WorldWideScience

Sample records for telescope ultraviolet spectra

  1. The ultraviolet telescope on the Astron satellite

    International Nuclear Information System (INIS)

    Boyarchuk, A.A.

    1987-01-01

    On 23 March 1983 in the USSR, the Astron astrophysical satellite, with the largest ultraviolet telescope (the UVT) in the world (main mirror diameter 80 cm) and a set of X-ray instruments on board was placed in a high-apogee orbit. The design of the ultraviolet telescope and the results of some of the observations carried out with it are described here. The X-ray instruments are discussed in a separate article. The ultraviolet telescope on the Astron astrophysical satellite is a result of the joint efforts of scientists and engineers at the Crimean Astrophysical Observatory (Academy of Sciences of the USSR), the Byurakan Astrophysical Observatory (Academy of Sciences of the Armenian USSR), and several industrial enterprises in our country. The Laboratoire d'Astronomie Spatiale (CNRS, Marseille, France) played a large role in building the spectrometer for the UVT

  2. JUDE: An Ultraviolet Imaging Telescope pipeline

    Science.gov (United States)

    Murthy, J.; Rahna, P. T.; Sutaria, F.; Safonova, M.; Gudennavar, S. B.; Bubbly, S. G.

    2017-07-01

    The Ultraviolet Imaging Telescope (UVIT) was launched as part of the multi-wavelength Indian AstroSat mission on 28 September, 2015 into a low Earth orbit. A 6-month performance verification (PV) phase ended in March 2016, and the instrument is now in the general observing phase. UVIT operates in three channels: visible, near-ultraviolet (NUV) and far-ultraviolet (FUV), each with a choice of broad and narrow band filters, and has NUV and FUV gratings for low-resolution spectroscopy. We have written a software package (JUDE) to convert the Level 1 data from UVIT into scientifically useful photon lists and images. The routines are written in the GNU Data Language (GDL) and are compatible with the IDL software package. We use these programs in our own scientific work, and will continue to update the programs as we gain better understanding of the UVIT instrument and its performance. We have released JUDE under an Apache License.

  3. Ultraviolet spectra of planetary nebulae

    International Nuclear Information System (INIS)

    Adams, S.; Seaton, M.J.

    1982-01-01

    Features observed in infrared spectra suggest that certain very low excitation (VLE) nebulae have low C/O abundance ratios (Cohen and Barlow 1980; Aitken and Roche 1982). Fluxes in the multiplets [O II] lambda 2470 and C II] lambda 2326 have been measured for the VLE nebula He He 2-131 = HD 138403 using IUE high-dispersion spectra. An analysis similar to that of Harrington et al. (1980) for IC 418 gives C/O = 0.3 for He 2-131, compared with C/O = 1.3 for IC 418 and 0.6 for the Sun. (author)

  4. Ultraviolet spectra of Mg in liquid helium

    International Nuclear Information System (INIS)

    Moriwaki, Y.; Morita, N.

    1999-01-01

    Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

  5. Ultraviolet spectra of planetary nebulae

    International Nuclear Information System (INIS)

    Harrington, J.P.; Seaton, M.J.; Adams, S.; Lutz, J.H.

    1982-01-01

    A detailed study of NGC 7662 is based on UV results obtained from 15 IUE spectra and on observations of other workers at optical, IR and radio wavelengths. Improved techniques are used to extract IUE data for an extended source. Relative fluxes in the different apertures which have been used are obtained using the brightness contours of Coleman, Reay and Worswick. There is close agreement between the reddening deduced from the ratios He II (lambda 1640)/(lambda 4686) and (radio)/(Hβ) and the nebular continuum emission observed with the IUE large slots agrees closely with that predicted using absolute radio and Hβ fluxes. The fluxes in nebular emission lines observed with the small slots are smaller than expected from brightness distributions; it is concluded that, for an extended source, the small slots have aperture transmission factors of 0.85 for SWP and 0.46 for LWR. The central star is fainter than has been previously supposed (by more than two magnitudes). The blackbody He II Zanstra temperature of 113 000 K is consistent with the UV colour temperature. Previous work on colour temperatures of central stars is discussed critically. Two models are discussed. (author)

  6. Molecular geometry in the ultraviolet absorption spectra

    International Nuclear Information System (INIS)

    Albuquerque, S.F. de; Monteiro, L.S.; Adamis, L.M.B.; Baltar, M.C.P.; Silva, R.M. da

    1977-01-01

    The ultraviolet absorption spectra may be sensibly affected by steric effects. These effects can cause a lot of difficulties and unexpected changes in spectrum. The most general source of such difficulties is steric inhibition of resonance. In addition to this, ultraviolet epectra may be markedly changed by steric factors which change the positions of dipoles in the molecule with respect to each other and by the interaction of nonconjugated chromophores suitably located in space. We have studied in detail each of these effects presenting a lot of usual and importants examples in Organic Chemistry. Others relevants subjects were not considerated in this present work [pt

  7. In-orbit Calibrations of the Ultraviolet Imaging Telescope

    Science.gov (United States)

    Tandon, S. N.; Subramaniam, Annapurni; Girish, V.; Postma, J.; Sankarasubramanian, K.; Sriram, S.; Stalin, C. S.; Mondal, C.; Sahu, S.; Joseph, P.; Hutchings, J.; Ghosh, S. K.; Barve, I. V.; George, K.; Kamath, P. U.; Kathiravan, S.; Kumar, A.; Lancelot, J. P.; Leahy, D.; Mahesh, P. K.; Mohan, R.; Nagabhushana, S.; Pati, A. K.; Kameswara Rao, N.; Sreedhar, Y. H.; Sreekumar, P.

    2017-09-01

    The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) channel (1300-1800 Å), and the other for the near-ultraviolet (NUV) channel (2000-3000 Å) and the visible (VIS) channel (3200-5500 Å). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1.″8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.

  8. In-orbit Calibrations of the Ultraviolet Imaging Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, S. N. [Inter-University Center for Astronomy and Astrophysics, Pune (India); Subramaniam, Annapurni; Sankarasubramanian, K.; Sriram, S.; Stalin, C. S.; Mondal, C.; Sahu, S.; Joseph, P.; Barve, I. V.; George, K.; Kamath, P. U.; Kathiravan, S.; Kumar, A.; Lancelot, J. P.; Mahesh, P. K. [Indian Institute of Astrophysics, Koramangala II Block, Bangalore-560034 (India); Girish, V. [ISRO Satellite Centre, HAL Airport Road, Bangalore 560017 (India); Postma, J.; Leahy, D. [University of Calgary, 2500 University Drive NW, Calgary, Alberta Canada (Canada); Hutchings, J. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Ghosh, S. K., E-mail: purni@iiap.res.in [National Centre for Radio Astrophysics, Pune (India); and others

    2017-09-01

    The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) channel (1300–1800 Å), and the other for the near-ultraviolet (NUV) channel (2000–3000 Å) and the visible (VIS) channel (3200–5500 Å). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1.″8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.

  9. Medium-resolution isaac newton telescope library of empirical spectra

    NARCIS (Netherlands)

    Sanchez-Blazquez, P.; Peletier, R. F.; Jimenez-Vicente, J.; Cardiel, N.; Cenarro, A. J.; Falcon-Barroso, J.; Gorgas, J.; Selam, S.; Vazdekis, A.

    2006-01-01

    A new stellar library developed for stellar population synthesis modelling is presented. The library consists of 985 stars spanning a large range in atmospheric parameters. The spectra were obtained at the 2.5-m Isaac Newton Telescope and cover the range lambda lambda 3525-7500 angstrom at 2.3

  10. Ultraviolet spectra of DA white dwarfs

    International Nuclear Information System (INIS)

    Nelan, E.P.

    1985-01-01

    Using the International Ultraviolet Explorer (IUE) satellite, observations of cool to moderately warm DA white dwarfs showed the presence of broad absorption features at lambda 1400 and 1600. The lambda 1600 feature is prominent for T/sub eff/ 0 K and the lambda 1400 feature is visible up to about T/sub eff/ = 18,000 0 K. Proposed mechanisms for absorption at lambda 1400 have included a Si V doublet, H 2 Lyman bands, and the Call ionization edge at lambda 1420. It was recently suggested that the lambda 1600 feature is due to the photoionization edge of Mg I at lambda 1625. None of these has been able to explain all of the observations without invoking some quite unconventional circumstances. On the basis of computer models, this thesis proposes that the absorption in both cases is due to perturbations of the energy level structure of neutral hydrogen atoms undergoing collisions. The lambda 1600 feature is due to absorption by the hydrogen quasi-molecule while that at lambda 1400 arises from a ground state transition of the hydrogen quasi-molecule ion

  11. Action spectra in mammalian cells exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    A review is given of the literature published since 1977 on action spectra in mammalian cells exposed to ultraviolet radiation in the wavelength region above 220 nm. Action spectra for lethal events are discussed for cell inactivation in normal cells, growth arrested cells and photosensitive cells. Action spectra for non-lethal events are also discussed in relation to pyrimidine dimer formation, photoreactivation and the use of photosensitisers. It was concluded from these studies that damage to the DNA, and the extent of the repair of this damage, seems to determine a cell's response to such parameters as inactivation, mutation, transformation, latent viral activation, cellular viral capacity and ultraviolet enhanced viral reactivation. In addition to the direct effects of UV on DNA, photosensitization of cellular responses with chemicals such as 8-MOP extend the wavelength range at which damage can be demonstrated. (U.K.)

  12. GLOBAL SIMULATION OF AN EXTREME ULTRAVIOLET IMAGING TELESCOPE WAVE

    International Nuclear Information System (INIS)

    Schmidt, J. M.; Ofman, L.

    2010-01-01

    We use the observation of an Extreme Ultraviolet Imaging Telescope (EIT) wave in the lower solar corona, seen with the two Solar Terrestrial Relations Observatory (STEREO) spacecraft in extreme ultraviolet light on 2007 May 19, to model the same event with a three-dimensional (3D) time-depending magnetohydrodynamic (MHD) code that includes solar coronal magnetic fields derived with Wilcox Solar Observatory magnetogram data, and a solar wind outflow accelerated with empirical heating functions. The model includes a coronal mass ejection (CME) of Gibson and Low flux rope type above the reconstructed active region with parameters adapted from observations to excite the EIT wave. We trace the EIT wave running as circular velocity enhancement around the launching site of the CME in the direction tangential to the sphere produced by the wave front, and compute the phase velocities of the wave front. We find that the phase velocities are in good agreement with theoretical values for a fast magnetosonic wave, derived with the physical parameters of the model, and with observed phase speeds of an incident EIT wave reflected by a coronal hole and running at about the same location. We also produce in our 3D MHD model the observed reflection of the EIT wave at the coronal hole boundary, triggered by the magnetic pressure difference between the wave front hitting the hole and the boundary magnetic fields of the coronal hole, and the response of the coronal hole, which leads to the generation of secondary reflected EIT waves radiating away in different directions than the incident EIT wave. This is the first 3D MHD model of an EIT wave triggered by a CME that includes realistic solar magnetic field, with results comparing favorably to STEREO Extreme Ultraviolet Imager observations.

  13. Hubble Space Telescope Ultraviolet Light Curves Reveal Interesting Properties of CC Sculptoris and RZ Leonis

    Energy Technology Data Exchange (ETDEWEB)

    Szkody, Paula; Mukadam, Anjum S. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Toloza, Odette; Gänsicke, Boris T.; Pala, Anna F. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Dai, Zhibin [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China); Waagen, Elizabeth O. [AAVSO, 48 Bay State Rd, Cambridge, MA 02138 (United States); Godon, Patrick; Sion, Edward M., E-mail: szkody@astro.washington.edu [Department of Astrophysics and Planetary Science, Villanova University, Villanova, PA 19085 (United States)

    2017-03-01

    Time-tag ultraviolet data obtained on the Hubble Space Telescope in 2013 reveal interesting variability related to the white dwarf spin in the two cataclysmic variables RZ Leo and CC Scl. RZ Leo shows a period at 220 s and its harmonic at 110 s, thus identifying it as a likely Intermediate Polar (IP). The spin signal is not visible in a short single night of ground-based data in 2016, but the shorter exposures in that data set indicate a possible partial eclipse. The much larger UV amplitude of the spin signal in the known IP CC Scl allows the spin of 389 s, previously only seen at outburst, to be visible at quiescence. Spectra created from the peaks and troughs of the spin times indicate a hotter temperature of several thousand degrees during the peak phases, with multiple components contributing to the UV light.

  14. Vacuum ultraviolet (VUV) absorption spectra of chromatin and its components

    International Nuclear Information System (INIS)

    Dodonova, N.Y.; Kiseleva, M.N.; Petrov, M.Y.; Tsyganenko, N.M.; Bubyakina, V.V.; Chikhirzhina, G.I.

    1984-01-01

    The electron absorption spectra of thin films of chromatin and chromatin components in the ultraviolet region (140-280 nm) were investigated. The absorption coefficients μ(lambda) of chromatin, nucleosomes with and without histone H1, total histones (TH), and DNA were compared. The spectra of nucleosomes differ from the sum-spectrum of DNA plus TH. The chromatin and nucleosome spectra are not similar in the spectral region of 190-160 nm. The lack of additivity of absorption coefficients at different wavelengths may be explained by different conformational changes of DNA, TH in nucleosomes and chromatin during the process of drying aqueous solutions for the preparation of thin films. The μ(lambda) values are useful for an estimate of the DNA and TH absorption in chromatin and nucleosomes in discussing UV and VUV irradiation damages. (Auth.)

  15. EVIDENCE FOR TYPE Ia SUPERNOVA DIVERSITY FROM ULTRAVIOLET OBSERVATIONS WITH THE HUBBLE SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaofeng [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Wang Lifan [Physics and Astronomy Department, Texas A and M University, College Station, TX 77843 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Baron, Eddie [Department of Physics, University of Oklahoma, Norman, OK 73019 (United States); Kromer, Markus [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Jack, Dennis [Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg (Germany); Zhang Tianmeng [National Astronomical Observatory of China, Chinese Academy of Sciences, Beijing 100012 (China); Aldering, Greg [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Antilogus, Pierre [Laboratoire de Physique Nucleaire des Hautes Energies, Paris (France); Arnett, W. David [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Baade, Dietrich [European Southern Observatory, 85748 Garching (Germany); Barris, Brian J. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Benetti, Stefano; Cappellaro, Enrico [Osservatorio Astronomico di Padova, 35122 Padova (Italy); Bouchet, Patrice [CEA/DSM/DAPNIA/Service d' Astrophysique, 91191 Gif-sur-Yvette Cedex (France); Burrows, Adam S. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Canal, Ramon [Department d' Astronomia i Meterorologia, Universidad de Barcelona, Barcelona 8007 (Spain); Carlberg, Raymond G. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3J3 (Canada); Di Carlo, Elisa [INAF, Osservatorio Astronomico di Teramo, 64100 Teramo (Italy); Challis, Peter J., E-mail: wang_xf@mail.tsinghua.edu.cn [Harvard/Smithsonian Center Astrophysics, Cambridge, MA 02138 (United States); and others

    2012-04-20

    We present ultraviolet (UV) spectroscopy and photometry of four Type Ia supernovae (SNe 2004dt, 2004ef, 2005M, and 2005cf) obtained with the UV prism of the Advanced Camera for Surveys on the Hubble Space Telescope. This data set provides unique spectral time series down to 2000 A. Significant diversity is seen in the near-maximum-light spectra ({approx}2000-3500 A) for this small sample. The corresponding photometric data, together with archival data from Swift Ultraviolet/Optical Telescope observations, provide further evidence of increased dispersion in the UV emission with respect to the optical. The peak luminosities measured in the uvw1/F250W filter are found to correlate with the B-band light-curve shape parameter {Delta}m{sub 15}(B), but with much larger scatter relative to the correlation in the broadband B band (e.g., {approx}0.4 mag versus {approx}0.2 mag for those with 0.8 mag < {Delta}m{sub 15}(B) < 1.7 mag). SN 2004dt is found as an outlier of this correlation (at > 3{sigma}), being brighter than normal SNe Ia such as SN 2005cf by {approx}0.9 mag and {approx}2.0 mag in the uvw1/F250W and uvm2/F220W filters, respectively. We show that different progenitor metallicity or line-expansion velocities alone cannot explain such a large discrepancy. Viewing-angle effects, such as due to an asymmetric explosion, may have a significant influence on the flux emitted in the UV region. Detailed modeling is needed to disentangle and quantify the above effects.

  16. Ultraviolet Imaging Telescope images of the reflection nebula NGC 7023 - Derivation of ultraviolet scattering properties of dust grains

    Science.gov (United States)

    Witt, Adolf N.; Petersohn, Jens K.; Bohlin, Ralph C.; O'Connell, Robert W.; Roberts, Morton S.; Smith, Andrew M.; Stecher, Theodore P.

    1992-01-01

    The Ultraviolet Imaging Telescope as part of the Astro-1 mission, was used to obtain high-resolution surface brightness distribution data in six ultraviolet wavelength bands for the bright reflection nebula NGC 7023. From the quantitative comparison of the measured surface brightness gradients ratios of nebular to stellar flux, and detail radial surface brightness profiles with corresponding data from the visible, two major conclusions results: (1) the scattering in the near- and far-ultraviolet in this nebula is more strongly forward-directed than in the visible; (2) the dust albedo in the ultraviolet for wavelengths not less than 140 nm is identical to that in the visible, with the exception of the 220 nm bump in the extinction curve. In the wavelengths region of the bump, the albedo is reduced by 25 to 30 percent in comparison with wavelengths regions both shorter and longer. This lower albedo is expected, if the bump is a pure absorption feature.

  17. Ultraviolet photometry from the Orbiting Astronomical Observatory. XXXII - An atlas of ultraviolet stellar spectra

    Science.gov (United States)

    Code, A. D.; Meade, M. R.

    1979-01-01

    Ultraviolet stellar fluxes are presented in graphs and tables for 164 bright stars in the spectral region from 1200 to 3600 A. The spectra represent a subset of OAO 2 spectrometer data on file at the National Space Science Data Center. The monochromatic flux is given in units of erg per (sq cm-s-A) with a spectral resolution of about 22 A in the region from 3600 to 1850 A and of approximately 12 A in the region from 1850 to 1160 A.

  18. WebPlotDigitizer, a polyvalent and free software to extract spectra from old astronomical publications: application to ultraviolet spectropolarimetry

    Science.gov (United States)

    Marin, F.; Rohatgi, A.; Charlot, S.

    2017-12-01

    In this contribution, we present WebPlotDigitizer, a polyvalent and free software developed to facilitate easy and accurate data extraction from a variety of plot types. We describe the numerous features of this numerical tool and present its relevance when applied to astrophysical archival research. We exploit WebPlotDigitizer to extract ultraviolet spectropolarimetric spectra from old publications that used the Hubble Space Telescope, Lick Observatory 3 m Shane telescope and Astro-2 mission to observe the Seyfert-2 AGN NGC 1068. By doing so, we compile all the existing ultraviolet polarimetric data on NGC 1068 to prepare the ground for further investigations with the future high-resolution spectropolarimeter POLLUX on-board of the proposed Large UV/Optical/Infrared Surveyor (LUVOIR) NASA mission.

  19. The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas (MegaSaura). II. Stacked Spectra

    Science.gov (United States)

    Rigby, J. R.; Bayliss, M. B.; Chisholm, J.; Bordoloi, R.; Sharon, K.; Gladders, M. D.; Johnson, T.; Paterno-Mahler, R.; Wuyts, E.; Dahle, H.; Acharyya, A.

    2018-01-01

    We stack the rest-frame ultraviolet spectra of N = 14 highly magnified gravitationally lensed galaxies at redshifts 1.6high redshift with the James Webb Space Telescope (JWST). We report equivalent widths to aid in proposing for and interpreting JWST spectra. We examine the velocity profiles of strong absorption features in the composite, and in a matched composite of z∼ 0 COS/HST galaxy spectra. We find remarkable similarity in the velocity profiles at z∼ 0 and z∼ 2, suggesting that similar physical processes control the outflows across cosmic time. While the maximum outflow velocity depends strongly on ionization potential, the absorption-weighted mean velocity does not. As such, the bulk of the high-ionization absorption traces the low-ionization gas, with an additional blueshifted absorption tail extending to at least ‑2000 km s‑1. We interpret this tail as arising from the stellar wind and photospheres of massive stars. Starburst99 models are able to replicate this high-velocity absorption tail. However, these theoretical models poorly reproduce several of the photospheric absorption features, indicating that improvements are needed to match observational constraints on the massive stellar content of star-forming galaxies at z∼ 2. We publicly release our composite spectra.

  20. Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

    Science.gov (United States)

    Wu, Tao; Higashiguchi, Takeshi; Li, Bowen; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Dunne, Padraig; O'Reilly, Fergal; Sokell, Emma; Liu, Luning; O'Sullivan, Gerry

    2015-08-01

    Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1-7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 1014 W cm-2 for the former and 5.5 × 1012 W cm-2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3-6.3 nm and 1.5-4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5-4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p64dN-4p54dN+1 + 4p64dN-14f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7-5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3-4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified.

  1. Ultraviolet spectropolarimetry of high-redshift quasars with the Hubble Space Telescope

    Science.gov (United States)

    Impey, C. D.; Malkan, Matthew A.; Webb, Wayne; Petry, C. E.

