, John; Smith, J.-D. T.; da Cunha, Elisabete; Jarrett, T. H.; Imanishi, Masatoshi; Armus, Lee; Brandl, Bernhard R.; Peek, J. E. G.

    2014-06-01

    We present an atlas of 129 spectral energy distributions for nearby galaxies, with wavelength coverage spanning from the ultraviolet to the mid-infrared. Our atlas spans a broad range of galaxy types, including ellipticals, spirals, merging galaxies, blue compact dwarfs, and luminous infrared galaxies. We have combined ground-based optical drift-scan spectrophotometry with infrared spectroscopy from Spitzer and Akari with gaps in spectral coverage being filled using Multi-wavelength Analysis of Galaxy Physical Properties spectral energy distribution models. The spectroscopy and models were normalized, constrained, and verified with matched-aperture photometry measured from Swift, Galaxy Evolution Explorer, Sloan Digital Sky Survey, Two Micron All Sky Survey, Spitzer, and Wide-field Infrared Space Explorer images. The availability of 26 photometric bands allowed us to identify and mitigate systematic errors present in the data. Comparison of our spectral energy distributions with other template libraries and the observed colors of galaxies indicates that we have smaller systematic errors than existing atlases, while spanning a broader range of galaxy types. Relative to the prior literature, our atlas will provide improved K-corrections, photometric redshifts, and star-formation rate calibrations.

  11. Exploring frontal asymmetry using functional near-infrared spectroscopy: a preliminary study of the effects of social anxiety during interaction and performance tasks.

    Science.gov (United States)

    Tuscan, Lori-Ann; Herbert, James D; Forman, Evan M; Juarascio, Adrienne S; Izzetoglu, Meltem; Schultheis, Maria

    2013-06-01

    Preliminary studies examining brain function associated with social anxiety suggest the possibility of right-sided prefrontal activation associated with phobic stimulation. Although most existing neuroimaging techniques preclude participants from engaging in ecologically valid social tasks during assessment, functional near-infrared spectroscopy (fNIRS) is a promising new technique that permits such assessment. The present study investigated the utility of the fNIRS procedure and explored frontal asymmetry during in vivo social challenge tasks among female undergraduate students who scored in top and bottom percentiles on a social anxiety screening measure. Results revealed that participants in both groups experienced a significant increase in concentration of blood volume and oxygenated hemoglobin in the right hemisphere compared to the left hemisphere while giving a speech. Non-hemispheric effects were also observed. In addition, the high anxiety group showed a non-significant trend toward greater right frontal activity than the low anxiety group. This study highlights the utility of the fNIRS device in successfully assessing real-time changes in cerebrovascular response as a function of naturalistic social behavior, and supports the potential utility of this technology in the study of the neurophysiology of social anxiety.

  12. Exploring the neural basis of real-life joint action: measuring brain activation during joint table setting with functional near-infrared spectroscopy (fNIRS

    Directory of Open Access Journals (Sweden)

    Johanna eEgetemeir

    2011-09-01

    Full Text Available Many everyday life situations require two or more individuals to execute actions together. Assessing brain activation during naturalistic tasks to uncover relevant processes underlying such real-life joint action situations has remained a methodological challenge. In the present study, we introduce a novel joint action paradigm that enables the assessment of brain activation during real-life joint action tasks using functional near-infrared spectroscopy (fNIRS. We monitored brain activation of participants who coordinated complex actions with a partner sitting opposite them. Participants performed table-setting tasks, either alone (solo action or in cooperation with a partner (joint action, or they observed the partner performing the task (action observation. Comparing joint action and solo action revealed stronger activation (higher [oxy-Hb]-concentration during joint action in a number of areas. Among these were areas in the inferior parietal lobule (IPL that additionally showed an overlap of activation during action observation and solo action. Areas with such a close link between action observation and action execution have been associated with action simulation processes. The magnitude of activation in these IPL areas also varied according to joint action type and its respective demand on action simulation. The results validate fNIRS as an imaging technique for exploring the functional correlates of interindividual action coordination in real-life settings and suggest that coordinating actions in real-life situations requires simulating the actions of the partner.

  13. Infrared Photometric Properties of 709 Candidate Stellar Bowshock Nebulae

    Science.gov (United States)

    Kobulnicky, Henry A.; Schurhammer, Danielle P.; Baldwin, Daniel J.; Chick, William T.; Dixon, Don M.; Lee, Daniel; Povich, Matthew S.

    2017-11-01

    Arcuate infrared nebulae are ubiquitous throughout the Galactic Plane and are candidates for partial shells, bubbles, or bowshocks produced by massive runaway stars. We tabulate infrared photometry for 709 such objects using images from the Spitzer Space Telescope, the Wide-field Infrared Explorer, and the Herschel Space Observatory (HSO). Of the 709 objects identified at 24 or 22 μm, 422 are detected at the HSO 70 μm bandpass. Of these, only 39 are detected at HSO 160 μm. The 70 μm peak surface brightnesses are 0.5–2.5 Jy arcmin‑2. Color temperatures calculated from the 24 to 70 μm ratios range from 80 to 400 K. Color temperatures from 70 to 160 μm ratios are systematically lower, 40–200 K. Both of these temperature are, on average, 75% higher than the nominal temperatures derived by assuming that dust is in steady-state radiative equilibrium. This may be evidence of stellar wind bowshocks sweeping up and heating—possibly fragmenting but not destroying—interstellar dust. Infrared luminosity correlates with standoff distance, R 0, as predicted by published hydrodynamical models. Infrared spectral energy distributions are consistent with interstellar dust exposed to either single radiant energy density, U={10}3{--}{10}5 (in more than half of the objects) or a range of radiant energy densities U min = 25 to U max = 103–105 times the mean interstellar value for the remainder. Hence, the central OB stars dominate the energetics, making these enticing laboratories for testing dust models in constrained radiation environments. The spectral energy densities are consistent with polycyclic aromatic hydrocarbon fractions {q}{PAH}≲ 1 % in most objects.

  14. Wide-Field Survey around Local Group Dwarf Spheroidal Galaxy Leo II: Spatial Distribution of Stellar Content

    Science.gov (United States)

    Komiyama, Yutaka; Doi, Mamoru; Furusawa, Hisanori; Hamabe, Masaru; Imi, Katsumi; Kimura, Masahiko; Miyazaki, Satoshi; Nakata, Fumiaki; Okada, Norio; Okamura, Sadanori; Ouchi, Masami; Sekiguchi, Maki; Shimasaku, Kazuhiro; Yagi, Masafumi; Yasuda, Naoki

    2007-08-01

    We carried out a wide-field V, I imaging survey of the Local Group dwarf spheroidal galaxy Leo II using the Subaru Prime Focus Camera on the 8.2 m Subaru Telescope. The survey covered an area of 26.67×26.67 arcmin2, far beyond the tidal radius of Leo II (8.63'), down to the limiting magnitude of V~=26, which is roughly 1 mag deeper than the turnoff point of the main-sequence stars of Leo II. Radial number density profiles of bright and faint red giant branch (RGB) stars were found to change their slopes at around the tidal radius, and extend beyond the tidal radius with shallower slopes. A smoothed surface brightness map of Leo II suggests the existence of a small substructure (4×2.5 arcmin2, 270×170 pc 2 in physical size) of globular cluster luminosity beyond the tidal radius. We investigated the properties of the stellar population by means of a color-magnitude diagram. The horizontal branch (HB) morphology index shows a radial gradient in which red HB stars are more concentrated than blue HB stars, which is common to many Local Group dwarf spheroidal galaxies. The color distribution of RGB stars around the mean RGB sequence shows a larger dispersion at the center than in the outskirts, indicating a mixture of stellar populations at the center and a more homogeneous population in the outskirts. Based on the age estimation using subgiant branch stars, we found that although the major star formation took place ~8 Gyr ago, a considerable stellar population younger than 8 Gyr is found at the center; such a younger population is insignificant in the outskirts. The following star formation history is suggested for Leo II. Star-forming activity occurred more than ~8 Gyr ago throughout the galaxy at a modest star formation rate. The star-forming region gradually shrank from the outside toward the center, and star-forming activity finally dropped to ~0 by ~4 Gyr ago, except for the center, where a small population younger than 4 Gyr is present. Based on data collected

  15. Infrared Solar Physics

    Directory of Open Access Journals (Sweden)

    Matthew J. Penn

    2014-05-01

    Full Text Available The infrared solar spectrum contains a wealth of physical data about our Sun, and is explored using modern detectors and technology with new ground-based solar telescopes. The scientific motivation behind exploring these wavelengths is presented, along with a brief look at the rich history of observations here. Several avenues of solar physics research exploiting and benefiting from observations at infrared wavelengths from roughly 1000 nm to 12 400 nm are discussed, and the instrument and detector technology driving this research is briefly summarized. Finally, goals for future work at infrared wavelengths are presented in conjunction with ground and space-based observations.

  16. Robotic Anatrophic Nephrolithotomy Utilizing Near-infrared Fluorescence Image-guidance: Idea, Development, Exploration, Assessment, and Long-term Monitoring (IDEAL) Stage 0 Animal Model Study.

    Science.gov (United States)

    Sood, Akshay; Hemal, Ashok K; Assimos, Dean G; Peabody, James O; Menon, Mani; Ghani, Khurshid R

    2016-08-01

    To test the feasibility of robotic anatrophic nephrolithotomy (RANL) using near-infrared fluorescence (NIRF) image-guidance for treating staghorn stones, in an in vivo stone surgery model. We developed a novel technique of RANL in a preclinical setting following guidelines on safe surgical innovation from the Idea, Development, Exploration, Assessment, Long-term monitoring (IDEAL) collaborative. We performed 2 RANL procedures on 2 live Yorkshire porcine females (IDEAL stage 0 study). The robot was docked in the flank position and a mini-GelPOINT was placed periumbilically as an assistant port. A model staghorn "stone" was created in vivo by injecting low-viscosity DenMat precision material into the renal pelvis. NIRF image-guidance, following clamping of the posterior renal artery, was used to determine if an anatrophic plane could be identified. One procedure was assessed under cold ischemia, with ice-slush injected onto the renal surface via the mini-GelPOINT. Both porcine subjects underwent RANL successfully. Replica staghorn models could be created reliably (mean size 5.1 cm; solidification time 2-3 minutes). NIRF image-guidance afforded clear vascular demarcation for precise scoring of an anatrophic plane in both kidneys. The staghorn models were removed in toto through the anatrophic incision in both subjects. Mean blood loss was 160 cc. Mean console and ischemia times were 114 minutes and 34.5 minutes, respectively; ice-slush hypothermia led to a renal surface temperature of 15.4°C. In this IDEAL stage 0 preclinical study, we demonstrated that NIRF image-guidance is able to accurately identify the renal avascular plane, thus permitting an anatrophic approach for robotic excision of staghorn stones. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. A PANCHROMATIC CATALOG OF EARLY-TYPE GALAXIES AT INTERMEDIATE REDSHIFT IN THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 EARLY RELEASE SCIENCE FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Rutkowski, M. J.; Cohen, S. H.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Kaviraj, S.; Crockett, R. M.; Silk, J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); O' Connell, R. W. [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Hathi, N. P.; McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Ryan, R. E. Jr.; Koekemoer, A.; Bond, H. E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Kimble, R. A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Disney, M. J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Physics and Astronomy, The Australian National University, ACT 2611 (Australia); Frogel, J. A. [Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah (Saudi Arabia); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); and others

    2012-03-01

    In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 {approx}< z {approx}< 1.5, with each redshift spectroscopically confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and Advanced Camera for Surveys (ACS) GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broadband photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 10{sup 11} < M{sub *}[M{sub Sun }]<10{sup 12}. By transforming the observed photometry into the Galaxy Evolution Explorer FUV and NUV, Johnson V, and Sloan Digital Sky Survey g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V) = 3.5 and (NUV-V) = 3.3, with 1{sigma} standard deviations {approx_equal}1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent ({approx}<50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star formation episodes are activated, are discussed.

  18. ANALYZING STAR CLUSTER POPULATIONS WITH STOCHASTIC MODELS: THE HUBBLE SPACE TELESCOPE/WIDE FIELD CAMERA 3 SAMPLE OF CLUSTERS IN M83

    Energy Technology Data Exchange (ETDEWEB)

    Fouesneau, Morgan; Lancon, Ariane [Observatoire astronomique and CNRS UMR 7550, Universite de Strasbourg, Strasbourg (France); Chandar, Rupali [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States); Whitmore, Bradley C., E-mail: morgan.fouesneau@astro.u-strasbg.fr [Space Telescope Science Institute, Baltimore, MD (United States)

    2012-05-01

    The majority of clusters in the universe have masses well below 10{sup 5} M{sub Sun }. Hence, their integrated fluxes and colors can be affected by the presence or absence of a few bright stars introduced by stochastic sampling of the stellar mass function. Specific methods are being developed to extend the analysis of cluster energy distributions into the low-mass regime. In this paper, we apply such a method to real observations of star clusters, in the nearby spiral galaxy M83. We reassess the ages and masses of a sample of 1242 clusters for which UBVIH{alpha} fluxes were obtained from observations with the Wide Field Camera 3 instrument on board the Hubble Space Telescope. Synthetic clusters with known properties are used to characterize the limitations of the method (valid range and resolution in age and mass, method artifacts). The ensemble of color predictions of the discrete cluster models are in good agreement with the distribution of observed colors. We emphasize the important role of the H{alpha} data in the assessment of the fraction of young objects, particularly in breaking the age-extinction degeneracy that hampers an analysis based on UBVI data only. We find the mass distribution of the cluster sample to follow a power law of index -2.1 {+-} 0.2, and the distribution of ages a power law of index -1.0 {+-} 0.2 for log (M/ M{sub Sun }) > 3.5, and ages between 10{sup 7} and 10{sup 9} yr. An extension of our main method, which makes full use of the probability distributions of age and mass obtained for the individual clusters of the sample, is explored. It produces similar power-law slopes and will deserve further investigation. Although the properties derived for individual clusters significantly differ from those obtained with traditional, non-stochastic models in about 30% of the objects, the first-order aspect of the age and mass distributions is similar to those obtained previously for this M83 sample in the range of overlap of the studies. We

  19. Signal-to-noise characterization of time-gated intensifiers used for wide-field time-domain FLIM

    Energy Technology Data Exchange (ETDEWEB)

    McGinty, J; Requejo-Isidro, J; Munro, I; Talbot, C B; Dunsby, C; Neil, M A A; French, P M W [Photonics Group, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BW (United Kingdom); Kellett, P A; Hares, J D, E-mail: james.mcginty@imperial.ac.u [Kentech Instruments Ltd, Isis Building, Howbery Park, Wallingford, OX10 8BA (United Kingdom)

    2009-07-07

    Time-gated imaging using gated optical intensifiers provides a means to realize high speed fluorescence lifetime imaging (FLIM) for the study of fast events and for high throughput imaging. We present a signal-to-noise characterization of CCD-coupled micro-channel plate gated intensifiers used with this technique and determine the optimal acquisition parameters (intensifier gain voltage, CCD integration time and frame averaging) for measuring mono-exponential fluorescence lifetimes in the shortest image acquisition time for a given signal flux. We explore the use of unequal CCD integration times for different gate delays and show that this can improve the lifetime accuracy for a given total acquisition time.

  20. Simulations of the x-ray imaging capabilities of the silicon drift detectors (SDD) for the LOFT wide-field monitor

    DEFF Research Database (Denmark)

    Evangelista, Y.; Campana, R.; Del Monte, E.

    2012-01-01

    The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionize the study of compact objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. The Large Area...... Detector (LAD), carrying an unprecedented effective area of 10 m^2, is complemented by a coded-mask Wide Field Monitor, in charge of monitoring a large fraction of the sky potentially accessible to the LAD, to provide the history and context for the sources observed by LAD and to trigger its observations...

  1. Wide-field-of-view phase-contrast imaging of nanostructures with a comparatively large polychromatic soft x-ray plasma source.

    Science.gov (United States)

    Gasilov, S V; Faenov, A Ya; Pikuz, T A; Fukuda, Y; Kando, M; Kawachi, T; Skobelev, I Yu; Daido, H; Kato, Y; Bulanov, S V

    2009-11-01

    Polychromatic soft x-ray plasma sources were not previously considered to be among the sources suitable for the propagation based phase contrast imaging because of their comparatively large emission-zone size. In the current work a scheme based on the combination of soft x-ray emission of multicharged ions, generated by the interaction of femtosecond laser pulses with an ultrasonic jet of gas clusters, and an LiF crystal detector was used to obtain phase-enhanced high-resolution images of micro- and nanoscale objects in a wide field of view.

  2. An automated wide-field time-gated optically sectioning fluorescence lifetime imaging multiwell plate reader for high-content analysis of protein-protein interactions

    Science.gov (United States)

    Alibhai, Dominic; Kumar, Sunil; Kelly, Douglas; Warren, Sean; Alexandrov, Yuriy; Munro, Ian; McGinty, James; Talbot, Clifford; Murray, Edward J.; Stuhmeier, Frank; Neil, Mark A. A.; Dunsby, Chris; French, Paul M. W.

    2011-03-01

    We describe an optically-sectioned FLIM multiwell plate reader that combines Nipkow microscopy with wide-field time-gated FLIM, and its application to high content analysis of FRET. The system acquires sectioned FLIM images in protein. It has been applied to study the formation of immature HIV virus like particles (VLPs) in live cells by monitoring Gag-Gag protein interactions using FLIM FRET of HIV-1 Gag transfected with CFP or YFP. VLP formation results in FRET between closely packed Gag proteins, as confirmed by our FLIM analysis that includes automatic image segmentation.

  3. First Extended Catalogue of Galactic bubble infrared fluxes from WISE and Herschel surveys

    Science.gov (United States)

    Bufano, F.; Leto, P.; Carey, D.; Umana, G.; Buemi, C.; Ingallinera, A.; Bulpitt, A.; Cavallaro, F.; Riggi, S.; Trigilio, C.; Molinari, S.

    2018-01-01

    In this paper, we present the first extended catalogue of far-infrared fluxes of Galactic bubbles. Fluxes were estimated for 1814 bubbles, defined here as the 'golden sample', and were selected from the Milky Way Project First Data Release (Simpson et al.) The golden sample was comprised of bubbles identified within the Wide-field Infrared Survey Explorer (WISE) dataset (using 12- and 22-μm images) and Herschel data (using 70-, 160-, 250-, 350- and 500-μm wavelength images). Flux estimation was achieved initially via classical aperture photometry and then by an alternative image analysis algorithm that used active contours. The accuracy of the two methods was tested by comparing the estimated fluxes for a sample of bubbles, made up of 126 H II regions and 43 planetary nebulae, which were identified by Anderson et al. The results of this paper demonstrate that a good agreement between the two was found. This is by far the largest and most homogeneous catalogue of infrared fluxes measured for Galactic bubbles and it is a step towards the fully automated analysis of astronomical datasets.

  4. The Optical-infrared Extinction Curve and Its Variation in the Milky Way

    Science.gov (United States)

    Schlafly, E. F.; Meisner, A. M.; Stutz, A. M.; Kainulainen, J.; Peek, J. E. G.; Tchernyshyov, K.; Rix, H.-W.; Finkbeiner, D. P.; Covey, K. R.; Green, G. M.; Bell, E. F.; Burgett, W. S.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Magnier, E. A.; Martin, N. F.; Metcalfe, N.; Wainscoat, R. J.; Waters, C.

    2016-04-01

    The dust extinction curve is a critical component of many observational programs and an important diagnostic of the physics of the interstellar medium. Here we present new measurements of the dust extinction curve and its variation toward tens of thousands of stars, a hundred-fold larger sample than in existing detailed studies. We use data from the APOGEE spectroscopic survey in combination with ten-band photometry from Pan-STARRS1, the Two Micron All-Sky Survey, and Wide-field Infrared Survey Explorer. We find that the extinction curve in the optical through infrared is well characterized by a one-parameter family of curves described by R(V). The extinction curve is more uniform than suggested in past works, with σ (R(V))=0.18, and with less than one percent of sight lines having R(V)\\gt 4. Our data and analysis have revealed two new aspects of Galactic extinction: first, we find significant, wide-area variations in R(V) throughout the Galactic plane. These variations are on scales much larger than individual molecular clouds, indicating that R(V) variations must trace much more than just grain growth in dense molecular environments. Indeed, we find no correlation between R(V) and dust column density up to E(B-V)≈ 2. Second, we discover a strong relationship between R(V) and the far-infrared dust emissivity.

  5. Active optics and the axisymmetric case: MINITRUST wide-field three-reflection telescopes with mirrors aspherized from tulip and vase forms

    Science.gov (United States)

    Lemaitre, Gerard R.; Montiel, Pierre; Joulie, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2004-09-01

    Wide-field astronomy requires larger size telescopes. Compared to the catadioptric Schmidt, the optical properties of a three mirror telescope provides significant advantages. (1) The flat field design is anastigmatic at any wavelength, (2) the system is extremely compact -- four times shorter than a Schmidt -- and, (3) compared to a Schmidt with refractive corrector -- requiring the polishing of three optical surfaces --, the presently proposed Modified-Rumsey design uses all of eight available free parameters of a flat fielded anastigmatic three mirror telescope for mirrors generated by active optics methods. Compared to a Rumsey design, these parameters include the additional slope continuity condition at the primary-tertiary link for in-situ stressing and aspherization from a common sphere. Then, active optics allows the polishing of only two spherical surfaces: the combined primary-tertiary mirror and the secondary mirror. All mirrors are spheroids of the hyperboloid type. This compact system is of interest for space and ground-based astronomy and allows to built larger wide-field telescopes such as demonstrated by the design and construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° FOV, consisting of an in-situ stressed double vase form primary-tertiary and of a stress polished tulip form secondary. Optical tests of these telescopes, showing diffraction limited images, are presented.

  6. 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.

  7. Design of 1-μm-pitch liquid crystal spatial light modulators having dielectric shield wall structure for holographic display with wide field of view

    Science.gov (United States)

    Isomae, Yoshitomo; Shibata, Yosei; Ishinabe, Takahiro; Fujikake, Hideo

    2017-04-01

    In the development of electronic holographic displays with a wide field of view, one issue is the realization of 1-μm-pitch spatial light modulators (SLMs) using liquid crystal on silicon (LCOS) techniques. We clarified that it is necessary to suppress not only the leakage of fringe electric fields from adjacent pixels but also the effect of elastic forces in the liquid crystal to achieve full-phase modulation (2 π) in individual pixels. We proposed a novel LCOS-SLM with a dielectric shield wall structure, and achieved driving of individual 1-μm-pitch pixels. We also investigated the optimum values for width and dielectric constant of the wall structure when enlarging the area that can modulate light in the pixels. These results contribute to the design of 1-μm-pitch LCOS-SLM devices for wide-viewing-angle holographic displays.

  8. Chirped-pulse Fourier transform millimeter-wave spectroscopy of ten vibrationally excited states of i-propyl cyanide: exploring the far-infrared region.

    Science.gov (United States)

    Arenas, Benjamin E; Gruet, Sébastien; Steber, Amanda L; Giuliano, Barbara M; Schnell, Melanie

    2017-01-18

    We report here further spectroscopic investigation of the astrochemically relevant molecule i-propyl cyanide. We observed and analysed the rotational spectra of the ground state of the molecule and ten vibrationally excited states with energies between 180-500 cm(-1). For this, we used a segmented W-band spectrometer (75-110 GHz) and performed the experiments under room temperature conditions. This approach thus provides access to high-resolution, pure rotational data of vibrational modes that occur in the far-infrared fingerprint region, and that can be difficult to access with other techniques. The obtained, extensive data set will support further astronomical searches and identifications, such as in warmer regions of the interstellar space where contributions from vibrationally excited states become increasingly relevant.

  9. Green-to-red photoconvertible fluorescent proteins: tracking cell and protein dynamics on standard wide-field mercury arc-based microscopes

    Directory of Open Access Journals (Sweden)

    Buckheit Robert W

    2010-02-01

    Full Text Available Abstract Background Green fluorescent protein (GFP and other FP fusions have been extensively utilized to track protein dynamics in living cells. Recently, development of photoactivatable, photoswitchable and photoconvertible fluorescent proteins (PAFPs has made it possible to investigate the fate of discrete subpopulations of tagged proteins. Initial limitations to their use (due to their tetrameric nature were overcome when monomeric variants, such as Dendra, mEos, and mKikGR were cloned/engineered. Results Here, we report that by closing the field diaphragm, selective, precise and irreversible green-to-red photoconversion (330-380 nm illumination of discrete subcellular protein pools was achieved on a wide-field fluorescence microscope equipped with standard DAPI, Fluorescein, and Rhodamine filter sets and mercury arc illumination within 5-10 seconds. Use of a DAPI-filter cube with long-pass emission filter (LP420 allowed the observation and control of the photoconversion process in real time. Following photoconversion, living cells were imaged for up to 5 hours often without detectable phototoxicity or photobleaching. Conclusions We demonstrate the practicability of this technique using Dendra2 and mEos2 as monomeric, photoconvertible PAFP representatives fused to proteins with low (histone H2B, medium (gap junction channel protein connexin 43, and high (α-tubulin; clathrin light chain dynamic cellular mobility as examples. Comparable efficient, irreversible green-to-red photoconversion of selected portions of cell nuclei, gap junctions, microtubules and clathrin-coated vesicles was achieved. Tracking over time allowed elucidation of the dynamic live-cycle of these subcellular structures. The advantage of this technique is that it can be performed on a standard, relatively inexpensive wide-field fluorescence microscope with mercury arc illumination. Together with previously described laser scanning confocal microscope-based photoconversion

  10. Optomechanical design concept for GMACS: a wide-field multi-object moderate resolution optical spectrograph for the Giant Magellan Telescope (GMT)

    Science.gov (United States)

    Smee, Stephen A.; Prochaska, Travis; Shectman, Stephen A.; Hammond, Randolph P.; Barkhouser, Robert H.; DePoy, D. L.; Marshall, J. L.

    2012-09-01

    We describe the conceptual optomechanical design for GMACS, a wide-field, multi-object, moderate-resolution optical spectrograph for the Giant Magellan Telescope (GMT). GMACS is a candidate first-light instrument for the GMT and will be one of several instruments housed in the Gregorian Instrument Rotator (GIR) located at the Gregorian focus. The instrument samples a 9 arcminute x 18 arcminute field of view providing two resolution modes (i.e, low resolution, R ~ 2000, and moderate resolution, R ~ 4000) over a 3700 Å to 10200 Å wavelength range. To minimize the size of the optics, four fold mirrors at the GMT focal plane redirect the full field into four individual "arms", that each comprises a double spectrograph with a red and blue channel. Hence, each arm samples a 4.5 arcminute x 9 arcminute field of view. The optical layout naturally leads to three separate optomechanical assemblies: a focal plane assembly, and two identical optics modules. The focal plane assembly contains the last element of the telescope's wide-field corrector, slit-mask, tent-mirror assembly, and slit-mask magazine. Each of the two optics modules supports two of the four instrument arms and houses the aft-optics (i.e. collimators, dichroics, gratings, and cameras). A grating exchange mechanism, and articulated gratings and cameras facilitate multiple resolution modes. In this paper we describe the details of the GMACS optomechanical design, including the requirements and considerations leading to the design, mechanism details, optics mounts, and predicted flexure performance.

  11. Retinal Astrocytes and GABAergic Wide-Field Amacrine Cells Express PDGFRα: Connection to Retinal Ganglion Cell Neuroprotection by PDGF-AA.

    Science.gov (United States)

    Takahama, Shokichi; Adetunji, Modupe O; Zhao, Tantai; Chen, Shan; Li, Wei; Tomarev, Stanislav I

    2017-09-01

    Our previous experiments demonstrated that intravitreal injection of platelet-derived growth factor-AA (PDGF-AA) provides retinal ganglion cell (RGC) neuroprotection in a rodent model of glaucoma. Here we used PDGFRα-enhanced green fluorescent protein (EGFP) mice to identify retinal cells that may be essential for RGC protection by PDGF-AA. PDGFRα-EGFP mice expressing nuclear-targeted EGFP under the control of the PDGFRα promoter were used. Localization of PDGFRα in the neural retina was investigated by confocal imaging of EGFP fluorescence and immunofluorescent labeling with a panel of antibodies recognizing different retinal cell types. Primary cultures of mouse RGCs were produced by immunopanning. Neurobiotin injection of amacrine cells in a flat-mounted retina was used for the identification of EGFP-positive amacrine cells in the inner nuclear layer. In the mouse neural retina, PDGFRα was preferentially localized in the ganglion cell and inner nuclear layers. Immunostaining of the retina demonstrated that astrocytes in the ganglion cell layer and a subpopulation of amacrine cells in the inner nuclear layer express PDGFRα, whereas RGCs (in vivo or in vitro) did not. PDGFRα-positive amacrine cells are likely to be Type 45 gamma-aminobutyric acidergic (GABAergic) wide-field amacrine cells. These data indicate that the neuroprotective effect of PDGF-AA in a rodent model of glaucoma could be mediated by astrocytes and/or a subpopulation of amacrine cells. We suggest that after intravitreal injection of PDGF-AA, these cells secrete factors protecting RGCs.

  12. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

    Science.gov (United States)

    Poddar, Raju; Migacz, Justin V.; Schwartz, Daniel M.; Werner, John S.; Gorczynska, Iwona

    2017-10-01

    We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of view of 16 deg (5 mm×5 mm) and 30 deg (9 mm×9 mm). Data were presented in en face projections generated from single volumes and in en face projection mosaics generated from up to 4 datasets. OCTA imaging at 1.7 MHz A-scan rate was compared with results obtained from a commercial OCTA instrument and with conventional ophthalmic diagnostic methods: fundus photography, fluorescein, and indocyanine green angiography. Comparison of images obtained from all methods is demonstrated using the same eye of a healthy volunteer. For example, imaging of retinal pathology is presented in three cases of advanced age-related macular degeneration.

  13. Evaluation of Visunex Medical's PanoCam(TM) LT and PanoCam(TM) Pro wide-field imaging systems for the screening of ROP in newborn infants.

    Science.gov (United States)

    Wood, Edward H; Moshfeghi, Andrew A; Nudleman, Eric D; Moshfeghi, Darius M

    2016-08-01

    Retinopathy of Prematurity (ROP) is a leading cause of childhood blindness. The incidence of ROP is rising, placing greater demands on the healthcare providers that serve these patients and their families. Telemedicine remote digital fundus imaging (TM-RDFI) plays a pivotal role in ROP management, and has allowed for the expansion of ROP care into previously underserved areas. A broad literature review through the pubmed index was undertaken with the goal of summarizing the current state of ROP and guidelines for its screening . Furthermore, all currently used telemedicine remote digital fundus imaging devices were analyzed both via the literature and the companies' websites/brochures. Finally, the PanoCam LT™ and PanoCam™ Pro created by Visunex Medical were analyzed via the company website/brochures. Expert commentary: The PanoCam LT™ and PanoCam™ Pro have recently been approved for use within the USA and CE marked for international commercialization in European Union and other countries requiring CE mark. These wide-field imaging systems have the intended use of ophthalmic imaging of all newborn babies and meet the requirements for ROP screening, thereby serving as competition within the ROP screening market previously dominated by one camera imaging system.

  14. Reflection, phase and en- face sectional imaging of scattering objects using quasi-single-shot wide-field optical coherence tomography

    Science.gov (United States)

    Anna, Tulsi; Kimura, Satoshi; Mehta, Dalip Singh; Sato, Manabu

    2015-10-01

    We report a quasi-single-shot wide-field optical coherence tomography system that enables to measure the reflection, phase and en- face OCT images from the same setup using the glass jig. The jig consisting of a wedge glass substrate and a glue dot is contacted to the tissue surfaces, and the data within glue dot is used to reduce the phase noise of the interference signal. The reconstructed image size of the object was 4.0 mm × 4.3 mm. The standard deviation (STD) of the phase variation was minimized by 54 % and obtained to be 0.027 rad for the poke tissue. The corresponding STD in optical path length change was measured to be 1.4 nm. The refractive index of the water and poke tissue at the surface is also evaluated as 1.36 and 1.39, respectively, using reflection intensity images. Further, the en- face sectional images of the tissue sample are also measured.

  15. 3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology

    Science.gov (United States)

    Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Tankam, Patrice; Santhanam, Anand; Rolland, Jannick P.

    2017-02-01

    Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between numerical aperture and depth of focus, enabling advances in biotechnology. Furthermore, distortion-free imaging with no post-processing is achieved with a compact, lightweight handheld MEMS scanner that obtained a 12-fold reduction in volume and 17-fold reduction in weight over a previous dual-mirror galvanometer-based scanner. Approaching the holy grail of medical imaging - noninvasive real-time imaging with histologic resolution - GD-OCM demonstrates invariant resolution of 2 μm throughout a volume of 1 x 1 x 0.6 mm3, acquired and visualized in less than 2 minutes with parallel processing on graphics processing units. Results on the metrology of manufactured materials and imaging of human tissue with GD-OCM are presented.

  16. Noncontact and Wide-Field Characterization of the Absorption and Scattering Properties of Apple Fruit Using Spatial-Frequency Domain Imaging

    Science.gov (United States)

    Hu, Dong; Fu, Xiaping; He, Xueming; Ying, Yibin

    2016-12-01

    Spatial-frequency domain imaging (SFDI), as a noncontact, low-cost and wide-field optical imaging technique, offers great potential for agro-product safety and quality assessment through optical absorption (μa) and scattering (μ) property measurements. In this study, a laboratory-based SFDI system was constructed and developed for optical property measurement of fruits and vegetables. The system utilized a digital light projector to generate structured, periodic light patterns and illuminate test samples. The diffuse reflected light was captured by a charge coupled device (CCD) camera with the resolution of 1280 × 960 pixels. Three wavelengths (460, 527, and 630 nm) were selected for image acquisition using bandpass filters in the system. The μa and μ were calculated in a region of interest (ROI, 200 × 300 pixels) via nonlinear least-square fitting. Performance of the system was demonstrated through optical property measurement of ‘Redstar’ apples. Results showed that the system was able to acquire spatial-frequency domain images for demodulation and calculation of the μa and μ. The calculated μa of apple tissue experiencing internal browning (IB) were much higher than healthy apple tissue, indicating that the SFDI technique had potential for IB tissue characterization.

  17. A Wide-Field Fluorescence Microscope Extension for Ultrafast Screening of One-Bead One-Compound Libraries Using a Spectral Image Subtraction Approach.

    Science.gov (United States)

    Heusermann, Wolf; Ludin, Beat; Pham, Nhan T; Auer, Manfred; Weidemann, Thomas; Hintersteiner, Martin

    2016-05-09

    The increasing involvement of academic institutions and biotech companies in drug discovery calls for cost-effective methods to identify new bioactive molecules. Affinity-based on-bead screening of combinatorial one-bead one-compound libraries combines a split-mix synthesis design with a simple protein binding assay operating directly at the bead matrix. However, one bottleneck for academic scale on-bead screening is the unavailability of a cheap, automated, and robust screening platform that still provides a quantitative signal related to the amount of target protein binding to individual beads for hit bead ranking. Wide-field fluorescence microscopy has long been considered unsuitable due to significant broad spectrum autofluorescence of the library beads in conjunction with low detection sensitivity. Herein, we demonstrate how such a standard microscope equipped with LED-based excitation and a modern CMOS camera can be successfully used for selecting hit beads. We show that the autofluorescence issue can be overcome by an optical image subtraction approach that yields excellent signal-to-noise ratios for the detection of bead-associated target proteins. A polymer capillary attached to a semiautomated bead-picking device allows the operator to efficiently isolate individual hit beads in less than 20 s. The system can be used for ultrafast screening of >200,000 bead-bound compounds in 1.5 h, thereby making high-throughput screening accessible to a wider group within the scientific community.

  18. Self-Management of Patient Body Position, Pose, and Motion Using Wide-Field, Real-Time Optical Measurement Feedback: Results of a Volunteer Study

    Energy Technology Data Exchange (ETDEWEB)

    Parkhurst, James M. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Price, Gareth J., E-mail: gareth.price@christie.nhs.uk [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom); Sharrock, Phil J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Jackson, Andrew S.N. [Clinical Oncology, Southampton University Hospitals Foundation Trust, Southampton (United Kingdom); Stratford, Julie [Department of Radiotherapy, The Christie NHS Foundation Trust, Manchester (United Kingdom); Moore, Christopher J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom)

    2013-12-01

    Purpose: We present the results of a clinical feasibility study, performed in 10 healthy volunteers undergoing a simulated treatment over 3 sessions, to investigate the use of a wide-field visual feedback technique intended to help patients control their pose while reducing motion during radiation therapy treatment. Methods and Materials: An optical surface sensor is used to capture wide-area measurements of a subject's body surface with visualizations of these data displayed back to them in real time. In this study we hypothesize that this active feedback mechanism will enable patients to control their motion and help them maintain their setup pose and position. A capability hierarchy of 3 different level-of-detail abstractions of the measured surface data is systematically compared. Results: Use of the device enabled volunteers to increase their conformance to a reference surface, as measured by decreased variability across their body surfaces. The use of visual feedback also enabled volunteers to reduce their respiratory motion amplitude to 1.7 ± 0.6 mm compared with 2.7 ± 1.4 mm without visual feedback. Conclusions: The use of live feedback of their optically measured body surfaces enabled a set of volunteers to better manage their pose and motion when compared with free breathing. The method is suitable to be taken forward to patient studies.

  19. Reconsidering the advantages of the three-dimensional representation of the interferometric transform for imaging with non-coplanar baselines and wide fields of view

    Science.gov (United States)

    Smith, D. M. P.; Young, A.; Davidson, D. B.

    2017-07-01

    Radio telescopes with baselines that span thousands of kilometres and with fields of view that span tens of degrees have been recently deployed, such as the Low Frequency Array, and are currently being developed, such as the Square Kilometre Array. Additionally, there are proposals for space-based instruments with all-sky imaging capabilities, such as the Orbiting Low Frequency Array. Such telescopes produce observations with three-dimensional visibility distributions and curved image domains. In most work to date, the visibility distribution has been converted to a planar form to compute the brightness map using a two-dimensional Fourier transform. The celestial sphere is faceted in order to counter pixel distortion at wide angles, with each such facet requiring a unique planar form of the visibility distribution. Under the above conditions, the computational and storage complexities of this approach can become excessive. On the other hand, when using the direct Fourier transform approach, which maintains the three-dimensional shapes of the visibility distribution and celestial sphere, the non-coplanar visibility component requires no special attention. Furthermore, as the celestial samples are placed directly on the curved surface of the celestial sphere, pixel distortion at wide angles is avoided. In this paper, a number of examples illustrate that under these conditions (very long baselines and very wide fields of view) the costs of the direct Fourier transform may be comparable to (or even lower than) methods that utilise the two-dimensional fast Fourier transform.

  20. Wide-field color imaging of scatter-based tissue contrast using both high spatial frequency illumination and cross-polarization gating.

    Science.gov (United States)

    Carlson, Mackenzie L; McClatchy, David M; Gunn, Jason R; Elliott, Jonathan T; Paulsen, Keith D; Kanick, Stephen C; Pogue, Brian W

    2017-08-11

    This study characterizes the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross-polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi-illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide-field imaging. Measurements in tissue-simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter-only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter-based contrast achieved with HSF, CP and HSF-CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter-based contrast within images of tissue. The results suggest that visible CP-HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The Fifteen-Year Attitude History of the Wide Field Planetary Camera 2 Radiator and Collection Efficiencies for Micrometeoroids and Orbital Debris

    Science.gov (United States)

    Anz-Meador, Phillip D.; Liou, Jer-Chyi; Cooke, William J.; Koehler, H.

    2010-01-01

    An examination of the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC-2) radiator assembly was conducted at NASA Goddard Space Flight Center (GSFC) during the summer of 2009. Immediately apparent was a distinct biasing of the largest 45 impact features towards one side of the radiator, in contrast to an approximately uniform distribution of smaller impacts. Such a distribution may be a consequence of the HST s attitude history and pointing requirements for the cold radiator, or of environmental effects, such as an anisotropic distribution of the responsible population in that size regime. Understanding the size-dependent spatial distribution of impact features is essential to the general analysis of these features. We have obtained from GSFC a 15 minute temporal resolution record of the state vector (Earth Centered Inertial position and velocity) and HST attitude, consisting of the orientation of the velocity and HST-sun vectors in HST body coordinates. This paper reviews the actual state vector and attitude history of the radiator in the context of the randomly tumbling plate assumption and assesses the statistical likelihood (or collection efficiency) of the radiator for the micrometeoroid and orbital debris environments. The NASA Marshall Space Flight Center s Meteoroid Environment Model is used to assess the micrometeoroid component. The NASA Orbital Debris Engineering Model (ORDEM) is used to model the orbital debris component. Modeling results are compared with observations of the impact feature spatial distribution, and the relative contribution of each environmental component are examined in detail.

  2. Lensfree optofluidic plasmonic sensor for real-time and label-free monitoring of molecular binding events over a wide field-of-view

    Science.gov (United States)

    Coskun, Ahmet F.; Cetin, Arif E.; Galarreta, Betty C.; Alvarez, Daniel Adrianzen; Altug, Hatice; Ozcan, Aydogan

    2014-01-01

    We demonstrate a high-throughput biosensing device that utilizes microfluidics based plasmonic microarrays incorporated with dual-color on-chip imaging toward real-time and label-free monitoring of biomolecular interactions over a wide field-of-view of >20 mm2. Weighing 40 grams with 8.8 cm in height, this biosensor utilizes an opto-electronic imager chip to record the diffraction patterns of plasmonic nanoapertures embedded within microfluidic channels, enabling real-time analyte exchange. This plasmonic chip is simultaneously illuminated by two different light-emitting-diodes that are spectrally located at the right and left sides of the plasmonic resonance mode, yielding two different diffraction patterns for each nanoaperture array. Refractive index changes of the medium surrounding the near-field of the nanostructures, e.g., due to molecular binding events, induce a frequency shift in the plasmonic modes of the nanoaperture array, causing a signal enhancement in one of the diffraction patterns while suppressing the other. Based on ratiometric analysis of these diffraction images acquired at the detector-array, we demonstrate the proof-of-concept of this biosensor by monitoring in real-time biomolecular interactions of protein A/G with immunoglobulin G (IgG) antibody. For high-throughput on-chip fabrication of these biosensors, we also introduce a deep ultra-violet lithography technique to simultaneously pattern thousands of plasmonic arrays in a cost-effective manner. PMID:25346102

  3. Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation

    Directory of Open Access Journals (Sweden)

    Whitney Susan L

    2004-12-01

    Full Text Available Abstract Background Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. Methods Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. Results The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. Conclusion The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation.

  4. Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation.

    Science.gov (United States)

    Sparto, Patrick J; Whitney, Susan L; Hodges, Larry F; Furman, Joseph M; Redfern, Mark S

    2004-12-23

    BACKGROUND: Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. METHODS: Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. RESULTS: The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. CONCLUSION: The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation.

  5. A Panchromatic Catalog of Early-type Galaxies at Intermediate Redshift in the Hubble Space Telescope Wide Field Camera 3 Early Release Science Field

    Science.gov (United States)

    Rutkowski, M. J.; Cohen, S. H.; Kaviraj, S.; O'Connell, R. W.; Hathi, N. P.; Windhorst, R. A.; Ryan, R. E., Jr.; Crockett, R. M.; Yan, H.; Kimble, R. A.; Silk, J.; McCarthy, P. J.; Koekemoer, A.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; Holtzman, J. A.; Paresce, F.; Saha, A.; Trauger, J. T.; Walker, A. R.; Whitmore, B. C.; Young, E. T.

    2012-03-01

    In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 lsim z lsim 1.5, with each redshift spectroscopically confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and Advanced Camera for Surveys (ACS) GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broadband photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 1011 publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star formation episodes are activated, are discussed.

  6. THE FLAT TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ1214b FROM WIDE FIELD CAMERA 3 ON THE HUBBLE SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Berta, Zachory K.; Charbonneau, David; Desert, Jean-Michel; Irwin, Jonathan [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Miller-Ricci Kempton, Eliza; Fortney, Jonathan J.; Nutzman, Philip [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); McCullough, Peter R. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Burke, Christopher J. [SETI Institute/NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Homeier, Derek, E-mail: zberta@cfa.harvard.edu [Centre de Recherche Astrophysique de Lyon, UMR 5574, CNRS, Universite de Lyon, Ecole Normale Superieure de Lyon, F-69364 Lyon Cedex 07 (France)

    2012-03-01

    Capitalizing on the observational advantage offered by its tiny M dwarf host, we present Hubble Space Telescope/Wide Field Camera 3 (WFC3) grism measurements of the transmission spectrum of the super-Earth exoplanet GJ1214b. These are the first published WFC3 observations of a transiting exoplanet atmosphere. After correcting for a ramp-like instrumental systematic, we achieve nearly photon-limited precision in these observations, finding the transmission spectrum of GJ1214b to be flat between 1.1 and 1.7 {mu}m. Inconsistent with a cloud-free solar composition atmosphere at 8.2{sigma}, the measured achromatic transit depth most likely implies a large mean molecular weight for GJ1214b's outer envelope. A dense atmosphere rules out bulk compositions for GJ1214b that explain its large radius by the presence of a very low density gas layer surrounding the planet. High-altitude clouds can alternatively explain the flat transmission spectrum, but they would need to be optically thick up to 10 mbar or consist of particles with a range of sizes approaching 1 {mu}m in diameter.

  7. Optimizing ultrafast wide field-of-view illumination for high-throughput multi-photon imaging and screening of mutant fluorescent proteins

    Science.gov (United States)

    Stoltzfus, Caleb; Mikhailov, Alexandr; Rebane, Aleksander

    2017-02-01

    Fluorescence induced by 1wo-photon absorption (2PA) and three-photon absorption (3PA) is becoming an increasingly important tool for deep-tissue microscopy, especially in conjunction with genetically-encoded functional probes such as fluorescent proteins (FPs). Unfortunately, the efficacy of the multi-photon excitation of FPs is notoriously low, and because relations between a biological fluorophore's nonlinear-optical properties and its molecular structure are inherently complex, there are no practical avenues available that would allow boosting the performance of current FPs. Here we describe a novel method, where we apply directed evolution to optimize the 2PA properties of EGFP. Key to the success of this approach consists in high-throughput screening of mutants that would allow selection of variants with promising 2PA and 3PA properties in a broad near-IR excitation range of wavelength. For this purpose, we construct and test a wide field-of-view (FOV), femtosecond imaging system that we then use to quantify the multi-photon excited fluorescence in the 550- 1600 nm range of tens of thousands of E. coli colonies expressing randomly mutated FPs in a standard 10 cm diameter Petri dish configuration. We present a quantitative analysis of different factors that are currently limiting the maximum throughput of the femtosecond multi-photon screening techniques and also report on quantitative measurement of absolute 2PA and 3PA cross sections spectra.

  8. Globular Cluster Photometry with the Hubble Space Telescope. VII. Color Gradients and Blue Stragglers in the Central Region of M30 from Wide Field Planetary Camera 2 Observations

    Science.gov (United States)

    Guhathakurta, Puragra; Webster, Zodiac T.; Yanny, Brian; Schneider, Donald P.; Bahcall, John N.

    1998-10-01

    We present F555W (V), F439W (B), and F336W (U) photometry of 9507 stars in the central 2' of the dense, post-core-collapse cluster M30 (NGC 7099) derived from Hubble Space Telescope Wide Field Planetary Camera 2 images. These data are used to study the mix of stellar populations in the central region of the cluster. Forty-eight blue straggler stars are identified; they are found to be strongly concentrated toward the cluster center. The specific frequency of blue stragglers, F_BSS = N(BSS)/N(V responsible for about half of the observed color gradient; the rest of the gradient is caused by the relative underabundance of faint red main-sequence stars near the cluster center (presumably a result of mass segregation). The luminosity function of M30's evolved stars does not match the luminosity function shape derived from standard stellar evolutionary models: the ratio of the number of bright giants to the number of turnoff stars in the cluster is 30% higher than predicted by the model (3.8 sigma effect), roughly independent of red giant brightness over the range M_V = -2 to +2. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Lick Observatory Bulletin No. 1377.

  9. On the Incidence of Wise Infrared Excess Among Solar Analog, Twin, and Sibling Stars

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, A. D.; Martins, B. L. Canto; Lima Jr, J. E.; Silva, D. Freire da; Medeiros, J. R. De [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Campus Universitário, Natal, RN, 59072-970 (Brazil); Leão, I. C. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Freitas, D. B. de, E-mail: dgerson@fisica.ufrn.br [Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-900, Fortaleza, Ceará (Brazil)

    2017-03-01

    This study presents a search for infrared (IR) excess in the 3.4, 4.6, 12, and 22 μ m bands in a sample of 216 targets, composed of solar sibling, twin, and analog stars observed by the Wide-field Infrared Survey Explorer ( WISE ) mission. In general, an IR excess suggests the existence of warm dust around a star. We detected 12 μ m and/or 22 μ m excesses at the 3 σ level of confidence in five solar analog stars, corresponding to a frequency of 4.1% of the entire sample of solar analogs analyzed, and in one out of 29 solar sibling candidates, confirming previous studies. The estimation of the dust properties shows that the sources with IR excesses possess circumstellar material with temperatures that, within the uncertainties, are similar to that of the material found in the asteroid belt in our solar system. No photospheric flux excess was identified at the W1 (3.4 μ m) and W2 (4.6 μ m) WISE bands, indicating that, in the majority of stars of the present sample, no detectable dust is generated. Interestingly, among the 60 solar twin stars analyzed in this work, no WISE photospheric flux excess was detected. However, a null-detection excess does not necessarily indicate the absence of dust around a star because different causes, including dynamic processes and instrument limitations, can mask its presence.

  10. Classification study of WISE infrared sources: identification of candidate asymptotic giant branch stars

    Science.gov (United States)

    Tu, Xun; Wang, Zhong-Xiang

    2013-03-01

    In the Wide-field Infrared Survey Explorer (WISE) all-sky source catalog there are 76 million mid-infrared point sources that were detected in the first three WISE bands and have association with only one 2MASS near-IR source within 3″. We search for their identifications in the SIMBAD database and find 3.2 million identified sources. Based on these known sources, we establish three criteria for selecting candidate asymptotic giant branch (AGB) stars in the Galaxy, which are three defined zones in a color-color diagram, Galactic latitude |b| W3c W3c, we estimate their distances and derive their Galactic distributions. The candidates are generally distributed around the Galactic center uniformly, with 68% (1-σ) of them within approximately 8 kpc. We discuss the idea that optical spectroscopy can be used to verify the C-rich AGB stars in our candidates, and thus a fraction of them (~10%) will be good targets for the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey that is planned to start in fall of 2012.

  11. Calibration of Ultraviolet, Mid-infrared, and Radio Star Formation Rate Indicators

    Science.gov (United States)

    Brown, Michael J. I.; Moustakas, John; Kennicutt, Robert C.; Bonne, Nicolas J.; Intema, Huib T.; de Gasperin, Francesco; Boquien, Mederic; Jarrett, T. H.; Cluver, Michelle E.; Smith, J.-D. T.; da Cunha, Elisabete; Imanishi, Masatoshi; Armus, Lee; Brandl, Bernhard R.; Peek, J. E. G.

    2017-10-01

    We present calibrations for star formation rate (SFR) indicators in the ultraviolet, mid-infrared, and radio-continuum bands, including one of the first direct calibrations of 150 MHz as an SFR indicator. Our calibrations utilize 66 nearby star-forming galaxies with Balmer-decrement-corrected {{H}}α luminosities, which span five orders of magnitude in SFR and have absolute magnitudes of -24spectrophotometry are measured from the same region of each galaxy, and our spectrophotometry has been validated with SDSS photometry, so our random and systematic errors are small relative to the intrinsic scatter seen in SFR indicator calibrations. We find that the Wide-field Infrared Space Explorer W4 (22.8 μm), Spitzer 24 μm, and 1.4 GHz bands have tight correlations with the Balmer-decrement-corrected Hα luminosity, with a scatter of only 0.2 dex. Our calibrations are comparable to those from the prior literature for L ∗ galaxies, but for dwarf galaxies, our calibrations can give SFRs that are far greater than those derived from most previous literature.

  12. Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

    Science.gov (United States)

    Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

    2012-01-01

    We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

  13. Infrared Camera

    Science.gov (United States)

    1997-01-01

    A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.

  14. Infrared photoretinoscope.

    Science.gov (United States)

    Schaeffel, F; Farkas, L; Howland, H C

    1987-04-15

    A modification of the technique of photoretinoscopy is presented which allows measurement of the refractive state of the eye in noncooperative subjects and in very small eyes. Infrared light provided by high-output infrared LEDs permits measurement at large pupil sizes and thereby better resolution. Arrangement of the IR LEDs at different eccentricities from the optical axis of the video camera markedly increases the range of measurement. The current sensitivity for a measurement distance of 1.5 m in a human eye is +/- 0.3 diopter or better over a range of +/-5 diopters. Higher amounts of defocus can be better determined at shorter distances.

  15. A COMPREHENSIVE SEARCH FOR STELLAR BOWSHOCK NEBULAE IN THE MILKY WAY: A CATALOG OF 709 MID-INFRARED SELECTED CANDIDATES

    Energy Technology Data Exchange (ETDEWEB)

    Kobulnicky, Henry A.; Chick, William T.; Schurhammer, Danielle P.; Andrews, Julian E.; Munari, Stephan A.; Olivier, Grace M.; Sorber, Rebecca L.; Wernke, Heather N.; Dale, Daniel A. [Dept. of Physics and Astronomy, University of Wyoming, Laramie, WY 82070 (United States); Povich, Matthew S.; Dixon, Don M. [Department of Physics and Astronomy, California State Polytechnic University, 3801 West Temple Avenue, Pomona, CA 91768 (United States)

    2016-12-01

    We identify 709 arc-shaped mid-infrared nebula in 24 μ m Spitzer Space Telescope or 22 μ m Wide Field Infrared Explorer surveys of the Galactic Plane as probable dusty interstellar bowshocks powered by early-type stars. About 20% are visible at 8 μ m or at shorter mid-infrared wavelengths. The vast majority (660) have no previous identification in the literature. These extended infrared sources are strongly concentrated near the Galactic mid-plane, with an angular scale height of ∼0.°6. All host a symmetrically placed star implicated as the source of a stellar wind sweeping up interstellar material. These are candidate “runaway” stars potentially having high velocities in the reference frame of the local medium. Among the 286 objects with measured proper motions, we find an unambiguous excess with velocity vectors aligned with the infrared morphology—kinematic evidence that many of these are “runaway” stars with large peculiar motions responsible for the bowshock signature. We discuss a population of “in situ” bowshocks (∼103 objects) that face giant H ii regions where the relative motions between the star and ISM may be caused by bulk outflows from an overpressured bubble. We also identify ∼58 objects that face 8 μ m bright-rimmed clouds and apparently constitute a sub-class of in situ bowshocks where the stellar wind interacts with a photoevaporative flow (PEF) from an eroding molecular cloud interface (i.e., “PEF bowshocks”). Orientations of the arcuate nebulae exhibit a correlation over small angular scales, indicating that external influences such as H ii regions are responsible for producing some bowshock nebulae. However, the vast majority of the nebulae in this sample appear to be isolated (499 objects) from obvious external influences.