    1995-01-01

    Ultraviolet spectropolarimetry of three bright high-redshift low-polarization quasars (LPQs) was obtained with the Faint Object Spectrograph of the Hubble Space Telescope (HST). Two of the quasars, PG 1634+706 and PG 2302+029, had polarizations p approximately = 0.5%-1.0% throughout the ultraviolet, and showed no significant variation of polarization amplitude or position angle with wavelength. PG 2302+029 was also marginally (2.4 sigma) circularly polarized in the optical continuum. For the highest redshift quasar, PG 1222+228 (Ton 1530), the polarization was measured down to rest wavelengths below 800 A. Although the continuum of PG 1222+228 was weakened by Lyman limit absorption from an intergalactic gas cloud, the polarization increased sharply from 1% to about 4.5%, a change of 4 sigma significance. This abrupt rise in polarization does not appear attributable to any known instrumental artifact. These UV polarizations were only slightly less than those previously observed for these same objects in the optical. The polarization spectra were flat with a typical slope of the polarized flux pF(sub nu) proportional to nu(exp -0.8 +/- 0.5). Unlike the case of several high luminosity Seyfert 1 nuclei studied previously, polarization caused by scattering from dust grains does not provide the best fit to the polarization spectra of these luminous quasars. These observed spectra are consistent with a wavelength-independent polarization proportional to the total nonstellar light or, possibly, to the contribution of the blue thermal component. The polarization spectra have insufficient signal-to-noise to locate the scatterers with respect to the continuum source and the much larger broad line region. A decrease in amplitude and rotation of the position angle of the polarization vector at the shortest wavelengths, which could result from general relativistic effects near a spinning black hole, was not observed. In fact, in PG 1222+228, the polarization was observed to

  2. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

  3. Analysis of extreme ultraviolet spectra from laser produced rhenium plasmas

    International Nuclear Information System (INIS)

    Wu, Tao; Dunne, Padraig; O’Reilly, Fergal; Sokell, Emma; Liu, Luning; O’Sullivan, Gerry; Higashiguchi, Takeshi; Suzuki, Yuhei; Arai, Goki; Dinh, Thanh-Hung; Li, Bowen

    2015-01-01

    Extreme ultraviolet spectra of highly-charged rhenium ions were observed in the 1–7 nm region using two Nd:YAG lasers with pulse lengths of 150 ps and 10 ns, respectively, operating at a number of laser power densities. The maximum focused peak power density was 2.6 × 10 14 W cm −2 for the former and 5.5 × 10 12 W cm −2 for the latter. The Cowan suite of atomic structure codes and unresolved transition array (UTA) approach were used to calculate and interpret the emission properties of the different spectra obtained. The results show that n = 4-n = 4 and n = 4-n = 5 UTAs lead to two intense quasi-continuous emission bands in the 4.3–6.3 nm and 1.5–4.3 nm spectral regions. As a result of the different ion stage distributions in the plasmas induced by ps and ns laser irradiation the 1.5–4.3 nm UTA peak moves to shorter wavelength in the ps laser produced plasma spectra. For the ns spectrum, the most populated ion stage during the lifetime of this plasma that could be identified from the n = 4-n = 5 transitions was Re 23+ while for the ps plasma the presence of significantly higher stages was demonstrated. For the n = 4-n = 4 4p 6 4d N -4p 5 4d N+1  + 4p 6 4d N−1 4f transitions, the 4d-4f transitions contribute mainly in the most intense 4.7–5.5 nm region while the 4p-4d subgroup gives rise to a weaker feature in the 4.3–4.7 nm region. A number of previously unidentified spectral features produced by n = 4-n = 5 transitions in the spectra of Re XVI to Re XXXIX are identified. (paper)

  4. New Fe i Level Energies and Line Identifications from Stellar Spectra. II. Initial Results from New Ultraviolet Spectra of Metal-poor Stars

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Ruth C. [SETI Institute and Astrophysical Advances, 607 Marion Place, Palo Alto, CA 94301 (United States); Kurucz, Robert L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ayres, Thomas R., E-mail: peterson@ucolick.org [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309-0389 (United States)

    2017-04-01

    The Fe i spectrum is critical to many areas of astrophysics, yet many of the high-lying levels remain uncharacterized. To remedy this deficiency, Peterson and Kurucz identified Fe i lines in archival ultraviolet and optical spectra of metal-poor stars, whose warm temperatures favor moderate Fe i excitation. Sixty-five new levels were recovered, with 1500 detectable lines, including several bound levels in the ionization continuum of Fe i. Here, we extend the previous work by identifying 59 additional levels, with 1400 detectable lines, by incorporating new high-resolution UV spectra of warm metal-poor stars recently obtained by the Hubble Space Telescope Imaging Spectrograph. We provide gf values for these transitions, both computed as well as adjusted to fit the stellar spectra. We also expand our spectral calculations to the infrared, confirming three levels by matching high-quality spectra of the Sun and two cool stars in the H -band. The predicted gf values suggest that an additional 3700 Fe i lines should be detectable in existing solar infrared spectra. Extending the empirical line identification work to the infrared would help confirm additional Fe i levels, as would new high-resolution UV spectra of metal-poor turnoff stars below 1900 Å.

  5. The photoluminescence spectra of micropowder of aromatic compounds under ultraviolet laser excitation

    International Nuclear Information System (INIS)

    Rakhmatullaev, I.A.; Kurbonov, A.K. et al.; Gorelik, V.S.

    2016-01-01

    The method of diagnostics of aromatic compounds on the example of novocaine, aspirin and anthracene is presented. The method is based on optical detection of photoluminescence spectra at ultraviolet laser (266 nm) excitation. Employing this method the photoluminescence spectra are obtained which allows one to establish the differences of the composition and structure of compounds. The developed method can be used for analysis the quality of the large class of luminescent bioactive structures under the ultraviolet radiation. (authors)

  6. Observations of ultraviolet spectra of H II regions and galaxies with IUE

    International Nuclear Information System (INIS)

    Gondhalekar, P.M.

    1982-08-01

    The ultraviolet spectra, obtained with the International Ultraviolet Explorer, of a sample of H II regions and the nuclear regions of spiral and elliptical galaxies are described. The star formation rates in the nuclei of spiral galaxies are similar to the star formation rate in the solar neighbourhood. The data indicate that the current thinking on the synthesis of carbon and nitrogen in galaxies has to be revised and the K-corrections determined from the ultraviolet spectra of galaxies when compared with the photometry of distant galaxies suggests colour evolution of galaxies at z > 0.3. (author)

  7. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Oliver; Stark, Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.

  8. Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    M. El Ghazaly

    Full Text Available Photoluminescence (PL emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53–4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV to 400 (3.10 eV nm in step of 10 nm and the corresponding photoluminescence (PL emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC, the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation. Keywords: Photoluminescence spectra, Makrofol® DE 1-1, UV–vis spectrophotometry, Attenuation coefficient, Ultraviolet radiation

  9. Ultraviolet spectra of CeO2 nano-particles

    International Nuclear Information System (INIS)

    Tsunekawa, S.; Sivamohan, R.; Ohsuna, T.; Kasuya, A.; Takahashi, H.; Tohji, K.

    1998-01-01

    Full text: Quantum size effect is generally expected in nanometer size materials. The effect has been observed in many metal clusters and semiconducting nano-particles, but seldom in oxides, because the size control of crystalline oxides is generally difficult due to the ionic bond character. CeO 2 (ceria) is one of the rare-earth oxides and the size effect is worth studying from the viewpoint of an ultraviolet (u.v.) spectroscopy and applications. This report describes the first observation of a blue shift of u.v. spectra in ceria nano-particles of 2-5 nm in diameter with its deviation within 20%. A ceria aqueous sol (pH ≅ 2.5) having particle sizes under 6 nm in diameter was produced by ultrafiltration with a polyether sulfone membrane (SIP-1013, Asahi Chemical Industry Co.) from an original ceria aqueous sol (pH ≅ 1.5) having particle sizes extending over a wide range. Obtained sol contains a high concentration of Ce 3+ ions because of the high acidity. In order to separate ceria particles from Ce 3+ ions and fractionate the particle size, two kinds of anion-type surfactants were used in microemulsification process with toluene and water. One is sodium dodecylbenzene sulfonate (SD-BS) which is 2 nm in length and another is sodium octyl sulfonate (SOS) which is 1.2 nm in length. U.v. spectroscopic measurements and high resolution transmission electron microscopic (HRTEM) observations were performed for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t , where (SOS) t is a ceria suspension in toluene obtained by an emulsification with SOS surfactant, (SOS+SOS) t indicates the same product obtained by the further emulsification with SOS for an aqueous phase of the emulsion with SOS, and (SDBS+SOS+SDBS) t means that obtained by an additional emulsification with SDBS for an aqueous phase obtained by two successive emulsifications with SDBS and SOS. Optical density data for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t show absorption edges at 4076 Angstroms, 3997

  10. Extreme ultraviolet observations of G191-B2B and the local interstellar medium with the Hopkins Ultraviolet Telescope

    Science.gov (United States)

    Kimble, Randy A.; Davidsen, Arthur F.; Blair, William P.; Bowers, Charles W.; Van Dyke Dixon, W.; Durrance, Samuel T.; Feldman, Paul D.; Ferguson, Henry C.; Henry, Richard C.; Kriss, Gerard A.

    1993-01-01

    During the Astro-l mission in 1990 December, the Hopkins Ultraviolet Telescope (HUT) was used to observe the extreme ultraviolet spectrum (415-912 A) of the hot DA white dwarf GI91-B2B. Absorption by neutral helium shortward of the 504 A He I absorption edge is clearly detected in the raw spectrum. Model fits to the observed spectrum require interstellar neutral helium and neutral hydrogen column densities of 1.45 +/- 0.065 x 10 exp 17/sq cm and 1.69 +/- 0.12 x 10 exp 18/sq cm, respectively. Comparison of the neutral columns yields a direct assessment of the ionization state of the local interstellar cloud surrounding the Sun. The neutral hydrogen to helium ratio of 11.6 +/- 1.0 observed by HUT strongly contradicts the widespread view that hydrogen is much more ionized than helium in the local interstellar medium, a view which has motivated some exotic theoretical explanations for the supposed high ionization.

  11. Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

    Science.gov (United States)

    El Ghazaly, M.; Aydarous, Abdulkadir

    Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53-4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV) to 400 (3.10 eV) nm in step of 10 nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

  12. Test of the decaying dark matter hypothesis using the Hopkins Ultraviolet Telescope

    Science.gov (United States)

    Davidsen, A. F.; Kriss, G. A.; Ferguson, H. C.; Blair, W. P.; Bowers, C. W.; Kimble, R. A.

    1991-01-01

    Sciama's hypothesis that the dark matter associated with galaxies, galaxy clusters, and the intergalactic medium consists of tau neutrinos of rest mass 28-30 eV whose decay generates ultraviolet photons of energy roughly 14-15 eV, has been tested using the Hopkins Ultraviolet Telescope flows aboard the Space Shuttle Columbia. A straightforward application of Sciama's model predicts that a spectral line from neutrino decay photons should be observed from the rich galaxy cluster Abell 665 with an SNR of about 30. No such emission was detected. For neutrinos in the mass range 27.2-32.1 eV, the observations set a lower lifetime limit significantly greater than Sciama's model requires.

  13. The Preflight Photometric Calibration of the Extreme-Ultraviolet Imaging Telescope EIT

    Science.gov (United States)

    Dere, K. P.; Moses, J. D.; Delaboudiniere, J. -P.; Brunaud, J.; Carabetian, C.; Hochedez, J. -F.; Song, X. Y.; Catura, R. C.; Clette, F.; Defise, J. -M.

    2000-01-01

    This paper presents the preflight photometric calibration of the Extreme-ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory (SOHO). The EIT consists of a Ritchey-Chretien telescope with multilayer coatings applied to four quadrants of the primary and secondary mirrors, several filters and a backside-thinned CCD detector. The quadrants of the EIT optics were used to observe the Sun in 4 wavelength bands that peak near 171, 195, 284, and 304 . Before the launch of SOHO, the EIT mirror reflectivities, the filter transmissivities and the CCD quantum efficiency were measured and these values are described here. The instrumental throughput in terms of an effective area is presented for each of the various mirror quadrant and filter wheel combinations. The response to a coronal plasma as a function of temperature is also determined and the expected count rates are compared to the count rates observed in a coronal hole, the quiet Sun and an active region.

  14. EIT: Solar corona synoptic observations from SOHO with an Extreme-ultraviolet Imaging Telescope

    Science.gov (United States)

    Delaboudiniere, J. P.; Gabriel, A. H.; Artzner, G. E.; Michels, D. J.; Dere, K. P.; Howard, R. A.; Catura, R.; Stern, R.; Lemen, J.; Neupert, W.

    1988-01-01

    The Extreme-ultraviolet Imaging Telescope (EIT) of SOHO (solar and heliospheric observatory) will provide full disk images in emission lines formed at temperatures that map solar structures ranging from the chromospheric network to the hot magnetically confined plasma in the corona. Images in four narrow bandpasses will be obtained using normal incidence multilayered optics deposited on quadrants of a Ritchey-Chretien telescope. The EIT is capable of providing a uniform one arc second resolution over its entire 50 by 50 arc min field of view. Data from the EIT will be extremely valuable for identifying and interpreting the spatial and temperature fine structures of the solar atmosphere. Temporal analysis will provide information on the stability of these structures and identify dynamical processes. EIT images, issued daily, will provide the global corona context for aid in unifying the investigations and in forming the observing plans for SOHO coronal instruments.

  15. Space Telescope and Optical Reverberation Mapping Project.I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope

    NARCIS (Netherlands)

    De Rosa, G.; Peterson, B.M.; Ely, J.; Kriss, G.A.; Crenshaw, D.M.; Horne, K.; Korista, K.T.; Netzer, H.; Pogge, R.W.; Arévalo, P.; Barth, A.J.; Bentz, M.C.; Brandt, W.N.; Breeveld, A.A.; Brewer, B.J.; Dalla Bontà, E.; De Lorenzo-Cáceres, A.; Denney, K.D.; Dietrich, M.; Edelson, R.; Evans, P.A.; Fausnaugh, M.M.; Gehrels, N.; Gelbord, J.M.; Goad, M.R.; Grier, C.J.; Grupe, D.; Hall, P.B.; Kaastra, J.; Kelly, B.C.; Kennea, J.A.; Kochanek, C.S.; Lira, P.; Mathur, S.; McHardy, I.M.; Nousek, J.A.; Pancoast, A.; Papadakis, I.; Pei, L.; Schimoia, J.S.; Siegel, M.; Starkey, D.; Treu, T.; Uttley, P.; Vaughan, S.; Vestergaard, M.; Villforth, C.; Yan, H.; Young, S.; Zu, Y.

    2015-01-01

    We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Significant correlated variability is found in the continuum and

  16. Production and analysis of some atomic emission spectra in the vacuum ultraviolet

    International Nuclear Information System (INIS)

    Meijer, F.G.

    1979-01-01

    The development of technical facilities for spectra analysis are described including the design, construction and adjustment of a grazing incidence spectrograph for the extreme ultraviolet and the improvements in light sources. The investigations of the fifth and fourth spectra of tantalum, the analysis of the sixth spectrum of tungsten, the extension of the analysis of the fourth spectrum of hafnium and a start of the analysis of the seventh spectrum of rhenium are presented. (C.F.)

  17. Unearthing a Treasure Trove of Ultraviolet Galaxy Spectra

    Science.gov (United States)

    Leitherer, Claus

    2014-10-01

    We propose an archival study of a set of COS M-mode spectra of star-forming galaxies whose quality vastly supsersedes that of previously obtained data with FOS, GHRS, and STIS. The originally proposed science focused on the interstellar lines, requiring high S/N and spectral resolution. Our project addresses the stellar population as observed in the UV lines of, e.g., N V, Si IV, and C IV. The data set enables new discovery space by allowing us to study the behavior of weak stellar features at low metallicity and the bias introduced by the blending of interstellar and stellar-wind lines. We will create a set of galaxy templates for comparison with star-forming galaxies at low and high redshift. Comparison with population synthesis models will provide constraints on ages, IMF and metallicities and a first calibration of new stellar evolution models accounting for the rotation of massive stars.

  18. Plastocyanin conformation: an analysis of its near ultraviolet absorption and circular dichroic spectra

    International Nuclear Information System (INIS)

    Draheim, J.E.; Anderson, G.P.; Duane, J.W.; Gross, E.L.

    1986-01-01

    The near-ultraviolet absorption and circular dichroic spectra of plastocyanin are dependent upon the redox state, solution pH, and ammonium sulfate concentration. This dependency was observed in plastocyanin isolated from spinach, poplar, and lettuce. Removal of the copper atom also perturbed the near-ultraviolet spectra. Upon reduction there are increases in both extinction and ellipticity at 252 nm. Further increases at 252 nm were observed upon formation of apo plastocyanin eliminating charge transfer transitions as the cause. The spectral changes in the near-ultraviolet imply a flexible tertiary conformation for plastocyanin. There are at least two charge transfer transitions at ∼295-340 nm. One of these transitions is sensitive to low pH's and is attributed to the His 87 copper ligand. The redox state dependent changes observed in the near-ultraviolet spectra of plastocyanin are attenuated either by decreasing the pH to 5 or by increasing the ammonium sulfate concentration to 2.7 M. This attenuation cannot be easily explained by simple charge screening. Hydrophobic interactions probably play an important role in this phenomenon. The pH and redox state dependent conformational changes may play an important role in regulating electron transport

  19. Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars

    DEFF Research Database (Denmark)

    Ganguly, Rajib; Brotherton, Michael S.; Arav, Nahum

    2007-01-01

    We present low-resolution ultraviolet spectra of 14 low redshift (z zz 1.4 Large Bright Quasar samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the v ~ L^0.62 relation derived by Laor & Brandt (2002). Another quasar......, HE0441-2826, contains extremely weak emission lines and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud, but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles...... the spectra of the quasars PG1407+265, SDSSJ1136+0242, and PKS1004+13 for which several possible explanations have been entertained....

  20. Hubble space telescope near-ultraviolet spectroscopy of the bright cemp-no star BD+44°493

    International Nuclear Information System (INIS)

    Placco, Vinicius M.; Beers, Timothy C.; Smith, Verne V.; Roederer, Ian U.; Cowan, John J.; Frebel, Anna; Filler, Dan; Ivans, Inese I.; Lawler, James E.; Schatz, Hendrik; Sneden, Christopher; Sobeck, Jennifer S.; Aoki, Wako

    2014-01-01

    We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44°493 a ninth magnitude subgiant with [Fe/H] =–3.8 and enhanced carbon, based on data acquired with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This star is the brightest example of a class of objects that, unlike the great majority of carbon-enhanced metal-poor (CEMP) stars, does not exhibit over-abundances of heavy neutron-capture elements (CEMP-no). In this paper, we validate the abundance determinations for a number of species that were previously studied in the optical region, and obtain strong upper limits for beryllium and boron, as well as for neutron-capture elements from zirconium to platinum, many of which are not accessible from ground-based spectra. The boron upper limit we obtain for BD+44°493, log ε (B) <–0.70, the first such measurement for a CEMP star, is the lowest yet found for very and extremely metal-poor stars. In addition, we obtain even lower upper limits on the abundances of beryllium, log ε (Be) <–2.3, and lead, log ε (Pb) <–0.23 ([Pb/Fe] <+1.90), than those reported by previous analyses in the optical range. Taken together with the previously measured low abundance of lithium, the very low upper limits on Be and B suggest that BD+44°493 was formed at a very early time, and that it could well be a bona-fide second-generation star. Finally, the Pb upper limit strengthens the argument for non-s-process production of the heavy-element abundance patterns in CEMP-no stars.

  1. Ultraviolet action spectra for aerobic and anaerobic inactivation of Escherichia coli strains specifically sensitive and resistant to near ultraviolet radiations

    International Nuclear Information System (INIS)

    Peak, J.G.; Peak, M.J.; Tuveson, R.W.

    1983-01-01

    Action spectra for the lethal effects of ultraviolet light (254-434 nm) irradiation delivered under aerobic or anaerobic conditions to Escherichia coli RT2 (specifically sensitive to near-UV radiation; > 320 nm) and E. coli RT4 (near-UV resistant) were prepared. Negligible oxygen dependence was observed for both strains below about 315 nm. The oxygen enhancement ratio (OER) for RT4 increased above this wavelength to the longest wavelength used, whereas for RT2 there was a greater increase in the OER to a large peak at 365 nm, then a progressive decrease at longer wavelengths. The results are consistent with the possibility that the sensitivity of strain RT2 to near-UV radiation may be due to hyperproduction of photosensitizer, operating via photodynamic type reactions involving excited species of oxygen. (author)

  2. Macrostructure of ultraviolet continuous spectra of stars according to the data of OAO-2

    International Nuclear Information System (INIS)

    Rustambekova, S.S.

    1984-01-01

    On the basis of OAO-2 data, the presence of a depression has been established in the ultraviolet continuous spectra of 22 hot stars out of 134 that were analyzed. The depression is mainly in the region 2200-2400 A. However, the wavelength corresponding to the maximum of the depression drifts to shorter wavelengths on the transition to stars of earlier classes. The errors in taking into account the influence of interstellar absorption do not influence the final conclusions with regard to the presence or absence of depression. The obtained results confirm an earlier conclusion, namely, that a depression in the ultraviolet is a fairly common phenomenon among hot stars and that this depression can be regarded as a sensitive indicator of the presence of circumstellar clouds. 14 references

  3. Measurements of the Ultraviolet Fluorescence Cross Sections and Spectra of Bacillus Anthracis Simulants

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, J.R.

    1998-09-01

    Measurements of the ultraviolet autofluorescence spectra and absolute cross sections of the Bacillus anthracis (Ba) simulants Bacillus globigii (Bg), Bacillus megaterium (Bm), Bacillus subtilis (Bs), and Bacillus cereus (Bc) were measured. Fluorescence spectra and cross sections of pine pollen (Pina echinata) were measured for comparison. Both dried vegetative cells and spores separated from the sporulated vegetative material were studied. The spectra were obtained by suspending a small number (<10) of particles in air in our Single Particle Spectroscopy Apparatus (SPSA), illuminating the particles with light from a spectrally filtered arc lamp, and measuring the fluorescence spectra of the particles. The illumination was 280 nm (20 nm FWHM) and the fluorescence spectra was measured between 300 and 450 nm. The fluorescence cross section of vegetative Bg peaks at 320 nm with a maximum cross section of 5 X 10{sup -14} cm{sup 2}/sr-nm-particle while the Bg spore fluorescence peaks at 310 nm with peak fluorescence of 8 X 10{sup -15} cm{sup 2}/sr-nm-particle. Pine pollen particles showed a higher fluorescence peaking at 355 nm with a cross section of 1.7 X 10{sup -13} cm{sup 2}/sr-nm-particle. Integrated cross sections ranged from 3.0 X 10{sup -13} for the Bg spores through 2.25 X 10{sup -12} (cm{sup 2}/sr-particle) for the vegetative cells.

  4. Fluorescence spectra of blood plasma treated with ultraviolet irradiation in vivo

    Science.gov (United States)

    Zalesskaya, G. A.; Maslova, T. O.

    2010-09-01

    We have studied the fluorescence spectra of blood plasma from patients with acute coronary syndrome, and also the effect of therapeutic doses of in vivo ultraviolet blood irradiation (UBI) on the spectra. We have established that the maxima in the fluorescence spectra of the original plasma samples, obtained from unirradiated blood, are located in the wavelength interval 330-340 nm, characteristic for the fluorescence of tryptophan residues. In extracorporeal UBI ( λ = 254 nm), we observed changes in the shape and also both a blue and a red shift in the maxima of the fluorescence spectra, differing in magnitude for blood plasma samples from different patients in the test group. We show that UBI-initiated changes in the fluorescence spectra of the plasma depend on the original pathological disturbances of metabolite levels, and also on the change in the oxygen-transport function of the blood and the acid-base balance, affecting the oxidative stability of the plasma. We have concluded that UV irradiation, activating buffer systems in the blood, has an effect on the universal and specific interactions of the tryptophan residue with the amino acid residues and water surrounding it.

  5. INFRARED AND ULTRAVIOLET SPECTRA OF METHANE DILUTED IN SOLID NITROGEN AND IRRADIATED WITH ELECTRONS DURING DEPOSITION AT VARIOUS TEMPERATURES

    International Nuclear Information System (INIS)

    Chin, Chih-Hao; Chen, Sian-Cong; Liu, Meng-Chen; Huang, Tzu-Ping; Wu, Yu-Jong

    2016-01-01

    We recorded the infrared and ultraviolet absorption spectra of CH 4 :N 2 matrix samples that underwent electron bombardment during deposition in the temperature range of 10–44 K. In contrast to a previous experiment on the IR spectroscopy of electron-bombarded icy samples, methyl and azide radicals became the main products upon electron bombardment during deposition; furthermore, reduced production of nitrile species was observed for deposition at 10 and 20 K. On the other hand, for deposition above 33 K, the observed bands of the radical species (such as methyl and azide) decreased, and bands of large nitriles appeared. This observation may suggest that radical species easily diffuse and recombine to form more complex molecules in solid nitrogen at higher temperatures. Further measurements of similar samples at 10–33 K in the UV region revealed the intense band of azide radicals at 272.5 nm and weak, broad, overlapping features of methyl and azide radicals in the 225–197 nm region. For deposition at 44 K, only a broad feature centered at 219.4 nm was observed, and the possible carriers of nitrile species were proposed based on the corresponding IR spectrum and theoretical predictions of excitation energy. This band is similar to the observed absorption feature of Pluto’s surface recorded by the Hubble telescope in terms of both band position and bandwidth. Our findings therefore further support the suggestion that complex nitrile species may exist on the surface of Pluto.