  16. A Comprehensive Search for Stellar Bowshock Nebulae in the Milky Way: A Catalog of 709 Mid-infrared Selected Candidates

    Science.gov (United States)

    Kobulnicky, Henry A.; Chick, William T.; Schurhammer, Danielle P.; Andrews, Julian E.; Povich, Matthew S.; Munari, Stephan A.; Olivier, Grace M.; Sorber, Rebecca L.; Wernke, Heather N.; Dale, Daniel A.; Dixon, Don M.

    2016-12-01

    We identify 709 arc-shaped mid-infrared nebula in 24 μm Spitzer Space Telescope or 22 μm Wide Field Infrared Explorer surveys of the Galactic Plane as probable dusty interstellar bowshocks powered by early-type stars. About 20% are visible at 8 μm or at shorter mid-infrared wavelengths. The vast majority (660) have no previous identification in the literature. These extended infrared sources are strongly concentrated near the Galactic mid-plane, with an angular scale height of ˜0.°6. All host a symmetrically placed star implicated as the source of a stellar wind sweeping up interstellar material. These are candidate “runaway” stars potentially having high velocities in the reference frame of the local medium. Among the 286 objects with measured proper motions, we find an unambiguous excess with velocity vectors aligned with the infrared morphology—kinematic evidence that many of these are “runaway” stars with large peculiar motions responsible for the bowshock signature. We discuss a population of “in situ” bowshocks (˜103 objects) that face giant H ii regions where the relative motions between the star and ISM may be caused by bulk outflows from an overpressured bubble. We also identify ˜58 objects that face 8 μm bright-rimmed clouds and apparently constitute a sub-class of in situ bowshocks where the stellar wind interacts with a photoevaporative flow (PEF) from an eroding molecular cloud interface (i.e., “PEF bowshocks”). Orientations of the arcuate nebulae exhibit a correlation over small angular scales, indicating that external influences such as H ii regions are responsible for producing some bowshock nebulae. However, the vast majority of the nebulae in this sample appear to be isolated (499 objects) from obvious external influences.

  17. Mid-infrared Excess from the West Hot Spot of the Radio Galaxy Pictor A Unveiled by WISE

    Science.gov (United States)

    Isobe, Naoki; Koyama, Shoko; Kino, Motoki; Wada, Takehiko; Nakagawa, Takao; Matsuhara, Hideo; Niinuma, Kotaro; Tashiro, Makoto

    2017-12-01

    Mid-infrared properties are reported of the west hot spot of the radio galaxy Pictor A with the Wide-field Infrared Survey Explorer (WISE). The mid-infrared counterpart to the hot spot, WISE J051926.26‑454554.1, is listed in the AllWISE source catalog. The source was detected in all four of the WISE photometric bands. A comparison between the WISE and radio images reinforces the physical association of the WISE source to the hot spot. The WISE flux density of the source was carefully evaluated. A close investigation of the multi-wavelength synchrotron spectral energy distribution from the object reveals a mid-infrared excess at the wavelength of λ =22 μm with a statistical significance of 4.8σ over the simple power-law extrapolation from the synchrotron radio spectrum. The excess is reinforced by single and double cutoff power-law modeling of the radio-to-optical spectral energy distribution. The synchrotron cutoff frequency of the main and excess components was evaluated as 7.1× {10}14 Hz and 5.5× {10}13 Hz, respectively. From the cutoff frequency, the magnetic field of the emission region was constrained as a function of the region size. In order to interpret the excess component, an electron population different from the main one dominating the observed radio spectrum is necessary. The excess emission is proposed to originate in a substructure within the hot spot, in which the magnetic field is a factor of a few stronger than that in the minimum-energy condition. The relation of the mid-infrared excess to the X-ray emission is briefly discussed.

  18. Flight performance of an advanced CZT imaging detector in a balloon-borne wide-field hard X-ray telescope—ProtoEXIST1

    Science.gov (United States)

    Hong, J.; Allen, B.; Grindlay, J.; Barthelemy, S.; Baker, R.; Garson, A.; Krawczynski, H.; Apple, J.; Cleveland, W. H.

    2011-10-01

    We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes such as the High Energy Telescope (HET) in the Energetic X-ray Imaging Survey Telescope (EXIST). The CZT detector plane in ProtoEXIST1 consists of an 8×8 array of closely tiled 2 cm×2 cm×0.5 cm thick pixellated CZT crystals, each with 8×8 pixels, mounted on a set of readout electronics boards and covering a 256 cm2 active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30-600 keV band for imaging, allowing a fully coded field of view of 9°×9° (and 19°×19° for 50% coding fraction) with an angular resolution of 20‧. In order to reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. On the back side, a 26 cm×26 cm×2 cm CsI(Na) active shield provides signals to tag charged particle induced events as well as ≳100keV background photons from below. The flight duration was only about 7.5 h due to strong winds (60 knots) at float altitude (38-39 km). Throughout the flight, the CZT detector performed excellently. The telescope observed Cyg X-1, a bright black hole binary system, for ˜1h at the end of the flight. Despite a few problems with the pointing and aspect systems that caused the telescope to track about 6.4° off the target, the analysis of the Cyg X-1 data revealed an X-ray source at 7.2σ in the 30-100 keV energy band at the expected location from the optical images taken by the onboard daytime star camera. The success of this first flight is very

  19. Infrared Thermometers

    Science.gov (United States)

    Schaefers, John

    2006-01-01

    An infrared (IR) thermometer lab offers the opportunity to give science students a chance to measure surface temperatures, utilizing off-the-shelf technology. Potential areas of study include astronomy (exoplanets), electromagnetic spectrum, chemistry, evaporation rates, anatomy, crystal formation, and water or liquids. This article presents one…

  20. An Optically Faint Quasar Survey at z ˜ 5 in the CFHTLS Wide Field: Estimates of the Black Hole Masses and Eddington Ratios

    Science.gov (United States)

    Ikeda, H.; Nagao, T.; Matsuoka, K.; Kawakatu, N.; Kajisawa, M.; Akiyama, M.; Miyaji, T.; Morokuma, T.

    2017-09-01

    We present the result of our spectroscopic follow-up observation for faint quasar candidates at z ˜ 5 in part of the Canada-France-Hawaii Telescope Legacy Survey wide field. We select nine photometric candidates and identify three z ˜ 5 faint quasars, one z ˜ 4 faint quasar, and a late-type star. Since two faint quasar spectra show the C IV emission line without suffering from a heavy atmospheric absorption, we estimate their black hole masses ({M}{BH}) and Eddington ratios (L/{L}{Edd}). The inferred {log}{M}{BH} are 9.04 ± 0.14 and 8.53 ± 0.20, respectively. In addition, the inferred {log}(L/{L}{Edd}) are -1.00 ± 0.15 and -0.42 ± 0.22, respectively. If we adopt that L/{L}{Edd}={constant} {or}\\propto {(1+z)}2, the seed black hole masses ({M}{seed}) of our z ˜ 5 faint quasars are expected to be > {10}5 {M}⊙ in most cases. We also compare the observational results with a mass accretion model, where angular momentum is lost due to supernova explosions. Accordingly, {M}{BH} of the z ˜ 5 faint quasars in our sample can be explained even if {M}{seed} is ˜ {10}3 {M}⊙ . Since z ˜ 6 luminous qusars and our z ˜ 5 faint quasars are not on the same evolutionary track, z ˜ 6 luminous quasars and our z ˜ 5 quasars are not the same populations but different populations, due to the difference of a period of the mass supply from host galaxies. Furthermore, we confirm that one can explain {M}{BH} of z ˜ 6 luminous quasars and our z ˜ 5 faint quasars even if their seed black holes are formed at z ˜ 7.

  1. Surgical feasibility and biocompatibility of wide-field dual-array suprachoroidal-transretinal stimulation prosthesis in middle-sized animals.

    Science.gov (United States)

    Lohmann, Tibor Karl; Kanda, Hiroyuki; Morimoto, Takeshi; Endo, Takao; Miyoshi, Tomomitsu; Nishida, Kentaro; Kamei, Motohiro; Walter, Peter; Fujikado, Takashi

    2016-04-01

    To investigate the safety and efficacy of a newly-developed wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis in middle-sized animals. The prosthesis consisted of two arrays with 50 to 74 electrodes. To test the feasibility of implanting the prosthesis and its efficacy, the prosthesis was implanted for 14 days into two rabbits. Optical coherence tomography (OCT) and ophthalmoscopy were performed 7 and 14 days after the implantation. Then the rabbits were euthanized, eyes were enucleated, and the posterior segment of the eye was examined histologically. In a second experiment, the arrays were implanted into two cats, and their ability to elicit neural responses was determined by electrically evoked potentials (EEPs) at the chiasm and by optical imaging of the retina. All arrays were successfully implanted, and no major complications occurred during the surgery or during the 2-week postoperative period. Neither OCT nor ophthalmoscopy showed any major complications or instability of the arrays. Histological evaluations showed only mild cellular infiltration and overall good retinal preservation. Stimulation of the retina by the arrays evoked EEPs recorded from the chiasm. Retinal imaging showed that the electrical pulses from the arrays altered the retinal images indicating an activation of retinal neurons. The thresholds were as low as 100 μA for a chiasm response and 300 μA for the retinal imaging. Implantation of a newly-developed dual-array STS prosthesis for 2 weeks in rabbits was feasible surgically, and safe. The results of retinal imaging showed that the dual-array system was able to activate retinal neurons. We conclude that the dual-array design can be implanted without complication and is able to activate retinal neurons and optic nerve axons.

  2. A Wide-field Study of the z 0.8 Cluster RX J0152.7-1357: The Role of Environment in Galaxy Evolution

    Science.gov (United States)

    Patel, Shannon; Kelson, D. D.; Holden, B. P.; Illingworth, G. D.; Franx, M.; van der Wel, A.; Ford, H.

    2009-01-01

    We study the influence of local environment on the formation and evolution of galaxies in the z 0.8 galaxy cluster RX J0152.7-1357 (RXJ0152-13) and its outskirts. Simulations show that massive clusters like RXJ0152-13 will grow in mass by a factor of 2-3 by z=0 through accretion of infalling galaxies and groups of galaxies. Our goal is to understand the transformation process that changes these infalling galaxies into red, early-type cluster members. We used a low-dispersion prism in the IMACS spectrograph at Magellan to obtain low-resolution spectroscopy for large numbers of galaxies over a wide field (D 30') in order to identify members in the vicinity of the cluster. With a mass limited sample (M>4x1010 MSun), we examined the rest-frame colors of galaxies as a function of local projected galaxy density. We found that the high-density regions in the core of the cluster and in the infalling groups support a high fraction of red galaxies compared to the lower density regions, as others have found at lower redshift. Intermediate density regions also revealed an elevated fraction of red galaxies. We also studied the star formation rates (SFRs) of members using Spitzer MIPS 24µm flux as a tracer. Our initial results show a lack of star-forming galaxies in the core of the cluster and in the high-density regions of the groups in the outskirts, which is consistent with their red colors discussed above. These results suggest that many future cluster members are transformed into passively evolving, red, early-types in infalling groups and in the surrounding filamentary structure of the cluster.

  3. Microneedles rollers as a potential device to increase ALA diffusion and PpIX production: evaluations by wide-field fluorescence imaging and fluorescence spectroscopy

    Science.gov (United States)

    Gracielli Sousa, R. Phamilla; de Menezes, Priscila F. C.; Fujita, Alessandra K. L.; Requena, Michelle B.; Govone, Angelo Biassi; Escobar, André; de Nardi, Andrigo B.; Kurachi, Cristina; Bagnato, Vanderlei Salvador

    2014-03-01

    One of the limitations of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is the poor ability to penetrate biological barriers of skin and the recurrence rates in treatments. This study aimed to identify possible signs of increased diffusion of ALA-induced PpIX by fluorescence images and fluorescence spectroscopy. The research was done using in vivo porcine skin model. Before the cream application, microholes was performed with microneedles rollers in only one direction, afterward the ALA cream was applied at a 2.5cm2 area in triplicate and an occlusive dressing was placed. PpIX production was monitored using fluorescence spectroscopy collected at skin surface after 70, 100, 140, and 180 minutes of ALA incubation. About 100 fluorescence spectra of each treatment were collected, distributed by about five points for each site. Wide-field fluorescence imaging was made after 70, 90, and 170 minutes after treatment. The results obtained by imaging analysis indicated increase of the PpIX diffusion in the skin surface using the microneedles rollers (MNs) before ALA application. Circular regions of red fluorescence around the microholes were observed. In addition, the fluorescence spectra showed a greater intensity (2 times as many) in groups microneedles rollers associated. In conclusion, our data shown greater homogeneity and PpIX production in the groups pre-treated with microneedles indicating that the technique can be used to greater uniformity of PpIX production throughout the area to be treated reducing the chances of recurrent tumor as well as has potential for decreasing the time of therapy. (FUNDING SUPPORT:CAPES, CNPq and FAPESP)

  4. The ArTéMiS wide-field sub-millimeter camera: preliminary on-sky performance at 350 microns

    Science.gov (United States)

    Revéret, Vincent; André, Philippe; Le Pennec, Jean; Talvard, Michel; Agnèse, Patrick; Arnaud, Agnès.; Clerc, Laurent; de Breuck, Carlos; Cigna, Jean-Charles; Delisle, Cyrille; Doumayrou, Eric; Duband, Lionel; Dubreuil, Didier; Dumaye, Luc; Ercolani, Eric; Gallais, Pascal; Groult, Elodie; Jourdan, Thierry; Leriche, Bernadette; Maffei, Bruno; Lortholary, Michel; Martignac, Jérôme; Rabaud, Wilfried; Relland, Johan; Rodriguez, Louis; Vandeneynde, Aurélie; Visticot, François

    2014-07-01

    ArTeMiS is a wide-field submillimeter camera operating at three wavelengths simultaneously (200, 350 and 450 μm). A preliminary version of the instrument equipped with the 350 μm focal plane, has been successfully installed and tested on APEX telescope in Chile during the 2013 and 2014 austral winters. This instrument is developed by CEA (Saclay and Grenoble, France), IAS (France) and University of Manchester (UK) in collaboration with ESO. We introduce the mechanical and optical design, as well as the cryogenics and electronics of the ArTéMiS camera. ArTeMiS detectors consist in Si:P:B bolometers arranged in 16×18 sub-arrays operating at 300 mK. These detectors are similar to the ones developed for the Herschel PACS photometer but they are adapted to the high optical load encountered at APEX site. Ultimately, ArTeMiS will contain 4 sub-arrays at 200 μm and 2×8 sub-arrays at 350 and 450 μm. We show preliminary lab measurements like the responsivity of the instrument to hot and cold loads illumination and NEP calculation. Details on the on-sky commissioning runs made in 2013 and 2014 at APEX are shown. We used planets (Mars, Saturn, Uranus) to determine the flat-field and to get the flux calibration. A pointing model was established in the first days of the runs. The average relative pointing accuracy is 3 arcsec. The beam at 350 μm has been estimated to be 8.5 arcsec, which is in good agreement with the beam of the 12 m APEX dish. Several observing modes have been tested, like "On- The-Fly" for beam-maps or large maps, spirals or raster of spirals for compact sources. With this preliminary version of ArTeMiS, we concluded that the mapping speed is already more than 5 times better than the previous 350 μm instrument at APEX. The median NEFD at 350 μm is 600 mJy.s1/2, with best values at 300 mJy.s1/2. The complete instrument with 5760 pixels and optimized settings will be installed during the first half of 2015.

  5. Wide field of view computed tomography and mid carpal instability: The value of the sagittal radius–lunate–capitate axis – Preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Repse, Stephen E., E-mail: stephrep@gmail.com [Department of Diagnostic Imaging, Monash Health, VIC (Australia); Koulouris, George, E-mail: GeorgeK@melbourneradiology.com.au [Melbourne Radiology Clinic, Ground Floor, 3-6/100 Victoria Parade, East Melbourne, VIC (Australia); Centre for Orthopaedic Research, School of Surgery, University of Western Australia, Nedlands, WA (Australia); Troupis, John M., E-mail: john.troupis@gmail.com [Department of Diagnostic Imaging & Monash Cardiovascular Research Centre, Monash Health and Department of Biomedical Radiation Sciences, Faculty of Medicine, Nursing & Health Sciences, Monash University, VIC (Australia)

    2015-05-15

    Highlights: • Unique insight into the assessment of mid carpal instability. • 4D CT using sagittal reconstructions along the radius–lunate–capitate axis. • 4D CT observations of vacuum phenomenon, trigger lunate and capitate subluxation. • Earlier recognition of mid carpal instability. - Abstract: Purpose: Dynamic four dimensional (4D) computed tomography (CT) has recently emerged as a practical method for evaluating complex functional abnormality of joints. We retrospectively analysed 4D CT studies undertaken as part of the clinical management of hand and wrist symptoms. We present our initial experience of 4D CT in the assessment of functional abnormalities of the wrist in a group of patients with mid carpal instability (MCI), specifically carpal instability non-dissociative. We aim to highlight unique features in assessment of the radius–lunate–capitate (RLC) axis which allows insight and understanding of abnormalities in function, not just morphology, which may be contributing to symptoms. Materials and methods: Wide field of view multi-detector CT scanner (320 slices, 0.5 mm detector thickness) was used to acquire bilateral continuous motion assessment in hand flexion and extension. A maximum z-axis coverage of 16 cm was available for each acquisition, and a large field of view (FOV) was used. Due to the volume acquisition during motion, reconstructions at multiple time points were undertaken. Dynamic and anatomically targeted multi-planar-reconstructions (MPRs) were then used to establish the kinematic functionality of the joint. Results: Our initial cohort of 20 patients was reviewed. Three findings were identified which were present either in isolation or in combination. These are vacuum phenomenon, triggering of the lunate and capitate subluxation. We provide 4D CT representations of each and highlight features considered of clinical importance and their significance. We also briefly discuss how the current classifications of dynamic wrist

  6. Infrared retina

    Science.gov (United States)

    Krishna, Sanjay [Albuquerque, NM; Hayat, Majeed M [Albuquerque, NM; Tyo, J Scott [Tucson, AZ; Jang, Woo-Yong [Albuquerque, NM

    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.

  7. On Infrared Excesses Associated with Li-Rich K Giants

    Science.gov (United States)

    Rebull, Luisa M.; Carlberg, Joleen K.; Gibbs, John C.; Deeb, J. Elin; Larsen, Estefania; Black, David V.; Altepeter, Shailyn; Bucksbee, Ethan; Cashen, Sarah; Clarke, Matthew; hide

    2015-01-01

    Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant lithium and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched lithium, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and lithium abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be lithium-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by approximately 20 micrometers (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few lithium-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, 12C/13C. IR excesses by 20 micrometers, though relatively rare, are at least twice as common among our sample of lithium-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported

  8. ON INFRARED EXCESSES ASSOCIATED WITH Li-RICH K GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Rebull, Luisa M. [Spitzer Science Center (SSC) and Infrared Science Archive (IRSA), Infrared Processing and Analysis Center - IPAC, 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Carlberg, Joleen K. [NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Gibbs, John C.; Cashen, Sarah; Datta, Ashwin; Hodgson, Emily; Lince, Megan [Glencoe High School, 2700 NW Glencoe Rd., Hillsboro, OR 97124 (United States); Deeb, J. Elin [Bear Creek High School, 9800 W. Dartmouth Pl., Lakewood, CO 80227 (United States); Larsen, Estefania; Altepeter, Shailyn; Bucksbee, Ethan; Clarke, Matthew [Millard South High School, 14905 Q St., Omaha, NE 68137 (United States); Black, David V., E-mail: rebull@ipac.caltech.edu [Walden School of Liberal Arts, 4230 N. University Ave., Provo, UT 84604 (United States)

    2015-10-15

    Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by ∼20 μm (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few Li-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, {sup 12}C/{sup 13}C. IR excesses by 20 μm, though relatively rare, are at least twice as common among our sample of Li-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported by theoretical calculations. Conversely, the

  9. Transformative Colloidal Nanomaterials for Mid- Infrared Devices

    Science.gov (United States)

    2015-06-11

    Distribution Unlimited Final Report: Transformative Colloidal Nanomaterials for Mid- Infrared Devices The views, opinions and/or findings contained in this...reviewed journals: Final Report: Transformative Colloidal Nanomaterials for Mid-Infrared Devices Report Title The grant focused on the Photoluminescence...explored for mid-infrared photoluminescence, in view of applying it to LEDs, lasers or negative luminescence devices. Colloidal nanomaterials are already

  10. Mid-infrared Flare of TDE Candidate PS16dtm: Dust Echo and Implications for the Spectral Evolution

    Science.gov (United States)

    Jiang, Ning; Wang, Tinggui; Yan, Lin; Xiao, Ting; Yang, Chenwei; Dou, Liming; Wang, Huiyuan; Cutri, Roc; Mainzer, Amy

    2017-11-01

    PS16dtm was classified as a candidate tidal disruption event in a dwarf Seyfert 1 galaxy with a low-mass black hole (∼ {10}6 {M}ȯ ) and has presented various intriguing photometric and spectra characteristics. Using the archival Wide-field Infrared Survey Explorer and the newly released NEOWISE data, we found that PS16dtm is experiencing a mid-infrared (MIR) flare that started ∼11 days before the first optical detection. Interpreting the MIR flare as a dust echo requires close pre-existing dust with a high covering factor and suggests that the optical flare may have brightened slowly for some time before it became bright detectable from the ground. More evidence is given at the later epochs. At the peak of the optical light curve, the new inner radius of the dust torus has grown to a much larger size (i.e., a factor of seven of the initial radius) due to the strong radiation field. At ∼150 days after the first optical detection, the dust temperature has dropped well below the sublimation temperature. Other peculiar spectral features shown by PS16dtm are the transient, prominent Fe ii emission lines and outflows indicated by broad absorption lines detected during the optical flare. Our model explains the enhanced Fe ii emission from iron that is newly released from the evaporated dust. The observed broad absorption line outflow could be explained by accelerated gas in the dust torus due to the radiation pressure.

  11. Backyard Infrared Trapping

    Science.gov (United States)

    Gibbons, Thomas C.

    2014-12-01

    In this time of concern over climate change due to the atmospheric greenhouse effect,1 teachers often choose to extend relevant classroom work by the use of physical models to test statements. Here we describe an activity in which inexpensive backyard models made from cardboard boxes covered with various household transparent materials allow students to explore how transmission of visible and infrared light can affect the temperature.2 Our basic setup is shown schematically in Fig. 1, in which a black-lined box with a thermometer in contact with the bottom is covered with transparent (to visible light) household materials.

  12. Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe - III. Global star-forming properties and the lack of a connection to nuclear activity

    Science.gov (United States)

    Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.

    2017-04-01

    We combine the Herschel Space Observatory PACS (Photoconductor Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver) photometry with archival WISE (Wide-field Infrared Survey Explorer) photometry to construct the spectral energy distributions (SEDs) for over 300 local (z 0.5), especially at higher luminosities (L14 - 195 keV > 1042.5 erg s-1). Finally, we measure the local SFR-AGN luminosity relationship, finding a slope of 0.18, large scatter (0.37 dex), and no evidence for an upturn at high AGN luminosity. We conclude with a discussion on the implications of our results within the context of galaxy evolution with and without AGN feedback.

  13. The ESO-Spitzer Imaging extragalactic Survey (ESIS). II. VIMOS I, z wide field imaging of ELAIS-S1 and selection of distant massive galaxies

    Science.gov (United States)

    Berta, S.; Rubele, S.; Franceschini, A.; Held, E. V.; Rizzi, L.; Rodighiero, G.; Cimatti, A.; Dias, J. E.; Feruglio, C.; La Franca, F.; Lonsdale, C. J.; Maiolino, R.; Matute, I.; Rowan-Robinson, M.; Sacchi, N.; Zamorani, G.

    2008-09-01

    Context: The ESO-Spitzer Imaging extragalactic Survey (ESIS) is the optical follow up of the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) in the ELAIS-S1 region of the sky. Aims: In the era of observational cosmology, the main efforts are focused on the study of galaxy evolution and its environmental dependence. Wide area, multiwavelength, extragalactic surveys are needed in order to probe sufficiently large volumes, minimize cosmic variance and find significant numbers of rare objects. Methods: We present VIMOS I and z band imaging belonging to the ESIS survey. A total of ~4 deg2 was targeted in I and ~1 deg2 in z. Accurate data processing includes removal of fringing, and mosaicking of the complex observing pattern. Completeness levels and photometric uncertainties are estimated through simulations. The multi-wavelength data available in the area are exploited to identify high-redshift galaxies, using the IR-peak technique. Results: More than 300 000 galaxies have been detected in the I band and ~50 000 in the z band. Object coordinates are defined within an uncertainty of ~0.2 arcsec rms, with respect to GSC 2.2. We reach a 90% average completeness at 23.1 and 22.5 mag (Vega) in the I and z bands, respectively. On the basis of IRAC colors, we identify galaxies having the 1.6 μm stellar peak shifted to z = 1-3. The new I, z band data provide reliable constraints to help avoid low-redshift interlopers and reinforce this selection. Roughly 1000 galaxies between z = 2-3 are identified over the ESIS ~4 deg^2, at the SWIRE 5.8 μm depth (25.8 μJy at 3σ). These are the best galaxy candidates to dominate the massive tail (M > 1011 M_⊙) of the z > 2 mass function. Based on observations collected at the European Southern Observatory, Chile, ESO No. 168.A-0322(A). ESIS web page:http://www.astro.unipd.it/esis Appendix A, Tables 4 and 5 are only available at http://www.aanda.org The full I and z band catalogs (see Table [see full textsee full textsee full

  14. Image-Guided Surgery Using Invisible Near-Infrared Light: Fundamentals of Clinical Translation

    Directory of Open Access Journals (Sweden)

    Sylvain Gioux

    2010-09-01

    Full Text Available The field of biomedical optics has matured rapidly over the last decade and is poised to make a significant impact on patient care. In particular, wide-field (typically > 5 cm, planar, near-infrared (NIR fluorescence imaging has the potential to revolutionize human surgery by providing real-time image guidance to surgeons for tissue that needs to be resected, such as tumors, and tissue that needs to be avoided, such as blood vessels and nerves. However, to become a clinical reality, optimized imaging systems and NIR fluorescent contrast agents will be needed. In this review, we introduce the principles of NIR fluorescence imaging, analyze existing NIR fluorescence imaging systems, and discuss the key parameters that guide contrast agent development. We also introduce the complexities surrounding clinical translation using our experience with the Fluorescence-Assisted Resection and Exploration (FLARE™ imaging system as an example. Finally, we introduce state-of-the-art optical imaging techniques that might someday improve image-guided surgery even further.

  15. Predictive modeling of infrared detectors and material systems

    Science.gov (United States)

    Pinkie, Benjamin

    Detectors sensitive to thermal and reflected infrared radiation are widely used for night-vision, communications, thermography, and object tracking among other military, industrial, and commercial applications. System requirements for the next generation of ultra-high-performance infrared detectors call for increased functionality such as large formats (> 4K HD) with wide field-of-view, multispectral sensitivity, and on-chip processing. Due to the low yield of infrared material processing, the development of these next-generation technologies has become prohibitively costly and time consuming. In this work, it will be shown that physics-based numerical models can be applied to predictively simulate infrared detector arrays of current technological interest. The models can be used to a priori estimate detector characteristics, intelligently design detector architectures, and assist in the analysis and interpretation of existing systems. This dissertation develops a multi-scale simulation model which evaluates the physics of infrared systems from the atomic (material properties and electronic structure) to systems level (modulation transfer function, dense array effects). The framework is used to determine the electronic structure of several infrared materials, optimize the design of a two-color back-to-back HgCdTe photodiode, investigate a predicted failure mechanism for next-generation arrays, and predict the systems-level measurables of a number of detector architectures.