  6. The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters

    Science.gov (United States)

    Louis, Thibaut; Grace, Emily; Hasselfield, Matthew; Lungu, Marius; Maurin, Loic; Addison, Graeme E.; Adem Peter A. R.; Aiola, Simone; Allison, Rupert; Amiri, Mandana; hide

    2017-01-01

    We present the temperature and polarization angular power spectra measuredby the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time datacollected during 2013-14 using two detector arrays at 149 GHz, from 548 deg(exp. 2) of sky onthe celestial equator. We use these spectra, and the spectra measured with the MBAC camera on ACT from 2008-10, in combination with Planck and WMAP data to estimate cosmological parameters from the temperature, polarization, and temperature-polarization cross-correlations. We find the new ACTPol data to be consistent with the CDM model. The ACTPol temperature-polarization cross-spectrum now provides stronger constraints on multiple parameters than the ACTPol temperature spectrum, including the baryon density, the acoustic peak angular scale, and the derived Hubble constant. The new ACTPol dataprovide information on damping tail parameters. The joint uncertainty on the number of neutrino species and the primordial helium fraction is reduced by 20% when adding ACTPol to Planck temperature data alone.

  7. The Atacama Cosmology Telescope: two-season ACTPol spectra and parameters

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Thibaut [UPMC Univ Paris 06, UMR7095, Institut d' Astrophysique de Paris, F-75014, Paris (France); Grace, Emily; Aiola, Simone; Choi, Steve K. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Hasselfield, Matthew [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Lungu, Marius; Angile, Elio [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Maurin, Loïc [Instituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Addison, Graeme E. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Ade, Peter A. R. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales, CF24 3AA (United Kingdom); Allison, Rupert; Calabrese, Erminia [Sub-Department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom); Amiri, Mandana [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada); Battaglia, Nicholas [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Beall, James A.; Britton, Joe; Cho, Hsiao-mei [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); De Bernardis, Francesco [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Bond, J Richard, E-mail: louis@iap.fr [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON, M5S 3H8 (Canada); and others

    2017-06-01

    We present the temperature and polarization angular power spectra measured by the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time data collected during 2013–14 using two detector arrays at 149 GHz, from 548 deg{sup 2} of sky on the celestial equator. We use these spectra, and the spectra measured with the MBAC camera on ACT from 2008–10, in combination with planck and wmap data to estimate cosmological parameters from the temperature, polarization, and temperature-polarization cross-correlations. We find the new ACTPol data to be consistent with the ΛCDM model. The ACTPol temperature-polarization cross-spectrum now provides stronger constraints on multiple parameters than the ACTPol temperature spectrum, including the baryon density, the acoustic peak angular scale, and the derived Hubble constant. The new ACTPol data provide information on damping tail parameters. The joint uncertainty on the number of neutrino species and the primordial helium fraction is reduced by 20% when adding ACTPol to Planck temperature data alone.

  8. Library of Giant Planet Reflection Spectra for WFirst and Future Space Telescopes

    Science.gov (United States)

    Smith, Adam J. R. W.; Fortney, Jonathan; Morley, Caroline; Batalha, Natasha E.; Lewis, Nikole K.

    2018-01-01

    Future large space space telescopes will be able to directly image exoplanets in optical light. The optical light of a resolved planet is due to stellar flux reflected by Rayleigh scattering or cloud scattering, with absorption features imprinted due to molecular bands in the planetary atmosphere. To aid in the design of such missions, and to better understand a wide range of giant planet atmospheres, we have built a library of model giant planet reflection spectra, for the purpose of determining effective methods of spectral analysis as well as for comparison with actual imaged objects. This library covers a wide range of parameters: objects are modeled at ten orbital distances between 0.5 AU and 5.0 AU, which ranges from planets too warm for water clouds, out to those that are true Jupiter analogs. These calculations include six metalicities between solar and 100x solar, with a variety of different cloud thickness parameters, and across all possible phase angles.

  9. Interpretation of the photoelectron, ultraviolet, and vacuum ultraviolet photoabsorption spectra of bromobenzene by ab initio configuration interaction and DFT computations

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Michael H., E-mail: m.h.palmer@ed.ac.uk; Ridley, Trevor, E-mail: t.ridley@ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@sns.it, E-mail: kipeters@wsu.edu [School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland (United Kingdom); Hoffmann, Søren Vrønning, E-mail: t.ridley@ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@sns.it, E-mail: kipeters@wsu.edu; Jones, Nykola C., E-mail: t.ridley@ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@sns.it, E-mail: kipeters@wsu.edu [ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Coreno, Marcello, E-mail: t.ridley@ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@sns.it, E-mail: kipeters@wsu.edu [CNR-IMIP, Montelibretti, c/o Laboratorio Elettra, Trieste (Italy); Simone, Monica de, E-mail: t.ridley@ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@sns.it, E-mail: kipeters@wsu.edu [CNR-IOM Laboratorio TASC, Trieste (Italy); Grazioli, Cesare [CNR-IOM Laboratorio TASC, Trieste (Italy); Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste (Italy); Zhang, Teng [Department of Physics and Astronomy, University of Uppsala, Uppsala (Sweden); and others

    2015-10-28

    New photoelectron, ultraviolet (UV), and vacuum UV (VUV) spectra have been obtained for bromobenzene by synchrotron study with higher sensitivity and resolution than previous work. This, together with use of ab initio calculations with both configuration interaction and time dependent density functional theoretical methods, has led to major advances in interpretation. The VUV spectrum has led to identification of a considerable number of Rydberg states for the first time. The Franck-Condon (FC) analyses including both hot and cold bands lead to identification of the vibrational structure of both ionic and electronically excited states including two Rydberg states. The UV onset has been interpreted in some detail, and an interpretation based on the superposition of FC and Herzberg-Teller contributions has been performed. In a similar way, the 6 eV absorption band which is poorly resolved is analysed in terms of the presence of two ππ* states of {sup 1}A{sub 1} (higher oscillator strength) and {sup 1}B{sub 2} (lower oscillator strength) symmetries, respectively. The detailed analysis of the vibrational structure of the 2{sup 2}B{sub 1} ionic state is particularly challenging, and the best interpretation is based on equation-of-motion-coupled cluster with singles and doubles computations. A number of equilibrium structures of the ionic and singlet excited states show that the molecular structure is less subject to variation than corresponding studies for iodobenzene. The equilibrium structures of the 3b{sub 1}3s and 6b{sub 2}3s (valence shell numbering) Rydberg states have been obtained and compared with the corresponding ionic limit structures.

  10. Study of Ultraviolet Emission Spectra in ZnO Thin Films

    Directory of Open Access Journals (Sweden)

    Y. M. Lu

    2013-01-01

    Full Text Available Photoluminescence (PL of ZnO thin films prepared on c-Al2O3 substrates by pulsed laser deposition (PLD are investigated. For all samples, roomtemperature (RT spectra show a strong band-edge ultraviolet (UV emission with a pronounced low-energy band tail. The origin of this UV emission is analyzed by the temperature dependence of PL spectra. The result shows that the UV emission at RT contains different recombination processes. At low temperature donor-bound exciton (D0X emission plays a major role in PL spectra, while the free exciton transition (FX gradually dominates the spectrum with increasing temperatures. It notes that at low temperature an emission band (FA appears in low energy side of D0X and FX and can survive up to RT. Further confirmation shows that the origin of the band FA can be attributed to the transitions of conduction band electrons to acceptors (e, A0, in which the acceptor binding energy is estimated to be approximately 121 meV. It is concluded that at room temperature UV emission originates from the corporate contributions of the free exciton and free electrons-to-acceptor transitions.

  11. Ultraviolet absorption spectra and kinetics of CH3S and CH2SH radicals

    DEFF Research Database (Denmark)

    Anastasi, C.; Broomfield, M.; Nielsen, O.J.

    1991-01-01

    The ultraviolet absorption spectra of CH3S and CH2SH radicals have been measured between 215 and 380 nm using the pulse-radiolysis/kinetic-absorption method. One absorption band between 250 and 300 nm and one around 215 nm have been tentatively assigned to the CH2SH and CH3S radicals, respectively....... This spectrum has been used to measure the self-reaction rates of these radicals. Rate constants of 4 x 10(-11) and 7 x 10(-11) cm3 molecule-1 s-1 have been measured at 298 K for CH3S and CH2SH recombination, respectively. The possible reaction pathways are discussed....

  12. Scaling plant ultraviolet spectral responses from laboratory action spectra to field spectral weighting factors

    International Nuclear Information System (INIS)

    Flint, S.D.; Caldwell, M.M.

    1996-01-01

    Biological spectral weighting functions (BSWF) play a key role in calculating the increase of biologically effective solar ultraviolet-B radiation (UV-BBE) due to ozone reduction, assessing current latitudinal gradients of UV-B BE . and comparing solar UV-B BE with that from lamps and filters in plant experiments. Plant UV action spectra (usually determined with monochromatic radiation in the laboratory with exposure periods on the order of hours) are often used as BSWF. The realism of such spectra for plants growing day after day in polychromatic solar radiation in the field is questionable. We tested the widely used generalized plant action spectrum since preliminary data from an action spectrum being developed with monochromatic radiation for a cultivated oat variety indicate reasonable agreement with the generalized spectrum. These tests involved exposing plants to polychromatic radiation either from a high-pressure xenon arc lamp in growth chambers or in the field under solar radiation with supplemental UV-B lamps. Different broad-spectrum combinations were achieved by truncating the spectrum at successively longer UV wavelengths with various filters. In the growth chamber experiments, the generalized plant spectrum appeared to predict plant growth responses at short (<310nm) wavelengths but not at longer wavelengths. The field experiment reinforced these conclusions, showing (in addition to the expected direct UV-B effects) both direct UV-A effects and UV-A mitigation of UV-B effects. (author)

  13. Method of composing two-dimensional scanned spectra observed by the New Vacuum Solar Telescope

    Science.gov (United States)

    Cai, Yun-Fang; Xu, Zhi; Chen, Yu-Chao; Xu, Jun; Li, Zheng-Gang; Fu, Yu; Ji, Kai-Fan

    2018-04-01

    In this paper we illustrate the technique used by the New Vacuum Solar Telescope (NVST) to increase the spatial resolution of two-dimensional (2D) solar spectroscopy observations involving two dimensions of space and one of wavelength. Without an image stabilizer at the NVST, large scale wobble motion is present during the spatial scanning, whose instantaneous amplitude can reach 1.3″ due to the Earth’s atmosphere and the precision of the telescope guiding system, and seriously decreases the spatial resolution of 2D spatial maps composed with scanned spectra. We make the following effort to resolve this problem: the imaging system (e.g., the TiO-band) is used to record and detect the displacement vectors of solar image motion during the raster scan, in both the slit and scanning directions. The spectral data (e.g., the Hα line) which are originally obtained in time sequence are corrected and re-arranged in space according to those displacement vectors. Raster scans are carried out in several active regions with different seeing conditions (two rasters are illustrated in this paper). Given a certain spatial sampling and temporal resolution, the spatial resolution of the composed 2D map could be close to that of the slit-jaw image. The resulting quality after correction is quantitatively evaluated with two methods. A physical quantity, such as the line-of-sight velocities in multiple layers of the solar atmosphere, is also inferred from the re-arranged spectrum, demonstrating the advantage of this technique.

  14. Mutagenesis and cytotoxicity in human epithelial cells by far- and near-ultraviolet radiations: action spectra

    International Nuclear Information System (INIS)

    Jones, C.A.; Huberman, E.; Cunningham, M.L.; Peak, M.J.

    1987-01-01

    Action spectra were determined for cell killing and mutation by monochromatic ultraviolet and visible radiations (254-434 nm) in cultured human epithelial P3 cells. Cell killing was more efficient following radiation at the shorter wavelengths (254-434 nm) than at longer wavelengths (365-434 nm). At 254 nm, for example, a fluence of 11 Jm-2 gave 37% cell survival, while at 365 nm, 17 X 10(5) Jm-2 gave equivalent survival. At 434 nm little killing was observed with fluences up to 3 X 10(6) Jm-2. Mutant induction, determined at the hypoxanthine-guanine phosphoribosyltransferase locus, was caused by radiation at 254, 313, and 365 nm. There was no mutant induction at 334 nm although this wavelength was highly cytotoxic. Mutagenesis was not induced by 434 nm radiation, either. There was a weak response at 405 nm; the mutant frequencies were only slightly increased above background levels. For the mutagenic wavelengths, log-log plots of the mutation frequency against fluence showed linear regressions with positive slopes of 2.5, consistent with data from a previous study using Escherichia coli. The data points of the action spectra for lethality and mutagenesis were similar to the spectrum for DNA damage at wavelengths shorter than 313 nm, whereas at longer wavelengths the lethality spectrum had a shoulder, and the mutagenesis spectrum had a secondary peak at 365 nm. No correlation was observed for the P3 cells between the spectra for cell killing and mutagenesis caused by wavelengths longer than 313 nm and the induction of DNA breakage or the formation of DNA-to-protein covalent bonds in these cells

  15. The far-ultraviolet spectra of two hot PG 1159 stars

    Science.gov (United States)

    Werner, K.; Rauch, T.; Kruk, J. W.

    2016-09-01

    PG 1159 stars are hot, hydrogen-deficient (pre-) white dwarfs with atmospheres mainly composed of helium, carbon, and oxygen. The unusual surface chemistry is the result of a late helium-shell flash. Observed element abundances enable us to test stellar evolution models quantitatively with respect to their nucleosynthesis products formed near the helium-burning shell of the progenitor asymptotic giant branch stars. Because of the high effective temperatures (Teff), abundance determinations require ultraviolet spectroscopy and non-local thermodynamic equilibrium model atmosphere analyses. Up to now, we have presented results for the prototype of this spectral class and two cooler members (Teff in the range 85 000-140 000 K). Here we report on the results for two even hotter stars (PG 1520+525 and PG 1144+005, both with Teff = 150 000 K) which are the only two objects in this temperature-gravity region for which useful far-ultraviolet spectra are available, and revisit the prototype star. Previous results on the abundances of some species are confirmed, while results on others (Si, P, S) are revised. In particular, a solar abundance of sulphur is measured in contrast to earlier claims of a strong S deficiency that contradicted stellar evolution models. For the first time, we assess the abundances of Na, Al, and Cl with newly constructed non-LTE model atoms. Besides the main constituents (He, C, O), we determine the abundances (or upper limits) of N, F, Ne, Na, Al, Si, P, S, Cl, Ar, and Fe. Generally, good agreement with stellar models is found.

  16. High-resolution vacuum-ultraviolet photoabsorption spectra of 1-butyne and 2-butyne

    Energy Technology Data Exchange (ETDEWEB)

    Jacovella, U. [Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich (Switzerland); Holland, D. M. P. [STFC, Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Boyé-Péronne, S.; Gans, B. [Institut des Sciences Moléculaires d’Orsay, UMR 8214, CNRS and Université Paris-Sud, F-91405 Orsay (France); Oliveira, N. de; Joyeux, D.; Archer, L. E. [Synchrotron Soleil, L’Orme des Merisiers, F-91192 Gif-sur-Yvette (France); Lucchese, R. R. [Department of Chemistry, Texas A& M University, College Station, Texas 77843 (United States); Xu, H.; Pratt, S. T. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-07-21

    The absolute photoabsorption cross sections of 1- and 2-butyne have been recorded at high resolution by using the vacuum-ultraviolet Fourier-Transform spectrometer at the SOLEIL Synchrotron. Both spectra show more resolved structure than previously observed, especially in the case of 2-butyne. In this work, we assess the potential importance of Rydberg states with higher values of orbital angular momentum, l, than are typically observed in photoabsorption experiments from ground state molecules. We show how the character of the highest occupied molecular orbitals in 1- and 2-butyne suggests the potential importance of transitions to such high-l (l = 3 and 4) Rydberg states. Furthermore, we use theoretical calculations of the partial wave composition of the absorption cross section just above the ionization threshold and the principle of continuity of oscillator strength through an ionization threshold to support this conclusion. The new absolute photoabsorption cross sections are discussed in light of these arguments, and the results are consistent with the expectations. This type of argument should be valuable for assessing the potential importance of different Rydberg series when sufficiently accurate direct quantum chemical calculations are difficult, for example, in the n ≥ 5 manifolds of excited states of larger molecules.

  17. Far-ultraviolet Spectroscopy of Recent Comets with the Cosmic Origins Spectrograph on the Hubble Space Telescope

    Science.gov (United States)

    Feldman, Paul D.; Weaver, Harold A.; A’Hearn, Michael F.; Combi, Michael R.; Dello Russo, Neil

    2018-05-01

    Since its launch in 1990, the Hubble Space Telescope (HST) has served as a platform with unique capabilities for remote observations of comets in the far-ultraviolet region of the spectrum. Successive generations of imagers and spectrographs have seen large advances in sensitivity and spectral resolution enabling observations of the diverse properties of a representative number of comets during the past 25 years. To date, four comets have been observed in the far-ultraviolet by the Cosmic Origins Spectrograph (COS), the last spectrograph to be installed in HST, in 2009: 103P/Hartley 2, C/2009 P1 (Garradd), C/2012 S1 (ISON), and C/2014 Q2 (Lovejoy). COS has unprecedented sensitivity, but limited spatial information in its 2.″5 diameter circular aperture, and our objective was to determine the CO production rates from measurements of the CO Fourth Positive system in the spectral range of 1400–1700 Å. In the two brightest comets, 19 bands of this system were clearly identified. The water production rates were derived from nearly concurrent observations of the OH (0,0) band at 3085 Å by the Space Telescope Imaging Spectrograph. The derived CO/{{{H}}}2{{O}} production rate ratio ranged from ∼0.3% for Hartley 2 to ∼22% for Garradd. In addition, strong partially resolved emission features due to multiplets of S I, centered at 1429 Å and 1479 Å, and of C I at 1561 Å and 1657 Å, were observed in all four comets. Weak emission from several lines of the {{{H}}}2 Lyman band system, excited by solar Lyα and Lyβ pumped fluorescence, were detected in comet Lovejoy.

  18. Ultraviolet-B-effects on plants: Spectra of harmful effects, primary damage and UV protective mechanisms

    International Nuclear Information System (INIS)

    Wellmann, E.; Beggs, C.; Moehle, B.; Schneider-Ziebert, U.; Steinmetz, V.; Koch, U.

    1986-01-01

    In two model systems of higher plants, damage caused by ultraviolet-B-radiation was analysed as to its mechanism of action and the spectral quantum efficiency. These investigations were to provide information on the relevance of such UV effects in cases of increased ultraviolet-B-irradiation owing to the destruction of ozone. The results indicate the very high tolerance of the plants to ultraviolet-B-radiation which obviously is the result of very effective protective mechanisms, and show at the same time that potential damage must already be reckoned with, given the current share of ultraviolet-B-radiation in solar radiation. Should ultraviolet-B-radiation be increased, then indirect damage to the plant from the destruction of ultraviolet protective mechanisms through UV-B-radiation will probably constitute a particular risk. (orig./MG) [de

  19. Comparative ultraviolet action spectra (254-320 nm) of five wild-type eukaryotic microorganisms and Escherichia coli

    International Nuclear Information System (INIS)

    Calkins, J.; Wheeler, J.S.; Keller, C.I.; Colley, E.; Hazle, J.D.

    1988-01-01

    The action spectra of five eukaryotic organisms and the prokaryote, Escherichia coli, were examined over the wavelength range, 254-320 nm. Both the repair competent and three repair defective strains (E. coli, Caenorhabditis elegans, Saccharomyces) were examined. Tetrahymena pyriformis action spectra were performed with and without the excision repair inhibitor caffeine present. Others have observed that lethality, mutation, and the production of pyrimidine dimers show much the same wavelength dependence as DNA absorption. The results presented here demonstrate several action spectra which deviate from the DNA absorption spectra. Ultraviolet sensitization ratios (repair competent/repair defective) were also examined and were shown to change over the wavelength range. These findings suggest that DNA may not be the only important chromophore leading to cell death in the uv wavelength range studied. Since uv-B is of major importance in solar uv damage, these findings may also yield important implications for solar uv studies

  20. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, S.; Pogge, R. W.; Adams, S. M.; Beatty, T. G.; Bisogni, S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Gupta, A. [Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Page, K.; Goad, M. R. [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Krongold, Y. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Cuidad de Mexico (Mexico); Anderson, M. D.; Bazhaw, C.; Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Suite 605, Atlanta, GA 30303 (United States); Arévalo, P. [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretana N 1111, Playa Ancha, Valparaíso (Chile); Barth, A. J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Bigley, A. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Borman, G. A. [Crimean Astrophysical Observatory, P/O Nauchny, Crimea 298409 (Russian Federation); Boroson, T. A. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Bottorff, M. C. [Fountainwood Observatory, Department of Physics FJS 149, Southwestern University, 1011 East University Avenue, Georgetown, TX 78626 (United States); Brandt, W. N. [Department of Astronomy and Astrophysics, Eberly College of Science, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Breeveld, A. A. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); and others

    2017-09-01

    During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly.

  1. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

    International Nuclear Information System (INIS)

    Mathur, S.; Pogge, R. W.; Adams, S. M.; Beatty, T. G.; Bisogni, S.; Gupta, A.; Page, K.; Goad, M. R.; Krongold, Y.; Anderson, M. D.; Bazhaw, C.; Bentz, M. C.; Arévalo, P.; Barth, A. J.; Bigley, A.; Borman, G. A.; Boroson, T. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.

    2017-01-01

    During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly.

  2. The Photometric Investigation of V921 Her Using the Lunar-Based Ultraviolet Telescope of Chang’e-3 Mission

    Directory of Open Access Journals (Sweden)

    Xiao Zhou

    2016-01-01

    Full Text Available The light curve of V921 Her in ultraviolet band observed by the Lunar-based Ultraviolet Telescope (LUT is analyzed by the Wilson-Devinney code. Our solutions conclude that V921 Her is an early type marginal contact binary system with an additional close-in component. The binary system is under poor thermal contact with a temperature difference of nearly 700 K between the two components. The close-in component contributes about 19% of the total luminosity in the triple system. Combining the radial velocity study together with our photometric solutions, the mass of the primary star and secondary one is calculated to be M1=1.784  (±0.055M⊙, M2=0.403  (±0.012M⊙. The evolutionary scenario of V921 Her is discussed. All times of light minimum of V921 Her available in the bibliography are taken into account and the O-C curve is analyzed for the first time. The most probable fitting results are discussed in the paper, which also confirm the existence of a third component (P3=10.2 year around the binary system. The period of V921 Her is also undergoing a continuously rapid increase at a rate of dP/dt=+2.79×10-7  day·year-1, which may be due to mass transfer from the less massive component to the more massive one.

  3. A SEARCH FOR LYMAN BREAK GALAXIES IN THE CHANDRA DEEP FIELD SOUTH USING SWIFT ULTRAVIOLET/OPTICAL TELESCOPE

    International Nuclear Information System (INIS)

    Basu-Zych, Antara R.; Hornschemeier, Ann E.; Hoversten, Erik A.; Gronwall, Caryl; Lehmer, Bret

    2011-01-01

    While the Swift satellite is primarily designed to study gamma-ray bursts, its ultraviolet and optical imaging and spectroscopy capabilities are also being used for a variety of scientific programs. In this study, we use the UV/Optical Telescope (UVOT) instrument on board Swift to discover 0.5 2 at >60 ks exposure time, achieving a limiting magnitude of u * /M sun ) = 9.4 ± 0.6, which is slightly lower than z ∼ 3 LBGs ((logM * /Ms un ) = 10.2 ± 0.4) and slightly higher compared with the z ∼ 1 CDF-S galaxies ((logM * /M sun ) = 8.7 ± 0.7). Similarly, our sample of z ∼ 1 LBGs has SFRs (derived using both ultraviolet and infrared data, where available) of (logSFR/(M sun yr -1 )) = 0.7 ± 0.6, nearly an order of magnitude lower than z ∼ 3 LBGs ((logSFR/M sun yr -1 ) = 1.5 ± 0.4), but slightly higher than the comparison z ∼ 1 sample of CDF-S galaxies ((logSFR/M sun yr -1 ) = 0.2 ± 0.7). We find that our z ∼ 1 UV-dropouts have (A FUV ) = 2.0 ± 1.0, which is higher than z ∼ 3 LBGs ((A FUV ) = 1.0 ± 0.5), but similar to the distribution of dust attenuations in the other CDF-S galaxies ((A FUV ) ∼ 2.8 ± 1.5). Using the GOODS-South multiwavelength catalog of galaxies, we simulate a larger and fainter sample of LBGs to compare their properties with those of the UVOT-selected LBG sample. We conclude that UVOT can be useful for finding and studying the bright end of 0.5 < z < 2.0 LBGs.

  4. Electronic structure, photoemission spectra, and vacuum-ultraviolet optical spectra of CsPbCl3 and CsPbBr3

    Science.gov (United States)

    Heidrich, K.; Schäfer, W.; Schreiber, M.; Söchtig, J.; Trendel, G.; Treusch, J.; Grandke, T.; Stolz, H. J.

    1981-11-01

    Optical spectra of CsPbCl3 and CsPbBr3 have been measured in the range from 2 to 10 eV and have been combined with ultraviolet-photoemission-spectroscopy (UPS)-measurements at 21.1 and 40.8 eV. A quantitative band calculation is presented, which takes into account anion-anion interaction as well as electronic states of the Cs+ ion. The prominent features of earlier band models and measurements are reestablished through our measurements and calculations, namely that the valence band consists of anionic p functions and Pb 6s functions, the lowest conduction band being Pb 6p type, and the lowest gap occuring at the R point of the Brillouin zone. Inclusion of a further (Cs 6s-type) conduction band, however, is necessary to bring the calculated joint density of states into agreement with vacuum-ultraviolet optical spectra. The calculated densities of states of the valence bands are in quantitative agreement with those deduced from our UPS measurements.

  5. UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra

    Science.gov (United States)

    Rosenberg, Jake; Parker, W. Ryan; Cammarata, Michael B.; Brodbelt, Jennifer S.

    2018-04-01

    UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at http://uv-posit.cm.utexas.edu. UV-POSIT is available under the MIT license, and the source code is available at https://github.com/jarosenb/UV_POSIT. [Figure not available: see fulltext.

  6. UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra.

    Science.gov (United States)

    Rosenberg, Jake; Parker, W Ryan; Cammarata, Michael B; Brodbelt, Jennifer S

    2018-04-06

    UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at http://uv-posit.cm.utexas.edu . UV-POSIT is available under the MIT license, and the source code is available at https://github.com/jarosenb/UV_POSIT . Graphical Abstract.

  7. HUBBLE SPACE TELESCOPE DETECTION OF THE DOUBLE PULSAR SYSTEM J0737–3039 IN THE FAR-ULTRAVIOLET

    Energy Technology Data Exchange (ETDEWEB)

    Durant, Martin [Department of Medical Biophysics, Sunnybrook Hospital M6 623, 2075 Bayview Avenue, Toronto M4N 3M5 (Canada); Kargaltsev, Oleg [Department of Physics, The George Washington University, 725 21st Street NW, Washington, DC 20052 (United States); Pavlov, George G., E-mail: mdurant@sri.utoronto.ca, E-mail: kargaltsev@email.gwu.edu, E-mail: pavlov@astro.psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2014-03-01

    We report on detection of the double pulsar system J0737–3039 in the far-UV with the Advanced Camera for Surveys/Solar-blind Channel detector aboard Hubble Space Telescope. We measured the energy flux F = (4.6 ± 1.0) × 10{sup –17} erg cm{sup –2} s{sup –1} in the 1250-1550 Å band, which corresponds to the extinction-corrected luminosity L ≈ 1.5 × 10{sup 28} erg s{sup –1} for the distance d = 1.1 kpc and a plausible reddening E(B – V) = 0.1. If the detected emission comes from the entire surface of one of the neutron stars with a 13 km radius, the surface blackbody temperature is in the range T ≅ (2-5) × 10{sup 5} K for a reasonable range of interstellar extinction. Such a temperature requires an internal heating mechanism to operate in old neutron stars, or, less likely, it might be explained by heating of the surface of the less energetic Pulsar B by the relativistic wind of Pulsar A. If the far-ultraviolet emission is non-thermal (e.g., produced in the magnetosphere of Pulsar A), its spectrum exhibits a break between the UV and X-rays.

  8. HUBBLE SPACE TELESCOPE DETECTION OF THE DOUBLE PULSAR SYSTEM J0737–3039 IN THE FAR-ULTRAVIOLET

    International Nuclear Information System (INIS)

    Durant, Martin; Kargaltsev, Oleg; Pavlov, George G.

    2014-01-01

    We report on detection of the double pulsar system J0737–3039 in the far-UV with the Advanced Camera for Surveys/Solar-blind Channel detector aboard Hubble Space Telescope. We measured the energy flux F = (4.6 ± 1.0) × 10 –17  erg cm –2 s –1 in the 1250-1550 Å band, which corresponds to the extinction-corrected luminosity L ≈ 1.5 × 10 28  erg s –1 for the distance d = 1.1 kpc and a plausible reddening E(B – V) = 0.1. If the detected emission comes from the entire surface of one of the neutron stars with a 13 km radius, the surface blackbody temperature is in the range T ≅ (2-5) × 10 5  K for a reasonable range of interstellar extinction. Such a temperature requires an internal heating mechanism to operate in old neutron stars, or, less likely, it might be explained by heating of the surface of the less energetic Pulsar B by the relativistic wind of Pulsar A. If the far-ultraviolet emission is non-thermal (e.g., produced in the magnetosphere of Pulsar A), its spectrum exhibits a break between the UV and X-rays

  9. Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra

    International Nuclear Information System (INIS)

    Persaud, K.

    1965-01-01

    We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [fr

  10. Results from the Ultraviolet Imaging Telescope on the Astro-2 Mission

    Science.gov (United States)

    Stecher, T. P.; Bohlin, R. C.; Neff, S. G.; O'Connell, R. W.; Roberts, M. R.; Smith, A. M.

    1995-03-01

    The solar-blind UIT camera with a CsI cathode obtained 722 frames with a cumulative exposure time of 260705 seconds during the March 1995 Astro-2 mission of Space Shuttle Endeavour. Filters were used to isolate selected bandpasses in the range 1200-1800 Angstroms, over the 40 arcmin field of view. Spatial resolution on most of the images is about 3 arcsec. Calibrated data, converted to machine-readable form, are under analysis and several posters on these investigations are presented in the Astro-2 poster session at this meeting (a first look at the UIT observations of Omega Cen, M31, and the Cygnus Loop is further elaborated here). UIT imagery of 20 spiral galaxies was obtained as part of a Guest Investigator program (Wendy Freedman et al.). UV imaging suppresses the red stellar population as expected and enhances the appearance of tracers of recent star formation. Known \\hii regions in these galaxies are made apparent through the scattering of stellar ultraviolet light by interstellar dust; typically their shapes differ from those seen in \\ha. A radial color gradient investigation will be delayed until ground observations can be made as the long-wavelength camera failed on launch and only the 1520 Angstroms and 1620 Angstroms images were made. The far-UV (1520 Angstroms) features are detected well beyond the Holmberg radius. UV/visible color-magnitude diagrams will be made as they were for the data from Astro-1. Our deepest images of the Magellanic Clouds reveal a rich field of luminous clusters and stars that are being searched for UV counterparts of the known x-ray sources in the photographed areas. The observed stars in the Clouds will be used to determine the current mass function. The respective contributions of nebular and stellar UV light in reflection nebulae are will be studied as several nebulae were observed with differing geometries and will provide interesting results on the far-UV albedo and phase function of nebular dust. A dozen globular and

  11. Spatial-Resolved Measurement and Analysis of Extreme-Ultraviolet Emission Spectra from Laser-Produced Al Plasmas

    International Nuclear Information System (INIS)

    Cao Shi-Quan; Su Mao-Gen; Sun Dui-Xiong; Min Qi; Dong Chen-Zhong

    2016-01-01

    Extreme ultraviolet emission from laser-produced Al plasma is experimentally and theoretically investigated. Spatial-evolution emission spectra are measured by using the spatio-temporally resolved laser produced plasma technique. Based on the assumptions of a normalized Boltzmann distribution among the excited states and a steady-state collisional-radiative model, we succeed in reproducing the spectra at different detection positions, which are in good agreement with experiments. The decay curves about the electron temperature and electron density, as well as the fractions of individual Al ions and average ionization stage with increasing the detection distance are obtained by comparison with the experimental measurements. These parameters are critical points for deeply understanding the expanding and cooling of laser produced plasmas in vacuum. (paper)

  12. Near ultraviolet spectra of a group of early-type stars with Balmer emission

    International Nuclear Information System (INIS)

    Ringuelet, A.E.

    1980-01-01

    In the near ultraviolet region some absorption features in B stars are easily recognizable as criteria for assigning luminosity class. In the same region the characteristics displayed by Be stars suggest higher luminosities than in the photographic region. It appears that Fe II 2538-2548 A should be useful for studying the outer layers of stellar atmospheres. (author)

  13. Near ultraviolet spectra of a group of early-type stars with Balmer emission

    Energy Technology Data Exchange (ETDEWEB)

    Ringuelet, A E [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)

    1980-08-01

    In the near ultraviolet region some absorption features in B stars are easily recognizable as criteria for assigning luminosity class. In the same region the characteristics displayed by Be stars suggest higher luminosities than in the photographic region. It appears that Fe II 2538-2548 A should be useful for studying the outer layers of stellar atmospheres.

  14. A comparison of telescopic and Phobos-2 ISM spectra of Mars in the short-wave near-infrared (0.76-1.02 microns)

    Science.gov (United States)

    Bell, James F., III; Mustard, John F.

    1993-01-01

    Recent analyses of near-IR (0.76-3.16 microns) Mars surface reflectance spectra obtained by the Phobos-2 ISM instrument during early 1989 have revealed the presence of substantial variability in surface spectral properties. Strong absorption features seen in the 0.85-1.05 micron region are up to 10-15 percent deep relative to the local continuum and have been interpreted as evidence of Fe(2+) and Fe(3+) bearing minerals (pyroxenes and iron oxides, respectively). Though these observed band depths are comparable to those seen in laboratory reflectance spectra, they are up to three times larger than most previously reported band depths for Mars spectra at these wavelengths. Six regions of variable albedo and geologic setting were identified where ISM and 1988 opposition telescopic coverage either overlapped physically or sampled the same surface geologic unit. The areal sizes and positions of the regions measured telescopically were compiled by Bell et al. ISM pixels falling within these spots were averaged to produce a spatially convolved spectrum that simulates what would have been seen telescopically. To facilitate comparisons of absorption band positions and relative strengths, the convolved ISM data and the 1988 telescopic spectra were scaled to unity at 0.81 microns and are presented. The data have also been convolved to equivalent band pass normalized reflectances in the region of spectral overlap. A scatter diagram of telescopic vs. ISM reflectances is shown. The results from the investigation are discussed.

  15. 40 CFR 796.1050 - Absorption in aqueous solution: Ultraviolet/visible spectra.

    Science.gov (United States)

    2010-07-01

    ... applied to measure the absorption spectra. (b) Method—(1)(i) Introduction, purpose, scope, relevance... volume of HCl or NaOH in aqueous solution ([HCl], [NaOH]=1 mol/L). (4) In theory, all chemical species...) Katelaar, J.A.A., Photoelectric Spectrometry Group Bulletin, 8, (Cambridge, 1955). (3) Chemical Rubber...

  16. Skylab ultraviolet stellar spectra - A new white dwarf, HD 149499 B

    Science.gov (United States)

    Parsons, S. B.; Wray, J. D.; Benedict, G. F.; Henize, K. G.; Laget, M.

    1976-01-01

    The letter reports the discovery of a cool star with excess brightness in the vacuum ultraviolet on an objective-prism photograph obtained during the second Skylab mission. This star, HD 149499, is of type K0 V and has a companion with an apparent magnitude of about 11.8; the relatively flat UV spectrum observed at the position of HD 149499 is characteristic of a 10th or 11th magnitude unreddened O- or early B-type star. It is shown that the excess VUV brightness is due to the companion, HD 149499B, which probably lies in the region of the H-R diagram occupied by the hot white dwarfs. Inspection of white dwarf lists indicates that this star is the sixth or seventh brightest white dwarf known. A maximum orbital motion of 0.025 arcsec/yr is estimated along with a period of just under 500 yr.

  17. A HOT COMPANION TO A BLUE STRAGGLER IN NGC 188 AS REVEALED BY THE ULTRA-VIOLET IMAGING TELESCOPE (UVIT) ON ASTROSAT

    Energy Technology Data Exchange (ETDEWEB)

    Subramaniam, Annapurni; Sindhu, N.; Tandon, S. N.; Rao, N. Kameswara; George, K.; Mohan, R.; Murthy, J.; Sankarasubramanian, K.; Stalin, C. S.; Sutaria, F.; Mondal, C.; Sahu, S. [Indian Institute of Astrophysics, Koramangala II Block, Bangalore-560034 (India); Postma, J. [University of Calgary, Calgary, Alberta (Canada); Côté, Patrick; Hutchings, J. B. [National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Ghosh, S. K. [National Centre for Radio Astrophysics, Pune (India); Girish, V., E-mail: purni@iiap.res.in [ISRO Satellite Centre, HAL Airport Road, Bangalore 560017 (India)

    2016-12-20

    We present early results from the Ultra-Violet Imaging Telescope (UVIT) on board the ASTROSAT observatory. We report the discovery of a hot companion associated with one of the blue straggler stars (BSSs) in the old open cluster, NGC 188. Using fluxes measured in four filters in UVIT’s far-UV (FUV) channel, and two filters in the near-UV (NUV) channel, we have constructed the spectral energy distribution (SED) of the star WOCS-5885, after combining with flux measurements from GALEX , Ultraviolet Imaging Telescope, Ultraviolet Optical Telescope, SPITZER , WISE , and several ground-based facilities. The resulting SED spans a wavelength range of 0.15 μ m to 7.8 μ m. This object is found to be one of the brightest FUV sources in the cluster. An analysis of the SED reveals the presence of two components. The cooler component is found to have a temperature of 6000 ± 150 K, confirming that it is a BSS. Assuming it to be a main-sequence star, we estimate its mass to be ∼1.1–1.2 M {sub ⊙}. The hotter component, with an estimated temperature of 17,000 ± 500 K, has a radius of ∼ 0.6 R {sub ⊙} and L ∼30 L {sub ⊙}. Bigger and more luminous than a white dwarf, yet cooler than a sub-dwarf, we speculate that it is a post-AGB/HB star that has recently transferred its mass to the BSS, which is known to be a rapid rotator. This binary system, which is the first BSS with a post-AGB/HB companion identified in an open cluster, is an ideal laboratory to study the process of BSS formation via mass transfer.

  18. A HOT COMPANION TO A BLUE STRAGGLER IN NGC 188 AS REVEALED BY THE ULTRA-VIOLET IMAGING TELESCOPE (UVIT) ON ASTROSAT

    International Nuclear Information System (INIS)

    Subramaniam, Annapurni; Sindhu, N.; Tandon, S. N.; Rao, N. Kameswara; George, K.; Mohan, R.; Murthy, J.; Sankarasubramanian, K.; Stalin, C. S.; Sutaria, F.; Mondal, C.; Sahu, S.; Postma, J.; Côté, Patrick; Hutchings, J. B.; Ghosh, S. K.; Girish, V.

    2016-01-01

    We present early results from the Ultra-Violet Imaging Telescope (UVIT) on board the ASTROSAT observatory. We report the discovery of a hot companion associated with one of the blue straggler stars (BSSs) in the old open cluster, NGC 188. Using fluxes measured in four filters in UVIT’s far-UV (FUV) channel, and two filters in the near-UV (NUV) channel, we have constructed the spectral energy distribution (SED) of the star WOCS-5885, after combining with flux measurements from GALEX , Ultraviolet Imaging Telescope, Ultraviolet Optical Telescope, SPITZER , WISE , and several ground-based facilities. The resulting SED spans a wavelength range of 0.15 μ m to 7.8 μ m. This object is found to be one of the brightest FUV sources in the cluster. An analysis of the SED reveals the presence of two components. The cooler component is found to have a temperature of 6000 ± 150 K, confirming that it is a BSS. Assuming it to be a main-sequence star, we estimate its mass to be ∼1.1–1.2 M _⊙. The hotter component, with an estimated temperature of 17,000 ± 500 K, has a radius of ∼ 0.6 R _⊙ and L ∼30 L _⊙. Bigger and more luminous than a white dwarf, yet cooler than a sub-dwarf, we speculate that it is a post-AGB/HB star that has recently transferred its mass to the BSS, which is known to be a rapid rotator. This binary system, which is the first BSS with a post-AGB/HB companion identified in an open cluster, is an ideal laboratory to study the process of BSS formation via mass transfer.

  19. A generalized sine condition and performance comparison of Wolter type II and Wolter-Schwarzschild extreme ultraviolet telescopes

    Science.gov (United States)

    Saha, T. T.

    1984-01-01

    An equation similar to the Abbe sine condition is derived for a Wolter type II telescope. This equation and the sine condition are then combined to produce a so called generalized sine condition. Using the law of reflection, Fermat's principle, the generalized sine condition, and simple geometry the surface equations for a Wolter type II telescope and an equivalent Wolter-Schwarzschild telescope are calculated. The performances of the telescopes are compared in terms of rms blur circle radius at the Gaussian focal plane and at best focus.

  20. Ultraviolet spectra of field horizontal-branch A-type stars. II

    International Nuclear Information System (INIS)

    Philip, A.G.D.; Hayes, D.S.; Adelman, S.J.

    1990-01-01

    The spectra of six additional A-type stars have been obtained at low resolution between 1200 and 1900 A with the IUE. The energy distributions of four of the stars match that of the field horizontal branch (FHB) distribution in Huenemoerder et al. (1984) while those of the other two do not. Three of the FHB stars fall above a line in the C(19 - V)0 vs. (b-y)0 diagram; however, HD 60825 is anomalously blue for its C(19 - V) color. 7 refs

  1. Extreme-ultraviolet limb spectra of a prominence observed from SKYLAB

    International Nuclear Information System (INIS)

    Mariska, J.T.; Doschek, G.A.; Feldman, U.

    1979-01-01

    Line profiles of extreme ultraviolet emission lines observed in a solar prominence at positions above the white-light limb with the NRL slit spectrograph on Skylab are discussed. Absolute line intensities and full widths at half-maximum are presented for lines formed over the temperature range approx.1 x 10 4 to 2.2 x 10 5 K. The volume emission measures calculated using resonance line intensities are greater than quiet-Sun emission measures at the same height above the limb and indicate a somewhat different distribution of material with temperature in the prominence compared to the quiet-Sun emission measure at +8''. Electron densities in the prominence determined using the calculated emission measures and the intensities of density-sensitive intersystem lines are between the quiet-Sun electron density and half the quiet-Sun electron density. Random mass-motion velocities calculated from the measured full widths at half-maximum show a range of velocities. For T/sub e/> or approx. =4 x 10 4 K, the nonthermal velocity decreases with increasing height in the prominence. For T/sub e/ 4 K, the calculated mass motions are near zero. From the He II 1640 A line profile we derive an average temperature of 27,000 K for the region in which He II is emitted

  2. Action spectra for inactivation of normal and xeroderma pigmentosum human skin fibroblasts by ultraviolet radiations

    International Nuclear Information System (INIS)

    Keyse, S.M.; Moss, S.H.; Davies, D.J.G.

    1983-01-01

    Action spectra for UV-induced lethality as measured by colony forming ability were determined both for a normal human skin fibroblast strain (1BR) and for an excision deficient xeroderma pigmentosum strain (XP4LO) assigned to complementation group A using 7 monochromatic wavelengths in the range 254-365 nm. The relative sensitivity of the XP strain compared to the normal skin fibroblasts shows a marked decrease at wavelengths longer than 313 nm, changing from a ratio of about 20 at the shorter wavelengths to just greater than 1.0 at the longer wavelengths. The action spectra thus indicate that the influence on cell inactivation of the DNA repair defect associated with XP cells is decreased and almost reaches zero at longer UV wavelengths. This would occur, for example, if the importance of pyrimidine dimers as the lethal lesion decreased with increasing wavelength. These results are consistent with pyrimidine dimers induced in DNA being the major lethal lesion in both cell strains over the wavelength range 254-313 nm. However, it is indicated that different mechanisms of inactivation operate at wavelengths longer than 313 nm. (author)

  3. A Comparison of Maps and Power Spectra Determined from South Pole Telescope and Planck Data

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Z.; Aylor, K.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H-M.; Chown, R.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W. B.; Follin, B.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Omori, Y.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2018-01-17

    We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the \\textit{Planck} satellite over the 2540 $\\text{deg}^2$ patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the map residuals appear consistent with noise after we account for differences in angular resolution and filtering. To make a more quantitative comparison, we calculate (1) the cross-spectrum between two independent halves of SPT 150 GHz data, (2) the cross-spectrum between two independent halves of \\textit{Planck} 143 GHz data, and (3) the cross-spectrum between SPT 150 GHz and \\textit{Planck} 143 GHz data. We find the three cross-spectra are well-fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free parameter characterizing the relative calibration between the two. As a by-product of this analysis, we improve the calibration of SPT data by nearly an order of magnitude, from 2.6\\% to 0.3\\% in power; the best-fit power calibration factor relative to the most recent published SPT calibration is $1.0174 \\pm 0.0033$. Finally, we compare all three cross-spectra to the full-sky \\textit{Planck} $143 \\times 143$ power spectrum and find a hint ($\\sim$1.5$\\sigma$) for differences in the power spectrum of the SPT-SZ footprint and the full-sky power spectrum, which we model and fit as a power law in the spectrum. The best-fit value of this tilt is consistent between the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt---assuming it is real---is a sample variance fluctuation in the SPT-SZ region relative to the full sky. Despite the precision of our tests, we find no evidence for systematic errors in either data set. The consistency of cosmological parameters derived from these datasets is discussed in a companion paper.

  4. Vacuum ultraviolet photochemistry of CH4 and isotopomers. II. Product channel fields and absorption spectra

    International Nuclear Information System (INIS)

    Wang, Jen-Han; Liu, Kopin; Min, Zhiyuan; Su, Hongmei; Bersohn, Richard; Preses, Jack; Larese, John Z.