  16. The Extremely Luminous Quasar Survey in the SDSS Footprint. I. Infrared-based Candidate Selection

    Science.gov (United States)

    Schindler, Jan-Torge; Fan, Xiaohui; McGreer, Ian D.; Yang, Qian; Wu, Jin; Jiang, Linhua; Green, Richard

    2017-12-01

    Studies of the most luminous quasars at high redshift directly probe the evolution of the most massive black holes in the early universe and their connection to massive galaxy formation. However, extremely luminous quasars at high redshift are very rare objects. Only wide-area surveys have a chance to constrain their population. The Sloan Digital Sky Survey (SDSS) has so far provided the most widely adopted measurements of the quasar luminosity function at z> 3. However, a careful re-examination of the SDSS quasar sample revealed that the SDSS quasar selection is in fact missing a significant fraction of z≳ 3 quasars at the brightest end. We identified the purely optical-color selection of SDSS, where quasars at these redshifts are strongly contaminated by late-type dwarfs, and the spectroscopic incompleteness of the SDSS footprint as the main reasons. Therefore, we designed the Extremely Luminous Quasar Survey (ELQS), based on a novel near-infrared JKW2 color cut using Wide-field Infrared Survey Explorer mission (WISE) AllWISE and 2MASS all-sky photometry, to yield high completeness for very bright ({m}{{i}}learning algorithms on SDSS and WISE photometry for quasar-star classification and photometric redshift estimation. The ELQS will spectroscopically follow-up ˜230 new quasar candidates in an area of ˜12,000 deg2 in the SDSS footprint to obtain a well-defined and complete quasar sample for an accurate measurement of the bright-end quasar luminosity function (QLF) at 3.0≤slant z≤slant 5.0. In this paper, we present the quasar selection algorithm and the quasar candidate catalog.

  17. The physical properties of galaxies with unusually red mid-infrared colours

    Science.gov (United States)

    Kauffmann, Guinevere

    2018-02-01

    The goal of this paper is to investigate the physical nature of galaxies in the redshift range 0.02 infrared wavelengths and to determine whether they host a population of accreting black holes that cannot be identified using optical emission lines. We show that at fixed stellar mass M* and Dn(4000), the distribution of [3.4]-[4.6] μm (Wide-field Infrared Survey Explorer, W1 - W2 band) colours is sharply peaked, with a long tail to much redder W1 - W2 colours. We introduce a procedure to pull out the red outlier population based on a combination of three stellar population diagnostics. When compared with optically selected active galactic nucleus (AGN), red outliers are more likely to be found in massive galaxies, and they tend to have lower stellar mass densities, younger stellar ages and higher dust content than optically selected AGN hosts. They are twice as likely to be detected at radio wavelengths. We examine W1 - W2 colour profiles for a subset of the nearest, reddest outliers and find that most are not centrally peaked, indicating that the hot dust emission is spread throughout the galaxy. We find that radio luminosity is the quantity that is most predictive of a redder central W1 - W2 colour. Radio-loud galaxies with centrally concentrated hot dust emission are almost always morphologically disturbed, with compact, unresolved emission at 1.4 GHz. The 80 per cent of such systems are identifiable as AGN using optical emission line diagnostics.

  18. THE HIGH A{sub V} Quasar Survey: Reddened Quasi-Stellar Objects selected from optical/near-infrared photometry. II

    Energy Technology Data Exchange (ETDEWEB)

    Krogager, J.-K.; Fynbo, J. P. U.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Geier, S. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Ledoux, C. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Møller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei München (Germany); Noterdaeme, P. [Institut d’Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Kangas, T.; Pursimo, T.; Smirnova, O. [Nordic Optical Telescope, Apartado 474, E-38700 Santa Cruz de La Palma (Spain); Saturni, F. G. [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiö (Finland)

    2015-03-15

    Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2 μm flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2 μm relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.

  19. Welcome to the Twilight Zone: The Mid-infrared Properties of Post-starburst Galaxies

    Science.gov (United States)

    Alatalo, Katherine; Bitsakis, Theodoros; Lanz, Lauranne; Lacy, Mark; Brown, Michael J. I.; French, K. Decker; Ciesla, Laure; Appleton, Philip N.; Beaton, Rachael L.; Cales, Sabrina L.; Crossett, Jacob; Falcón-Barroso, Jesús; Kelson, Daniel D.; Kewley, Lisa J.; Kriek, Mariska; Medling, Anne M.; Mulchaey, John S.; Nyland, Kristina; Rich, Jeffrey A.; Urry, C. Meg

    2017-07-01

    We investigate the optical and Wide-field Survey Explorer (WISE) colors of “E+A” identified post-starburst galaxies, including a deep analysis of 190 post-starbursts detected in the 2 μm All Sky Survey Extended Source Catalog. The post-starburst galaxies appear in both the optical green valley and the WISE Infrared Transition Zone. Furthermore, we find that post-starbursts occupy a distinct region of [3.4]-[4.6] versus [4.6]-[12] WISE colors, enabling the identification of this class of transitioning galaxies through the use of broadband photometric criteria alone. We have investigated possible causes for the WISE colors of post-starbursts by constructing a composite spectral energy distribution (SED), finding that the mid-infrared (4-12 μm) properties of post-starbursts are consistent with either 11.3 μm polycyclic aromatic hydrocarbon emission, or thermally pulsating asymptotic giant branch (TP-AGB) and post-AGB stars. The composite SED of extended post-starburst galaxies with 22 μm emission detected with signal-to-noise ratio ≥slant 3 requires a hot dust component to produce their observed rising mid-infrared SED between 12 and 22 μm. The composite SED of WISE 22 μm non-detections (S/N images, is also flat, requiring a hot dust component. The most likely source of the mid-infrared emission of these E+A galaxies is a buried active galactic nucleus (AGN). The inferred upper limits to the Eddington ratios of post-starbursts are 10-2-10-4, with an average of 10-3. This suggests that AGNs are not radiatively dominant in these systems. This could mean that including selections capable of identifying AGNs as part of a search for transitioning and post-starburst galaxies would create a more complete census of the transition pathways taken as a galaxy quenches its star formation.

  20. Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results.

    Science.gov (United States)

    Collier, Michael R; Porter, F Scott; Sibeck, David G; Carter, Jenny A; Chiao, Meng P; Chornay, Dennis J; Cravens, Thomas E; Galeazzi, Massimiliano; Keller, John W; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, Kip; Read, Andy M; Robertson, Ina P; Sembay, Steve; Snowden, Steven L; Thomas, Nicholas; Uprety, Youaraj; Walsh, Brian M

    2015-07-01

    We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].

  1. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  2. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  3. The Cosmic Background Explorer

    Science.gov (United States)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  4. Review The Ooty Wide Field Array

    Indian Academy of Sciences (India)

    latitude, effectively making the telescope equatorially mounted. The sky can hence be tracked by rotation ..... spectral index (Bera et al. 2016). Clearly transient searches with the OWFA would be of high ... We are grateful to the staff at the Radio Astronomy. Centre (RAC) Ooty, whose help formed a critical com- ponent of this ...

  5. An Infrared View of Saturn

    Science.gov (United States)

    1998-01-01

    above the rings. This view is possible due to a rare geometry during the observation. The next time this observable from Earth will be in 2006. An accurate investigation of the ring's shadow also shows sunlight shining through the Encke Gap, a thin division very close to the outer edge of the ring system.Two of Saturn's satellites were recorded, Dione on the lower left and Tethys on the upper right. Tethys is just ending its transit across the disk of Saturn. They appear in different colors, yellow and green, indicating different conditions on their icy surfaces.Wavelengths: A color image consists of three exposures (or three film layers). For visible true-color images, the wavelengths of these three exposures are 0.4, 0.5, and 0.6 micrometers for blue, green, and red light, respectively. This Saturn image was taken at longer infrared wavelengths of 1.0, 1.8, and 2.1 micrometers, displayed as blue, green, and red. Reflected sunlight is seen at all these wavelengths, since Saturn's own heat glows only at wavelengths above 4 micrometers.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  6. Galaxy and Mass Assembly (GAMA): Exploring the WISE Web in G12

    Science.gov (United States)

    Jarrett, T. H.; Cluver, M. E.; Magoulas, C.; Bilicki, M.; Alpaslan, M.; Bland-Hawthorn, J.; Brough, S.; Brown, M. J. I.; Croom, S.; Driver, S.; Holwerda, B. W.; Hopkins, A. M.; Loveday, J.; Norberg, P.; Peacock, J. A.; Popescu, C. C.; Sadler, E. M.; Taylor, E. N.; Tuffs, R. J.; Wang, L.

    2017-02-01

    We present an analysis of the mid-infrared Wide-field Infrared Survey Explorer (WISE) sources seen within the equatorial GAMA G12 field, located in the North Galactic Cap. Our motivation is to study and characterize the behavior of WISE source populations in anticipation of the deep multiwavelength surveys that will define the next decade, with the principal science goal of mapping the 3D large-scale structures and determining the global physical attributes of the host galaxies. In combination with cosmological redshifts, we identify galaxies from their WISE W1 (3.4 μm) resolved emission, and we also perform a star-galaxy separation using apparent magnitude, colors, and statistical modeling of star counts. The resulting galaxy catalog has ≃590,000 sources in 60 deg2, reaching a W1 5σ depth of 31 μJy. At the faint end, where redshifts are not available, we employ a luminosity function analysis to show that approximately 27% of all WISE extragalactic sources to a limit of 17.5 mag (31 μJy) are at high redshift, z> 1. The spatial distribution is investigated using two-point correlation functions and a 3D source density characterization at 5 Mpc and 20 Mpc scales. For angular distributions, we find that brighter and more massive sources are strongly clustered relative to fainter sources with lower mass; likewise, based on WISE colors, spheroidal galaxies have the strongest clustering, while late-type disk galaxies have the lowest clustering amplitudes. In three dimensions, we find a number of distinct groupings, often bridged by filaments and superstructures. Using special visualization tools, we map these structures, exploring how clustering may play a role with stellar mass and galaxy type.

  7. Short infrared laser pulses block action potentials in neurons

    Science.gov (United States)

    Walsh, Alex J.; Tolstykh, Gleb P.; Martens, Stacey L.; Ibey, Bennett L.; Beier, Hope T.

    2017-02-01

    Short infrared laser pulses have many physiological effects on cells including the ability to stimulate action potentials in neurons. Here we show that short infrared laser pulses can also reversibly block action potentials. Primary rat hippocampal neurons were transfected with the Optopatch2 plasmid, which contains both a blue-light activated channel rhodopsin (CheRiff) and a red-light fluorescent membrane voltage reporter (QuasAr2). This optogenetic platform allows robust stimulation and recording of action potential activity in neurons in a non-contact, low noise manner. For all experiments, QuasAr2 was imaged continuously on a wide-field fluorescent microscope using a Krypton laser (647 nm) as the excitation source and an EMCCD camera operating at 1000 Hz to collect emitted fluorescence. A co-aligned Argon laser (488 nm, 5 ms at 10Hz) provided activation light for CheRiff. A 200 mm fiber delivered infrared light locally to the target neuron. Reversible action potential block in neurons was observed following a short infrared laser pulse (0.26-0.96 J/cm2; 1.37-5.01 ms; 1869 nm), with the block persisting for more than 1 s with exposures greater than 0.69 J/cm2. Action potential block was sustained for 30 s with the short infrared laser pulsed at 1-7 Hz. Full recovery of neuronal activity was observed 5-30s post-infrared exposure. These results indicate that optogenetics provides a robust platform for the study of action potential block and that short infrared laser pulses can be used for non-contact, reversible action potential block.

  8. IDENTIFICATION OF 1.4 MILLION ACTIVE GALACTIC NUCLEI IN THE MID-INFRARED USING WISE DATA

    Energy Technology Data Exchange (ETDEWEB)

    Secrest, N. J.; Dudik, R. P.; Dorland, B. N.; Zacharias, N.; Makarov, V.; Fey, A.; Frouard, J.; Finch, C. [U.S. Naval Observatory, 3450 Massachusetts Avenue NW, Washington, DC 20392 (United States)

    2015-11-15

    We present an all-sky sample of ≈1.4 million active galactic nuclei (AGNs) meeting a two-color infrared photometric selection criteria for AGNs as applied to sources from the Wide-field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution and optical properties of our sample and find that the results are consistent with expectations for AGNs. These sources have a mean density of ≈38 AGNs per square degree on the sky, and their apparent magnitude distribution peaks at g ≈ 20, extending to objects as faint as g ≈ 26. We test the AGN selection criteria against a large sample of optically identified stars and determine the “leakage” (that is, the probability that a star detected in an optical survey will be misidentified as a quasi-stellar object (QSO) in our sample) rate to be ≤4.0 × 10{sup −5}. We conclude that our sample contains almost no optically identified stars (≤0.041%), making this sample highly promising for future celestial reference frame work as it significantly increases the number of all-sky, compact extragalactic objects. We further compare our sample to catalogs of known AGNs/QSOs and find a completeness value of ≳84% (that is, the probability of correctly identifying a known AGN/QSO is at least 84%) for AGNs brighter than a limiting magnitude of R ≲ 19. Our sample includes approximately 1.1 million previously uncataloged AGNs.

  9. A chemometric evaluation of the underlying physical and chemical patterns that support near infrared spectroscopy of barley seeds as a tool for explorative classification of endosperm genes and gene combinations

    DEFF Research Database (Denmark)

    Jacobsen, Susanne; Søndergaard, Ib; Møller, Birthe

    2005-01-01

    Near infrared spectroscopic (NIR; 1100-2500 nm), chemical and genetic data were combined to study the pleiotropic secondary effects of mutant genes on milled samples in a barley seed model. NIR and chemical data were both effective in classifying gene and gene combinations by Principal Component...... revealing pleiotropic gene effects in expression timing that supporting the gene classification. To verify that NIR spectroscopy data represents a physio-chemical fingerprint of the barley seed, physical and chemical spectral components were partially separated by Multiple Scatter Correction...... and their genetic classification ability verified. Wavelength bands with known water binding and (I -> 3, 1 -> 4)-beta-glucan assignments were successfully predicted by partial least squares regression giving insight into how NIR-data works in classification. Highly reproducible gene-specific, covariate...

  10. Near-infrared spectroscopic tissue imaging for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Demos; Stavros (Livermore, CA), Staggs; Michael C. (Tracy, CA)

    2006-03-21

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  11. Near-infrared spectroscopic tissue imaging for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Demos, Stavros (Livermore, CA); Staggs, Michael C. (Tracy, CA)

    2006-12-12

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  12. Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime

    Science.gov (United States)

    Fischer, William J.; Megeath, S. Thomas; Tobin, John J.; Stutz, Amelia M.; Ali, Babar; Remming, Ian; Kounkel, Marina; Stanke, Thomas; Osorio, Mayra; Henning, Thomas; Manoj, P.; Wilson, T. L.

    2012-09-01

    Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by Caratti o Garatti et al. to have recently undergone an order-of-magnitude increase in luminosity. Our near-infrared spectra of the source have strong blueshifted He I λ10830 absorption, strong H2O and CO absorption, and no H I emission, all typical of FU Orionis sources. With data from the Infrared Telescope Facility, the Two Micron All Sky Survey, the Hubble Space Telescope, Spitzer, the Wide-field Infrared Survey Explorer, Herschel, and the Atacama Pathfinder Experiment that span from 1 to 70 μm pre-outburst and from 1 to 870 μm post-outburst, we estimate that the outburst began between 2005 April and 2007 March. We also model the pre- and post-outburst spectral energy distributions of the source, finding it to be in the late stages of accreting its envelope with a disk-to-star accretion rate that increased from ~2 × 10-6 M ⊙ yr-1 to ~10-5 M ⊙ yr-1 during the outburst. The post-outburst luminosity at the epoch of the FU Orionis-like near-IR spectra is 28 L ⊙, making V2775 Ori the least luminous documented FU Orionis outburster with a protostellar envelope. The existence of low-luminosity outbursts supports the notion that a range of episiodic accretion phenomena can partially explain the observed spread in protostellar luminosities.

  13. FIRI-A far-infrared interferometer

    NARCIS (Netherlands)

    Helmich, Frank P.; Ivison, R. J.

    Half of the energy ever emitted by stars and accreting objects comes to us in the far-infrared (FIR) waveband and has yet to be properly explored. We propose a powerful Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging spectroscopy in the FIR. This key observational

  14. X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X. [Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), E-39005, Santander (Spain); Ramos, A. Asensio; Almeida, C. Ramos [Instituto de Astrofísica de Canarias, E-38205, La Laguna, Tenerife (Spain); Watson, M. G.; Blain, A. [Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Caccianiga, A.; Ballo, L. [INAF-Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy); Braito, V., E-mail: mateos@ifca.unican.es [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (Italy)

    2016-03-10

    We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  15. The thermal infrared continuum in solar flares

    Science.gov (United States)

    Fletcher, Lyndsay; Simoes, Paulo; Kerr, Graham Stewart; Hudson, Hugh S.; Gimenez de Castro, C. Guillermo; Penn, Matthew J.

    2017-08-01

    Observations of the Sun with the Atacama Large Millimeter Array have now started, and the thermal infrared will regularly be accessible from the NSF’s Daniel K. Inouye Solar Telescope. Motivated by the prospect of these new observations, and by recent flare detections in the mid infrared, we set out here to model and understand the source of the infrared continuum in flares, and to explore its diagnostic capability for the physical conditions in the flare atmosphere. We use the 1D radiation hydrodynamics code RADYN to calculate mid-infrared continuum emission from model atmospheres undergoing sudden deposition of energy by non-thermal electrons. We identify and characterise the main continuum thermal emission processes relevant to flare intensity enhancement in the mid- to far-infrared (2-200 micron) spectral range as free-free emission on neutrals and ions. We find that the infrared intensity evolution tracks the energy input to within a second, albeit with a lingering intensity enhancement, and provides a very direct indication of the evolution of the atmospheric ionization. The prediction of highly impulsive emission means that, on these timescales, the atmospheric hydrodynamics need not be considered in analysing the mid-IR signatures.

  16. Brown Dwarfs in the UKIRT Infrared Deep Sky Survey (UKIDSS)

    Science.gov (United States)

    Hambly, Nigel; UKIDSS Consortium

    2003-06-01

    During the final quarter of 2003, UKIRT will take delivery of WFCAM. This new wide--field camera will have a FOV of 0.2 square degrees, and is therefore well suited to large--scale survey work. A consortium of more than 60 astronomers has successfully bid for a large fraction of all UKIRT time over the next 5 years to undertake several public surveys using this new facility. These surveys are collectively known as the UKIRT Infrared Deep Sky Survey (UKIDSS). In this short paper I will describe the project and review the prospects for BD research using UKIDSS data, highlighting some of the major science goals related to BDs that we hope will be achieved.

  17. A DIRECT MEASUREMENT OF THE LINEAR BIAS OF MID-INFRARED-SELECTED QUASARS AT z ≈ 1 USING COSMIC MICROWAVE BACKGROUND LENSING

    Energy Technology Data Exchange (ETDEWEB)

    Geach, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Hickox, R. C.; Hainline, K. N. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Bleem, L. E.; Benson, B. A.; Bhattacharya, S.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Holder, G. P.; De Haan, T.; Dobbs, M. A.; Dudley, J. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States); Cho, H.-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States); George, E. M.; Holzapfel, W. L. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Halverson, N. W., E-mail: j.geach@herts.ac.uk [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); and others

    2013-10-20

    We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of Type 1 and 2 (unobscured and obscured) quasars at (z) ∼ 1 selected with the Wide-field Infrared Survey Explorer, over 2500 deg{sup 2}. The cross-power spectrum is detected at ≈7σ, and we measure a linear bias b = 1.61 ± 0.22, consistent with clustering analyses. Using an independent lensing map, derived from Planck observations, to measure the cross-spectrum, we find excellent agreement with the SPT analysis. The bias of the combined sample of Type 1 and 2 quasars determined in this work is similar to that previously determined for Type 1 quasars alone; we conclude that obscured and unobscured quasars trace the matter field in a similar way. This result has implications for our understanding of quasar unification and evolution schemes.

  18. Hubble Space Telescope WFC3 Early Release Science: Emission-Line Galaxies from Infrared Grism Observations

    OpenAIRE

    Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S H; Gardner, J P; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.; McCarthy, P. J.; Hathi, N. P.; Malhotra, S; Rhoads, J.; Balick, B.

    2010-01-01

    We present grism spectra of emission-line galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 on the Hubble Space Telescope. These new infrared grism data augment previous optical Advanced Camera for Surveys G800L 0.6-0.95 micron grism data in GOODS-South from the PEARS program, extending the wavelength covereage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are ...

  19. Infrared Sky Surveys

    Science.gov (United States)

    Price, Stephan D.

    2009-02-01

    A retrospective is given on infrared sky surveys from Thomas Edison’s proposal in the late 1870s to IRAS, the first sensitive mid- to far-infrared all-sky survey, and the mid-1990s experiments that filled in the IRAS deficiencies. The emerging technology for space-based surveys is highlighted, as is the prominent role the US Defense Department, particularly the Air Force, played in developing and applying detector and cryogenic sensor advances to early mid-infrared probe-rocket and satellite-based surveys. This technology was transitioned to the infrared astronomical community in relatively short order and was essential to the success of IRAS, COBE and ISO. Mention is made of several of the little known early observational programs that were superseded by more successful efforts.

  20. Variability of particulate organic carbon concentration in the north polar Atlantic based on ocean color observations with Sea-viewing Wide Field-of-view Sensor (SeaWiFS)

    Science.gov (United States)

    Stramska, Malgorzata; Stramski, Dariusz

    2005-01-01

    We use satellite data from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to investigate distributions of particulate organic carbon (POC) concentration in surface waters of the north polar Atlantic Ocean during the spring summer season (April through August) over a 6-year period from 1998 through 2003. By use of field data collected at sea, we developed regional relationships for the purpose of estimating POC from remote-sensing observations of ocean color. Analysis of several approaches used in the POC algorithm development and match-up analysis of coincident in situ derived and satellite-derived estimates of POC resulted in selection of an algorithm that is based on the blue-to-green ratio of remote-sensing reflectance R(sub rs) (or normalized water-leaving radiance L(sub wn)). The application of the selected algorithm to a 6-year record of SeaWiFS monthly composite data of L(sub wn) revealed patterns of seasonal and interannual variability of POC in the study region. For example, the results show a clear increase of POC throughout the season. The lowest values, generally less than 200 mg per cubic meters, and at some locations often less than 50 mg per cubic meters, were observed in April. In May and June, POC can exceed 300 or even 400 mg per cubic meters in some parts of the study region. Patterns of interannual variability are intricate, as they depend on the geographic location within the study region and particular time of year (month) considered. By comparing the results averaged over the entire study region and the entire season (April through August) for each year separately, we found that the lowest POC occurred in 2001 and the highest POC occurred in 2002 and 1999.

  1. A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs

    Science.gov (United States)

    Zhou, Yifan; Apai, Dániel; Lew, Ben W. P.; Schneider, Glenn

    2017-06-01

    The Hubble Space Telescope Wide Field Camera 3 (WFC3) near-IR channel is extensively used in time-resolved observations, especially for transiting exoplanet spectroscopy as well as brown dwarf and directly imaged exoplanet rotational phase mapping. The ramp effect is the dominant source of systematics in the WFC3 for time-resolved observations, which limits its photometric precision. Current mitigation strategies are based on empirical fits and require additional orbits to help the telescope reach a thermal equilibrium. We show that the ramp-effect profiles can be explained and corrected with high fidelity using charge trapping theories. We also present a model for this process that can be used to predict and to correct charge trap systematics. Our model is based on a very small number of parameters that are intrinsic to the detector. We find that these parameters are very stable between the different data sets, and we provide best-fit values. Our model is tested with more than 120 orbits (∼40 visits) of WFC3 observations and is proved to be able to provide near photon noise limited corrections for observations made with both staring and scanning modes of transiting exoplanets as well as for starting-mode observations of brown dwarfs. After our model correction, the light curve of the first orbit in each visit has the same photometric precision as subsequent orbits, so data from the first orbit no longer need to be discarded. Near-IR arrays with the same physical characteristics (e.g., JWST/NIRCam) may also benefit from the extension of this model if similar systematic profiles are observed.

  2. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  3. Integrated photonics for infrared spectroscopic sensing

    Science.gov (United States)

    Lin, Hongtao; Kita, Derek; Han, Zhaohong; Su, Peter; Agarwal, Anu; Yadav, Anupama; Richardson, Kathleen; Gu, Tian; Hu, Juejun

    2017-05-01

    Infrared (IR) spectroscopy is widely recognized as a gold standard technique for chemical analysis. Traditional IR spectroscopy relies on fragile bench-top instruments located in dedicated laboratory settings, and is thus not suitable for emerging field-deployed applications such as in-line industrial process control, environmental monitoring, and point-ofcare diagnosis. Recent strides in photonic integration technologies provide a promising route towards enabling miniaturized, rugged platforms for IR spectroscopic analysis. Chalcogenide glasses, the amorphous compounds containing S, Se or Te, have stand out as a promising material for infrared photonic integration given their broadband infrared transparency and compatibility with silicon photonic integration. In this paper, we discuss our recent work exploring integrated chalcogenide glass based photonic devices for IR spectroscopic chemical analysis, including on-chip cavityenhanced chemical sensing and monolithic integration of mid-IR waveguides with photodetectors.

  4. Low-mass Stars with Extreme Mid-Infrared Excesses: Potential Signatures of Planetary Collisions

    Science.gov (United States)

    Theissen, Christopher; West, Andrew

    2018-01-01

    I investigate the occurrence of extreme mid-infrared (MIR) excesses, a tracer of large amounts of dust orbiting stars, in low-mass stellar systems. Extreme MIR excesses, defined as an excess IR luminosity greater than 1% of the stellar luminosity (LIR/L* ≥ 0.01), have previously only been observed around a small number of solar-mass (M⊙) stars. The origin of this excess has been hypothesized to be massive amounts of orbiting dust, created by collisions between terrestrial planets or large planetesimals. Until recently, there was a dearth of low-mass (M* ≤ 0.6M⊙) stars exhibiting extreme MIR excesses, even though low-mass stars are ubiquitous (~70% of all stars), and known to host multiple terrestrial planets (≥ 3 planets per star).I combine the spectroscopic sample of low-mass stars from the Sloan Digital Sky Survey (SDSS) Data Release 7 (70,841 stars) with MIR photometry from the Wide-field Infrared Survey Explorer (WISE), to locate stars exhibiting extreme MIR excesses. I find the occurrence frequency of low-mass field stars (stars with ages ≥ 1 Gyr) exhibiting extreme MIR excesses is much larger than that for higher-mass field stars (0.41 ± 0.03% versus 0.00067 ± 0.00033%, respectively).In addition, I build a larger sample of low-mass stars based on stellar colors and proper motions using SDSS, WISE, and the Two-Micron All-Sky Survey (8,735,004 stars). I also build a galactic model to simulate stellar counts and kinematics to estimate the number of stars missing from my sample. I perform a larger, more complete study of low-mass stars exhibiting extreme MIR excesses, and find a lower occurrence frequency (0.020 ± 0.001%) than found in the spectroscopic sample but that is still orders of magnitude larger than that for higher-mass stars. I find a slight trend for redder stars (lower-mass stars) to exhibit a higher occurrence frequency of extreme MIR excesses, as well as a lower frequency with increased stellar age. These samples probe important

  5. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  6. NEAR-INFRARED THERMAL EMISSION DETECTIONS OF A NUMBER OF HOT JUPITERS AND THE SYSTEMATICS OF GROUND-BASED NEAR-INFRARED PHOTOMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Croll, Bryce [5525 Olund Road, Abbotsford, B.C. (Canada); Albert, Loic; Lafreniere, David [Département de physique, Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7 (Canada); Jayawardhana, Ray [Department of Physics and Astronomy, York University, Toronto, ON L3T 3R1 (Canada); Cushing, Michael [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Moutou, Claire [Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Highway, Kamuela, HI 96743 (United States); Johnson, John Asher [Harvard-Smithsonian Center for Astrophysics, Institute for Theory and Computation, 60 Garden St, MS-51, Cambridge, MA 02138 (United States); Bonomo, Aldo S. [INAF-Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese (Italy); Deleuil, Magali [Aix Marseille University, CNRS, LAM (Laboratoire d' Astrophysique de Marseille), UMR 7326, F-13388 Marseille cedex 13 (France); Fortney, Jonathan, E-mail: croll@space.mit.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2015-03-20

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K {sub CONT}-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations.