    2000-01-01

    In part I of this work the relative velocities and anisotropies of the atomic H and D fragments from methane photolysis at 10.2 eV were measured. In this paper the relative abundance of the methyl and methylene fragments are reported. A complete set of quantum yields for the different photodissociation channels of each isotopomer is obtained by combining the two sets of data. Previously it was found that H atoms are almost four times more likely than D atoms to be ejected; now it is found that hydrogen molecule photofragments are much richer in H atoms than in D. Overall, the heavier D atoms are more likely than the H atoms to remain attached to the carbon atom. An implication for astrophysics is discussed. The VUV absorption spectra of CH 4 and CH 3 D are almost identical both at room temperature and 75 K. There is, as expected, no variation in the absorption spectrum with temperature. Evidence is given that all or almost all of the methylene is produced in the a 1 A 1 and not in the ground 3 B 1 state. (c) 2000 American Institute of Physics

  5. THE MUSCLES TREASURY SURVEY. II. INTRINSIC LY α AND EXTREME ULTRAVIOLET SPECTRA OF K AND M DWARFS WITH EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke [Laboratory for Atmospheric and Space Physics, University of Colorado, 600 UCB, Boulder, CO 80309 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Redfield, Seth [Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123 (United States); Schneider, P. Christian [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Wood, Brian E. [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States); Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Froning, Cynthia [Dept. of Astronomy C1400, University of Texas, Austin, TX 78712 (United States); Miguel, Yamila [Laboratoire Lagrange, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d’Azur, CNRS, Blvd de l’Observatoire, CS 34229, F-06304 Nice cedex 4 (France); Rugheimer, Sarah [Department of Earth and Environmental Sciences, Irvine Building, University of St. Andrews, St. Andrews KY16 9AL (United Kingdom); Walkowicz, Lucianne, E-mail: allison.youngblood@colorado.edu [The Adler Planetarium, 1300 S Lakeshore Dr, Chicago, IL 60605 (United States)

    2016-06-20

    The ultraviolet (UV) spectral energy distributions (SEDs) of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Ly α line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar H i absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES Hubble Space Telescope Treasury Survey has obtained UV observations of 11 nearby M and K dwarfs hosting exoplanets. This paper presents the Ly α and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Ly α profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV SED from the intrinsic Ly α flux in ∼100 Å bins from 100–1170 Å. The reconstructed Ly α profiles have 300 km s{sup −1} broad cores, while >1% of the total intrinsic Ly α flux is measured in extended wings between 300 and 1200 km s{sup −1}. The Ly α surface flux positively correlates with the Mg ii surface flux and negatively correlates with the stellar rotation period. Stars with larger Ly α surface flux also tend to have larger surface flux in ions formed at higher temperatures, but these correlations remain statistically insignificant in our sample of 11 stars. We also present H i column density measurements for 10 new sightlines through the local interstellar medium.

  6. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days.

    Science.gov (United States)

    Grifoni, D; Zipoli, G; Sabatini, F; Messeri, G; Bacci, L

    2013-12-01

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photokeratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process.

  7. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days

    International Nuclear Information System (INIS)

    Grifoni, D.; Zipoli, G.; Sabatini, F.; Messeri, G.; Bacci, L.

    2013-01-01

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photo-keratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process. (authors)

  8. Hubble Space Telescope STIS observations of GRB 000301C: CCD imaging and near-ultraviolet MAMA spectroscopy

    DEFF Research Database (Denmark)

    Smette, A.; Fruchter, A.S.; Gull, T.R.

    2001-01-01

    We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the c-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R similar or equal to 21.50 +/- 0.15 source with no apparent host galaxy...... Telescope images appear to lie on the stellar field of a host galaxy, and as the large H I column density measured here and in later ground-based observations is unlikely on a random line of sight, we believe we are probably seeing absorption from H I in the host galaxy. In any case, this represents...

  9. Reduction of spectra exposed by the 700mm CCD camera of the Ondřejov telescope coudé spectrograph

    Science.gov (United States)

    Skoda, Petr; Slechta, Miroslav

    We present a brief cook-book for the reduction of spectra exposed by the Ondřejov 2-meter telescope coudé spectrograph. For the data reduction, we use standard IRAF packages running on Solaris and Linux. The sequence of commands is given for the typical reduction session together with short explanation and detailed list of parameter settings. The reduction progress is illustrated by example plots.

  10. Synthesis and investigation of solvent effects on the ultraviolet absorption spectra of 5-substituted-4-methyl-3-cyano-6-hydroxy-2-pyridones

    Directory of Open Access Journals (Sweden)

    NATASA V. VALENTIC

    2001-08-01

    Full Text Available A number of 5-substituted-4-methyl-3-cyano-6-hydroxy-2-pyridones from cyanoacetamide and the corresponding alkyl ethyl acetoacetates were synthesized according to modified literature procedures. The alkyl ethyl acetoacetates were obtained by the reaction of C-alkylation of ethyl acetoacetate. An investigation of the reaction conditions for the synthesis of 4-methyl-3-cyano-6-hydroxy-2-pyridone from cyanoacetamide and ethyl acetoacetate in eight different solvents was also performed. The ultraviolet absorption spectra of synthesized pyridones were measured in nine different solvents in the range 200–400 nm. The effects of solvent polarity and hydrogen bonding on the absorption spectra are interpreted by means of linear solvation energy relationships using a general equation of the form n = n0 + sp* + aa + bb, where p* is a measure of the solvent polarity, a is the scale of the solvent hydrogen bond donor acidities and b is the scale of the solvent hydrogen bond acceptor basicities.

  11. A MISMATCH IN THE ULTRAVIOLET SPECTRA BETWEEN LOW-REDSHIFT AND INTERMEDIATE-REDSHIFT TYPE Ia SUPERNOVAE AS A POSSIBLE SYSTEMATIC UNCERTAINTY FOR SUPERNOVA COSMOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Ryan J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Kessler, Richard; Frieman, Joshua A. [Kavli Institute for Cosmological Physics, The University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bassett, Bruce; Smith, Mathew [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Garnavich, Peter M. [Department of Physics, University of Notre Dame, 225 Nieuwland Science, Notre Dame, IN 46556-5670 (United States); Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Konishi, Kohki [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Lampeitl, Hubert [Institute of Cosmology and Gravitation, University of Portsmouth, Mercantile House, Hampshire Terrace, Portsmouth PO1 2EG (United Kingdom); Riess, Adam G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Sako, Masao [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Sollerman, Jesper, E-mail: rfoley@cfa.harvard.edu [Oskar Klein Centre, Department of Astronomy, Stockholm University, 106 91 Stockholm (Sweden)

    2012-05-15

    We present Keck high-quality rest-frame ultraviolet (UV) through optical spectra of 21 Type Ia supernovae (SNe Ia) in the redshift range 0.11 {<=} z {<=} 0.37 and a mean redshift of 0.22 that were discovered during the Sloan Digital Sky Survey-II (SDSS-II) SN Survey. Using the broadband photometry of the SDSS survey, we are able to reconstruct the SN host-galaxy spectral energy distributions (SEDs), allowing for a correction for the host-galaxy contamination in the SN Ia spectra. Comparison of composite spectra constructed from a subsample of 17 high-quality spectra to those created from a low-redshift sample with otherwise similar properties shows that the Keck/SDSS SNe Ia have, on average, extremely similar rest-frame optical spectra but show a UV flux excess. This observation is confirmed by comparing synthesized broadband colors of the individual spectra, showing a difference in mean colors at the 2.4{sigma}-4.4{sigma} level for various UV colors. We further see a slight difference in the UV spectral shape between SNe with low-mass and high-mass host galaxies. Additionally, we detect a relationship between the flux ratio at 2770 and 2900 A and peak luminosity that differs from that observed at low redshift. We find that changing the UV SED of an SN Ia within the observed dispersion can change the inferred distance moduli by {approx}0.1 mag. This effect only occurs when the data probe the rest-frame UV. We suggest that this discrepancy could be due to differences in the host-galaxy population of the two SN samples or to small-sample statistics.

  12. Ultraviolet Extensions

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view This ultraviolet image from NASA's Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra. Ultraviolet light traces young populations of stars; in this image, young stars can be seen way beyond the main spiral disk of M83 up to 140,000 light-years from its center. Could life exist around one of these far-flung stars? Scientists say it's unlikely because the outlying regions of a galaxy are lacking in the metals required for planets to form. The image was taken at scheduled intervals between March 15 and May 20, 2007. It is one of the longest-exposure, or deepest, images ever taken of a nearby galaxy in ultraviolet light. Near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow, and far-ultraviolet light is blue. What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms. The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials. The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of time. In fact, it is one of the

  13. A RADIAL VELOCITY STUDY OF COMPOSITE-SPECTRA HOT SUBDWARF STARS WITH THE HOBBY-EBERLY TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, Brad N.; Wade, Richard A.; Liss, Sandra E. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Ostensen, Roy H.; Van Winckel, Hans [Instituut voor Sterrenkunde, K.U. Leuven, B-3001 Leuven (Belgium)

    2012-10-10

    Many hot subdwarf stars show composite spectral energy distributions indicative of cool main-sequence (MS) companions. Binary population synthesis (BPS) models demonstrate such systems can be formed via Roche lobe overflow or common envelope evolution but disagree on whether the resulting orbital periods will be long (years) or short (days). Few studies have been carried out to assess the orbital parameters of these spectroscopic composite binaries; current observations suggest the periods are long. To help address this problem, we selected 15 moderately bright (V {approx} 13) hot subdwarfs with F-K dwarf companions and monitored their radial velocities from 2005 January to 2008 July using the bench-mounted Medium Resolution Spectrograph on the Hobby-Eberly Telescope (HET). Here we describe the details of our observing, reduction, and analysis techniques, and present preliminary results for all targets. By combining the HET data with recent observations from the Mercator Telescope, we are able to calculate precise orbital solutions for three systems using more than six years of observations. We also present an up-to-date period histogram for all known hot subdwarf binaries, which suggests those with F-K MS companions tend to have orbital periods on the order of several years. Such long periods challenge the predictions of conventional BPS models, although a larger sample is needed for a thorough assessment of the models' predictive success. Lastly, one of our targets has an eccentric orbit, implying some composite-spectrum systems might have formerly been hierarchical triple systems, in which the inner binary merged to create the hot subdwarf.

  14. Absolutely calibrated vacuum ultraviolet spectra in the 150-250-nm range from plasmas generated by the NIKE KrF laser

    International Nuclear Information System (INIS)

    Seely, J.F.; Feldman, Uri; Holland, G.E.; Weaver, J.L.; Mostovych, A.N.; Obenschain, S.P.; Schmitt, A.J.; Lehmberg, R.; Kjornarattanawanich, Benjawan; Back, C.A.

    2005-01-01

    High-resolution vacuum ultraviolet (VUV) spectra were recorded from plasmas generated by the NIKE KrF laser for the purpose of observing emission from the two-plasmon decay instability (TPDI) at 2/3 the NIKE wavelength (165 nm). The targets were irradiated by up to 43 overlapping beams with intensity up to ≅10 14 W/cm 2 and with beam smoothing by induced spatial incoherence (ISI). The targets consisted of planar foils of CH, BN, Al, Si, S, Ti, Pd, and Au. Titanium-doped silica aerogels in Pyrex cylinders were also irradiated. The spectra of the target elements were observed from charge states ranging from the neutral atoms to five times ionized. The spectrometer was absolutely calibrated using synchrotron radiation, and absolute VUV plasma emission intensities were determined. Emission from the TPDI at 165-nm wavelength was not observed from any of the irradiated targets. An upper bound on the possible TPDI emission was less than 4x10 -8 the incident NIKE laser energy. The NIKE laser radiation backscattered from the silica aerogel targets at 248 nm was typically 6x10 -6 the incident NIKE laser energy, and the spectral broadening corresponded to the 1-THz bandwidth of the ISI smoothing. The spectra from the moderately charged plasma ions (up to five times ionized), spectral linewidths, absolute continuum emission level, and slope of the continuum were consistent with plasma temperatures in the 100-300-eV range

  15. Vacuum-ultraviolet ellipsometry spectra and structural properties of Pb(Zr,Ti)O.sub.3./sub. films

    Czech Academy of Sciences Publication Activity Database

    Suchaneck, G.; Chvostová, Dagmar; Kousal, J.; Železný, Vladimír; Lynnyková, Anna; Jastrabík, Lubomír; Gerlach, G.; Dejneka, Alexandr

    2011-01-01

    Roč. 519, č. 9 (2011), s. 2885-2888 ISSN 0040-6090 R&D Projects: GA ČR GC202/09/J017; GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002; GA ČR GA202/08/1009 Institutional research plan: CEZ:AV0Z10100522 Keywords : PZT film * vacuum-ultraviolet ellipsometry * film structure * optical properties Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.890, year: 2011

  16. Observation of forbidden (E2) lines in the ultraviolet spectra of Ca II, Sr II, and Ba II by inductively coupled plasma emission spectroscopy

    International Nuclear Information System (INIS)

    Doidge, Peter S.

    2013-01-01

    Forbidden (electric quadrupole, E2) transitions of the type ns 2 S 1/2 –nd 2 D 3/2 and ns 2 S 1/2 –nd 2 D 5/2 in the ultraviolet spectra of singly ionized Ca, Sr, and Ba (with n = 4, 5 or 6 for Ca, Sr, and Ba, respectively) have been observed in the emission spectrum of an inductively coupled argon plasma. Wavelengths and wavenumbers of the six lines are reported and the values are in good agreement with those expected from literature data for the energy levels involved. - Highlights: • Wavelengths measured using commercially available ICP emission spectrometer • First wavelength and wavenumber measurements of some E2 lines of Ba +, Ca +, Sr + • Evidence for small plasma shifts in the wavenumbers of Ba + and Sr +

  17. Extreme Ultraviolet Imaging Telescope (EIT)

    Science.gov (United States)

    Lemen, J. R.; Freeland, S. L.

    1997-01-01

    Efforts concentrated on development and implementation of the SolarSoft (SSW) data analysis system. From an EIT analysis perspective, this system was designed to facilitate efficient reuse and conversion of software developed for Yohkoh/SXT and to take advantage of a large existing body of software developed by the SDAC, Yohkoh, and SOHO instrument teams. Another strong motivation for this system was to provide an EIT analysis environment which permits coordinated analysis of EIT data in conjunction with data from important supporting instruments, including Yohkoh/SXT and the other SOHO coronal instruments; CDS, SUMER, and LASCO. In addition, the SSW system will support coordinated EIT/TRACE analysis (by design) when TRACE data is available; TRACE launch is currently planned for March 1998. Working with Jeff Newmark, the Chianti software package (K.P. Dere et al) and UV /EUV data base was fully integrated into the SSW system to facilitate EIT temperature and emission analysis.

  18. Spitzer mid-infrared spectra of cool-core galaxy clusters

    NARCIS (Netherlands)

    de Messières, G.E.; O'Connell, R.W.; McNamara, B.R.; Donahue, M.; Nulsen, P.E.J.; Voit, G.M.; Wise, M.W.; Smith, B.; Higdon, J.; Higdon, S.; Bastian, N.

    2010-01-01

    We have obtained mid-infrared spectra of nine cool-core galaxy clusters with the Infrared Spectrograph aboard the Spitzer Space Telescope. X-ray, ultraviolet and optical observations have demonstrated that each of these clusters hosts a cooling flow which seems to be fueling vigorous star formation

  19. A Comparison of Cosmological Parameters Determined from CMB Temperature Power Spectra from the South Pole Telescope and the Planck Satellite

    Science.gov (United States)

    Aylor, K.; Hou, Z.; Knox, L.; Story, K. T.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H.-M.; Chown, R.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W. B.; George, E. M.; Halverson, N. W.; Harrington, N. L.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Keisler, R.; Lee, A. T.; Leitch, E. M.; Luong-Van, D.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Millea, M.; Mocanu, L. M.; Mohr, J. J.; Natoli, T.; Omori, Y.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Staniszewski, Z.; Stark, A. A.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.

    2017-11-01

    The Planck cosmic microwave background temperature data are best fit with a ΛCDM model that mildly contradicts constraints from other cosmological probes. The South Pole Telescope (SPT) 2540 {\\deg }2 SPT-SZ survey offers measurements on sub-degree angular scales (multipoles 650≤slant {\\ell }≤slant 2500) with sufficient precision to use as an independent check of the Planck data. Here we build on the recent joint analysis of the SPT-SZ and Planck data in Hou et al. by comparing ΛCDM parameter estimates using the temperature power spectrum from both data sets in the SPT-SZ survey region. We also restrict the multipole range used in parameter fitting to focus on modes measured well by both SPT and Planck, thereby greatly reducing sample variance as a driver of parameter differences and creating a stringent test for systematic errors. We find no evidence of systematic errors from these tests. When we expand the maximum multipole of SPT data used, we see low-significance shifts in the angular scale of the sound horizon and the physical baryon and cold dark matter densities, with a resulting trend to higher Hubble constant. When we compare SPT and Planck data on the SPT-SZ sky patch to Planck full-sky data but keep the multipole range restricted, we find differences in the parameters n s and {A}s{e}-2τ . We perform further checks, investigating instrumental effects and modeling assumptions, and we find no evidence that the effects investigated are responsible for any of the parameter shifts. Taken together, these tests reveal no evidence for systematic errors in SPT or Planck data in the overlapping sky coverage and multipole range and at most weak evidence for a breakdown of ΛCDM or systematic errors influencing either the Planck data outside the SPT-SZ survey area or the SPT data at {\\ell }> 2000.

  20. Ultraviolet Spectroscopy of Asteroid(4) Vesta

    Science.gov (United States)

    Li, Jian-Yang; Bodewits, Dennis; Feaga, Lori M.; Landsman, Wayne; A'Hearn, Michael F.; Mutchler, Max J.; Russell, Christopher T.; McFadden, Lucy A.; Raymond, Carol A.

    2011-01-01

    We report a comprehensive review of the UV-visible spectrum and rotational lightcurve of Vesta combining new observations by Hubble Space Telescope and Swift with archival International Ultraviolet Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm arc derived by carefully comparing these observations from various instruments at different times and observing geometries. Vesta has a rotationally averaged geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673 nm, and 0.30 at 950 nm. The linear spectral slope in the ultraviolet displays a sharp minimum ncar sub-Earth longitude of 20deg, and maximum in the eastern hemisphere. This is completely consistent with the distribution of the spectral slope in the visible wavelength. The uncertainty of the measurement in the ultraviolet is approx.20%, and in the visible wavelengths better than 10%. The amplitude of Vesta's rotational lightcurves is approx.10% throughout the range of wavelengths we observed, but is smaller at 950 nm (approx.6%) ncar the 1-micron mafic band center. Contrary to earlier reports, we found no evidence for any difference between the phasing of the ultraviolet and visible/ncar-infrared lightcurves with respect to sub-Earth longitude. Vesta's average spectrum between 220 and 950 nm can well be described by measured reflectance spectra of fine particle howardite-like materials of basaltic achondrite meteorites. Combining this with the in-phase behavior of the ultraviolet, visible. and ncar-infrared lightcurves, and the spectral slopes with respect to the rotational phase, we conclude that there is no global ultraviolet/visible reversal on Vesta. Consequently, this implies lack of global space weathering on Vesta. Keyword,: Asteroid Vesta; Spectrophotometry; Spectroscopy; Ultraviolet observations; Hubble Space Telescope observations

  1. X-ray spectra of PG quasars. II - the X-ray-ultraviolet excess of PG 1211 + 143

    International Nuclear Information System (INIS)

    Bechtold, J.; Czerny, B.; Elvis, M.; Fabbiano, G.; Green, R.F.; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA; Kitt Peak National Observatory, Tucson, AZ)

    1987-01-01

    Observations of the quasar PG 1211 + 143 are presented and its continuum is modelled in terms of an accretion disk and an underlying power law. The X-ray spectrum in the Einstein imaging proportional counter band is well described by a power law with the very steep spectral index 2.2 + or - 0.4. The overall continuum spectral energy distribution can be described as a power law with alpha roughly 1.2 from the infrared to about 1 keV, with the optical, ultraviolet, and soft X-rays forming a large excess above this power law. If the soft X-ray excess is attributed to emission from a physically thin, optically thick accretion disk, then the implied accretion rate is super-Eddington, from which it is concluded that the application of this simple model is not valid. The observed broad-line ratios in PG 1211 + 143 imply broad-line cloud densities that are somewhat higher than those usually derived for quasars. 82 references

  2. Outer atmospheres of cool stars. XII - A survey of IUE ultraviolet emission line spectra of cool dwarf stars

    Science.gov (United States)

    Linsky, J. L.; Bornmann, P. L.; Carpenter, K. G.; Hege, E. K.; Wing, R. F.; Giampapa, M. S.; Worden, S. P.

    1982-01-01

    Quantitative information is obtained on the chromospheres and transition regions of M dwarf stars, in order to determine how the outer atmospheres of dMe stars differ from dM stars and how they compare with the outer atmospheres of quiet and active G and K type dwarfs. IUE spectra of six dMe and four dM stars, together with ground-based photometry and spectroscopy of the Balmer and Ca II H and K lines, show no evidence of flares. It is concluded, regarding the quiescent behavior of these stars, that emission-line spectra resemble that of the sun and contain emission lines formed in regions with 4000-20,000 K temperatures that are presumably analogous to the solar chromosphere, as well as regions with temperatures of 20,000-200,000 K that are presumably analogous to the solar transition region. Emission-line surface fluxes are proportional to the emission measure over the range of temperatures at which the lines are formed.

  3. ASASSN-15LH: A SUPERLUMINOUS ULTRAVIOLET REBRIGHTENING OBSERVED BY SWIFT AND HUBBLE

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Peter J.; Yang, Yi; Wang, Lifan [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Cooke, Jeff; Mould, Jeremy [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122 (Australia); Olaes, Melanie; Quimby, Robert M. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Baade, Dietrich [European Organisation for Astronomical Research in the Southern Hemisphere (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching b. München (Germany); Gehrels, Neil [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hoeflich, Peter [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Maund, Justyn [Department of Physics and Astronomy F39 Hicks Building, Hounsfield Road Sheffield, S3 7RH (United Kingdom); Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)

    2016-09-01

    We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope , all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Ly α absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs.

  4. Effects of glycerol upon the biological actions of near-ultraviolet light: spectra and concentration dependence for transforming DNA and for Escherichia coli B/r

    International Nuclear Information System (INIS)

    Peak, J.G.; Peak, M.J.; Foote, C.S.

    1982-01-01

    The concentration dependence for the protection of isolated transforming DNA and Escherichia coli by glycerol against 365-nm monochromatic near-ultraviolet light (UV) was measured. Glycerol protection saturates at a concentration of about 0.1 M for DNA and 1.0 M for E. coli. Action spectra for glycerol protection of transforming DNA (tryptophan and histidine markers) are similar to those obtained previously for diazobicyclo[2.2.2.]octane (DABCO) protection, with protection reaching a maximum near 350-nm UV and decreasing rapidly at wavelengths above and below 350 nm. However, glycerol protects against near-UV about twice as efficiently as DABCO. The action spectrum for protection of E. coli by glycerol against the lethal effects of near-UV was not the same as the spectrum for DNA since glycerol sensitized the cells, but not the DNA, at wavelengths longer than about 380 nm. A possible role of hydroxyl or other radicals was supported by the observation that benzoate also protected DNA against inactivation by 334-nm UV. (author)

  5. Lethal action of ultraviolet and visible (blue violet) radiations at defined wavelengths on human lymphoblastoid cells; action spectra and interaction sites

    Energy Technology Data Exchange (ETDEWEB)

    Tyrrell, R.M.; Werfelli, P.; Moraes, E.C. (Institut Suisse de Recherches Experimentales sur le Cancer, Lausanne)

    1984-02-01

    The repair proficient human lymphoblastoid line (TK6) has been employed to construct an action spectrum for the lethal action of ultraviolet (UV) radiation in the range 254 to 434 nm and to examine possible interactions between longer (334, 365 and 405 nm) and shorter wavelength (254 and 313 nm) radiations. The action spectrum follows a DNA absorption spectrum fairly closely out to 360 nm. As in previously determined lethal action spectra for procaryotic and eucaryotic cell populations, there is a broad shoulder in the 334 to 405 nm region which could reflect the existence of either (a) a non-DNA chromophore or (b) a unique photochemical reaction in the DNA over this region. Pre-treatment with radiation at 334 or 365 nm causes either a slight sensitivity to (low fluences) or protection from (higher fluences) subsequent exposure to radiation at a shorter wavelength (254 or 313 nm). Pre-irradiation at a visible wavelength (405 nm) at all fluence levels employed sensitizes the populations to treatment with 254 or 313 nm radiations. These interactions will influence the lethal outcome of cellular exposure to broad-band radiation sources.

  6. Lethal action of ultraviolet and visible (blue violet) radiations at defined wavelengths on human lymphoblastoid cells; action spectra and interaction sites

    International Nuclear Information System (INIS)

    Tyrrell, R.M.; Werfelli, P.; Moraes, E.C.

    1984-01-01

    The repair proficient human lymphoblastoid line (TK6) has been employed to construct an action spectrum for the lethal action of ultraviolet (UV) radiation in the range 254 to 434 nm and to examine possible interactions between longer (334, 365 and 405 nm) and shorter wavelength (254 and 313 nm) radiations. The action spectrum follows a DNA absorption spectrum fairly closely out to 360 nm. As in previously determined lethal action spectra for procaryotic and eucaryotic cell populations, there is a broad shoulder in the 334 to 405 nm region which could reflect the existence of either (a) a non-DNA chromophore or (b) a unique photochemical reaction in the DNA over this region. Pre-treatment with radiation at 334 or 365 nm causes either a slight sensitivity to (low fluences) or protection from (higher fluences) subsequent exposure to radiation at a shorter wavelength (254 or 313 nm). Pre-irradiation at a visible wavelength (405 nm) at all fluence levels employed sensitizes the populations to treatment with 254 or 313 nm radiations. These interactions will influence the lethal outcome of cellular exposure to broad-band radiation sources. (author)

  7. The correlation between the ultraviolet lambda 220 feature and the diffuse lambda 4430 band

    International Nuclear Information System (INIS)

    Nandy, K.; Thompson, G.I.

    1975-01-01

    Observations of the ultraviolet feature which occurs close to 2200 A are presented for over 60 stars for which interstellar lambda 4430 data are available in the literature. Observational material used here is obtained from the ultraviolet spectra taken with the Sky Survey telescope (S2/68) in the ESRO TD1 satellite. The equivalent widths of the lambda 2200 feature have been determined from ultraviolet extinction at 2190 and 2500 A, and the relation between the equivalent width of the ultraviolet feature and the central depth of the lambda 4430 band has been determined. It is found that they are well correlated and the correlation coefficient, including allowance for errors, is greater than 0.9; this indicates that the carriers for the lambda 2200 feature and diffuse band lambda 4430 coexist in the interstellar medium. (author)

  8. Fine and hyperfine structure spectra of the ultra-violet 23S → 53P transition in 4He and 3He with a frequency doubled CW ring laser, detected via associative ionization

    International Nuclear Information System (INIS)

    Runge, S.; Pesnelle, A.; Perdrix, M.; Sevin, D.; Wolffer, N.; Watel, G.

    1982-01-01

    High resolution laser spectroscopy coupled to a sensitive method of detection via mass analysis of He + 2 ions produced in He(5 3 P) + He(1 1 S) collisions, is used to obtain the fine and hyperfine spectra of the ultra-violet He 2 3 S → 5 3 P transition. A cw tunable UV radiation around 294.5 nm is generated by intracavity frequency doubling a Rhodamine 6G single mode ring dye laser using an ADA crystal. Both spectra enable fine and hyperfine structures to be determined within a few MHz. The magnetic dipole coupling constant A of the 5 3 P term of 3 He is found to be -4326 +- 9 MHz (-0.1443 +- 0.0003 cm -1 ). (orig.)

  9. Stellar extreme ultraviolet astronomy

    International Nuclear Information System (INIS)

    Cash, W.C. Jr.

    1978-01-01

    The design, calibration, and launch of a rocket-borne imaging telescope for extreme ultraviolet astronomy are described. The telescope, which employed diamond-turned grazing incidence optics and a ranicon detector, was launched November 19, 1976, from the White Sands Missile Range. The telescope performed well and returned data on several potential stellar sources of extreme ultraviolet radiation. Upper limits ten to twenty times more sensitive than previously available were obtained for the extreme ultraviolet flux from the white dwarf Sirius B. These limits fall a factor of seven below the flux predicted for the star and demonstrate that the temperature of Sirius B is not 32,000 K as previously measured, but is below 30,000 K. The new upper limits also rule out the photosphere of the white dwarf as the source of the recently reported soft x-rays from Sirius. Two other white dwarf stars, Feige 24 and G191-B2B, were observed. Upper limits on the flux at 300 A were interpreted as lower limits on the interstellar hydrogen column densities to these stars. The lower limits indicate interstellar hydrogen densitites of greater than .02 cm -3 . Four nearby stars (Sirius, Procyon, Capella, and Mirzam) were observed in a search for intense low temperature coronae or extended chromospheres. No extreme ultraviolet radiation from these stars was detected, and upper limits to their coronal emisson measures are derived

  10. Galactic cosmic ray spectra during solar cycle 23 and 24. Measurement capabilities of the electron proton helium telescope on board SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, Patrick; Dresing, Nina; Gieseler, Jan; Heber, Bernd; Klassen, Andreas [Christian-Albrechts Universitaet zu Kiel (Germany)

    2016-07-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra above 1.5 GeV/nucleon. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

  11. Spectra of alkali atoms

    International Nuclear Information System (INIS)

    Santoso, Budi; Arumbinang, Haryono.

    1981-01-01

    Emission spectra of alkali atoms has been determined by using spectrometer at the ultraviolet to infra red waves range. The spectra emission can be obtained by absorption spectrophotometric analysis. Comparative evaluations between experimental data and data handbook obtained by spark method were also presented. (author tr.)

  12. The effect of ultraviolet irradiation on the photothermal, photoluminescence and photoluminescence excitation spectra of Mn-doped ZnS nanoparticles

    International Nuclear Information System (INIS)

    Briones Cruz, Almira; Shen Qing; Toyoda, Taro

    2006-01-01

    Research involving Mn doped nanocrystalline ZnS (ZnS:Mn) has grown in recent years, partly due to the high quantum luminescence efficiencies that have been reported. We measured the photoacoustic (PA), the photoluminescence (PL) and the photoluminescence excitation (PLE) spectra of surface-passivated and unpassivated ZnS:Mn. The effects of UV irradiation on the PL and PLE spectra were also studied. A decrease in the PA intensity after UV exposure was observed for the ZnS:Mn, indicating a decrease in the nonradiative relaxation probability. The observed increase in PL intensity indicates a corresponding increase in the radiative transition probability. For the PLE spectra, possible aggregation of the primary particles could have resulted in the lower measured energy of the PLE peak compared to the value predicted by the effective mass approximation theory

  13. FAINT NEAR-ULTRAVIOLET/FAR-ULTRAVIOLET STANDARDS FROM SWIFT/UVOT, GALEX, AND SDSS PHOTOMETRY

    International Nuclear Information System (INIS)

    Siegel, Michael H.; Hoversten, Erik A.; Roming, Peter W. A.; Brown, Peter

    2010-01-01

    At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u ∼ 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer archives and combined with new data from the Swift Ultraviolet Optical Telescope to provide precise photometric measures extending from the near-infrared to the far-ultraviolet. These stars were chosen because they are known to be hot (20, 000 eff < 50, 000 K) DA white dwarfs with published Sloan spectra that should be photometrically stable. This careful selection allows us to compare the combined photometry and Sloan spectroscopy to models of pure hydrogen atmospheres to both constrain the underlying properties of the white dwarfs and test the ability of white dwarf models to predict the photometric measures. We find that the photometry provides good constraints on white dwarf temperatures, which demonstrates the ability of Swift/UVOT to investigate the properties of hot luminous stars. We further find that the models reproduce the photometric measures in all 11 passbands to within their systematic uncertainties. Within the limits of our photometry, we find the standard stars to be photometrically stable. This success indicates that the models can be used to calibrate additional filters to our standard system, permitting easier comparison of photometry from heterogeneous sources. The largest source of uncertainty in the model fitting is the uncertainty in the foreground reddening curve, a problem that is especially acute in the UV.

  14. Optical to ultraviolet spectra of sandwiches of benzene and transition metal atoms: Time dependent density functional theory and many-body calculations

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; García Lastra, Juan Maria; Lopez, M. J.

    2010-01-01

    The optical spectra of sandwich clusters formed by transition metal atoms (titanium, vanadium, and chromium) intercalated between parallel benzene molecules have been studied by time-dependent density functional theory (TDDFT) and many-body perturbation theory. Sandwiches with different number...

  15. The 3D-HST Survey: Hubble Space Telescope WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

    Science.gov (United States)

    Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica J.; Fumagalli, Mattia; Maseda, Michael V.; Leja, Joel; Franx, Marijn; Rix, Hans-Walter; Bezanson, Rachel; Da Cunha, Elisabete; Dickey, Claire; Förster Schreiber, Natascha M.; Illingworth, Garth; Kriek, Mariska; Labbé, Ivo; Ulf Lange, Johannes; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Tal, Tomer; Wake, David A.; van der Wel, Arjen; Wuyts, Stijn

    2016-08-01

    We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H 140 imaging, parallel ACS G800L spectroscopy, and parallel I 814 imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to {{JH}}{IR}≤slant 24 (79,609 unique objects down to {{JH}}{IR}≤slant 26). Of these, 5459 galaxies are at z\\gt 1.5 and 9621 are at 0.7\\lt z\\lt 1.5, where Hα falls in the G141 wavelength coverage. The typical redshift error for {{JH}}{IR}≤slant 24 galaxies is {σ }z≈ 0.003× (1+z), I.e., one native WFC3 pixel. The 3σ limit for emission line fluxes of point sources is 2.1× {10}-17 erg s-1 cm-2. All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.18

  16. Absorption spectra of localized surface plasmon resonance observed in an inline/picoliter spectrometer cell fabricated by a near ultraviolet femtosecond laser

    Science.gov (United States)

    Shiraishi, Masahiko; Nishiyama, Michiko; Watanabe, Kazuhiro; Kubodera, Shoichi

    2018-03-01

    Absorption spectra based on localized surface plasmon resonance (LSPR) were obtained with an inline/picoliter spectrometer cell. The spectrometer cell was fabricated into an optical glass fiber by focusing a near UV (NUV) femtosecond laser pulses at a wavelength of 400 nm with an energy of 30 μJ. The laser beam was focused from two directions opposite to each other to fabricate a through-hole spectrometer cell. A diameter of the cell was approximately 3 μm, and the length was approximately 62.5 μm, which was nearly equal to the core diameter of the optical fiber. Liquid solution of gold nanoparticles (GNPs) with a diameter of 5-10 nm was injected into the spectrometer cell with its volume of 0.4 pL. The absorption peak centered at 518 nm was observed. An increase of absorption associated with the increase of the number of nanoparticles was in agreement with the numerical calculation based on the Lambert-Beer law.

  17. STACKED REST-FRAME ULTRAVIOLET SPECTRA OF Lyα-EMITTING AND CONTINUUM-SELECTED GALAXIES AT 2 < z < 3.5

    International Nuclear Information System (INIS)

    Berry, Michael; Gawiser, Eric; Guaita, Lucia; Padilla, Nelson; Francke, Harold; Treister, Ezequiel; Blanc, Guillermo A.; Ciardullo, Robin; Gronwall, Caryl

    2012-01-01

    We present properties of individual and composite rest-UV spectra of continuum- and narrowband-selected star-forming galaxies (SFGs) at a redshift of 2 Lyα > 20 Å, the canonical limit to be classified as an Lyα-emitting galaxy. We divide our data set into subsamples based on properties that we are able to measure for each individual galaxy: Lyα equivalent width, rest-frame UV colors, and redshift. Among our subsample of galaxies with R Lyα > 20 Å have bluer UV continua, weaker low-ionization interstellar absorption lines, weaker C IV absorption, and stronger Si II* nebular emission than those with W Lyα –1 between Lyα emission and low-ionization absorption, which does not vary substantially among any of our subsamples. We find that the interstellar component, as opposed to the stellar component, dominates the high-ionization absorption line profiles. We find that the low- and high-ionization Si ionization states have similar kinematic properties, yet the low-ionization absorption is correlated with Lyα emission and the high-ionization absorption is not. These trends are consistent with outflowing neutral gas being in the form of neutral clouds embedded in ionized gas as previously suggested by Steidel et al. Moreover, our galaxies with bluer UV colors have stronger Lyα emission, weaker low-ionization absorption, and more prominent nebular emission line profiles. From a redshift of 2.7 Lyα Lyα > 20 Å exhibit weaker Lyα emission at lower redshifts, although we caution that this could be caused by spectroscopic confirmation of low Lyα equivalent width galaxies being harder at z ∼ 3 than z ∼ 2.

  18. Review of lunar telescope studies at MSFC

    Science.gov (United States)

    Hilchey, John D.; Nein, Max E.

    1993-09-01

    In the near future astronomers can take advantage of the lunar surface as the new 'high ground' from which to study the universe. Optical telescopes placed and operated on the lunar surface would be successors to NASA's Great Observatories. Four telescopes, ranging in aperture from a 16-m, IR/Vis/UV observatory down to a 1-m, UV 'transit' instrument, have been studied by the Lunar Telescope Working Group and the LUTE (lunar telescope ultraviolet experiment) Task Team of the Marshall Space Flight Center (MSFC). This paper presents conceptual designs of the telescopes, provides descriptions of the telescope subsystem options selected for each concept, and outlines the potential evolution of their science capabilities.

  19. Ultraviolet sterilization

    International Nuclear Information System (INIS)

    Schenck, G.O.

    1987-01-01

    Artificial ultraviolet radiation sources can supply bactericidal energy in such a high dosage that in less than a second a higher degree of disinfection is accomplished than by sun irradiation in hours. Bacteria, viruses, phages, and organic micropollutants can be degraded by photochemical wet combustion down to and below detection limits of organic carbon. There are no known ultraviolet-resistant microorganisms. There are limitations to ultraviolet treatment which can often be overcome by adequate technical measures. Unlike other water purification processes, ultraviolet irradiation only exterminates living organisms. The radiation must be able to penetrate to the objects of the kill; in a dose large enough to kill, and long enough to kill and prevent new growth. Contrary to filters, ultraviolet flow-through reactors do not restrict free flow significantly. In contrast to distillation, ultraviolet irradiation imposes no phase changes to the water. Used as a sequence in ultrapure water systems, maintenance requirements are virtually nonexistent; because of the absence of dissolved and particulate matter in purified water, mechanical cleaning of the photoreactor chambers is not essential. The process is highly economical; energy consumption is low and supervision minimal. 103 refs., 45 figs., 15 tabs

  20. Ultraviolet observations of AM Herculis

    International Nuclear Information System (INIS)

    Tanzi, E.G.; Treves, A.; Milan Univ.; Sandford, M.C.W.; Willis, A.J.; Wilson, R.

    1980-01-01

    Seven ultraviolet spectra (1100-3200 Angstroem) of AM Her were obtained with the low resolution spectrometer of the IUE satellite. Strong emission features appear superimposed on a well defined continuum which is well fitted by a Fsub(lambda) D lambda -2 law. The observations are compared with the expectations from models of the source. (orig.) 891 WL/orig. 892 HIS

  1. Vacuum ultraviolet spectra from highly ionized oxygen

    International Nuclear Information System (INIS)

    Sjoedin, R.; Pihl, J.; Hallin, R.; Lindskog, J.; Marelius, A.; Sharma, K.

    1976-03-01

    Transitions in Li-like, He-like and H-like oxygen have been observed in the wavelength region 350-1150 A. A number of lines assigned as transitions in the doubly excited quartet system of O VI are reported. Lifetimes for the 4f 3 F term in O VII, 4f 2 F, 4d 2 D, 4p 2 P terms and for the 2s4f 4 F term in O VI have been measured to 13+-6 ps, 48+-3 ps, 29+-4 ps, 73+-8 ps and 47+-4 ps respectively. (Auth.)

  2. Ultraviolet spectra in the diffuse auroral region

    International Nuclear Information System (INIS)

    Ishimoto, M.; Meng, C.I.; Romick, G.J.; Huffman, R.E.

    1988-01-01

    Nadir-viewing UV spectral/photometric measurements taken aboard the S3-4 satellite at 270 km were used to study the energetics of incident electrons in the nighttime aurora. The results suggest that the average energy of incident electrons was 3 + or - 1 kev. It is also found that the intensity ratio of the LBH (3-10) to VK (0-5) emissions is a good indicator of the average energy flux of the incident electrons. 31 references

  3. Near infrared and ultraviolet spectra of TLEs

    Czech Academy of Sciences Publication Activity Database

    Gordillo-Vázquez, F.J.; Luque, A.; Šimek, Milan

    2012-01-01

    Roč. 117, č. 5 (2012), s. 1-7 ISSN 0148-0227 Institutional research plan: CEZ:AV0Z20430508 Keywords : sprites * halos * spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.174, year: 2012

  4. HST/STIS ULTRAVIOLET SPECTROSCOPY OF THE COMPONENTS OF THE MASSIVE TRIPLE STAR δ ORI A

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Noel D.; Moffat, Anthony F. J. [Département de physique and Centre de Recherche en Astrophysique du Québec (CRAQ), Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7 (Canada); Gull, Theodore R.; Lindler, Don J. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gies, Douglas R. [Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 5060, Atlanta, GA 30302-5060 (United States); Corcoran, Michael F. [CRESST and X-ray Astrophysics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States); Chené, André-Nicolas, E-mail: richardson@astro.umontreal.ca, E-mail: moffat@astro.umontreal.ca, E-mail: theodore.r.gull@nasa.gov, E-mail: don.j.lindler@nasa.gov, E-mail: gies@chara.gsu.edu, E-mail: michael.f.corcoran@nasa.gov, E-mail: achene@gemini.edu [Gemini Observatory, Northern Operations Center, 670 North A’ohoku Place, Hilo, HI 96720 (United States)

    2015-07-20

    The multiple star system of δ Orionis is one of the closest examples of a system containing a luminous O-type, bright giant star (component Aa1). It is often used as a spectral-type standard and has the highest observed X-ray flux of any hot-star binary. The main component Aa1 is orbited by two lower mass stars, faint Aa2 in a 5.7 day eclipsing binary, and Ab, an astrometric companion with an estimated period of 346 years. Generally the flux from all three stars is recorded in ground-based spectroscopy, and the spectral decomposition of the components has proved difficult. Here we present Hubble Space Telescope/Space Telescope Imaging Spectrograph ultraviolet spectroscopy of δ Ori A that provides us with spatially separated spectra of Aa and Ab for the first time. We measured radial velocities for Aa1 and Ab in two observations made near the velocity extrema of Aa1. We show tentative evidence for the detection of the Aa2 component in cross-correlation functions of the observed and model spectra. We discuss the appearance of the UV spectra of Aa1 and Ab with reference to model spectra. Both stars have similar effective temperatures, but Ab is fainter and is a rapid rotator. The results will help in the interpretation of ground-based spectroscopy and in understanding the physical and evolutionary parameters of these massive stars.

  5. Performance of The Far Ultraviolet Spectroscopic Explorer Mirror Assemblies

    Science.gov (United States)

    Ohi, Raymond G.; Barkhouser, Robert H.; Conard, Steven J.; Friedman, Scott D.; Hampton, Jeffery; Moos, H. Warren; Nikulla, Paul; Oliveira, Cristina M.; Saha, Timo T.; Obenschain, Arthur (Technical Monitor)

    2000-01-01

    The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5-118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four coaligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 x 387 mm aperture and 2245 mm focal length and are attached to actuator assemblies, which provide on-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-flight optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-flight laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50 percent and 95 percent slit transmission for the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The far-ultraviolet reflectivity of the SiC- and AlLiF-coated mirrors decreased about six percent and three percent, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects.

  6. Comparison of wavefront control algorithms and first results on the high-contrast imager for complex aperture telescopes (hicat) testbed

    Science.gov (United States)

    Leboulleux, L.; N'Diaye, M.; Mazoyer, J.; Pueyo, L.; Perrin, M.; Egron, S.; Choquet, E.; Sauvage, J.-F.; Fusco, T.; Soummer, R.

    2017-09-01

    The next generation of space telescopes for direct imaging and spectroscopy of exoplanets includes telescopes with a monolithic mirror, such as the Wide Field Infrared Survey Telescope (WFIRST) [1] and Large Ultra-Violet Optical Infrared (LUVOIR) telescopes with segmented primary mirror, like ATLAST [2, 3] or HDST [4].

  7. Neutrino Telescope

    International Nuclear Information System (INIS)

    Coelin Baldo, Milla

    2009-01-01

    The present volume contains the proceedings of the 13. International Workshop on 'Neutrino Telescope', 17. of the series 'Un altro modo di guardare il cielo', held in Venice at the 'Istituto Veneto di Scienze, Lettere ed Arti' from March 10 to March 13, 2009. This series started in Venice 21 years ago, in 1988, motivated by the growing interest in the exciting field of the neutrino physics and astrophysics, with the aim to bring together experimentalists and theorists and encourage discussion on the most recent results and to chart the direction of future researchers.

  8. Combined ultraviolet studies of astronomical sources

    Science.gov (United States)

    Baliunas, S. L.; Dupree, A. K.; Elvis, M.; Huchra, J. P.; Kenyon, S.; Raymond, J. C.

    1986-01-01

    Topics addressed include: Cygnus Loop; P Cygni profiles in dwarf novae; YY Gem; nova shells; HZ Herculis; activity cycles in cluster giants; Alpha Ori; metal deficient giant stars; ultraviolet spectra of symbiotic stars detected by the Very Large Array; time variability in symbiotic stars; blue galaxies; and quasistellar objects with X-ray spectra.

  9. FAR-ULTRAVIOLET SPECTROSCOPY OF THE NOVA-LIKE VARIABLE KQ MONOCEROTIS: A NEW SW SEXTANTIS STAR?

    International Nuclear Information System (INIS)

    Wolfe, Aaron; Sion, Edward M.; Bond, Howard E.