  7. An extinction-free AGN selection by 18-band SED fitting in mid-infrared in the AKARI NEP deep field

    Science.gov (United States)

    Huang, Ting-Chi; Goto, Tomotsugu; Hashimoto, Tetsuya; Oi, Nagisa; Matsuhara, Hideo

    2017-11-01

    We have developed an efficient active galactic nucleus (AGN) selection method using 18-band spectral energy distribution (SED) fitting in mid-infrared (mid-IR). AGNs are often obscured by gas and dust, and those obscured AGNs tend to be missed in optical, UV and soft X-ray observations. Mid-IR light can help us to recover them in an obscuration-free way using their thermal emission. On the other hand, star-forming galaxies (SFGs) also have strong polycyclic aromatic hydrocarbon emission features in mid-IR. Hence, establishing an accurate method to separate populations of AGNs and SFGs is important. However, in previous mid-IR surveys, only three or four filters were available, and thus the selection was limited. We combined AKARI's continuous nine mid-IR bands with Wide field Infrared Survey Explorer (WISE) and Spitzer data to create 18 mid-IR bands for AGN selection. Among 4682 galaxies in the AKARI north ecliptic pole deep field, 1388 are selected to be AGN hosts, which implies an AGN fraction of 29.6 ± 0.8 per cent (among them 47 per cent are Seyfert 1.8 and 2). Comparing the result from SED fitting into WISE and Spitzer colour-colour diagram reveals that Seyferts are often missed by previous studies. Our result has been tested by stacking median magnitude for each sample. Using X-ray data from Chandra, we compared the result of our SED fitting with WISE's colour box selection. We recovered more X-ray detected AGNs than previous methods by 20 per cent.

  8. A Wide-Field Study of the z ~ 0.8 Cluster RX J0152.7-1357: The Role of Environment in the Formation of the Red Sequence

    Science.gov (United States)

    Patel, Shannon G.; Kelson, Daniel D.; Holden, Bradford P.; Illingworth, Garth D.; Franx, Marijn; van der Wel, Arjen; Ford, Holland

    2009-04-01

    We present the first results from the largest spectroscopic survey to date of an intermediate redshift galaxy cluster, the z = 0.834 cluster RX J0152.7-1357. We use the colors of galaxies, assembled from a D ~ 12 Mpc region centered on the cluster, to investigate the properties of the red sequence as a function of density and clustercentric radius. Our wide-field multislit survey with a low-dispersion prism in the Inamori Magellan Areal Camera and Spectrograph at the 6.5 m Baade telescope allowed us to identify 475 new members of the cluster and its surrounding large-scale structure with a redshift accuracy of σ z /(1 + z) ≈ 1% and a contamination rate of ~2% for galaxies with i' 4 × 1010 M sun (log M/M sun>10.6). We find that the red galaxy fraction is 93 ± 3% in the two merging cores of the cluster and declines to a level of 64 ± 3% at projected clustercentric radii R gsim 3 Mpc. At these large projected distances, the correlation between clustercentric radius and local density is nonexistent. This allows an assessment of the influence of the local environment on galaxy evolution, as opposed to mechanisms that operate on cluster scales (e.g., harassment, ram-pressure stripping). Even beyond R>3 Mpc we find an increasing fraction of red galaxies with increasing local density. The red galaxy fraction at the highest local densities in two large groups at R>3 Mpc matches the red galaxy fraction found in the two cores. Strikingly, galaxies at intermediate densities at R>3 Mpc, that are not obvious members of groups, also show signs of an enhanced red galaxy fraction. Our results point to such intermediate-density regions and the groups in the outskirts of the cluster, as sites where the local environment influences the transition of galaxies onto the red sequence. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California

  9. Exploration Review

    Science.gov (United States)

    Wilburn, D.R.; Stanley, K.A.

    2013-01-01

    This summary of international mineral exploration activities for 2012 draws upon information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration for 2012: 1) budgetary statistics expressed in U.S. nominal dollars provided by SNL Metals Economics Group (MEG) of Halifax, Nova Scotia; 2) regional and site-specific exploration activities that took place in 2012 as compiled by the USGS and 3) regional events including economic, social and political conditions that affected exploration activities, which were derived from published sources and unpublished discussions with USGS and industry specialists.

  10. Exploration technology

    Energy Technology Data Exchange (ETDEWEB)

    Roennevik, H.C. [Saga Petroleum A/S, Forus (Norway)

    1996-12-31

    The paper evaluates exploration technology. Topics discussed are: Visions; the subsurface challenge; the creative tension; the exploration process; seismic; geology; organic geochemistry; seismic resolution; integration; drilling; value creation. 4 refs., 22 figs.

  11. Emerging technologies for high performance infrared detectors

    OpenAIRE

    Tan Chee Leong; Mohseni Hooman

    2018-01-01

    Infrared photodetectors (IRPDs) have become important devices in various applications such as night vision, military missile tracking, medical imaging, industry defect imaging, environmental sensing, and exoplanet exploration. Mature semiconductor technologies such as mercury cadmium telluride and III–V material-based photodetectors have been dominating the industry. However, in the last few decades, significant funding and research has been focused to improve the performance of IRPDs such as...

  12. Infrared source test

    Energy Technology Data Exchange (ETDEWEB)

    Ott, L.

    1994-11-15

    The purpose of the Infrared Source Test (IRST) is to demonstrate the ability to track a ground target with an infrared sensor from an airplane. The system is being developed within the Advance Technology Program`s Theater Missile Defense/Unmanned Aerial Vehicle (UAV) section. The IRST payload consists of an Amber Radiance 1 infrared camera system, a computer, a gimbaled mirror, and a hard disk. The processor is a custom R3000 CPU board made by Risq Modular Systems, Inc. for LLNL. The board has ethernet, SCSI, parallel I/O, and serial ports, a DMA channel, a video (frame buffer) interface, and eight MBytes of main memory. The real-time operating system VxWorks has been ported to the processor. The application code is written in C on a host SUN 4 UNIX workstation. The IRST is the result of a combined effort by physicists, electrical and mechanical engineers, and computer scientists.

  13. Variable waveband infrared imager

    Science.gov (United States)

    Hunter, Scott R.

    2013-06-11

    A waveband imager includes an imaging pixel that utilizes photon tunneling with a thermally actuated bimorph structure to convert infrared radiation to visible radiation. Infrared radiation passes through a transparent substrate and is absorbed by a bimorph structure formed with a pixel plate. The absorption generates heat which deflects the bimorph structure and pixel plate towards the substrate and into an evanescent electric field generated by light propagating through the substrate. Penetration of the bimorph structure and pixel plate into the evanescent electric field allows a portion of the visible wavelengths propagating through the substrate to tunnel through the substrate, bimorph structure, and/or pixel plate as visible radiation that is proportional to the intensity of the incident infrared radiation. This converted visible radiation may be superimposed over visible wavelengths passed through the imaging pixel.

  14. Infrared drying of strawberry.

    Science.gov (United States)

    Adak, Nafiye; Heybeli, Nursel; Ertekin, Can

    2017-03-15

    The effects of different drying conditions, such as infrared power, drying air temperature and velocity, on quality of strawberry were evaluated. Drying time decreased with increased infrared power, air temperature and velocity. An increase in power from 100W to 300W, temperature from 60 to 80°C and velocity from 1.0m.s(-1) to 2.0m.s(-1) decreased fruit color quality index. For total phenol and anthocyanin content, 300W, 60°C, and 1.0m.s(-1) were superior to the other experimental conditions. The drying processes increased N, P and K and decreased Ca, Mg, Fe, Mn, Zn and Cu contents. The optimal conditions to preserve nutrients in infrared drying of strawberry were 200W, 100°C and 1.5m.s(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Near infrared spectroscopy of food systems using a supercontinuum laser

    DEFF Research Database (Denmark)

    Ringsted, Tine

    Mid-infrared and particularly near-infrared spectroscopy is extremely useful for food analysis because they measure chemical and physical properties fast and non-destructively. The advancement of a supercontinuum light source covering the near-infrared and parts of the ultraviolet and mid......)) can be obtained, (c) that the supercontinuum light is fiber compatible i.e. it can couple directly to fibers, and (d) that the fast repetition rate of the supercontinuum pulses makes it possible to do very fast measurements. For these reasons, the supercontinuum light stands out from the commonly...... applied near- and mid-infrared incandescent light bulbs. This thesis aim to explore the utility of using a supercontinuum source in two food applications. (1) The supercontinuum light was applied for the first time to barley seeds in transmission mode in the long wavelength near-infrared region from 2260...

  16. A wide-FoV athermalized infrared imaging system with a two-element lens

    Science.gov (United States)

    Feng, Bin; Shi, Zelin; Zhao, Yaohong; Liu, Haizheng; Liu, Li

    2017-12-01

    For infrared imaging systems to achieve wide field of view (FoV), wide operating temperature and low weight, this work designs a wide-FoV athermalized infrared imaging system (AIIS) with a two-element lens. Its principle, design, manufacture, measurement and performance validation are successively discussed. The two-element lens contains four surfaces, where three aspheric surfaces are introduced to reduce optical off-axis aberrations and a cubic surface is introduced to achieve athermalization. The key coding mask containing an aspheric surface and a cubic surface is manufactured by nano-metric machining of ion implanted material (NiIM). Experimental results validate that our wide-FoV wavefront coding AIIS has a full FoV of 26.10° and an operating temperature over -20 °C to +70 °C.

  17. Compact infrared cryogenic wafer-level camera: design and experimental validation.

    Science.gov (United States)

    de la Barrière, Florence; Druart, Guillaume; Guérineau, Nicolas; Lasfargues, Gilles; Fendler, Manuel; Lhermet, Nicolas; Taboury, Jean

    2012-03-10

    We present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120°. By merging the optics with the detector, the concept is compatible with both cryogenic constraints and wafer-level fabrication. The design strategy of such a camera is described, as well as its fabrication and integration process. Its characterization has been carried out in terms of the modulation transfer function and the noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images.

  18. FIGS—Faint Infrared Grism Survey: Description and Data Reduction

    Science.gov (United States)

    Pirzkal, Norbert; Malhotra, Sangeeta; Ryan, Russell E.; Rothberg, Barry; Grogin, Norman; Finkelstein, Steven L.; Koekemoer, Anton M.; Rhoads, James; Larson, Rebecca L.; Christensen, Lise; Cimatti, Andrea; Ferreras, Ignacio; Gardner, Jonathan P.; Gronwall, Caryl; Hathi, Nimish P.; Hibon, Pascale; Joshi, Bhavin; Kuntschner, Harald; Meurer, Gerhardt R.; O'Connell, Robert W.; Oestlin, Goeran; Pasquali, Anna; Pharo, John; Straughn, Amber N.; Walsh, Jeremy R.; Watson, Darach; Windhorst, Rogier A.; Zakamska, Nadia L.; Zirm, Andrew

    2017-09-01

    The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 μm-1.15 μm continuous coverage) with a total exposure time of 40 orbits (≈100 kilo-seconds) per field. This reaches a 3σ continuum depth of ≈ 26 AB magnitudes and probes emission lines to ˜ {10}-17 {erg} {{{s}}}-1 {{cm}}-2. This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than {m}F105W=26.5 mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey.

  19. Compression of Infrared images

    DEFF Research Database (Denmark)

    Mantel, Claire; Forchhammer, Søren

    2017-01-01

    This paper investigates the compression of infrared images with three codecs: JPEG2000, JPEG-XT and HEVC. Results are evaluated in terms of SNR, Mean Relative Squared Error (MRSE) and the HDR-VDP2 quality metric. JPEG2000 and HEVC perform fairy similar and better than JPEG-XT. JPEG2000 performs...

  20. Infrared Celestial Backgrounds Studies

    Science.gov (United States)

    Walker, Russell G.; Cohen, Martin

    1998-09-01

    The purpose of this program was to extend and improve the present capability to predict celestial phenomenology pertinent to the design and successful operation of space based surveillance systems using the ultraviolet, optical, and infrared spectral regions. We pursued this goal through analysis and application of existing datasets and, in particular, by analysis of new satellite measurements that became available during the course of the project. Our work was concentrated in four major areas: (1) extension of an existing analytical model of the infrared point source sky (SKY), (2) development of a set of absolutely calibrated spectral stellar irradiance standards for the infrared, (3) analysis of new celestial data obtained by satellite, and (4) support of the infrared celestial measurements taken by the Midcourse Space Experiment (MSX) satellite. Volume 1 summarizes the work performed under the contract, and includes reprints of the major papers published during the contractual period. Volume 2 presents the final release of an all sky network of 422 stars with absolutely calibrated stellar spectra in the 1.2 to 35 um region. Volume 2 also contains reprints of the complete series of published papers documenting the spectral calibration process and assumptions.

  1. Decoherence and infrared divergence

    Indian Academy of Sciences (India)

    Abstract. The dynamics of a particle which is linearly coupled to a boson field is investigated. The boson field induces superselection rules for the momentum of the particle, if the field is infrared divergent. Thereby the Hamiltonian of the total system remains bounded from below.

  2. Infrared upconversion hyperspectral imaging

    DEFF Research Database (Denmark)

    Kehlet, Louis Martinus; Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin

    2015-01-01

    conversion process. From this, a sequence of monochromatic images in the 3.2-3.4 mu m range is generated. The imaged object consists of a standard United States Air Force resolution target combined with a polystyrene film, resulting in the presence of both spatial and spectral information in the infrared...

  3. Infrared up-conversion telescope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented to an up-conversion infrared telescope (110) arranged for imaging an associated scene (130), wherein the up-conversion infrared telescope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein a first optical...

  4. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...

  5. Bringing the infrared to light

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    Infrared imaging is usually done by use of infrared cameras. We present an effective alternative approach where infrared light is converted to near visible light in a non-linear process, and then detected by low cost, high performance camera. The approach is generic and can be applied towards many...

  6. Memory and the infrared

    Science.gov (United States)

    Gomez, Cesar; Letschka, Raoul

    2017-10-01

    Memory effects in scattering processes are described in terms of the asymptotic retarded fields. These fields are completely determined by the scattering data and the zero mode part is set by the soft photon theorem. The dressed asymptotic states defining an infrared finite S-matrix for charged particles can be defined as quantum coherent states using the corpuscular resolution of the asymptotic retarded fields. Imposing that the net radiated energy in the scattering is zero leads to the new set of conservation laws for the scattering S-matrix which are equivalent to the decoupling of the soft modes. The actual observability of the memory requires a non-vanishing radiated energy and could be described using the infrared part of the differential cross section that only depends on the scattering data and the radiated energy. This is the IR safe cross section with any number of emitted photons carrying total energy equal to the energy involved in the actual memory detection.

  7. UVUDF: Ultraviolet Through Near-infrared Catalog and Photometric Redshifts of Galaxies in the Hubble Ultra Deep Field

    OpenAIRE

    Rafelski, Marc; Teplitz, Harry I.; Colbert, James W.; Hanish, Daniel J.

    2015-01-01

    We present photometry and derived redshifts from up to eleven bandpasses for 9927 galaxies in the Hubble Ultra Deep field (UDF), covering an observed wavelength range from the near-ultraviolet (NUV) to the near-infrared (NIR) with Hubble Space Telescope observations. Our Wide Field Camera 3 (WFC3)/UV F225W, F275W, and F336W image mosaics from the ultra-violet UDF (UVUDF) imaging campaign are newly calibrated to correct for charge transfer inefficiency, and use new dark calibrations to minimiz...

  8. The VISTA infrared camera

    Science.gov (United States)

    Dalton, G. B.; Caldwell, M.; Ward, A. K.; Whalley, M. S.; Woodhouse, G.; Edeson, R. L.; Clark, P.; Beard, S. M.; Gallie, A. M.; Todd, S. P.; Strachan, J. M. D.; Bezawada, N. N.; Sutherland, W. J.; Emerson, J. P.

    2006-06-01

    We describe the integration and test phase of the construction of the VISTA Infrared Camera, a 64 Megapixel, 1.65 degree field of view 0.9-2.4 micron camera which will soon be operating at the cassegrain focus of the 4m VISTA telescope. The camera incorporates sixteen IR detectors and six CCD detectors which are used to provide autoguiding and wavefront sensing information to the VISTA telescope control system.

  9. Infrared Semiconductor Metamaterials

    Science.gov (United States)

    2016-09-01

    AFRL-AFOSR-VA-TR-2016-0310 Infrared Semiconductor Metamaterials Jon Schuller UNIVERSITY OF CALIFORNIA SANTA BARBARA 3227 CHEADLE HL SANTA BARBARA, CA...S) AND ADDRESS(ES) University of California , Santa Barbara Office of Research, 3227 Cheadle Hall Santa Barbara, CA 93106-2050 8. PERFORMING...Using Heterojunction Resonators. Advanced Optical Materials, available online (2016). New discoveries, inventions, or patent disclosures: Do you have

  10. Integrated infrared array technology

    Science.gov (United States)

    Goebel, J. H.; Mccreight, C. R.

    1987-01-01

    An overview of integrated infrared (IR) array technology is presented. Although the array pixel formats are smaller, and the readout noise of IR arrays is larger than the corresponding values achieved with optical charge-coupled-device silicon technology, substantial progress is being made in IR technology. Both existing IR arrays and those being developed are described. Examples of astronomical images are given which illustrate the potential of integrated IR arrays for scientific investigations.

  11. Infrared diode lasers

    Science.gov (United States)

    Lo, Wayne

    1981-01-01

    This paper reviews the development of infrared diode lasers for automobile exhaust gas analysis and high resolution spectroscopy at the General Motors Research Laboratories. Advances in lead-salt crystal growth technology and laser fabrication techniques to achieve high temperature operation and wide frequency tuning range will be discussed. Recent developments in improving the long-term reliability of the laser will also be reviewed.

  12. Ultrafast infrared vibrational spectroscopy

    CERN Document Server

    Fayer, Michael D

    2013-01-01

    The past ten years or so have seen the introduction of multidimensional methods into infrared and optical spectroscopy. The technology of multidimensional spectroscopy is developing rapidly and its applications are spreading to biology and materials science. Edited by a recognized leader in the field and with contributions from top researchers, including experimentalists and theoreticians, this book presents the latest research methods and results and will serve as an excellent resource for other researchers.

  13. Exploring process dynamics by near infrared spectroscopy in lactic fermentations

    DEFF Research Database (Denmark)

    Svendsen, Carina; Cieplak, Tomasz; van der Berg, Franciscus Winfried J

    2016-01-01

    In the industrial production of yoghurt, measurement of pH is normally the only in-line technique applied as a real-time monitoring signalfor following the dynamics during the fermentation process. However, every dairy company would benefit from an in-line technique giving information about...

  14. Theoretical design of near - infrared organic compounds

    Science.gov (United States)

    Brymora, Katarzyna; Ducasse, Laurent; Dautel, Olivier; Lartigau-Dagron, Christine; Castet, FréDéRic

    The world follows the path of digital development faster than ever before. In consequence, the Human Machine Interfaces (HMI) market is growing as well and it requires some innovations. The goal of our work is to achieve an organic Infra-Red (IR) photodetectors hitting the performance requirements for HMI applications. The quantum chemical calculations are used to guide the synthesis and technology development. In this work, in the framework of density functional theory (DFT) and time-dependent density functional theory (TD-DFT), we consider a large variety of materials exploring small donor-acceptor-donor molecules and copolymers alternating donor and acceptor monomers. We provide a structure-property relationship in view of designing new Near-Infrared (NIR) absorbing organic molecules and polymers.

  15. Space exploration

    National Research Council Canada - National Science Library

    Chris Moore

    2012-01-01

      Here, Moore presents a year in review on space exploration programs. This 2012 NASA's strategy of stimulating the development of commercial capabilities to launch crew and cargo to the ISS began to pay off...

  16. Investigation of skin structures based on infrared wave parameter indirect microscopic imaging

    Science.gov (United States)

    Zhao, Jun; Liu, Xuefeng; Xiong, Jichuan; Zhou, Lijuan

    2017-02-01

    Detailed imaging and analysis of skin structures are becoming increasingly important in modern healthcare and clinic diagnosis. Nanometer resolution imaging techniques such as SEM and AFM can cause harmful damage to the sample and cannot measure the whole skin structure from the very surface through epidermis, dermis to subcutaneous. Conventional optical microscopy has the highest imaging efficiency, flexibility in onsite applications and lowest cost in manufacturing and usage, but its image resolution is too low to be accepted for biomedical analysis. Infrared parameter indirect microscopic imaging (PIMI) uses an infrared laser as the light source due to its high transmission in skins. The polarization of optical wave through the skin sample was modulated while the variation of the optical field was observed at the imaging plane. The intensity variation curve of each pixel was fitted to extract the near field polarization parameters to form indirect images. During the through-skin light modulation and image retrieving process, the curve fitting removes the blurring scattering from neighboring pixels and keeps only the field variations related to local skin structures. By using the infrared PIMI, we can break the diffraction limit, bring the wide field optical image resolution to sub-200nm, in the meantime of taking advantage of high transmission of infrared waves in skin structures.

  17. Dressed infrared quantum information

    Science.gov (United States)

    Carney, Daniel; Chaurette, Laurent; Neuenfeld, Dominik; Semenoff, Gordon Walter

    2018-01-01

    We study information-theoretic aspects of the infrared sector of quantum electrodynamics, using the dressed-state approach pioneered by Chung, Kibble, Faddeev-Kulish, and others. In this formalism QED has an IR-finite S -matrix describing the scattering of electrons dressed by coherent states of photons. We show that measurements sensitive only to the outgoing electronic degrees of freedom will experience decoherence in the electron momentum basis due to unobservable photons in the dressing. We make some comments on possible refinements of the dressed-state formalism, and how these considerations relate to the black hole information paradox.

  18. Infrared Quantum Information

    Science.gov (United States)

    Carney, Daniel; Chaurette, Laurent; Neuenfeld, Dominik; Semenoff, Gordon Walter

    2017-11-01

    We discuss information-theoretic properties of low-energy photons and gravitons in the S matrix. Given an incoming n -particle momentum eigenstate, we demonstrate that unobserved soft photons decohere nearly all outgoing momentum superpositions of charged particles, while the universality of gravity implies that soft gravitons decohere nearly all outgoing momentum superpositions of all the hard particles. Using this decoherence, we compute the entanglement entropy of the soft bosons and show that it is infrared-finite when the leading divergences are resummed in the manner of Bloch and Nordsieck.

  19. Atmospheric Infrared Radiance Variability.

    Science.gov (United States)

    1981-05-27

    ATMOSPHERIC VARIABILITY ON INFRARED RADIANCE PREDICTIONS - T. C. Degges 53 5. ATMOSPHERIC STRUCTURE - C.H. HLmphrey, C.R. Philbrick, S.M. Silverman , T.F. Tuan...variations similar to those shown in Figure 2. In arctic and subarctic regions, sudden warmings and coolings of the winter stratosphere and mesosphere... Silverman \\Jr I",rre. (;.L~~sIalmratorN Hanscom Air Force Base, Manss. T.F. Tuan Universitv of Cincinnati Cincinnati, (tio M. Anapol S.S.G.. Inc. Waltham

  20. Complementary Barrier Infrared Detector

    Science.gov (United States)

    Ting, David Z.; Bandara, Sumith V.; Hill, Cory J.; Gunapala, Sarath D.

    2009-01-01

    The complementary barrier infrared detector (CBIRD) is designed to eliminate the major dark current sources in the superlattice infrared detector. The concept can also be applied to bulk semiconductor- based infrared detectors. CBIRD uses two different types of specially designed barriers: an electron barrier that blocks electrons but not holes, and a hole barrier that blocks holes but not electrons. The CBIRD structure consists of an n-contact, a hole barrier, an absorber, an electron barrier, and a p-contact. The barriers are placed at the contact-absorber junctions where, in a conventional p-i-n detector structure, there normally are depletion regions that produce generation-recombination (GR) dark currents due to Shockley-Read- Hall (SRH) processes. The wider-bandgap complementary barriers suppress G-R dark current. The barriers also block diffusion dark currents generated in the diffusion wings in the neutral regions. In addition, the wider gap barriers serve to reduce tunneling dark currents. In the case of a superlattice-based absorber, the superlattice itself can be designed to suppress dark currents due to Auger processes. At the same time, the barriers actually help to enhance the collection of photo-generated carriers by deflecting the photo-carriers that are diffusing in the wrong direction (i.e., away from collectors) and redirecting them toward the collecting contacts. The contact layers are made from materials with narrower bandgaps than the barriers. This allows good ohmic contacts to be made, resulting in lower contact resistances. Previously, THALES Research and Technology (France) demonstrated detectors with bulk InAsSb (specifically InAs0.91Sb0.09) absorber lattice-matched to GaSb substrates. The absorber is surrounded by two wider bandgap layers designed to minimize impedance to photocurrent flow. The wide bandgap materials also serve as contacts. The cutoff wavelength of the InAsSb absorber is fixed. CBIRD may be considered as a modified

  1. Frequency selective infrared sensors

    Science.gov (United States)

    Davids, Paul; Peters, David W

    2013-05-28

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  2. Infrared diffuse interstellar bands

    Science.gov (United States)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

    2017-05-01

    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  3. WINGS: WFIRST Infrared Nearby Galaxy Survey

    Science.gov (United States)

    Williams, Benjamin

    WFIRST's combination of wide field and high resolution will revolutionize the study of nearby galaxies. We propose to produce and analyze simulated WFIRST data of nearby galaxies and their halos to maximize the scientific yield in the limited observing time available, ensuring the legacy value of WFIRST's eventual archive. We will model both halo structure and resolved stellar populations to optimize WFIRST's constraints on both dark matter and galaxy formation models in the local universe. WFIRST can map galaxy structure down to ~35 mag/square arcsecond using individual stars. The resulting maps of stellar halos and accreting dwarf companions will provide stringent tests of galaxy formation and dark matter models on galactic (and even sub-galactic) scales, which is where the most theoretical tension exists with the Lambda-CDM model. With a careful, coordinated plan, WFIRST can be expected to improve current sample sizes by 2 orders of magnitude, down to surface brightness limits comparable to those currently reached only in the Local Group, and that are >4 magnitudes fainter than achievable from the ground due to limitations in star-galaxy separation. WFIRST's maps of galaxy halos will simultaneously produce photometry for billions of stars in the main bodies of galaxies within 10 Mpc. These data will transform studies of star formation histories that track stellar mass growth as a function of time and position within a galaxy. They also will constrain critical stellar evolution models of the near-infrared bright, rapidly evolving stars that can contribute significantly to the integrated light of galaxies in the near-infrared. Thus, with WFIRST we can derive the detailed evolution of individual galaxies, reconstruct the complete history of star formation in the nearby universe, and put crucial constraints on the theoretical models used to interpret near-infrared extragalactic observations. We propose a three-component work plan that will ensure these gains by

  4. Farside explorer

    DEFF Research Database (Denmark)

    Mimoun, David; Wieczorek, Mark A.; Alkalai, Leon

    2012-01-01

    Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of the Moon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded...... the primary differentiation and evolution of the Moon, it can be continuously monitored from the Earth-Moon L2 Lagrange point, and there is a complete lack of reflected solar illumination from the Earth. Farside Explorer will exploit these properties and make the first radio-astronomy measurements from...... the most radio-quiet region of near-Earth space, determine the internal structure and thermal evolution of the Moon, from crust to core, and quantify impact hazards in near-Earth space by the measurement of flashes generated by impact events. The Farside Explorer flight system includes two identical solar...

  5. 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...

  6. Mid-Infrared Lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mid Infrared DIAL systems can provide vital data needed by atmospheric scientists to understand atmospheric chemistry. The Decadal Survey recommended missions, such...

  7. Discriminating oat and groat kernels from other grains using near infrared spectroscopy

    Science.gov (United States)

    Oat and groats can be discriminated from other grains such as barley, wheat, rye, and triticale (non-oats) using near infrared spectroscopy. The two instruments tested were the manual version of the ARS-USDA Single Kernel Near Infrared (SKNIR) and the automated QualySense QSorter Explorer high-speed...

  8. Near-infrared Thermal Emission Detections of a Number of Hot Jupiters and the Systematics of Ground-based Near-infrared Photometry

    Science.gov (United States)

    Croll, Bryce; Albert, Loic; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Lafreniere, David; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

    2015-03-01

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K CONT-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations. Based on observations obtained with WIRCam, a joint project of Canada-France-Hawaii Telescope (CFHT), Taiwan, Korea, Canada, France, at the CFHT, which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

  9. Nanostructures graphene plasmon works close to near-infrared window

    DEFF Research Database (Denmark)

    Wang, Zhongli; Li, Tao; Almdal, Kristoffer

    Due to strong mode-confinement, long propagation-distance, and unique tunability, graphene plasmons have been widely explored in the mid-infrared and terahertz windows. However, it remains a big challenge to push graphene plasmons to shorter wavelengths in order to integrate graphene plasmon...

  10. Infrared thermal imaging for automated detection of diabetic foot complications

    NARCIS (Netherlands)

    van Netten, Jaap J.; van Baal, Jeff G.; Liu, Chanjuan; van der Heijden, Ferdi; Bus, Sicco A.

    2013-01-01

    Although thermal imaging can be a valuable technology in the prevention and management of diabetic foot disease, it is not yet widely used in clinical practice. Technological advancement in infrared imaging increases its application range. The aim was to explore the first steps in the applicability

  11. Infrared thermal imaging for automated detection of diabetic foot complications

    NARCIS (Netherlands)

    van Netten, Jaap J.; van Baal, Jeff G.; Liu, C.; van der Heijden, Ferdinand; Bus, Sicco A.

    Background: Although thermal imaging can be a valuable technology in the prevention and management of diabetic foot disease, it is not yet widely used in clinical practice. Technological advancement in infrared imaging increases its application range. The aim was to explore the first steps in the

  12. Fourier–transform infrared spectroscopic characterization of natu ...

    Indian Academy of Sciences (India)

    WINTEC

    Essen E J and Fisher D C 1986 Science 234 189. Frondel C 1962 in Dana's system of minerology, 'Fulgurite'. Encyclopedia Britannica (New York: Wiley) p. 321. Jayakaran S C 1998 Curr. Sci. 75 765. King P L, McMillan P F and Moore G M 2004 Infrared spectro- scopy in geochemistry, exploration geochemistry and remote.

  13. Affordable, Accessible, Immediate: Capture Stunning Images with Digital Infrared Photography

    Science.gov (United States)

    Snyder, Mark

    2011-01-01

    Technology educators who teach digital photography should consider incorporating an infrared (IR) photography component into their program. This is an area where digital photography offers significant benefits. Either type of IR imaging is very interesting to explore, but traditional film-based IR photography is difficult and expensive. In…

  14. EXPLORING THE VARIABLE SKY WITH LINEAR. III. CLASSIFICATION OF PERIODIC LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Palaversa, Lovro; Eyer, Laurent; Rimoldini, Lorenzo [Observatoire Astronomique de l' Université de Genève, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland); Ivezić, Željko; Loebman, Sarah; Hunt-Walker, Nicholas; VanderPlas, Jacob; Westman, David; Becker, Andrew C. [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195-1580 (United States); Ruždjak, Domagoj; Sudar, Davor; Božić, Hrvoje [Hvar Observatory, Faculty of Geodesy, Kačićeva 26, 10000 Zagreb (Croatia); Galin, Mario [Faculty of Geodesy, Kačićeva 26, 10000 Zagreb (Croatia); Kroflin, Andrea; Mesarić, Martina; Munk, Petra; Vrbanec, Dijana [Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb (Croatia); Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, Caltech, Pasadena, CA 91125 (United States); Stuart, J. Scott [Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, MA 02420-9108 (United States); Srdoč, Gregor, E-mail: lovro.palaversa@unige.ch [Saršoni 90, 51216 Viškovo (Croatia); and others

    2013-10-01

    We describe the construction of a highly reliable sample of ∼7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg{sup 2} of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ∼0.03 mag at r = 15 to ∼0.20 mag at r = 18. Light curves include on average 250 data points, collected over about a decade. Using Sloan Digital Sky Survey (SDSS) based photometric recalibration of the LINEAR data for about 25 million objects, we selected ∼200,000 most probable candidate variables with r < 17 and visually confirmed and classified ∼7000 periodic variables using phased light curves. The reliability and uniformity of visual classification across eight human classifiers was calibrated and tested using a catalog of variable stars from the SDSS Stripe 82 region and verified using an unsupervised machine learning approach. The resulting sample of periodic LINEAR variables is dominated by 3900 RR Lyrae stars and 2700 eclipsing binary stars of all subtypes and includes small fractions of relatively rare populations such as asymptotic giant branch stars and SX Phoenicis stars. We discuss the distribution of these mostly uncataloged variables in various diagrams constructed with optical-to-infrared SDSS, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer photometry, and with LINEAR light-curve features. We find that the combination of light-curve features and colors enables classification schemes much more powerful than when colors or light curves are each used separately. An interesting side result is a robust and precise quantitative description of a strong correlation between the light-curve period and color/spectral type for close and contact eclipsing binary stars (β Lyrae and W UMa): as the color-based spectral type varies from K4 to F5, the

  15. Next-generation mid-infrared sources

    Science.gov (United States)

    Jung, D.; Bank, S.; Lee, M. L.; Wasserman, D.

    2017-12-01

    The mid-infrared (mid-IR) is a wavelength range with a variety of technologically vital applications in molecular sensing, security and defense, energy conservation, and potentially in free-space communication. The recent development and rapid commercialization of new coherent mid-infrared sources have spurred significant interest in the development of mid-infrared optical systems for the above applications. However, optical systems designers still do not have the extensive optical infrastructure available to them that exists at shorter wavelengths (for instance, in the visible and near-IR/telecom wavelengths). Even in the field of optoelectronic sources, which has largely driven the growing interest in the mid-infrared, the inherent limitations of state-of-the-art sources and the gaps in spectral coverage offer opportunities for the development of new classes of lasers, light emitting diodes and emitters for a range of potential applications. In this topical review, we will first present an overview of the current state-of-the-art mid-IR sources, in particular thermal emitters, which have long been utilized, and the relatively new quantum- and interband-cascade lasers, as well as the applications served by these sources. Subsequently, we will discuss potential mid-infrared applications and wavelength ranges which are poorly served by the current stable of mid-IR sources, with an emphasis on understanding the fundamental limitations of the current source technology. The bulk of the manuscript will then explore both past and recent developments in mid-infrared source technology, including narrow bandgap quantum well lasers, type-I and type-II quantum dot materials, type-II superlattices, highly mismatched alloys, lead-salts and transition-metal-doped II-VI materials. We will discuss both the advantages and limitations of each of the above material systems, as well as the potential new applications which they might serve. All in all, this topical review does not aim

  16. Strategies to Support Exploration of Mars' Surface

    Science.gov (United States)

    Kirkland, L.; Sykes, M.; Farr, T.; Adams, J.; Blaney, D.

    2003-01-01

    Surface Visible infrared spectroscopy has a long history of providing fundamental compositional discoveries in the solar system. However, we are entering a new era of Mars exploration in which missions will take place nearly every 2 years.The visible infrared spectral community thus faces a more rapid influx in data volume and variety than it has previously handled.Visible- infrared instruments are on the 1996 Mars Global Surveyor, 2001 Mars Odyssey 2003 Mars Exploration Rovers, 2003 Mars Express, 2005 Mars Reconnaissance Orbiter; and likely on the 2007 and 2009 missions. Interpretations of those data sets provide a critical foundation for geologic and climatic interpretations as well as an opportunity to select landing sites.

  17. Terahertz and Mid Infrared

    CERN Document Server

    Shulika, Oleksiy; Detection of Explosives and CBRN (Using Terahertz)

    2014-01-01

    The reader will find here a timely update on new THz sources and detection schemes as well as concrete applications to the detection of Explosives and CBRN. Included is a method to identify hidden RDX-based explosives (pure and plastic ones) in the frequency domain study by Fourier Transformation, which has been complemented by the demonstration of improvement of the quality of the images captured commercially available THz passive cameras. The presented examples show large potential for the detection of small hidden objects at long distances (6-10 m).  Complementing the results in the short-wavelength range, laser spectroscopy with a mid-infrared, room temperature, continuous wave, DFB laser diode and high performance DFB QCL have been demonstrated to offer excellent enabling sensor technologies for environmental monitoring, medical diagnostics, industrial and security applications.  From the new source point of view a number of systems have been presented - From superconductors to semiconductors, e.g. Det...

  18. Near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Virendra Jain

    2015-01-01

    Full Text Available Tissue ischaemia can be a significant contributor to increased morbidity and mortality. Conventional oxygenation monitoring modalities measure systemic oxygenation, but regional tissue oxygenation is not monitored. Near-infrared spectroscopy (NIRS is a non-invasive monitor for measuring regional oxygen saturation which provides real-time information. There has been increased interest in the clinical application of NIRS following numerous studies that show improved outcome in various clinical situations especially cardiac surgery. Its use has shown improved neurological outcome and decreased postoperative stay in cardiac surgery. Its usefulness has been investigated in various high risk surgeries such as carotid endarterectomy, thoracic surgeries, paediatric population and has shown promising results. There is however, limited data supporting its role in neurosurgical population. We strongly feel, it might play a key role in future. It has significant advantages over other neuromonitoring modalities, but more technological advances are needed before it can be used more widely into clinical practice.

  19. CINE: Comet INfrared Excitation

    Science.gov (United States)

    de Val-Borro, Miguel; Cordiner, Martin A.; Milam, Stefanie N.; Charnley, Steven B.

    2017-08-01

    CINE calculates infrared pumping efficiencies that can be applied to the most common molecules found in cometary comae such as water, hydrogen cyanide or methanol. One of the main mechanisms for molecular excitation in comets is the fluorescence by the solar radiation followed by radiative decay to the ground vibrational state. This command-line tool calculates the effective pumping rates for rotational levels in the ground vibrational state scaled by the heliocentric distance of the comet. Fluorescence coefficients are useful for modeling rotational emission lines observed in cometary spectra at sub-millimeter wavelengths. Combined with computational methods to solve the radiative transfer equations based, e.g., on the Monte Carlo algorithm, this model can retrieve production rates and rotational temperatures from the observed emission spectrum.

  20. Semiconductor optoelectronic infrared spectroscopy

    CERN Document Server

    Hollingworth, A R

    2001-01-01

    level separation. This showed for the first time evidence of the phonon bottleneck in a working laser device. A new technique called time resolved optically detected cyclotron resonance, was used as a precursor to finding the carrier dynamics within a spatially confined quantum dot. By moving to the case of a spatial QD using an optically detected intraband resonance it was possible to measure the energy separation interband levels and conduction and valence sublevels within the dot simultaneously. Furthermore this technique has been shown that the inhomogeneous broadening of the photoluminescence spectrum is not purely affected by just size and composition. We suggest that other processes such as state occupancy, In roughing, and exciton binding energies may account for the extra energy. We use spectroscopy to study infrared optoelectronic inter and intraband semiconductor carrier dynamics. The overall aim of this thesis was to study both III-V and Pb chalcogenide material systems in order to show their futu...

  1. Infrared Modifications Of Gravity

    CERN Document Server

    Rombouts, J

    2005-01-01

    In this thesis, we study theories that modify gravity at very large distances. Motivated by recent observations in cosmology, such as the dimming of type Ia supernovae and flattening of rotation curves of galaxies, we study two classes of theories that attempt to explain these observations as due to a change in the laws of gravity at large distances rather than due to the presence of new forms of exotic energy and matter. The first class of theories is massive gravity, obtained by adding a mass term to the action for the gravitational fluctuation in Einstein's general relativity. The second class of models we study are braneworlds that provide infrared modified gravity, in specific the Dvali-Gabadadze-Porrati model and its extension to higher codimensional branes. We stress in our discussion the field theoretical consistency, both classically and quantum-mechanically, of these models.

  2. Lateral conduction infrared photodetector

    Science.gov (United States)

    Kim, Jin K [Albuquerque, NM; Carroll, Malcolm S [Albuquerque, NM

    2011-09-20

    A photodetector for detecting infrared light in a wavelength range of 3-25 .mu.m is disclosed. The photodetector has a mesa structure formed from semiconductor layers which include a type-II superlattice formed of alternating layers of InAs and In.sub.xGa.sub.1-xSb with 0.ltoreq.x.ltoreq.0.5. Impurity doped regions are formed on sidewalls of the mesa structure to provide for a lateral conduction of photo-generated carriers which can provide an increased carrier mobility and a reduced surface recombination. An optional bias electrode can be used in the photodetector to control and vary a cut-off wavelength or a depletion width therein. The photodetector can be formed as a single-color or multi-color device, and can also be used to form a focal plane array which is compatible with conventional read-out integrated circuits.

  3. Exploring quadrangulations

    KAUST Repository

    Peng, Chihan

    2014-01-01

    Here we presented a framework to explore quad mesh topologies. The core of our work is a systematic enumeration algorithm that can generate all possible quadrangular meshes inside a defined boundary with an upper limit of v3-v5 pairs. The algorithm is orders of magnitude more efficient than previous work. The combination of topological enumeration and shape-space exploration demonstrates that mesh topology has a powerful influence on geometry. The Fig. 18. A gallery of different quadrilateral meshes for a Shuriken. The quadrilaterals of the model were colored in a postprocess. Topological variations have distinctive, interesting patterns of mesh lines. © 2014 ACM 0730-0301/2014/01-ART3 15.00.

  4. Infrared troubles of differential renormalization

    Science.gov (United States)

    Avdeev, L. V.; Kazakov, D. I.; Kondrashuk, I. N.

    The possibility of generalizing differential renormalization of D.Z. Freedman, K. Jonnson and J.I. Latorre in an invariant fashion to theories with infrared divergencies is investigated. It is concluded that the calculations on infrared differential renormalization lead to incorrect results.

  5. Mid-infrared upconversion spectroscopy

    DEFF Research Database (Denmark)

    Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin; Andersen, H. V.

    2016-01-01

    Mid-infrared (MIR) spectroscopy is emerging as an attractive alternative to near-infrared or visible spectroscopy. MIR spectroscopy offers a unique possibility to probe the fundamental absorption bands of a large number of gases as well as the vibrational spectra of complex molecules. In this paper...

  6. Infrared activities in the Netherlands

    NARCIS (Netherlands)

    Jong, A.N. de

    1987-01-01

    This presentation summarizes the infrared activities in the Netherlands during the past 30 years and indicates the directions for future work. The capabilities of infrared technology, being passive and useful for night vision applications were envisaged for a long time in our country. The dependence

  7. Combined Holographic Infrared Inspection Instrumentation

    Science.gov (United States)

    1989-12-01

    Shearography imaging system . As mentioned, the combination of Shearography and Infrared images could prove to be a successful method of defect characterization... system and more recent experience with newly available electronic shearography is that the shearography -infrared combination (Shearo-IR) offers... systems . Nevertheless, operation of the phase-locked Ho!o system requires exteiided control of environmental conditions. The shearography system , on

  8. Infrared Imaging Spectroscopy Using Massively Multiplexed Slit-Based Techniques and Sub-Field Motion Correction

    Science.gov (United States)

    Schad, Thomas; Lin, Haosheng

    2017-11-01

    Targeting dynamic spatially extended phenomena in the upper solar atmosphere, a new instrument concept has been developed and demonstrated at the Dunn Solar Telescope in New Mexico, USA, which provides wide-field, rapid-scanning, high-resolution imaging spectroscopy of the neutral helium λ10830 spectral triplet. The instrument combines a narrowband imaging channel with a novel cospatial grating-based spectrograph with 17 parallel long slits that are simultaneously imaged on a single HgCdTe detector. Over a 175'' × 125'' field of view, a temporal cadence of 8.5 s is achieved between successive maps that critically sample the diffraction limit of the Dunn Solar Telescope at 1083 nm (1.22 λ/D = 0.36'') and provide a resolving power (R = λ / δλ) up to {≈} 25{,}000 with a 1 nm bandwidth ( i.e. 275 km s^{-1} Doppler coverage). Capitalizing on the strict simultaneity of the narrowband channel relative to each spectral image (acquired at a rate of 9.53 Hz), this work demonstrates that sub-field image motion introduced by atmospheric seeing may be corrected post-facto in each mapped spectral data cube. This instrument furnishes essential infrared spectral imaging capabilities for current investigations while pioneering techniques for high-resolution wide-field time-domain solar astronomy.

  9. Formation of the thermal infrared continuum in solar flares

    Science.gov (United States)

    Simões, Paulo J. A.; Kerr, Graham S.; Fletcher, Lyndsay; Hudson, Hugh S.; Giménez de Castro, C. Guillermo; Penn, Matt

    2017-09-01

    Aims: Observations of the Sun with the Atacama Large Millimeter Array have now started, and the thermal infrared will regularly be accessible from the NSF's Daniel K. Inouye Solar Telescope. Motivated by the prospect of these new data, and by recent flare observations in the mid infrared, we set out here to model and understand the source of the infrared continuum in flares, and to explore its diagnostic capability for the physical conditions in the flare atmosphere. Methods: We use the one-dimensional (1D) radiation hydrodynamics code RADYN to calculate mid-infrared continuum emission from model atmospheres undergoing sudden deposition of energy by non-thermal electrons. Results: We identify and characterise the main continuum thermal emission processes relevant to flare intensity enhancement in the mid- to far-infrared (2-200 μm) spectral range as free-free emission on neutrals and ions. We find that the infrared intensity evolution tracks the energy input to within a second, albeit with a lingering intensity enhancement, and provides a very direct indication of the evolution of the atmospheric ionisation. The prediction of highly impulsive emission means that, on these timescales, the atmospheric hydrodynamics need not be considered in analysing the mid-IR signatures.

  10. Space exploration

    CERN Document Server

    2009-01-01

    Space Exploration, is one book in the Britannica Illustrated Science Library Series that is correlated to the science curriculum in grades 5-8. The Britannica Illustrated Science Library is a visually compelling set that covers earth science, life science, and physical science in 16 volumes.  Created for ages 10 and up, each volume provides an overview on a subject and thoroughly explains it through detailed and powerful graphics-more than 1,000 per volume-that turn complex subjects into information that students can grasp.  Each volume contains a glossary with full definitions for vocabulary help and an index.

  11. A Radiometric All-Sky Infrared Camera (RASICAM) for DES/CTIO

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Peter M.; Rogers, Howard; Schindler, Rafe H.; /SLAC

    2010-08-25

    A novel radiometric all-sky infrared camera [RASICAM] has been constructed to allow automated real-time quantitative assessment of night sky conditions for the Dark Energy Camera [DECam] located on the Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. The camera is optimized to detect the position, motion and optical depth of thin, high (8-10km) cirrus clouds and contrails by measuring their apparent temperature above the night sky background. The camera system utilizes a novel wide-field equiresolution catadioptic mirror system that provides sky coverage of 2{pi} azimuth and 14-90{sup o} from zenith. Several new technological and design innovations allow the RASICAM system to provide unprecedented cloud detection and IR-based photometricity quantification. The design of the RASICAM system is presented.

  12. Infrared Scanning For Electrical Maintenance

    Science.gov (United States)

    Eisenbath, Steven E.

    1983-03-01

    Given the technological age that we have now entered, the purpose of this paper is to relate how infrared scanning can be used for an electrical preventative maintenance program. An infrared scanner is able to produce an image because objects give off infrared radiation in relationship to their temperature. Most electrical problems will show up as an increase in temperature, thereby making the infrared scanner a useful preventative maintenance tool. Because of the sensitivity of most of the scanners, .1 to .2 of a degree, virtually all electrical problems can be pinpointed long before they become a costly failure. One of the early uses of infrared scanning was to check the power company's electrical distribution system. Most of this was performed via aircraft or truck mounted scanning devices which necessitated its semi-permanent mounting. With the advent of small hand held infrared imagers, along with more portability of the larger systems, infrared scanning has gained more popularity in checking electrical distribution systems. But the distribution systems are now a scaled down model, mainly the in-plant electrical systems. By in-plant, I mean any distribution of electricity; once it leaves the power company's grid. This can be in a hospital, retail outlet, warehouse or manufacturing facility.

  13. Fourier transform infrared spectra applications to chemical systems

    CERN Document Server

    Ferraro, John R

    1978-01-01

    Fourier Transform Infrared Spectroscopy: Applications to Chemical Systems presents the chemical applications of the Fourier transform interferometry (FT-IR).The book contains discussions on the applications of FT-IR in the fields of chromatography FT-IR, polymers and biological macromolecules, emission spectroscopy, matrix isolation, high-pressure interferometry, and far infrared interferometry. The final chapter is devoted to the presentation of the use of FT-IR in solving national technical problems such as air pollution, space exploration, and energy related subjects.Researc

  14. Review of Infrared Heating and Its Application to UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Blue, C A; Johnson, R

    2001-03-01

    The purpose of the cooperative research and development agreement between Smith & Nephew, Inc. (S&N) and ORNL was to explore the effects of infrared radiation heating on the physical properties of UHMWPE. Certified bars of ram extruded GUR 1050 UHMWPE were exposed to infrared heat under various conditions at ORNL. For comparison, specimens from the same bar stock were remelted using a conventional oven. The benefit to DOE was that knowledge was gained in low-temperature, vacuum heat-treating of polymers.

  15. A New Non-Linearity Correction Method for the JWST Near-Infrared Camera

    Science.gov (United States)

    Canipe, Alicia Michelle; Robberto, Massimo; Hilbert, Bryan

    2017-06-01

    JWST infrared detectors have an intrinsic non-linearity due to the change in PN junction capacitance as charge accumulates in the individual pixel capacitors. Correction of this non-linearity is a fundamental step in the JWST Science Calibration Pipeline. I evaluate a proposed method to calculate a more accurate non-linearity correction for the Near-Infrared Camera (NIRCam) using a function of the ideal linear signal count rate. This algorithm allows the reconstruction of the true linear signal to within 0.2% over ~97% of the full dynamic range, a substantial improvement over the current correction strategy adopted, for example, for the Wide Field Camera 3 infrared channel on Hubble. Using this method, I demonstrate that the coefficients derived to correct a regular ramp (i.e., a sequence of non-destructive samples) are also adequate to reconstruct the true signal in the case of grouped (averaged) samples, characteristic of JWST observations. The robustness of the method is tested using both real data and simulated ramps with different count rates. The new algorithm consistently provides highly accurate non-linearity corrections and can successfully be applied to all 10 NIRCam detectors.

  16. Wavelength standards in the infrared

    CERN Document Server

    Rao, KN

    2012-01-01

    Wavelength Standards in the Infrared is a compilation of wavelength standards suitable for use with high-resolution infrared spectrographs, including both emission and absorption standards. The book presents atomic line emission standards of argon, krypton, neon, and xenon. These atomic line emission standards are from the deliberations of Commission 14 of the International Astronomical Union, which is the recognized authority for such standards. The text also explains the techniques employed in determining spectral positions in the infrared. One of the techniques used includes the grating con

  17. Solar and infrared radiation measurements

    CERN Document Server

    Vignola, Frank; Michalsky, Joseph

    2012-01-01

    The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

  18. Mid-infrared tunable metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Brener, Igal; Miao, Xiaoyu; Shaner, Eric A.; Passmore, Brandon Scott

    2017-07-11

    A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.

  19. Mid-infrared tunable metamaterials

    Science.gov (United States)

    Brener, Igal; Miao, Xiaoyu; Shaner, Eric A; Passmore, Brandon Scott; Jun, Young Chul

    2015-04-28

    A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.

  20. Geoelectrical exploration

    Directory of Open Access Journals (Sweden)

    Mostafa Said Barseem

    2015-12-01

    Full Text Available Sinai development is a goal of successive governments in Egypt. The present study is a geoelectrical exploration to find appropriate solutions of the problems affecting the land of a Research Station in Southeast Al Qantara. This research station is one of the Desert Research Center stations to facilitate the development of desert land for agriculture by introducing applied research. It suffers from some problems which can be summarized in the shortage of irrigation water and water logging. The appropriate solutions of these problems have been delineated by the results of 1D and 2D geoelectrical measurements. Electrical resistivity (ER revealed the subsurface sedimentary sequences and extension of subsurface layers in the horizontal and vertical directions, especially, the water bearing layer. Additionally it helped to choose the most suitable places to drill productive wells with a good condition.

  1. Exploring ESASky

    Science.gov (United States)

    De Marchi, Guido; ESASky Team

    2017-06-01

    ESASky is a science-driven discovery portal for all ESA space astronomy missions. It also includes missions from international partners such as Suzaku and Chandra. The first public release of ESASky features interfaces for sky exploration and for single and multiple target searches. Using the application requires no prior-knowledge of any of the missions involved and gives users world-wide simplified access to high-level science-ready data products from space-based Astronomy missions, plus a number of ESA-produced source catalogues, including the Gaia Data Release 1 catalogue. We highlight here the latest features to be developed, including one that allows the user to project onto the sky the footprints of the JWST instruments, at any chosen position and orientation. This tool has been developed to aid JWST astronomers when they are defining observing proposals. We aim to include other missions and instruments in the near future.