    2013-01-01

    New optical spectra obtained with the SMARTS 1.5 m telescope and archival International Ultraviolet Explorer (IUE) far-ultraviolet (FUV) spectra of the nova-like variable KQ Mon are discussed. The optical spectra reveal Balmer lines in absorption as well as He I absorption superposed on a blue continuum. The 2011 optical spectrum is similar to the KPNO 2.1 m IIDS spectrum we obtained 33 years earlier except that the Balmer and He I absorption is stronger in 2011. Far-ultraviolet IUE spectra reveal deep absorption lines due to C II, Si III, Si IV, C IV, and He II, but no P Cygni profiles indicative of wind outflow. We present the results of the first synthetic spectral analysis of the IUE archival spectra of KQ Mon with realistic optically thick, steady-state, viscous accretion-disk models with vertical structure and high-gravity photosphere models. We find that the photosphere of the white dwarf (WD) contributes very little FUV flux to the spectrum and is overwhelmed by the accretion light of a steady disk. Disk models corresponding to a WD mass of ∼0.6 M ☉ , with an accretion rate of order 10 –9 M ☉ yr –1 and disk inclinations between 60° and 75°, yield distances from the normalization in the range of 144-165 pc. KQ Mon is discussed with respect to other nova-like variables. Its spectroscopic similarity to the FUV spectra of three definite SW Sex stars suggests that it is likely a member of the SW Sex class and lends support to the possibility that the WD is magnetic.

  10. Ultraviolet-radiation-curable paints

    Energy Technology Data Exchange (ETDEWEB)

    Grosset, A M; Su, W F.A.; Vanderglas, E

    1981-09-30

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

  11. Ultraviolet photoelectron spectroscopy of transient species

    International Nuclear Information System (INIS)

    Leeuw, D.M. de.

    1979-01-01

    Transient species are studied in the isolation of the gas phase using ultraviolet photoelectron spectroscopy (PES). A description of the equipment used and a discussion of some theoretical topics, which play a role in the interpretation of PE spectra, are given. Koopmans' theorem, Hartree-Fock-Slater (HFS) calculations and the sum rule are discussed. A versatile ultraviolet PE spectrometer, designed specifically for this purpose, has been built and the construction and performance of this instrument are described. (Auth.)

  12. Solar ultraviolet hazards

    International Nuclear Information System (INIS)

    Azmah Ali

    1995-01-01

    The paper discussed the following subjects: the sources of ultraviolet radiation, solar ultraviolet radiation definition, effects of over exposure to solar ultraviolet radiation, exposure limits and radiation protection of this radiation

  13. New infrared telescopic observation of Vesta

    Science.gov (United States)

    Palomba, E.; D'Aversa, E.; Sato, T.; Longobardo, A.; Aoki, S.; Sindoni, G.; Oliva, F.

    2017-09-01

    In this work we present new telescopic observations of the Vesta asteroid made at the Subaru Telescope by using the COMICS IR spectrometer. We were able to obtain 5 different observations in 5 day, at two different epochs. The obtained spectra do not exhibit Reststrahlen bands and show only weak features attributable to the Christiansen peak and to the transparency feature compatible with a fine grain size regolith.

  14. IUE's treasure-chest of the ultraviolet Universe

    Science.gov (United States)

    1997-11-01

    Sun and the Earth. IUEs long life also enabled it to observe rare and serendipitous events. The satellite was already more than sixteen years old when Comet Shoemaker-Levy 9 hit Jupiter in July 1994. The event was well anticipated, so IUE was able first to study Jupiter in a normal state, and then to see the changes in the ultraviolet spectra during and after the impacts of the comet fragments. The astronomers favourite satellite Operational and scientific statistics about IUE are remarkable. The satellites observations have resulted in more than 3600 scientific papers published by 3000 astronomers from 25 countries. In addition, about 500 doctoral theses using IUE data show the educational value of IUE in universities all over the world. Amateur astronomers have also shown a remarkable degree of interest in IUE results, which provide them with a valuable and important link between their activities and those of professional astronomers. "Although IUE never had the popular appeal of the Hubble Space Telescope, it was always the professional astronomers favourite satellite," remarks Willem Wamsteker, the Dutch astronomer who is ESA's project manager for IUE. "They could visit Villafranca or Goddard and supervise the operations, just as if they were at an observatory on the ground. Towards the end, they could make their observations remotely, without leaving their institutes. Historians of astronomy may well credit IUE with the big change in professional habits which made space observatories a tool, not just for a few hardware-minded specialists, but for all astronomers." The meeting in Sevilla will end on 14 November with a review of the prospects for new space missions for ultraviolet astronomy. The Hubble Space Telescope and some Space Shuttle missions offer limited opportunities for ultraviolet spectroscopy. So will ESA's XMM X-ray mission. The only confirmed mission fully dedicated to the ultraviolet region is NASA's FUSE spacecraft, due to be launched in the year

  15. Some aspects of vacuum ultraviolet radiation physics

    CERN Document Server

    Damany, Nicole; Vodar, Boris

    2013-01-01

    Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

  16. NEW OPTICAL/ULTRAVIOLET COUNTERPARTS AND THE SPECTRAL ENERGY DISTRIBUTIONS OF NEARBY, THERMALLY EMITTING, ISOLATED NEUTRON STARS

    International Nuclear Information System (INIS)

    Kaplan, D. L.; Kamble, A.; Van Kerkwijk, M. H.; Ho, W. C. G.

    2011-01-01

    We present Hubble Space Telescope optical and ultraviolet photometry for five nearby, thermally emitting neutron stars. With these measurements, all seven such objects have confirmed optical and ultraviolet counterparts. Combining our data with archival space-based photometry, we present spectral energy distributions for all sources and measure the 'optical excess': the factor by which the measured photometry exceeds that extrapolated from X-ray spectra. We find that the majority have optical and ultraviolet fluxes that are inconsistent with that expected from thermal (Rayleigh-Jeans) emission, exhibiting more flux at longer wavelengths. We also find that most objects have optical excesses between 5 and 12, but that one object (RX J2143.0+0654) exceeds the X-ray extrapolation by a factor of more than 50 at 5000 A, and that this is robust to uncertainties in the X-ray spectra and absorption. We consider explanations for this ranging from atmospheric effects, magnetospheric emission, and resonant scattering, but find that none is satisfactory.

  17. Ultraviolet spectrophotometry of three LINERs

    Science.gov (United States)

    Goodrich, R. W.; Keel, W. C.

    1986-01-01

    Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Comparison with the optical light profile of NGC 5005 indicates that the ultraviolet source is distributed spatially in the same manner as the optical starlight, probably indicating that the ultraviolet excess is due to a component of hot stars in the nucleus. These stars contribute detectable absorption features longward of 2500 A; together with optical data, the IUE spectra suggest a burst of star formation about 1 billion yr ago, with a lower rate continuing to produce a few OB stars. In NGC 4579, a point source contributing most of the ultraviolet excess is found that is much different than the optical light distribution. Furthermore, the ultraviolet to X-ray spectral index in NGC 4579 is 1.4, compatible with the UV to X-ray indices found for samples of Seyfert galaxies. This provides compelling evidence for the detection of the photoionizing continuum in NGC 4579 and draws the research fields of normal galaxies and active galactic nuclei closer together. The emission-line spectrum of NGC 4579 is compared with calculations from a photoionization code, CLOUDY, and several shock models. The photoionization code is found to give superior results, adding to the increasing weight of evidence that the LINER phenomenon is essentially a scaled-down version of the Seyfert phenomenon.

  18. Ultraviolet radiation

    International Nuclear Information System (INIS)

    Hawk, J.

    1986-01-01

    Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

  19. Further Development of Aperture: A Precise Extremely large Reflective Telescope Using Re-configurable Elements

    Data.gov (United States)

    National Aeronautics and Space Administration — One of the pressing needs for space ultraviolet-visible astronomy is a design to allow larger mirrors than the James Webb Space Telescope primary. The diameter of...

  20. Deployable reflector configurations. [for space telescope

    Science.gov (United States)

    Meinel, A. B.; Meinel, M. P.; Woolf, N. J.

    1983-01-01

    Both the theoretical reasons for considering a non-circular format for the Large Deployable Reflector, and a potentially realizable concept for such a device, are discussed. The optimum systems for diffraction limited telescopes with incoherent detection have either a single filled aperture, or two such apertures as an interferometer to synthesize a larger aperture. For a single aperture of limited area, a reflector in the form of a slot can be used to give increased angular resolution. It is shown how a 20 x 8 meter telescope can be configured to fit the Space Shuttle bay, and deployed with relatively simple operations. The relationship between the sunshield design and the inclination of the orbit is discussed. The possible use of the LDR as a basic module to permit the construction of supergiant space telescopes and interferometers both for IR/submm studies and for the entire ultraviolet through mm wave spectral region is discussed.

  1. The Ultraviolet Radiation Environment around M Dwarf Exoplanet Host Stars

    Science.gov (United States)

    France, Kevin; Froning, Cynthia S.; Linsky, Jeffrey L.; Roberge, Aki; Stocke, John T.; Tian, Feng; Bushinsky, Rachel; Desert, Jean-Michel; Mauas, Pablo; Mauas, Pablo; hide

    2013-01-01

    The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the ultraviolet spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No "UV-quiet" M dwarfs are observed. The bright stellar Lyman-alpha emission lines are reconstructed, and we find that the Lyman-alpha line fluxes comprise approximately 37%-75% of the total 1150-3100 A flux from most M dwarfs; approximately greater than 10(exp3) times the solar value. We develop an empirical scaling relation between Lyman-alpha and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Lyman-alpha. The intrinsic unreddened flux ratio is F(Lyman-alpha)/F(Mg II) = 10(exp3). The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O2 and O3, is shown to be approximately 0.5-3 for all M dwarfs in our sample, greather than 10(exp3) times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%.500% on 10(exp2)-10(exp3) s timescales. This effect should be taken

  2. THE ULTRAVIOLET RADIATION ENVIRONMENT AROUND M DWARF EXOPLANET HOST STARS

    Energy Technology Data Exchange (ETDEWEB)

    France, Kevin; Froning, Cynthia S.; Stocke, John T.; Bushinsky, Rachel [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Roberge, Aki [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Tian, Feng [Center for Earth System Sciences, Tsinghua University, Beijing 100084 (China); Desert, Jean-Michel [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Mauas, Pablo; Vieytes, Mariela [Instituto de Astronomsica del Espacio (CONICET-UBA), C.C. 67 Sucursal 28, 1428 Buenos Aires (Argentina); Walkowicz, Lucianne M., E-mail: kevin.france@colorado.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-02-15

    The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and production of potential biomarkers on Earth-like planets around these stars. At present, little observational or theoretical basis exists for understanding the ultraviolet spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both far-UV (FUV) and near-UV (NUV) wavelengths. The combined FUV+NUV spectra are publicly available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No 'UV-quiet' M dwarfs are observed. The bright stellar Ly{alpha} emission lines are reconstructed, and we find that the Ly{alpha} line fluxes comprise {approx}37%-75% of the total 1150-3100 A flux from most M dwarfs; {approx}>10{sup 3} times the solar value. We develop an empirical scaling relation between Ly{alpha} and Mg II emission, to be used when interstellar H I attenuation precludes the direct observation of Ly{alpha}. The intrinsic unreddened flux ratio is F(Ly{alpha})/F(Mg II) = 10 {+-} 3. The F(FUV)/F(NUV) flux ratio, a driver for abiotic production of the suggested biomarkers O{sub 2} and O{sub 3}, is shown to be {approx}0.5-3 for all M dwarfs in our sample, >10{sup 3} times the solar ratio. For the four stars with moderate signal-to-noise Cosmic Origins Spectrograph time-resolved spectra, we find UV emission line variability with amplitudes of 50%-500% on 10{sup 2}-10{sup 3} s timescales. This effect should be taken into account in future UV

  3. The Lockheed OSO-8 program. Task 2: Analysis of data from the high resolution ultraviolet spectrometer experiment. [carbon 4 and silicon 4 line and emission spectra from solar flares

    Science.gov (United States)

    Bruner, E. C., Jr.

    1980-01-01

    The complete set of C 4 time sequences generated by the University of Colorado high resolution ultraviolet spectrometer experiment on OSO-8 were examined in a comprehensive and systematic fashion. As a result a new limit is placed on the acoustic flux passing through the transition zone of the Sun's atmosphere. It is found to be three orders of magnitude too small to heat the corona, and is consistent with zero. In collaborative efforts, the properties of transient C 4 brightenings were examined in considerable detail.

  4. An Empirical Ultraviolet Iron Spectrum Template Applicable to Active Galaxies

    DEFF Research Database (Denmark)

    Vestergaard, Marianne; Wilkes, B. J.

    2001-01-01

    Iron emission is often a severe contaminant in optical-ultraviolet spectra of active galaxies. Its presence complicates emission line studies. A viable solution, already successfully applied at optical wavelengths, is to use an empirical iron emission template. We have generated FeII and Fe......III templates for ultraviolet active galaxy spectra based on HST archival 1100 - 3100 A spectra of IZw1. Their application allows fitting and subtraction of the iron emission in active galaxy spectra. This work has shown that in particular CIII] lambda 1909 can be heavily contaminated by other line emission...

  5. Ultraviolet luminosity density of the universe during the epoch of reionization.

    Science.gov (United States)

    Mitchell-Wynne, Ketron; Cooray, Asantha; Gong, Yan; Ashby, Matthew; Dolch, Timothy; Ferguson, Henry; Finkelstein, Steven; Grogin, Norman; Kocevski, Dale; Koekemoer, Anton; Primack, Joel; Smidt, Joseph

    2015-09-08

    The spatial fluctuations of the extragalactic background light trace the total emission from all stars and galaxies in the Universe. A multiwavelength study can be used to measure the integrated emission from first galaxies during reionization when the Universe was about 500 million years old. Here we report arcmin-scale spatial fluctuations in one of the deepest sky surveys with the Hubble Space Telescope in five wavebands between 0.6 and 1.6 μm. We model-fit the angular power spectra of intensity fluctuation measurements to find the ultraviolet luminosity density of galaxies at redshifts greater than 8 to be log ρ(UV) = 27.4(+0.2)(-1.2) ergs(-1) Hz(-1) Mpc(-3) (1σ). This level of integrated light emission allows for a significant surface density of fainter primeval galaxies that are below the point-source detection level in current surveys.

  6. Far-ultraviolet spectral changes of titanium dioxide with gold nanoparticles by ultraviolet and visible light

    Science.gov (United States)

    Tanabe, Ichiro; Kurawaki, Yuji

    2018-05-01

    Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤ 200 nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively.

  7. Virtual Telescope Alignment System

    Data.gov (United States)

    National Aeronautics and Space Administration — Next-generation space telescopes require two spacecraft to fly in a coordinated fashion in space forming a virtual telescope. Achieving and maintaining this precise...

  8. Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra; Synthese et purification de quelques alcoylphenanthrenes et presentation ds leurs spectres d'absorption infrarouge, ultraviolette, de resonance magnetique nucleaire et de masse

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, K. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-01-01

    We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [French] Nous avons realise la synthese: - du phenanthrene - de ses cinq derives monomethyles - de trois de ses derives dimethyles - de deux de ses derives trimethyles. Nous avons ensuite purifie ces produits ainsi qu'un certain nombre d'autres que nous avons obtenus de sources differentes. Nous avons pu atteindre, dans la plupart des cas, une purete egale ou superieure a 99,5 pour cent, chiffres determines par la spectrometrie de masse a basse tension. Enfin, nous avons enregistre les spectres infrarouges, ultraviolets, de resonance magnetique nucleaire et de masse de ces produits dont nous avons fait un atlas. (auteur)

  9. Extending Supernova Spectral Templates for Next Generation Space Telescope Observations

    Science.gov (United States)

    Roberts-Pierel, Justin; Rodney, Steven A.; Steven Rodney

    2018-01-01

    Widely used empirical supernova (SN) Spectral Energy Distributions (SEDs) have not historically extended meaningfully into the ultraviolet (UV), or the infrared (IR). However, both are critical for current and future aspects of SN research including UV spectra as probes of poorly understood SN Ia physical properties, and expanding our view of the universe with high-redshift James Webb Space Telescope (JWST) IR observations. We therefore present a comprehensive set of SN SED templates that have been extended into the UV and IR, as well as an open-source software package written in Python that enables a user to generate their own extrapolated SEDs. We have taken a sampling of core-collapse (CC) and Type Ia SNe to get a time-dependent distribution of UV and IR colors (U-B,r’-[JHK]), and then generated color curves are used to extrapolate SEDs into the UV and IR. The SED extrapolation process is now easily duplicated using a user’s own data and parameters via our open-source Python package: SNSEDextend. This work develops the tools necessary to explore the JWST’s ability to discriminate between CC and Type Ia SNe, as well as provides a repository of SN SEDs that will be invaluable to future JWST and WFIRST SN studies.

  10. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  11. Southern Fireworks above ESO Telescopes

    Science.gov (United States)

    1999-05-01

    New Insights from Observations of Mysterious Gamma-Ray Burst International teams of astronomers are now busy working on new and exciting data obtained during the last week with telescopes at the European Southern Observatory (ESO). Their object of study is the remnant of a mysterious cosmic explosion far out in space, first detected as a gigantic outburst of gamma rays on May 10. Gamma-Ray Bursters (GRBs) are brief flashes of very energetic radiation - they represent by far the most powerful type of explosion known in the Universe and their afterglow in optical light can be 10 million times brighter than the brightest supernovae [1]. The May 10 event ranks among the brightest one hundred of the over 2500 GRB's detected in the last decade. The new observations include detailed images and spectra from the VLT 8.2-m ANTU (UT1) telescope at Paranal, obtained at short notice during a special Target of Opportunity programme. This happened just over one month after that powerful telescope entered into regular service and demonstrates its great potential for exciting science. In particular, in an observational first, the VLT measured linear polarization of the light from the optical counterpart, indicating for the first time that synchrotron radiation is involved . It also determined a staggering distance of more than 7,000 million light-years to this GRB . The astronomers are optimistic that the extensive observations will help them to better understand the true nature of such a dramatic event and thus to bring them nearer to the solution of one of the greatest riddles of modern astrophysics. A prime example of international collaboration The present story is about important new results at the front-line of current research. At the same time, it is also a fine illustration of a successful collaboration among several international teams of astronomers and the very effective way modern science functions. It began on May 10, at 08:49 hrs Universal Time (UT), when the Burst

  12. Soft X-ray focusing Telescope aboard AstroSat

    DEFF Research Database (Denmark)

    Singh, K. P.; Dewangan, G. C.; Chandra, S.

    2017-01-01

    The Soft X-ray focusing Telescope (SXT) is a moderateresolution X-ray imaging spectrometer supplementing the ultraviolet and hard X-ray payloads for broadband studies of cosmic sources with AstroSat. Well suited for observing bright X-ray sources, SXT observations of nearby active galactic nuclei...

  13. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  14. Space telescopes capturing the rays of the electromagnetic spectrum

    CERN Document Server

    English, Neil

    2017-01-01

    Space telescopes are among humankind’s greatest scientific achievements of the last fifty years. This book describes the instruments themselves and what they were designed to discover about the Solar System and distant stars. Exactly how these telescopes were built and launched and the data they provided is explored. Only certain kinds of radiation can penetrate our planet's atmosphere, which limits what we can observe. But with space telescopes all this changed. We now have the means to "see" beyond Earth using ultraviolet, microwave, and infrared rays, X-rays and gamma rays. In this book we meet the pioneers and the telescopes that were built around their ideas. This book looks at space telescopes not simply chronologically but also in order of the electromagnetic spectrum, making it possible to understand better why they were made.

  15. Liverpool Telescope and Liverpool Telescope 2

    Science.gov (United States)

    Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Jermak, H.; Marchant, J. M.; Mottram, C. J.; Piascik, A.; Smith, R. J.

    2016-12-01

    The Liverpool Telescope is a fully robotic optical/near-infrared telescope with a 2-metre clear aperture, located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope is owned and operated by Liverpool John Moores University, with financial support from the UK's Science and Technology Facilities Council. The telescope began routine science operations in 2004 and is a common-user facility with time available through a variety of committees via an open, peer reviewed process. Seven simultaneously mounted instruments support a broad science programme, with a focus on transient follow-up and other time domain topics well suited to the characteristics of robotic observing. Development has also begun on a successor facility, with the working title `Liverpool Telescope 2', to capitalise on the new era of time domain astronomy which will be brought about by the next generation of survey facilities such as LSST. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time. In this paper we provide an overview of the current status of both facilities.

  16. Ultraviolet Spectrophotometry of VV Cephei

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1992-06-01

    Full Text Available The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 3250 Å, 2550 Å and 2850 Å have been analyzed by the modified Wilson and Devinney light curve program. The radii of the B star and M star were deduced to 0.05 and 0.22 of unit separation, respectively. The UV light curves show an evidence that the light was attenuated by the highly opaque atomsphere of the M star.

  17. GESE: A Small UV Space Telescope to Conduct a Large Spectroscopic Survey of Z-1 Galaxies

    Science.gov (United States)

    Heap, Sara R.; Gong, Qian; Hull, Tony; Kruk, Jeffrey; Purves, Lloyd

    2013-01-01

    One of the key goals of NASA's astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z is approximately 1 (look-back time of approximately 8 billion years). GESE is a 1.5-meter space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2-0.4 micrometers at a spectral resolving power, R approximately 500. This observed spectral range corresponds to 0.1-0.2 micrometers as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next- Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.

  18. The great Melbourne telescope

    CERN Document Server

    Gillespie, Richard

    2011-01-01

    Erected at Melbourne Observatory in 1869, the telescope was the second largest in the world, designed to explore the nature of the nebulae in the southern skies. Richard Gillespie, head of the History and Technology department at the Melbourne museum has written an entertaining account of the telescope's extraordinary history and tells the story through an amazing cast of characters whose lives intersected with the telescope.

  19. SWIFT ULTRAVIOLET OBSERVATIONS OF SUPERNOVA 2014J IN M82: LARGE EXTINCTION FROM INTERSTELLAR DUST

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Peter J.; Smitka, Michael T.; Wang, Lifan; Krisciunas, Kevin [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Breeveld, Alice; Kuin, N. Paul; Page, Mat [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking Surrey, RH5 6NT (United Kingdom); De Pasquale, Massimiliano [Instituto di Astrofisica Spaziale e Fisica Cosmica di Palermo Via Ugo la Malfa 153 90146 Palermo (Italy); Hartmann, Dieter H. [Clemson University, Department of Physics and Astronomy, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Milne, Peter A. [Steward Observatory, University of Arizona, Tucson, AZ 85719 (United States); Siegel, Michael [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2015-05-20

    We present optical and ultraviolet (UV) photometry and spectra of the very nearby and highly reddened supernova (SN) 2014J in M82 obtained with the Swift Ultra-Violet/Optical Telescope (UVOT). Comparison of the UVOT grism spectra of SN 2014J with Hubble Space Telescope observations of SN2011fe or UVOT grism spectra of SN 2012fr are consistent with an extinction law with a low value of R{sub V} ∼1.4. The high reddening causes the detected photon distribution in the broadband UV filters to have a much longer effective wavelength than for an unreddened SN. The light curve evolution is consistent with this shift and does not show a flattening due to photons being scattered back into the line of sight (LOS). The light curve shapes and color evolution are inconsistent with a contribution scattered into the LOS by circumstellar dust. We conclude that most or all of the high reddening must come from interstellar dust. We show that even for a single dust composition, there is not a unique reddening law caused by circumstellar scattering. Rather, when considering scattering from a time-variable source, we confirm earlier studies that the reddening law is a function of the dust geometry, column density, and epoch. We also show how an assumed geometry of dust as a foreground sheet in mixed stellar/dust systems will lead to a higher inferred R{sub V}. Rather than assuming the dust around SNe is peculiar, SNe may be useful probes of the interstellar reddening laws in other galaxies.

  20. 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.