  2. Uv-bright Nearby Early-type Galaxies Observed in the Mid-infrared: Eidence for a Multi-stage Formation History by Way of WISE and GALEX Imaging

    Science.gov (United States)

    Petty, S. M.; Neill, J. D.; Jarrett, T. H.; Blain, A. W.; Farrah, D. G.; Rich, R. M.; Tsai, C.-W.; Benford, D. J.; Bridge, C. R.; Lake, S. E.; hide

    2013-01-01

    In the local universe, 10% of massive elliptical galaxies are observed to exhibit a peculiar property: a substantial excess of ultraviolet emission than what is expected from their old, red stellar populations. Several origins for this ultraviolet excess (UVX) have been proposed including a population of hot young stars and a population of old, blue horizontal branch or extended horizontal branch (BHB or EHB) stars that have undergone substantial mass loss from their outer atmospheres. We explore the radial distribution of UVX in a selection of 49 nearby E/S0-type galaxies by measuring their extended photometry in the UV through mid-infrared (mid-IR) with the Galaxy Evolution Explorer (GALEX), the Sloan Digital Sky Survey, and the Wide-field Infrared Survey Explorer (WISE). We compare UV/optical and UV/mid-IR colors with the Flexible Stellar Population Synthesis models, which allow for the inclusion of EHB stars. We find that combined WISE mid-IR and GALEX UV colors are more effective in distinguishing models than optical colors, and that the UV/mid-IR combination is sensitive to the EHB fraction. There are strong color gradients, with the outer radii bluer than the inner half-light radii by approx.1 mag. This color difference is easily accounted for with an increase in the BHB fraction of 0.25 with radius. We estimated that the average ages for the inner and outer radii are 7.0 +/- 0.3 Gyr, and 6.2 +/- 0.2 Gyr, respectively, with the implication that the outer regions are likely to have formed approx. 1 Gyr after the inner regions. Additionally, we find that metallicity gradients are likely not a significant factor in the color difference. The separation of color between the inner and outer regions, which agrees with a specific stellar population difference (e.g., higher EHB populations), and the approx. 0.5-2 Gyr age difference suggests multi-stage formation. Our results are best explained by inside-out formation: rapid star formation within the core at early

  3. Infrared measurements in defence application

    CSIR Research Space (South Africa)

    Mudau, AE

    2011-03-01

    Full Text Available laser source, which causes missile guidance systems to abruptly steer away from the target aircraft. IRCM flares Airborne IRCM flares are defensive mechanisms employed from military aircraft to avoid detection and attack by enemy infrared seeker...

  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. Multi-functional Infrared Sensor

    Science.gov (United States)

    2014-05-11

    angle dependence; the effect of confinement barriers of InAs/ InGaAs sub-monolayer (SML) quantum dots-in-a-well based infrared photodetectors; and...characterization of multi-stack InAs/ InGaAs SML quantum dots (QDs) that are grown via Stranski-Krastanov growth method. The project demonstrated the first...monolithically integrated plasmonic infrared quantum dot pixelated focal plane array (FPA) to enhance the performance at specific wavelengths. The

  6. Infrared transparent conductive oxides

    Science.gov (United States)

    Johnson, Linda F.; Moran, Mark B.

    2001-09-01

    A novel class of complex metal oxides that have potential as transparent conducting oxides (TCOs) for the electromagnetic-interference (EMI) shielding on IR-seeker windows and missile domes has been identified. These complex metal oxides exhibit the rhombohedral (R3m) crystalline structure of naturally occurring delafossite, CuFeO2. The general chemical formula is ABO2 where A is a monovalent metal (Me+1 such as Cu, Ag, Au, Pt or Pd, and B is a trivalent metal (Me3+) such as Al,Ti,Cr,Co,Fe,Ni,Cs,Rh,Ga,Sn,In,Y,La,Pr,Nd,Sm or Eu. By adjusting the oxygen content, the conductivity can be varied over a wide range so that the delafossites behave as insulators, semiconductors or metals. This paper presents results for films of p-type CuxAlyOz and n-type CuxCryOz deposited by reactive magnetron co-sputtering from high-purity-metal targets. Films have been deposited using conventional RF- and DC-power supplies, and a new asymmetric-bipolar-pulsed- DC-power supply. Similar to the high-temperature-copper- oxide superconductors, the presence of Cu-O bonds is critical for the unique properties. Fourier transform infrared (FTIR) and electron spectroscopy for chemical analysis (ESCA) are used to understand the relationship between the optoelectornic properties and the molecular structure of the films. For example, FTIR absorption bands at 1470 and 1395cm-1 are present only in CuxAlyOz films that exhibit enhanced electrical conductivity. When these bands are absent, the CuxAlyOz films have high values of resistivity. In addition to the 1470 and 1395cm-1 bands observed in CuxAlyOz films, another pair of bands at 1040 and 970cm-1 is present in CuxCryOz films.

  7. Imaging in the Infrared

    Science.gov (United States)

    Falco, Charles

    2010-03-01

    Many common pigments are partially transparent to near infrared (IR) light, making it possible to use IR-sensitive imaging sensors to capture information from surfaces covered by several tens of micrometers of such pigments. Because of this, ``IR reflectograms'' have been made of paintings since the late 1960s, revealing important aspects of many works of art that are not observable in the visible. However, although a number of paintings have been studied this way, the high cost and specialized nature of available IR cameras have limited such work to a small fraction of the two- and three-dimensional works of art that could be usefully studied in the IR. After a brief introduction to IR reflectography, I will describe the characteristics of a high resolution imaging system based on a modified Canon EOS digital camera that operates over the wavelength range 830--1100 nm [1]. This camera and autofocus Canon 20 mm f/2.8 lens make it possible to obtain IR reflectograms of works of art ``in situ'' with standard museum lighting, resolving features finer than 0.35 mm on a 1.0x0.67 m painting. After describing its relevant imaging properties of sensitivity, resolution, noise and contrast, I will illustrate its capabilities with IR and visible images of various types of art in museums on three continents. IR reflectograms of one painting, in particular, have revealed important new information about the working practices of the 16th century artist Lorenzo Lotto who our previous work has shown used projected images as aids for producing some of the features in this painting [2]. [4pt] [1] Charles M. Falco, Rev. Sci. Instrum. 80, 071301 (2009). [0pt] [2] see, for example, David Hockney and Charles M. Falco, Proc. of the SPIE 5666, 326 (2005).

  8. Lens design for the infrared

    Science.gov (United States)

    Fischer, Robert E.

    1991-10-01

    Thermal, or infrared imaging systems have continued to increase in importance over the years. This is due to several factors: The applications of IR systems have grown dynamically in importance both in the military as well as in industrial applications IR detector technology has matured substantially, to the point where many IR detectors are available and economically producible This increased importance of infrared systems, combined with continually better performing and more cost effective IR detectors has put an ever increasing demand on the optical system and it's design. Although many of the classical optical design and engineering related derivations, guidelines, tradeoffs, and other considerations developed for visible systems can be applied directly to infrared systems, there are many important considerations, some of them quite subtle, that are considerably different in the infrared, and which can cause devastating problems if not properly taken into account. In fact, if one were to design the optics for an infrared scanning system using totally the guidelines derived from visible system engineering principles, there is a good chance that the system would perform poorly, if at all. In this paper we will review the many aspects of optical system design for the infrared. Although we intend to cover primarily those areas which are unique to IR systems, one will quickly realize that this will in reality cause us to cover most aspects of optical design technology.

  9. 21 CFR 890.5500 - Infrared lamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at infrared...

  10. Corrugated quantum well infrared photodetectors for far infrared detection

    Science.gov (United States)

    Choi, Kwong-Kit; Jhabvala, Murzy D.; Forrai, David; Sun, Jason; Endres, Darrel

    2011-06-01

    We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the Landsat Data Continuity Mission. To maintain a low dark current, we adopted a low doping density of 0.6×1018 cm-3 and a bound-to-bound state detector. The internal absorption quantum efficiency (QE) is calculated to be 25.4%. With a pixel fill factor of 80% and a substrate transmission of 70.9%, the external QE is 14.4%. To yield the theoretical conversion efficiency (CE), the photoconductive gain was measured and is 0.25 at 5 V, from which CE is predicted to be 3.6%. This value is in agreement with the 3.5% from the FPA measurement. Meanwhile, the dark current is measured to be 2.1×10-6 A/cm2 at 43 K. For regular infrared imaging above 8 μm, the FPA will have an noise equivalent temperature difference (NETD) of 16 mK at 2 ms integration time in the presence of 260 read noise electrons. The highest operability of the tested FPAs is 99.967%. With the CE agreement, we project the FPA performance in the far infrared regime up to 30 μm cutoff.

  11. An improved apparatus of infrared videopupillography for monitoring pupil size

    Science.gov (United States)

    Huang, T.-.; Ko, M.-.; Ouyang, Y.; Chen, Y.-.; Sone, B.-.; Ou-Yang, M.; Chiou, J.-.

    2014-10-01

    The intraocular pressure (IOP) that can diagnose or track glaucoma generally because it is one of the physiology parameters that are associated with glaucoma. But IOP is not easy and consistence to be measured under different measure conditions. Besides, diabetes is associated with diabetic autonomic neuropathy (DAN). Pupil size response might provide an indirect means about neuronal pathways, so the abnormal pupil size may relate with DAN. Hence an infrared videopupillography is needed for tracking glaucoma and exploring the relation between pupil size and DAN. Our previous research proposed an infrared videopupillography to monitoring the pupil size of different light stimulus in dark room. And this portable infrared videopupillography contains a camera, a beam splitter, the visible-light LEDs for stimulating the eyes, and the infrared LEDs for lighting the eyes. It can be mounted on any eyeglass frame. But it can modulate only two dimensions, we cannot zoom in/out the eyes. Moreover, the eye diameter curves were not smooth and jagged because of the light spots, lone eyelashes, and blink. Therefore, we redesign the optical path of our device to have three dimension modulation. Then we can zoom in the eye to increase the eye resolution and to avoid the LED light spots. The light spot could be solved by defining the distance between IR LED and CCD. This device smaller volume and less prices of our previous videopupillography. We hope this new infrared videopupillography proposed in this paper can achieving early detection about autonomic neuropathy in the future.

  12. A new apparatus of infrared videopupillography for monitoring pupil size

    Science.gov (United States)

    Ko, M.-L.; Huang, T.-W.; Chen, Y.-Y.; Sone, B.-S.; Huang, Y.-C.; Jeng, W.-D.; Chen, Y.-T.; Hsieh, Y.-F.; Tao, K.-H.; Li, S.-T.; Ou-Yang, M.; Chiou, J.-C.

    2013-09-01

    Glaucoma was diagnosed or tracked by the intraocular pressure (IOP) generally because it is one of the physiology parameters that are associated with glaucoma. But measurement of IOP is not easy and consistence under different measure conditions. An infrared videopupillography is apparatus to monitor the pupil size in an attempt to bypass the direct IOP measurement. This paper propose an infrared videopupillography to monitoring the pupil size of different light stimulus in dark room. The portable infrared videopupillography contains a camera, a beam splitter, the visible-light LEDs for stimulating the eyes, and the infrared LEDs for lighting the eyes. It is lighter and smaller than the present product. It can modulate for different locations of different eyes, and can be mounted on any eyeglass frame. An analysis program of pupil size can evaluate the pupil diameter by image correlation. In our experiments, the eye diameter curves were not smooth and jagged. It caused by the light spots, lone eyelashes, and blink. In the future, we will improve the analysis program of pupil size and seek the approach to solve the LED light spots. And we hope this infrared videopupillography proposed in this paper can be a measuring platform to explore the relations between the different diseases and pupil response.

  13. Wide-Field Astronomical Surveys in the Next Decade

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Michael A.; /Princeton U.; Tyson, J.Anthony; /UC, Davis; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Axelrod, T.S.; /LSST Corp.; Becker, Andrew C.; /Washington U., Seattle, Astron. Dept.; Bickerton, Steven J.; /Princeton U.; Blanton, Michael R.; /New York U.; Burke, David L.; /SLAC; Condon, J.J.; /NRAO, Socorro; Connolly, A.J.; /Washington U., Seattle, Astron. Dept.; Cooray, Asantha R.; /UC, Irvine; Covey, Kevin R.; /Harvard U.; Csabai, Istvan; /Eotvos U.; Ferguson, Henry C.; /Baltimore, Space Telescope Sci.; Ivezic, Zeljko; /Washington U., Seattle, Astron. Dept.; Kantor, Jeffrey; /LSST Corp.; Kent, Stephen M.; /Fermilab; Knapp, G.R.; /Princeton U.; Myers, Steven T.; /NRAO, Socorro; Neilsen, Eric H., Jr.; /Fermilab; Nichol, Robert C.; /Portsmouth U., ICG /Harish-Chandra Res. Inst. /Caltech, IPAC /Potsdam, Max Planck Inst. /Harvard U. /Hawaii U. /UC, Berkeley, Astron. Dept. /Baltimore, Space Telescope Sci. /NOAO, Tucson /Carnegie Mellon U. /Chicago U., Astron. Astrophys. Ctr.

    2011-11-14

    Wide-angle surveys have been an engine for new discoveries throughout the modern history of astronomy, and have been among the most highly cited and scientifically productive observing facilities in recent years. This trend is likely to continue over the next decade, as many of the most important questions in astrophysics are best tackled with massive surveys, often in synergy with each other and in tandem with the more traditional observatories. We argue that these surveys are most productive and have the greatest impact when the data from the surveys are made public in a timely manner. The rise of the 'survey astronomer' is a substantial change in the demographics of our field; one of the most important challenges of the next decade is to find ways to recognize the intellectual contributions of those who work on the infrastructure of surveys (hardware, software, survey planning and operations, and databases/data distribution), and to make career paths to allow them to thrive.

  14. Review The Receiver System for the Ooty Wide Field Array

    Indian Academy of Sciences (India)

    contains meta-data containing useful information like sequence number, identification, timestamp, delays and project code. Double buffers are provided using on- chip memory (Block RAMs) so that while one set of 6 frames are being filled in, the previous set of 6 frames are transported to the central processing system. For.

  15. Wide-Field Astronomical Surveys in the Next Decade

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Michael A.; /Princeton U.; Tyson, J.Anthony; /UC, Davis; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Axelrod, T.S.; /LSST Corp.; Becker, Andrew C.; /Washington U., Seattle, Astron. Dept.; Bickerton, Steven J.; /Princeton U.; Blanton, Michael R.; /New York U.; Burke, David L.; /SLAC; Condon, J.J.; /NRAO, Socorro; Connolly, A.J.

    2009-03-01

    Wide-angle surveys have been an engine for new discoveries throughout the modern history of astronomy, and have been among the most highly cited and scientifically productive observing facilities in recent years. This trend is likely to continue over the next decade, as many of the most important questions in astrophysics are best tackled with massive surveys, often in synergy with each other and in tandem with the more traditional observatories. We argue that these surveys are most productive and have the greatest impact when the data from the surveys are made public in a timely manner. The rise of the 'survey astronomer' is a substantial change in the demographics of our field; one of the most important challenges of the next decade is to find ways to recognize the intellectual contributions of those who work on the infrastructure of surveys (hardware, software, survey planning and operations, and databases/data distribution), and to make career paths to allow them to thrive.

  16. High Resolution Wide Field of View Stereographic Imaging System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overarching challenge of tele-presence is to provide an environment to the human operator that is sufficiently familiar that the interface itself does not become...

  17. FRB Event Rate Predictions for the Ooty Wide Field Array

    Indian Academy of Sciences (India)

    , India. International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102, Australia. Australian Research Council Centre of Excellence for All-Sky Astrophysics (CAASTRO), The University of Sydney, NSW 2006, Australia ...

  18. Wide-field fundus imaging with trans-palpebral illumination

    Science.gov (United States)

    Toslak, Devrim; Thapa, Damber; Chen, Yanjun; Erol, Muhammet Kazim; Chan, R. V. Paul; Yao, Xincheng

    2017-02-01

    In conventional fundus imaging devices, transpupillary illumination is used for illuminating the inside of the eye. In this method, the illumination light is directed into the posterior segment of the eye through the cornea and passes the pupillary area. As a result of sharing the pupillary area for the illumination beam and observation path, pupil dilation is typically necessary for wide-angle fundus examination, and the field of view is inherently limited. An alternative approach is to deliver light from the sclera. It is possible to image a wider retinal area with transcleral-illumination. However, the requirement of physical contact between the illumination probe and the sclera is a drawback of this method. We report here trans-palpebral illumination as a new method to deliver the light through the upper eyelid (palpebra). For this study, we used a 1.5 mm diameter fiber with a warm white LED light source. To illuminate the inside of the eye, the fiber illuminator was placed at the location corresponding to the pars plana region. A custom designed optical system was attached to a digital camera for retinal imaging. The optical system contained a 90 diopter ophthalmic lens and a 25 diopter relay lens. The ophthalmic lens collected light coming from the posterior of the eye and formed an aerial image between the ophthalmic and relay lenses. The aerial image was captured by the camera through the relay lens. An adequate illumination level was obtained to capture wide angle fundus images within ocular safety limits, defined by the ISO 15004-2: 2007 standard. This novel trans-palpebral illumination approach enables wide-angle fundus photography without eyeball contact and pupil dilation.

  19. Wide-field Fourier ptychographic microscopy using laser illumination source

    Science.gov (United States)

    Chung, Jaebum; Lu, Hangwen; Ou, Xiaoze; Zhou, Haojiang; Yang, Changhuei

    2016-01-01

    Fourier ptychographic (FP) microscopy is a coherent imaging method that can synthesize an image with a higher bandwidth using multiple low-bandwidth images captured at different spatial frequency regions. The method’s demand for multiple images drives the need for a brighter illumination scheme and a high-frame-rate camera for a faster acquisition. We report the use of a guided laser beam as an illumination source for an FP microscope. It uses a mirror array and a 2-dimensional scanning Galvo mirror system to provide a sample with plane-wave illuminations at diverse incidence angles. The use of a laser presents speckles in the image capturing process due to reflections between glass surfaces in the system. They appear as slowly varying background fluctuations in the final reconstructed image. We are able to mitigate these artifacts by including a phase image obtained by differential phase contrast (DPC) deconvolution in the FP algorithm. We use a 1-Watt laser configured to provide a collimated beam with 150 mW of power and beam diameter of 1 cm to allow for the total capturing time of 0.96 seconds for 96 raw FPM input images in our system, with the camera sensor’s frame rate being the bottleneck for speed. We demonstrate a factor of 4 resolution improvement using a 0.1 NA objective lens over the full camera field-of-view of 2.7 mm by 1.5 mm. PMID:27896016

  20. The Receiver System for the Ooty Wide Field Array

    Indian Academy of Sciences (India)

    OWFA is designed to retain the benefits of equatorial mount, continuous 9-hour tracking ability and large collecting area of the legacy telescope and use of modern digital techniques to enhance the instantaneous field-of-view by more than an order of magnitude. OWFA has unique advantages for contemporary ...

  1. Observing GRBs with the LOFT Wide Field Monitor

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Feroci, M.

    2013-01-01

    field of view and good energy resolution of GRBs and X-ray flashes. The WFM will be able to detect ~150 gamma ray bursts per year, and a burst alert system will enable the distribution of ~100 GRB positions per year with a ~1...

  2. Observing GRBs with the LOFT Wide Field Monitor

    NARCIS (Netherlands)

    Brandt, S.; Hernanz, M.; Feroci, M.; Amati, L.; Azzarello, A.P.; Barret, D.; Bozzo, E.; Budtz-Jørgensen, C.; Campana, R.; Castro-Tirado, A.; Cros, A.; Del Monte, E.; Donnarumma, I.; Evangelista, Y.; Galvez Sanchez, J.L.; Götz, D.; Hansen, F.; den Herder, J.W.; Hornstrup, A.; Hudec, R.; Karelin, D.; van der Klis, M.; Korpela, S.; Kuvvetli, I.; Lund, N.; Orleanski, P.; Pohl, M.; Rachevski, A.; Santangelo, A.; Schanne, S.; Schmid, C.; Stella, L.; Suchy, S.; Tenzer, C.; Vacchi, A.; Wilms, J.; Zampa, N.; in 't Zand, J.J.M.; Zdziarski, A.

    2013-01-01

    LOFT (Large Observatory For X-ray Timing) is one of the four candidate missions currently under assessment study for the M3 mission in ESAs Cosmic Vision program to be launched in 2024. LOFT will carry two instruments with prime sensitivity in the 2-30 keV range: a 10 m2 class large area detector

  3. High-Speed and Wide-Field Photometry with TORTORA

    Directory of Open Access Journals (Sweden)

    G. Greco

    2010-01-01

    Full Text Available We present the photometric analysis of the extended sky fields observed by the TORTORA optical monitoring system. The technology involved in the TORTORA camera is based on the use of a fast TV-CCD matrix with an image intensifier. This approach can both significantly reduce the readout noise and shorten the focal length following to monitor relatively large sky regions with high temporal resolution and adequate detection limit. The performance of the system has been tested using the relative magnitudes of standard stars by means of long image sequences collected at different airmasses and at various intensities of the moon illumination. As expected from the previous laboratory measurements, artifact sources are negligible and do not affect the photometric results. The following analysis is based on a large sample of images acquired by the TORTORA instrument since July 2006.

  4. Infrared Sapce Astrometry missions: JASMINE

    Science.gov (United States)

    Gouda, Naoteru

    2015-08-01

    JASMINE is an abbreviation for Japan Astrometry Satellite Mission for INfrared Exploration. We are now focusing on the development of two projects, those are Nano-JASMINE and Small-JASMINE. The Nano-JASMINE micro-satellite project, with a primary mirror aperture of 5-cm class, is currently underway to test part of the technologies used for Small-JASMINE and to produce scientific results based on the astrometric information of bright objects in the neighboring space. Despite its small aperture, the satellite is capable of a level of observational precision comparable to the Hipparcos satellite, and the combination of the observational data from Nano-JASMINE and the Hipparcos Catalogue is expected to produce more precise data on proper motions and annual parallaxes. The satellite is scheduled for launch in the near future. An additional plan is underway to launch a small-scale JASMINE satellite (Small-JASMINE), with a primary mirror aperture of 30-cm class, in around FY 2021. This satellite will engage in observations of only a limited area around the bulge and certain specific astronomical objects.. The main scientific objective of Small-JASMINE is to clarify the dynamical structure of the Galactic nuclear bulge and search for observational relics of a sequential merger of multiple black holes to form the supermassive black hole at the Galactic center. In particular, our main goal is that Small-JASMINE will provide an understanding of the past evolution processes of the supermassive black hole and a prediction of the future activities of our Galactic center through knowledge of the gravitational potential in the Galactic nuclear bulge, and that this understanding can contribute to a better understanding of the co-evolution of the supermassive black holes and bulges in external galaxies. Next to this primary goal, Small-JASMINE will have many other scientific targets. Small-JASMINE can measure the same target every 100 minutes, so it is useful to resolve phenomena

  5. Quantum-dot infrared photodetectors: a review

    Science.gov (United States)

    Stiff-Roberts, Adrienne D.

    2009-04-01

    Quantum-dot infrared photodetectors (QDIPs) are positioned to become an important technology in the field of infrared (IR) detection, particularly for high-temperature, low-cost, high-yield detector arrays required for military applications. High-operating temperature (>=150 K) photodetectors reduce the cost of IR imaging systems by enabling cryogenic dewars and Stirling cooling systems to be replaced by thermo-electric coolers. QDIPs are well-suited for detecting mid-IR light at elevated temperatures, an application that could prove to be the next commercial market for quantum dots. While quantum dot epitaxial growth and intraband absorption of IR radiation are well established, quantum dot non-uniformity remains as a significant challenge. Nonetheless, state-of-the-art mid-IR detection at 150 K has been demonstrated using 70-layer InAs/GaAs QDIPs, and QDIP focal plane arrays are approaching performance comparable to HgCdTe at 77 K. By addressing critical challenges inherent to epitaxial QD material systems (e.g., controlling dopant incorporation), exploring alternative QD systems (e.g., colloidal QDs), and using bandgap engineering to reduce dark current and enhance multi-spectral detection (e.g. resonant tunneling QDIPs), the performance and applicability of QDIPs will continue to improve.

  6. STRONG FIELD PHYSICS WITH MID INFRARED LASERS.

    Energy Technology Data Exchange (ETDEWEB)

    POGORELSKY,I.V.

    2001-08-27

    Mid-infrared gas laser technology promises to become a unique tool for research in strong-field relativistic physics. The degree to which physics is relativistic is determined by a ponderomotive potential. At a given intensity, a 10 {micro}m wavelength CO{sub 2} laser reaches a 100 times higher ponderomotive potential than the 1 {micro}m wavelength solid state lasers. Thus, we can expect a proportional increase in the throughput of such processes as laser acceleration, x-ray production, etc. These arguments have been confirmed in proof-of-principle Thomson scattering and laser acceleration experiments conducted at BNL and UCLA where the first terawatt-class CO{sub 2} lasers are in operation. Further more, proposals for the 100 TW, 100 fs CO{sub 2} lasers based on frequency-chirped pulse amplification have been conceived. Such lasers can produce physical effects equivalent to a hypothetical multi-petawatt solid state laser. Ultra-fast mid-infrared lasers will open new routes to the next generation electron and ion accelerators, ultra-bright monochromatic femtosecond x-ray and gamma sources, allow to attempt the study of Hawking-Unruh radiation, and explore relativistic aspects of laser-matter interactions. We review the present status and experiments with terawatt-class CO{sub 2} lasers, sub-petawatt projects, and prospective applications in strong-field science.

  7. Infrared spectroscopy of exoplanets: observational constraints.

    Science.gov (United States)

    Encrenaz, Thérèse

    2014-04-28

    The exploration of transiting extrasolar planets is an exploding research area in astronomy. With more than 400 transiting exoplanets identified so far, these discoveries have made possible the development of a new research field, the spectroscopic characterization of exoplanets' atmospheres, using both primary and secondary transits. However, these observations have been so far limited to a small number of targets. In this paper, we first review the advantages and limitations of both primary and secondary transit methods. Then, we analyse what kind of infrared spectra can be expected for different types of planets and discuss how to optimize the spectral range and the resolving power of the observations. Finally, we propose a list of favourable targets for present and future ground-based observations.

  8. Long Wave Infrared Cavity Enhanced Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Taubman, Matthew S.; Scott, David C.; Cannon, Bret D.; Myers, Tanya L.; Munley, John T.; Nguyen, Vinh T.; Schultz, John F.

    2005-12-01

    The principal goal of Pacific Northwest National Laboratory's (PNNL's) long wave infrared (LWIR) cavity enhanced sensor (CES) task is to explore ultra-sensitive spectroscopic chemical sensing techniques and apply them to detecting proliferation of weapons of mass destruction (WMD). Our primary application is detecting signatures of WMD production, but LWIR CES techniques are also capable of detecting chemical weapons. The LWIR CES task is concerned exclusively with developing novel point sensors; stand-off detection is addressed by other PNNL tasks and projects. PNNL's LWIR CES research is distinguished from that done by others by the use quantum cascade lasers (QCLs) as the light source. QCLs are novel devices, and a significant fraction of our research has been devoted to developing the procedures and hardware required to implement them most effectively for chemical sensing. This report details the progress we have made on LWIR CES sensor development.

  9. TALC: a new deployable concept for a 20m far-infrared space telescope

    Science.gov (United States)

    Durand, Gilles; Sauvage, Marc; Bonnet, Aymeric; Rodriguez, Louis; Ronayette, Samuel; Chanial, Pierre; Scola, Loris; Révéret, Vincent; Aussel, Hervé; Carty, Michael; Durand, Matthis; Durand, Lancelot; Tremblin, Pascal; Pantin, Eric; Berthe, Michel; Martignac, Jérôme; Motte, Frédérique; Talvard, Michel; Minier, Vincent; Bultel, Pascal

    2014-08-01

    TALC, Thin Aperture Light Collector is a 20 m space observatory project exploring some unconventional optical solutions (between the single dish and the interferometer) allowing the resolving power of a classical 27 m telescope. With TALC, the principle is to remove the central part of the prime mirror dish, cut the remaining ring into 24 sectors and store them on top of one-another. The aim of this far infrared telescope is to explore the 600 μm to 100 μm region. With this approach we have shown that we can store a ring-telescope of outer diameter 20m and ring thickness of 3m inside the fairing of Ariane 5 or Ariane 6. The general structure is the one of a bicycle wheel, whereas the inner sides of the segments are in compression to each other and play the rule of a rim. The segments are linked to each other using a pantograph scissor system that let the segments extend from a pile of dishes to a parabolic ring keeping high stiffness at all time during the deployment. The inner corners of the segments are linked to a central axis using spokes as in a bicycle wheel. The secondary mirror and the instrument box are built as a solid unit fixed at the extremity of the main axis. The tensegrity analysis of this structure shows a very high stiffness to mass ratio, resulting into 3 Hz Eigen frequency. The segments will consist of two composite skins and honeycomb CFRP structure build by replica process. Solid segments will be compared to deformable segments using the controlled shear of the rear surface. The adjustment of the length of the spikes and the relative position of the side of neighbor segments let control the phasing of the entire primary mirror. The telescope is cooled by natural radiation. It is protected from sun radiation by a large inflatable solar screen, loosely linked to the telescope. The orientation is performed by inertia-wheels. This telescope carries a wide field bolometer camera using cryocooler at 0.3K as one of the main instruments. This

  10. Infrared photodetectors based on reduced graphene oxide and graphene nanoribbons.

    Science.gov (United States)

    Chitara, Basant; Panchakarla, L S; Krupanidhi, S B; Rao, C N R

    2011-12-01

    The use of reduced graphene oxide (RGO) and graphene nanoribbons (GNRs) as infrared photodetectors is explored, based on recent results dealing with solar cells, light-emitting devices, photodetectors, and ultrafast lasers. IR detection is demonstrated by both RGO and GNRs in terms of the time-resolved photocurrent and photoresponse. The responsivity of the detectors and their functioning are presented. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. KIC 8462852: THE INFRARED FLUX

    Energy Technology Data Exchange (ETDEWEB)

    Marengo, Massimo; Hulsebus, Alan [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Willis, Sarah [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2015-11-20

    We analyzed the warm Spitzer/IRAC data of KIC 8462852. We found no evidence of infrared excess at 3.6 μm and a small excess of 0.43 ± 0.18 mJy at 4.5 μm below the 3σ threshold necessary to claim a detection. The lack of strong infrared excess 2 years after the events responsible for the unusual light curve observed by Kepler further disfavors the scenarios involving a catastrophic collision in a KIC 8462852 asteroid belt, a giant impact disrupting a planet in the system or a population of dust-enshrouded planetesimals. The scenario invoking the fragmentation of a family of comets on a highly elliptical orbit is instead consistent with the lack of strong infrared excess found by our analysis.

  12. Electrically tunable infrared metamaterial devices

    Science.gov (United States)

    Brener, Igal; Jun, Young Chul

    2015-07-21

    A wavelength-tunable, depletion-type infrared metamaterial optical device is provided. The device includes a thin, highly doped epilayer whose electrical permittivity can become negative at some infrared wavelengths. This highly-doped buried layer optically couples with a metamaterial layer. Changes in the transmission spectrum of the device can be induced via the electrical control of this optical coupling. An embodiment includes a contact layer of semiconductor material that is sufficiently doped for operation as a contact layer and that is effectively transparent to an operating range of infrared wavelengths, a thin, highly doped buried layer of epitaxially grown semiconductor material that overlies the contact layer, and a metallized layer overlying the buried layer and patterned as a resonant metamaterial.

  13. New maxillofacial infrared detection technologies

    Science.gov (United States)

    Reshetnikov, A. P.; Kopylov, M. V.; Nasyrov, M. R.; Soicher, E. M.; Fisher, E. L.; Chernova, L. V.

    2015-11-01

    At the dental clinic the infrared range radiation spectrum of tissues was used to study the dynamics of local temperature and structure of the skin, subcutaneous fat, and other tissues of the maxillofacial area in adult healthy volunteers and patients. In particular, we studied the dynamics of local temperature of mucous membranes of the mouth, teeth, and places in the mouth and dental structures in the norm and in various pathological conditions of the lips, gums, teeth, tongue, palate, and cheeks before, during and after chewing food, drinking water, medication, and inhalation of air. High safety and informational content of infrared thermography are prospective for the development of diagnostics in medicine. We have 3 new methods for infrared detection protected by patents in Russia.

  14. New maxillofacial infrared detection technologies

    Energy Technology Data Exchange (ETDEWEB)

    Reshetnikov, A. P.; Kopylov, M. V.; Nasyrov, M. R., E-mail: marat.1994@me.com; Fisher, E. L.; Chernova, L. V. [Izhevsk State Medical Academy, Izhevsk, Russia (426034, Izhevsk, Kommunarov street, 281) (Russian Federation); Soicher, E. M. [Moscow State University of Medicine and Dentistry named after A.I. Evdokimov of the Ministry of Health of the Russian Federation, Moscow, Russia, (127473, Moscow, Delegatskaya str., 20/1) (Russian Federation)

    2015-11-17

    At the dental clinic the infrared range radiation spectrum of tissues was used to study the dynamics of local temperature and structure of the skin, subcutaneous fat, and other tissues of the maxillofacial area in adult healthy volunteers and patients. In particular, we studied the dynamics of local temperature of mucous membranes of the mouth, teeth, and places in the mouth and dental structures in the norm and in various pathological conditions of the lips, gums, teeth, tongue, palate, and cheeks before, during and after chewing food, drinking water, medication, and inhalation of air. High safety and informational content of infrared thermography are prospective for the development of diagnostics in medicine. We have 3 new methods for infrared detection protected by patents in Russia.

  15. Mid-infrared Semiconductor Optoelectronics

    CERN Document Server

    Krier, Anthony

    2006-01-01

    The practical realisation of optoelectronic devices operating in the 2–10 µm (mid-infrared) wavelength range offers potential applications in a variety of areas from environmental gas monitoring around oil rigs and landfill sites to the detection of pharmaceuticals, particularly narcotics. In addition, an atmospheric transmission window exists between 3 µm and 5 µm that enables free-space optical communications, thermal imaging applications and the development of infrared measures for "homeland security". Consequently, the mid-infrared is very attractive for the development of sensitive optical sensor instrumentation. Unfortunately, the nature of the likely applications dictates stringent requirements in terms of laser operation, miniaturisation and cost that are difficult to meet. Many of the necessary improvements are linked to a better ability to fabricate and to understand the optoelectronic properties of suitable high-quality epitaxial materials and device structures. Substantial progress in these m...

  16. Germanium blocked impurity band far infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Rossington, C.S.

    1988-04-01

    The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the ''Star Wars'' nuclear defense scheme proposed by the Reagan administration.

  17. Veterinary applications of infrared thermography.

    Science.gov (United States)

    Rekant, Steven I; Lyons, Mark A; Pacheco, Juan M; Arzt, Jonathan; Rodriguez, Luis L

    2016-01-01

    Abnormal body temperature is a major indicator of disease; infrared thermography (IRT) can assess changes in body surface temperature quickly and remotely. This technology can be applied to a myriad of diseases of various etiologies across a wide range of host species in veterinary medicine. It is used to monitor the physiologic status of individual animals, such as measuring feed efficiency or diagnosing pregnancy. Infrared thermography has applications in the assessment of animal welfare, and has been used to detect soring in horses and monitor stress responses. This review addresses the variety of uses for IRT in veterinary medicine, including disease detection, physiologic monitoring, welfare assessment, and potential future applications.

  18. Quantum Infrared Photodetectors for Long Wavelength Infrared Imaging Applications

    Science.gov (United States)

    Bandara, S.; Gunapala, S. D.; Liu, J. K.; Luong, M.; Mumolo, J. M.; Hong, W.; McKelvey, M. J.

    1998-01-01

    Long wavelength Quantum Well Infrared Photodetector (QWIP) cameras developed at the Jet Propulsion Laboratory demonstrate the potential of GaAs/A1xGa1-xAs QWIP technology for highly sensitive, low power, low cost, and highly uniform large format FPA imaging systems.

  19. Advances in near-infrared measurements

    CERN Document Server

    Patonay, Gabor

    1991-01-01

    Advances in Near-Infrared Measurements, Volume 1 provides an overview of near-infrared spectroscopy. The book is comprised of six chapters that tackle various areas of near-infrared measurement. Chapter 1 discusses remote monitoring techniques in near-infrared spectroscopy with an emphasis on fiber optics. Chapter 2 covers the applications of fibers using Raman techniques, and Chapter 3 tackles the difficulties associated with near-infrared data analysis. The subsequent chapters present examples of the capabilities of near-infrared spectroscopy from various research groups. The text wi

  20. The development of WIFIS: a wide integral field infrared spectrograph

    Science.gov (United States)

    Sivanandam, Suresh; Chou, Richard C. Y.; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S.; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N.; Eisner, Joshua

    2012-09-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9 - 1.8 μm range and is most sensitive in the 0.9 - 1.35 μ,m range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.511x 1211 integral field at a 10-meter class telescope (or 2011 x 5011 at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensional spectroscopy such as the study of merging galaxies at moderate redshift and nearby star/planet-forming regions and supernova remnants. We discuss the final optical design of WIFIS, and its predicted on-sky performance on two reference telescope platforms: the 2.3-m Steward Bok telescope and the 10.4-m Gran Telescopio Canarias. We also present the results from our laboratory characterization of FISICA. IFU properties such as magnification, field-mapping, and slit width along the entire slit length were measured by our tests. The construction and testing of WIFIS is expected to be completed by early 2013. We plan to commission the instrument at the 2.3-m Steward Bok telescope at Kitt Peak, USA in Spring 2013.

  1. Optimizing an Infrared Camera for Observing Atmospheric Gravity Waves from a CubeSat Platform

    OpenAIRE

    Rønning, Snorre Stavik

    2012-01-01

    The NTNU Test Satellite (NUTS) is a double CubeSat deigned by master students at NTNU. The goal of the project is to image atmospheric gravity waves in the OH airglow layer. This thesis explores the theory behind gravity waves and discuss the design of an infrared camera as a payload onboard. Different requirement based on scientific and mechanical limitations are presented. Based on this a suitable infrared camera is presented.

  2. The WISE Survey of the Albedo Distribution of Main Belt Asteroids

    NARCIS (Netherlands)

    Masiero, J.; Mainzer, A.; Grav, T.; Delbó, M.; Mueller, M.; WISE Team, [No Value

    2010-01-01

    Using date from the Wide-field Infrared Survey Explorer (WISE) we investigate the albedo distribution across the main belt of asteroids. When complete WISE will measure albedos and diameters for ~100,000 asteroids.

  3. Infrared Spectroscopy of the H2/HD/D2-O2 Van Der Waals Complexes

    Science.gov (United States)

    Raston, Paul; Bunn, Hayley

    2016-06-01

    Hydrogen is the most abundant element in the universe and oxygen is the third, so understanding the interaction between the two in their different forms is important to understanding astrochemical processes. The interaction between H2 and O2 has been explored in low energy scattering experiments and by far infrared synchrotron spectroscopy of the van der Waals complex. The far infrared spectra suggest a parallel stacked average structure with seven bound rotationally excited states. Here, we present the far infrared spectrum of HD/D2-O2 and the mid infrared spectrum of H2-O2 at 80 K, recorded at the infrared beamline facility of the Australian Synchrotron. We observed 'sharp' peaks in the mid infrared region, corresponding to the end over end rotation of H2-O2, that are comparatively noisier than analogous peaks in the far infrared where the synchrotron light is brightest. The larger reduced mass of HD and D2 compared to H2 is expected to result in more rotational bound states and narrower bands. The latest results in our ongoing efforts to explore this system will be presented. Y. Kalugina, et al., Phys. Chem. Chem. Phys. 14, 16458 (2012) S. Chefdeville et al. Science 341, 1094 (2013) H. Bunn et al. ApJ 799, 65 (2015)

  4. Infrared activity in elemental crystals

    Science.gov (United States)

    Zallen, Richard; Martin, Richard M.; Natoli, Vincent

    1994-03-01

    In a previous paper, Zallen [Phys. Rev. 173, 824 (1968)] reported a group-theoretical analysis of the competition between unit-cell complexity and crystal symmetry in determining the presence or absence of infrared-active phonons in an elemental crystal. Here we correct an error in that paper's treatment of certain hexagonal space groups. Our results modify the minimum-complexity condition for infrared activity: For 228 of the 230 space groups, a necessary and sufficient condition for the existence of symmetry-allowed infrared-active modes in an elemental crystal is the presence of three or more atoms in the primitive unit cell. The two exceptional space groups are P6/mmm (D16h) and P63/mmc (D46h); for each of these symmetries, there exists one structure with four atoms per cell and no infrared modes. The P63/mmc structure includes, as special cases, Lonsdaleite (or ``wurtzite silicon'') as well as a c-axis-aligned hcp arrangement of diatomic molecules which is relevant to models of solid molecular hydrogen at high pressure.

  5. Landsat and Thermal Infrared Imaging

    Science.gov (United States)

    Arvidson, Terry; Barsi, Julia; Jhabvala, Murzy; Reuter, Dennis

    2012-01-01

    The purpose of this chapter is to describe the collection of thermal images by Landsat sensors already on orbit and to introduce the new thermal sensor to be launched in 2013. The chapter describes the thematic mapper (TM) and enhanced thematic mapper plus (ETM+) sensors, the calibration of their thermal bands, and the design and prelaunch calibration of the new thermal infrared sensor (TIRS).

  6. What powers luminous infrared galaxies?

    NARCIS (Netherlands)

    Lutz, D; Genzel, R; Sternberg, A; Netzer, H; Kunze, D; Rigopoulou, D; Sturm, E; Egami, E; Feuchtgruber, H; Moorwood, AFM; deGraauw, T

    1996-01-01

    Based on the initial data sets taken with the ISO short wavelength spectrometer (SWS) we present a first discussion of the source of luminosity of (ultra-)luminous infrared galaxies (ULIRGs). By comparison of observations of 2.5-45 mu m lines to classical starbursts and active galactic nuclei and by

  7. Mid-infrared fiber lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Jackson, Stuart D.; Sorokina, I.T.; Vodopyanov, K.L.

    2003-01-01

    The current state of the art in mid-infrared fiber lasers is reviewed in this chapter. The relevant fiber-host materials such as silicates, fluorides, chalcogenides, and ceramics, the fiber, pump, and resonator geometries, and the spectroscopic properties of rare-earth ions are introduced. Lasers at

  8. INSTRUMENTATION FOR FAR INFRARED SPECTROSCOPY.

    Energy Technology Data Exchange (ETDEWEB)

    GRIFFITHS, P.R.; HOMES, C.

    2001-05-04

    Fourier transform spectrometers developed in three distinct spectral regions in the early 1960s. Pierre Connes and his coworkers in France developed remarkably sophisticated step-scan interferometers that permitted near-infrared spectra to be measured with a resolution of better than 0.0 1 cm{sup {minus}1}. These instruments may be considered the forerunners of the step-scan interferometers made by Bruker, Bio-Rad (Cambridge, MA, USA) and Nicolet although their principal application was in the field of astronomy. Low-resolution rapid-scanning interferometers were developed by Larry Mertz and his colleagues at Block Engineering (Cambridge, MA, USA) for remote sensing. Nonetheless, the FT-IR spectrometers that are so prevalent in chemical laboratories today are direct descendants of these instruments. The interferometers that were developed for far-infrared spectrometry in Gebbie's laboratory ,have had no commercial counterparts for at least 15 years. However, it could be argued that these instruments did as much to demonstrate the power of Fourier transform spectroscopy to the chemical community as any of the instruments developed for mid- and near-infrared spectrometry. Their performance was every bit as good as today's rapid-scanning interferometers. However, the market for these instruments is so small today that it has proved more lucrative to modify rapid-scanning interferometers that were originally designed for mid-infrared spectrometry than to compete with these instruments with slow continuous scan or step-scan interferometers.

  9. INFRARED SPECTRA, THERMOGRAVIMETRIC ANALYSIS AND ...

    African Journals Online (AJOL)

    Preferred Customer

    characterized by melting point, molar conductivity, magnetic moment, elemental analysis, infrared spectra and thermal analyses. ... methyl-quinazolinone and the final products of the thermogravimetric analysis were recorded on a Perkin-Elmer FT-IR type ..... [Cu(CH3COO)(L)3]. CuO + 5C +12C2H2 + 4NO + NH3 + 0.5N2.

  10. Infrared astronomy seeing the heat : from William Herschel to the Herschel space observatory

    CERN Document Server

    Clements, David L

    2014-01-01

    Uncover the Secrets of the Universe Hidden at Wavelengths beyond Our Optical GazeWilliam Herschel's discovery of infrared light in 1800 led to the development of astronomy at wavelengths other than the optical. Infrared Astronomy - Seeing the Heat: from William Herschel to the Herschel Space Observatory explores the work in astronomy that relies on observations in the infrared. Author David L. Clements, a distinguished academic and science fiction writer, delves into how the universe works, from the planets in our own Solar System to the universe as a whole. The book first presents the major t

  11. Understanding the formation and evolution of early-type galaxies based on newly developed single-burst stellar population synthesis models in the infrared

    Science.gov (United States)

    Roeck, Benjamin

    2015-12-01

    The detailed study of the different stellar populations which can be observed in galaxies is one of the most promising methods to shed light on the evolutionary histories of galaxies. So far, stellar population analysis has been carried out mainly in the optical wavelength range. The infrared spectral range, on the other hand, has been poorly studied so far, although it provides very important insights, particularly into the cooler stellar populations which are present in galaxies. However, in the last years, space telescopes like the Spitzer Space Telescope or the Wide-field Infrared Survey Explorer and instruments like the spectrograph X-Shooter on the Very Large Telescope have collected more and more photometric and spectroscopic data in this wavelength range. In order to analyze these observations, it is necessary to dispose of reliable and accurate stellar population models in the infrared. Only a small number of stellar population models in the infrared exist in the literature. They are mostly based on theoretical stellar libraries and very often cover only the near-infrared wavelength range at a rather low resolution. Hence, we developed new single-burst stellar population models between 8150 and 50000Å which are exclusively based on 180 spectra from the empirical Infrared Telescope Facility stellar library. We computed our single stellar population models for two different sets of isochrones and various types of initial mass functions of different slopes. Since the stars of the Infrared Telescope Facility library present only a limited coverage of the stellar atmospheric parameter space, our models are of sufficient quality only for ages larger than 1 Gyr and metallicities between [Fe/H] = 0.40 and 0.26. By combining our single stellar population models in the infrared with the extended medium-resolution Isaac Newton Telescope library of empirical spectra in the optical spectral range, we created the first single stellar population models covering the

  12. Non-collinear upconversion of infrared light

    DEFF Research Database (Denmark)

    Pedersen, Christian; Hu, Qi; Høgstedt, Lasse

    2014-01-01

    Two dimensional mid-infrared upconversion imaging provides unique spectral and spatial information showing good potential for mid- infrared spectroscopy and hyperspectral imaging. However, to extract spectral or spatial information from the upconverted images an elaborate model is needed, which...

  13. Multi-robot system using low-cost infrared sensors

    Directory of Open Access Journals (Sweden)

    Anubhav Kakkar

    2013-03-01

    Full Text Available This paper presents a proposed set of the novel technique, methods, and algorithm for simultaneous path planning, area exploration, area retrieval, obstacle avoidance, object detection, and object retrieval   autonomously by a multi-robot system. The proposed methods and algorithms are built considering the use of low cost infrared sensors with the ultimate function of efficiently exploring the given unknown area and simultaneously identifying desired objects by analyzing the physical characteristics of several of the objects that come across during exploration. In this paper, we have explained the scenario by building a coordinative multi-robot system consisting of two autonomously operated robots equipped with low-cost and low-range infrared sensors to perform the assigned task by analyzing some of the sudden changes in their environment. Along with identifying and retrieving the desired object, the proposed methodology also provide an inclusive analysis of the area being explored. The novelties presented in the paper may significantly provide a cost-effective solution to the problem of area exploration and finding a known object in an unknown environment by demonstrating an innovative approach of using the infrared sensors instead of high cost long range sensors and cameras. Additionally, the methodology provides a speedy and uncomplicated method of traversing a complicated arena while performing all the necessary and inter-related tasks of avoiding the obstacles, analyzing the area as well as objects, and reconstructing the area using all these information collected and interpreted for an unknown environment. The methods and algorithms proposed are simulated over a complex arena to depict the operations and manually tested over a physical environment which provided 78% correct results with respect to various complex parameters set randomly.

  14. C-QWIPs for space exploration

    Science.gov (United States)

    Choi, K. K.; Jhabvala, M. D.; Forrai, D. P.; Sun, J.; Endres, D.

    2011-05-01

    We have extended our investigation of corrugated quantum well infrared photodetector focal plane arrays (C-QWIP FPAs) into the far infrared regime. Specifically, we are developing the detectors for the thermal infrared sensor (TIRS) used in the NASA Landsat Data Continuity Mission. This mission requires infrared detection cutoff at 12.5 μm and FPAs operated at ˜43 K. To maintain a low dark current in these extended wavelengths, we adopted a low doping density of 0.6 × 10 18 cm -3 and a bound-to-bound state detector in one of the designs. The internal absorption quantum efficiency η is calculated to be 25.4% for a pixel pitch of 25 μm and 60 periods of QWs. With a pixel fill factor of 80% and a substrate transmission of 70.9%, the external η is 14.4%. To yield the theoretical conversion efficiency CE, the photoconductive gain was measured and is 0.25 at 5 V, from which CE is predicted to be 3.6%. This value is in agreement with the 3.5% from the FPA measurement. Meanwhile, the dark current is measured to be 2.1 × 10 -6 A/cm 2 at 43 K. For regular infrared imaging above 8 μm, the FPA will have a noise equivalent temperature difference (NETD) of 16 mK at 2 ms integration time in the presence of 260 read noise electrons, and it increases to 22 mK at 51 K. The highest operability of the tested FPAs is 99.967%. With the CE agreement, we project the FPA performance in the far infrared regime up to 30-μm cutoff, which will be useful for the Jupiter-Europa deep space exploration. In this work, we also investigated the C-QWIP optical coupling when the detector substrate is thinned.

  15. Dual-Telescope Multi-Channel Thermal-Infrared Radiometer for Outer Planet Fly-By Missions

    Science.gov (United States)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; hide

    2016-01-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 microns, in five spectral pass bands, for outer planet fly-by missions is described. The dual- telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field- of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  16. Infrared landmine detection and thermal model analysis

    NARCIS (Netherlands)

    Schwering, P.B.W.; Kokonozi, A.; Carter, L.J.; Lensen, H.A.; Franken, E.M.

    2001-01-01

    Infrared imagers are capable of the detection of surface laid mines. Several sensor fused land mine detection systems make use of metal detectors, ground penetrating radar and infrared imagers. Infrared detection systems are sensitive to apparent temperature contrasts and their detection

  17. Atomic carbon in an infrared dark cloud

    NARCIS (Netherlands)

    Ossenkopf, Volker; Ormel, Chris W.; Simon, Robert; Sun, Kefeng; Stutzki, Jürgen

    2010-01-01

    Infrared dark clouds (IRDCs) are potential sites of massive star formation, dark in the near-infrared, but in many cases already with indications of active star-formation from far-infrared and submm observations. They are an ideal test bed to study the role of internal and external heating on the

  18. Identifying Cool Brown Dwarfs and Subdwarfs in the Solar Neighborhood: Prospects for a Near-Infrared Proper Motion Survey

    Science.gov (United States)

    Burgasser, A. J.

    2003-12-01

    Low-temperature stars and brown dwarfs emit predominantly in the near-infrared, and recent wide-field surveys sampling these wavelengths (2MASS, DENIS, SDSS) have unveiled a vast repository of intrinsically faint objects, including large numbers of field brown dwarfs and members of two new spectral classes. On the other hand, proper motion surveys have been exceptionally efficient at uncovering both the nearest stars and stars with high intrinsic motions; i.e., halo/thick disk dwarfs and white dwarfs. Unfortunately, proper motion surveys are insensitive to faint stars and brown dwarfs as they have been conducted primarily at optical bands. I therefore make a case for a wide-field near-infrared proper motion survey that would detect the nearest cool stars and brown dwarfs in an efficient and photometrically unbiased manner. I demonstrate how the currently known population of field brown dwarfs are easily discernible in such a survey, and how substellar subdwarfs could potentially be found in substantial numbers. This survey could make use of existing catalog data as its first epoch. I also describe a straightforward NIR survey program using a 2Kx2K IR camera on a dedicated 1-2m class automated telescope. This somewhat more ambitious program could repeatedly scan the sky on a 6-month cycle, and would be useful for cool dwarf searches, general variability studies, searches for transits around late-type stars, and deep survey programs. This research is supported by NASA through Hubble Fellowship grant HST-HF-01137.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  19. A COMPARISON OF NEAR-INFRARED PHOTOMETRY AND SPECTRA FOR Y DWARFS WITH A NEW GENERATION OF COOL CLOUDY MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, S. K. [Gemini Observatory, Northern Operations Center, 670 North A' ohoku Place, Hilo, HI 96720 (United States); Morley, Caroline V.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Marley, M. S. [NASA Ames Research Center, Mail Stop 245-3, Moffett Field, CA 94035 (United States); Saumon, D. [Los Alamos National Laboratory, P.O. Box 1663, MS F663, Los Alamos, NM 87545 (United States); Visscher, Channon, E-mail: sleggett@gemini.edu [Southwest Research Institute, Boulder, CO 80302 (United States)

    2013-02-15

    We present YJHK photometry, or a subset, for the six Y dwarfs discovered in Wide-field Infrared Survey Explorer (WISE) data by Cushing et al. The data were obtained using the Near-Infrared Imager on the Gemini North telescope; YJHK were obtained for WISEP J041022.71+150248.5, WISEP J173835.52+273258.9, and WISEPC J205628.90+145953.3; YJH for WISEPC J140518.40+553421.5 and WISEP J154151.65225025.2; and YJK for WISEP J182831.08+265037.8. We also present a far-red spectrum obtained using GMOS-North for WISEPC J205628.90+145953.3. We compare the data to Morley et al. models, which include cloud decks of sulfide and chloride condensates. We find that the models with these previously neglected clouds can reproduce the energy distributions of T9 to Y0 dwarfs quite well, other than near 5 {mu}m where the models are too bright. This is thought to be because the models do not include departures from chemical equilibrium caused by vertical mixing, which would enhance the abundance of CO and CO{sub 2}, decreasing the flux at 5 {mu}m. Vertical mixing also decreases the abundance of NH{sub 3}, which would otherwise have strong absorption features at 1.03 {mu}m and 1.52 {mu}m that are not seen in the Y0 WISEPC J205628.90+145953.3. We find that the five Y0 to Y0.5 dwarfs have 300 {approx}< T {sub eff} K {approx}< 450, 4.0 {approx}< log g {approx}< 4.5, and f {sub sed} Almost-Equal-To 3. These temperatures and gravities imply a mass range of 5-15 M {sub Jupiter} and ages around 5 Gyr. We suggest that WISEP J182831.08+265037.8 is a binary system, as this better explains its luminosity and color. We find that the data can be made consistent with observed trends, and generally consistent with the models, if the system is composed of a T {sub eff} Almost-Equal-To 325 K and log g {approx}< 4.5 primary, and a T {sub eff} Almost-Equal-To 300 K and log g {approx}> 4.0 secondary, corresponding to masses of 10 and 7 M {sub Jupiter} and an age around 2 Gyr. If our deconvolution is correct

  20. Infrared thermal imaging in medicine.

    Science.gov (United States)

    Ring, E F J; Ammer, K

    2012-03-01

    This review describes the features of modern infrared imaging technology and the standardization protocols for thermal imaging in medicine. The technique essentially uses naturally emitted infrared radiation from the skin surface. Recent studies have investigated the influence of equipment and the methods of image recording. The credibility and acceptance of thermal imaging in medicine is subject to critical use of the technology and proper understanding of thermal physiology. Finally, we review established and evolving medical applications for thermal imaging, including inflammatory diseases, complex regional pain syndrome and Raynaud's phenomenon. Recent interest in the potential applications for fever screening is described, and some other areas of medicine where some research papers have included thermal imaging as an assessment modality. In certain applications thermal imaging is shown to provide objective measurement of temperature changes that are clinically significant.