  1. Biological Action Spectra (invited paper)

    International Nuclear Information System (INIS)

    Gruijl, F.R. de

    2000-01-01

    Ultraviolet (UV) radiation induces a wide variety of biological responses: ranging in humans from well-known short-term effects like sunburn to long-term effects like skin cancer. The wavelength dependencies ('action spectra') of the responses can differ significantly, depending on the UV-targeted molecules (their absorption spectra), their localisation (transmission to the target depth) and the photochemical reactions involved (e.g. quantum yields, competing reaction). An action spectrum (e.g. of sunburn) is usually determined in a wavelength by wavelength analysis of the response. This is not always possible (e.g. in case of skin cancer), and an action spectrum may then be extracted mathematically from differences in responses to broadband UV sources of various spectral compositions (yielding 'biological spectral weights'). However, relative spectral weights may shift with exposure levels and contributions from different wavelengths may not always add up. Under these circumstances conventional analyses will yield different action spectra for different experimental conditions. (author)

  2. The ultraviolet variations of iota Cas

    Science.gov (United States)

    Molnar, M. R.; Mallama, A. D.; Soskey, D. G.; Holm, A. V.

    1976-01-01

    The Ap variable star iota Cas was observed with the photometers on OAO-2 covering the spectral range 1430-4250 A. The ultraviolet light curves show a double wave with primary minimum and maximum at phase ? 0.00 and 0.35, respectively. Secondary minimum light is at phase ? 0.65 with secondary maximum at phase ? 0.85. The light curves longward of 3150 A vary in opposition to those shortward of this 'null region'. Ground-based coude spectra show that the Fe II and Cr II line strengths have a double-wave variation such that maximum strength occurs at minimum ultraviolet light. We suggest that the strong ultraviolet opacities due to photoionization and line blanketing by these metals may cause the observed photometric variations. We have also constructed an oblique-rotator model which shows iron and chromium lying in a great circle band rather than in circular spots.

  3. Observing the Sun with Coronado telescopes telescopes

    CERN Document Server

    Pugh, Philip

    2007-01-01

    The Sun provides amateur astronomers with one of the few opportunities for daytime astronomy. In order to see the major features of our nearest star, special telescopes that have a very narrow visible bandwidth are essential. The bandwidth has to be as narrow as 1 A- 10-10 m (1 Angstrom) and centred on the absorption line of neutral hydrogen. This makes many major features of the Suna (TM)s chromosphere visible to the observer. Such narrow-band "Fabry-Perot etalon filters" are high technology, and until the introduction of the Coronado range of solar telescopes, were too expensive for amateur use. The entry-level Coronado telescope, the PST (Personal Solar Telescope) costs under 500. Solar prominences (vast columns of plasma, best seen at the edge of the solar disk), filaments, flares, sunspots, plage and active regions are all visible and can be imaged to produce spectacular solar photographs. Philip Pugh has assembled a team of contributors who show just how much solar work can be done with Coronado telesco...

  4. HARDERSEN IRTF ASTEROID NIR REFLECTANCE SPECTRA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset includes average near-infrared (NIR) reflectance spectra for 68 main-belt asteroids that were observed at the NASA Infrared Telescope Facility (IRTF),...

  5. Ghost telescope and ghost Fourier telescope with thermal light

    International Nuclear Information System (INIS)

    Gong Wenlin; Han Shensheng

    2011-01-01

    As important observation tools, telescopes are very useful in remote observations. We report a proof-of-principle experimental demonstration of ghost telescope scheme and show that, by measuring the intensity correlation of two light fields and only changing the position of the detector in the reference path, ghost telescope and ghost Fourier telescope can be obtained even if a single-pixel detector is fixed in Fresnel region of the object. Differences between conventional telescope and ghost telescope are also discussed.

  6. Ultraviolet Flux Variation of Epsilon Aurigae

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1990-06-01

    Full Text Available The eighteen ultraviolet light curves of Epsilon Aurigae have been plotted using the integrated fluxes reduced from the 233 IUE low dispersion spectra taken between 1978 and 1986. The times of contacts and depth of eclipse have been determined from the light curves at the wavelength from 2550 Å to 3050 Å. The UV light curves show two brightenings during the totality, the downward slope of the variation from the second to the third contacts, and asymmetry of the eclipse light curve. The two selected spectra note that the energy density distribution is not changed between the totality of the eclipse and out-of-eclipse.

  7. The large binocular telescope.

    Science.gov (United States)

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  8. HAZMAT. II. Ultraviolet Variability of Low-mass Stars in the GALEX Archive

    Energy Technology Data Exchange (ETDEWEB)

    Miles, Brittany E. [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Shkolnik, Evgenya L., E-mail: bmiles@ucsc.edu [School of Earth and Space Exploration, Arizona State University, 781 S Terrace Road, Tempe, AZ 85281 (United States)

    2017-08-01

    The ultraviolet (UV) light from a host star influences a planet’s atmospheric photochemistry and will affect interpretations of exoplanetary spectra from future missions like the James Webb Space Telescope . These effects will be particularly critical in the study of planetary atmospheres around M dwarfs, including Earth-sized planets in the habitable zone. Given the higher activity levels of M dwarfs compared to Sun-like stars, time-resolved UV data are needed for more accurate input conditions for exoplanet atmospheric modeling. The Galaxy Evolution Explorer ( GALEX ) provides multi-epoch photometric observations in two UV bands: near-ultraviolet (NUV; 1771–2831 Å) and far-ultraviolet (FUV; 1344–1786 Å). Within 30 pc of Earth, there are 357 and 303 M dwarfs in the NUV and FUV bands, respectively, with multiple GALEX observations. Simultaneous NUV and FUV detections exist for 145 stars in both GALEX bands. Our analyses of these data show that low-mass stars are typically more variable in the FUV than the NUV. Median variability increases with later spectral types in the NUV with no clear trend in the FUV. We find evidence that flares increase the FUV flux density far more than the NUV flux density, leading to variable FUV to NUV flux density ratios in the GALEX bandpasses.The ratio of FUV to NUV flux is important for interpreting the presence of atmospheric molecules in planetary atmospheres such as oxygen and methane as a high FUV to NUV ratio may cause false-positive biosignature detections. This ratio of flux density in the GALEX bands spans three orders of magnitude in our sample, from 0.008 to 4.6, and is 1 to 2 orders of magnitude higher than for G dwarfs like the Sun. These results characterize the UV behavior for the largest set of low-mass stars to date.

  9. Tips for deciphering and quick calculation of radiation spectra

    Science.gov (United States)

    Bondarenco, M. V.

    2018-04-01

    Radiation spectra from ultra-relativistic electrons in thin [Tll lf(ω)] and thick [Tgg lf(ω)] targets are discussed. The method of simplified averaging is described by examples of Landau-Pomeranchuk-Migdal effect and radiation at doughnut scattering. General infrared and ultraviolet asymptotic properties of radiation spectra are discussed.

  10. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    Science.gov (United States)

    1999-11-01

    Hubble's success is the advantage of being in orbit, beyond the Earth's atmosphere. From there it enjoys a crystal-clear view of the universe - without clouds and atmospheric disturbances to blur its vision. European astronomer Guido De Marchi from ESO in Munich has been using Hubble since the early days of the project. He explains: "HST can see the faintest and smallest details and lets us study the stars with great accuracy, even where they are packed together - just as with those in the centre of our Galaxy". Dieter Reimers from Hamburg Observatory adds: "HST has capabilities to see ultraviolet light, which is not possible from the ground due to the blocking effect of the atmosphere. And this is really vital to our work, the main aim of which is to discover the chemical composition of the Universe." The Servicing Missions In the early plans for telescope operations, maintenance visits were to have been made every 2.5 years. And every five years HST should have been transported back to the ground for thorough overhaul. This plan has changed somewhat over time and a servicing scheme, which includes Space Shuttle Servicing Missions every three years, was decided upon. The two first Servicing Missions, in December 1993 (STS-61) and February 1997 (STS-82) respectively, were very successful. In the first three years of operations HST did not meet expectations because its primary mirror was 2 microns too flat at the edge. The first Servicing Mission in 1993 (on which the European astronaut Claude Nicollier flew) dealt with this problem by installing a new instrument with corrective optics (COSTAR - Corrective Optics Space Telescope Axial Replacement). With this pair of "glasses" HST's golden age began. The images were as sharp as originally hoped and astonishing new results started to emerge on a regular basis. The first Servicing Mission also replaced the solar panels and installed a new camera (Wide Field and Planetary Camera 2 - WFPC2). The High-Speed Photometer (HSP) was

  11. Goddard Robotic Telescope (GRT)

    Data.gov (United States)

    National Aeronautics and Space Administration — Since it is not possible to predict when a Gamma-Ray Burst (GRB) occurs, the follow-up ground telescopes must be distributed as uniform as possible all over the...

  12. THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

    International Nuclear Information System (INIS)

    Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A.

    2011-01-01

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 ≤ z ≤ 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame ∼0.1-5 μm spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

  13. THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Ryan A.; Shemmer, Ohad [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States); Fan Xiaohui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam (Netherlands); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Strauss, Michael A., E-mail: RyanLane@my.unt.edu, E-mail: ohad@unt.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

    2011-12-20

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 {<=} z {<=} 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame {approx}0.1-5 {mu}m spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

  14. Automatic Photoelectric Telescope Service

    International Nuclear Information System (INIS)

    Genet, R.M.; Boyd, L.J.; Kissell, K.E.; Crawford, D.L.; Hall, D.S.; BDM Corp., McLean, VA; Kitt Peak National Observatory, Tucson, AZ; Dyer Observatory, Nashville, TN)

    1987-01-01

    Automatic observatories have the potential of gathering sizable amounts of high-quality astronomical data at low cost. The Automatic Photoelectric Telescope Service (APT Service) has realized this potential and is routinely making photometric observations of a large number of variable stars. However, without observers to provide on-site monitoring, it was necessary to incorporate special quality checks into the operation of the APT Service at its multiple automatic telescope installation on Mount Hopkins. 18 references

  15. Plans for the extreme ultraviolet explorer data base

    Science.gov (United States)

    Marshall, Herman L.; Dobson, Carl A.; Malina, Roger F.; Bowyer, Stuart

    1988-01-01

    The paper presents an approach for storage and fast access to data that will be obtained by the Extreme Ultraviolet Explorer (EUVE), a satellite payload scheduled for launch in 1991. The EUVE telescopes will be operated remotely from the EUVE Science Operation Center (SOC) located at the University of California, Berkeley. The EUVE science payload consists of three scanning telescope carrying out an all-sky survey in the 80-800 A spectral region and a Deep Survey/Spectrometer telescope performing a deep survey in the 80-250 A spectral region. Guest Observers will remotely access the EUVE spectrometer database at the SOC. The EUVE database will consist of about 2 X 10 to the 10th bytes of information in a very compact form, very similar to the raw telemetry data. A history file will be built concurrently giving telescope parameters, command history, attitude summaries, engineering summaries, anomalous events, and ephemeris summaries.

  16. Photodetector of ultraviolet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

    2000-01-01

    The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

  17. Sensitivity Calibration of Far-Ultraviolet Imaging Spectrograph

    Directory of Open Access Journals (Sweden)

    I. -J. Kim

    2004-12-01

    Full Text Available We describe the in-flight sensitivity calibration of the Far ultraviolet Imaging Spectrograph (FIMS, also known as SPEAR onboard the first Korean science satellite, STSAT-1, which was launched in September 2003. The sensitivity calibration is based on a comparison of the FIMS observations of the hot white dwarf G191B2B, and two O-type stars Alpha-Cam, HD93521 with the HUT (Hopkins Ultraviolet Telescope observations. The FIMS observations for the calibration targets have been conducted from November 2003 through May 2004. The effective areas calculated from the targets are compared with each other.

  18. The Swift Ultra-Violet/Optical Telescope

    International Nuclear Information System (INIS)

    Roming, Peter; Hunsberger, S.D.; Nousek, John; Mason, Keith

    2001-01-01

    The Ultra-Violet/Optical Telescope (UVOT) provides the Swift Gamma-Ray Burst Explorer with the capability of quickly detecting and characterizing the optical and ultraviolet properties of gamma ray burst counterparts. The UVOT design is based on the design of the Optical Monitor on XMM-Newton. It is a Ritchey-Chretien telescope with microchannel plate intensified charged-coupled devices (MICs) that deliver sub-arcsecond imaging. These MICs are photon-counting devices, capable of detecting low intensity signal levels. When flown above the atmosphere, the UVOT will have the sensitivity of a 4m ground based telescope, attaining a limiting magnitude of 24 for a 1000 second observation in the white light filter. A rotating filter wheel allows sensitive photometry in six bands spanning the UV and visible, which will provide photometric redshifts of objects in the 1-3.5z range. For bright counterparts, such as the 9th magnitude GRB990123, or for fainter objects down to 17th magnitude, two grisms provide low-resolution spectroscopy

  19. The Ultraviolet Albedo of Ganymede

    Science.gov (United States)

    McGrath, Melissa; Hendrix, A.

    2013-10-01

    A large set of ultraviolet images of Ganymede have been acquired with the Hubble Space Telescope over the last 15 years. These images have been used almost exclusively to study Ganymede’s stunning auroral emissions (Feldman et al. 2000; Eviatar et al. 2001; McGrath et al. 2004; Saur et al. 2011; McGrath et al. 2013), and even the most basic information about Ganymede’s UV albedo has yet to be gleaned from these data. We will present a first-cut analysis of both disk-averaged and spatially-resolved UV albedos of Ganymede, with focus on the spatially-resolved Lyman-alpha albedo, which has never been considered previously for this satellite. Ganymede's visibly bright regions are known to be rich in water ice, while the visibly dark regions seem to be more carbonaceous (Carlson et al., 1996). At Lyman-alpha, these two species should also have very different albedo values. References Carlson, R. and 39 co-authors, Near-infrared spectroscopy and spectral mapping of Jupiter and the Galilean satellites: Results from Galileo’s initial orbit, Science, 274, 385-388, 1996. Eviatar, A., D. F. Strobel, B. C. Wolven, P. D. Feldman, M. A. McGrath, and D. J. Williams, Excitation of the Ganymede ultraviolet aurora, Astrophys. J, 555, 1013-1019, 2001. Feldman, P. D., M. A. McGrath, D. F. Strobel, H. W. Moos, K. D. Retherford, and B. C. Wolven, HST/STIS imaging of ultraviolet aurora on Ganymede, Astrophys. J, 535, 1085-1090, 2000. McGrath M. A., Lellouch E., Strobel D. F., Feldman P. D., Johnson R. E., Satellite Atmospheres, Chapter 19 in Jupiter: The Planet, Satellites and Magnetosphere, ed. F. Bagenal, T. Dowling, W. McKinnon, Cambridge University Press, 2004. McGrath M. A., Jia, Xianzhe; Retherford, Kurt; Feldman, Paul D.; Strobel, Darrell F.; Saur, Joachim, Aurora on Ganymede, J. Geophys. Res., doi: 10.1002/jgra.50122, 2013. Saur, J., S. Duling, S., L. Roth, P. D. Feldman, D. F. Strobel, K. D. Retherford, M. A. McGrath, A. Wennmacher, American Geophysical Union, Fall Meeting

  20. Robotic and Survey Telescopes

    Science.gov (United States)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  1. The South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  2. GESE: a small UV space telescope to conduct a large spectroscopic survey of z˜1 Galaxies

    Science.gov (United States)

    Heap, Sara R.; Gong, Qian; Hull, Tony; Kruk, Jeffrey; Purves, Lloyd

    2014-11-01

    One of the key goals of NASA's astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z˜1 (look-back time of ˜8 billion years). GESE is a 1.5-m space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2-0.4 μm at a spectral resolving power, R˜500. This observed spectral range corresponds to 0.1-0.2 μm as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next-Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.

  3. Constraints on water vapor and sulfur dioxide at Ceres: Exploiting the sensitivity of the Hubble Space Telescope

    Science.gov (United States)

    Roth, Lorenz

    2018-05-01

    Far-ultraviolet observations of dwarf-planet (1) Ceres were obtained on several occasions in 2015 and 2016 by the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS), both on board the Hubble Space Telescope (HST). We report a search for neutral gas emissions at hydrogen, oxygen and sulfur lines around Ceres from a potential teneous exosphere. No detectable exosphere emissions are present in any of the analyzed HST observations. We apply analytical models to relate the derived upper limits for the atomic species to a water exosphere (for H and O) and a sulfur dioxide exosphere (for S and O), respectively. The H and O upper limits constrain the H2O production rate at the surface to (2 - 4) ×1026 molecules s-1 or lower, similar to or slightly larger than previous detections and upper limits. With low fluxes of energetic protons measured in the solar wind prior to the HST observations and the obtained non-detections, an assessment of the recently suggested sputter-generated water exosphere during solar energetic particle events is not possible. Investigating a sulfur dioxide-based exosphere, we find that the O and S upper limits constrain the SO2 density at the surface to values ∼ 1010 times lower than the equilibrium vapor pressure density. This result implies that SO2 is not present on Ceres' sunlit surface, contrary to previous findings in HST ultraviolet reflectance spectra but in agreement with the absence of SO2 infrared spectral features as observed by the Dawn spacecraft.

  4. Telescopes and Techniques

    CERN Document Server

    Kitchin, C R

    2013-01-01

    Telescopes and Techniques has proved itself in its first two editions, having become probably one of the most widely used astronomy texts, both for amateur astronomers and astronomy and astrophysics undergraduates. Both earlier editions of the book were widely used for introductory practical astronomy courses in many universities. In this Third Edition the author guides the reader through the mathematics, physics and practical techniques needed to use today's telescopes (from the smaller models to the larger instruments installed in many colleges) and how to find objects in the sky. Most of the physics and engineering involved is described fully and requires little prior knowledge or experience. Both visual and electronic imaging techniques are covered, together with an introduction to how data (measurements) should be processed and analyzed. A simple introduction to radio telescopes is also included. Brief coverage of the more advanced topics of photometry and spectroscopy are included, but mainly to enable ...

  5. Amateur Telescope Making

    Science.gov (United States)

    Tonkin, Stephen

    Many amateur astronomers make their own instruments, either because of financial considerations or because they are just interested. Amateur Telescope Making offers a variety of designs for telescopes, mounts and drives which are suitable for the home-constructor. The designs range from simple to advanced, but all are within the range of a moderately well-equipped home workshop. The book not only tells the reader what he can construct, but also what it is sensible to construct given what time is available commercially. Thus each chapter begins with reasons for undertaking the project, then looks at theoretical consideration before finishing with practical instructions and advice. An indication is given as to the skills required for the various projects. Appendices list reputable sources of (mail order) materials and components. The telescopes and mounts range from "shoestring" (very cheap) instruments to specialist devices that are unavailable commercially.

  6. HUBBLE SPACE TELESCOPE AND GROUND-BASED OBSERVATIONS OF V455 ANDROMEDAE POST-OUTBURST

    Energy Technology Data Exchange (ETDEWEB)

    Szkody, Paula; Mukadam, Anjum S.; Brown, Justin; Funkhouser, Kelsey [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Gänsicke, Boris T. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Henden, Arne [AAVSO, 49 Bay State Road, Cambridge, MA 02138 (United States); Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Townsley, Dean M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Christian, Damian [Department of Physics and Astronomy, California State University, Northridge, CA 91330 (United States); Falcon, Ross E. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Pyrzas, Stylianos, E-mail: szkody@astro.washington.edu, E-mail: anjum@astro.washington.edu, E-mail: boris.gaensicke@warwick.ac.uk, E-mail: arne@aavso.org, E-mail: edward.sion@villanova.edu, E-mail: Dean.M.Townsley@ua.edu, E-mail: damian.christian@csun.edu, E-mail: cylver@astro.as.utexas.edu, E-mail: stylianos.pyrzas@gmail.com [Instituto de Astronomia, Universidad Catolica del Norte, Avenida Angamos 0619, Antofagasta (Chile)

    2013-09-20

    Hubble Space Telescope spectra obtained in 2010 and 2011, 3 and 4 yr after the large amplitude dwarf nova outburst of V455 And, were combined with optical photometry and spectra to study the cooling of the white dwarf, its spin, and possible pulsation periods after the outburst. The modeling of the ultraviolet (UV) spectra shows that the white dwarf temperature remains ∼600 K hotter than its quiescent value at 3 yr post-outburst, and still a few hundred degrees hotter at 4 yr post-outburst. The white dwarf spin at 67.6 s and its second harmonic at 33.8 s are visible in the optical within a month of outburst and are obvious in the later UV observations in the shortest wavelength continuum and the UV emission lines, indicating an origin in high-temperature regions near the accretion curtains. The UV light curves folded on the spin period show a double-humped modulation consistent with two-pole accretion. The optical photometry 2 yr after outburst shows a group of frequencies present at shorter periods (250-263 s) than the periods ascribed to pulsation at quiescence, and these gradually shift toward the quiescent frequencies (300-360 s) as time progresses past outburst. The most surprising result is that the frequencies near this period in the UV data are only prominent in the emission lines, not the UV continuum, implying an origin away from the white dwarf photosphere. Thus, the connection of this group of periods with non-radial pulsations of the white dwarf remains elusive.

  7. A New Test of Copper and Zinc Abundances in Late-type Stars Using Ultraviolet Cu II and Zn II Lines

    Science.gov (United States)

    Roederer, Ian U.; Barklem, Paul S.

    2018-04-01

    We present new abundances derived from Cu I, Cu II, Zn I, and Zn II lines in six warm (5766 ≤ {T}eff} ≤ 6427 K), metal-poor (‑2.50 ≤ [Fe/H] ≤ ‑0.95) dwarf and subgiant (3.64 ≤ log g ≤ 4.44) stars. These abundances are derived from archival high-resolution ultraviolet spectra from the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope and ground-based optical spectra from several observatories. Ionized Cu and Zn are the majority species, and abundances derived from Cu II and Zn II lines should be largely insensitive to departures from local thermodynamic equilibrium (LTE). We find good agreement between the [Zn/H] ratios derived separately from Zn I and Zn II lines, suggesting that departures from LTE are, at most, minimal (≲0.1 dex). We find that the [Cu/H] ratios derived from Cu II lines are 0.36 ± 0.06 dex larger than those derived from Cu I lines in the most metal-poor stars ([Fe/H] McDonald Observatory of the University of Texas at Austin.

  8. On hot and cool stars, spectroscopic investigations in the ultraviolet

    International Nuclear Information System (INIS)

    Hucht, K.A. van der.

    1978-01-01

    Measured ultraviolet stellar spectra are compared with theoretically synthesised spectra. Three A-type and some B-type stars have been observed. The expanding outer layers of cool giants and supergiants are dealt with. K-type and M-type stars are discussed. The problem of the continuous energy distribution of Wolf-Tayet stars derived from observations is considered. (C.F.)

  9. The Dual-channel Extreme Ultraviolet Continuum Experiment: Sounding Rocket EUV Observations of Local B Stars to Determine Their Potential for Supplying Intergalactic Ionizing Radiation

    Science.gov (United States)

    Erickson, Nicholas; Green, James C.; France, Kevin; Stocke, John T.; Nell, Nicholas

    2018-06-01

    We describe the scientific motivation and technical development of the Dual-channel Extreme Ultraviolet Continuum Experiment (DEUCE). DEUCE is a sounding rocket payload designed to obtain the first flux-calibrated spectra of two nearby B stars in the EUV 650-1150Å bandpass. This measurement will help in understanding the ionizing flux output of hot B stars, calibrating stellar models and commenting on the potential contribution of such stars to reionization. DEUCE consists of a grazing incidence Wolter II telescope, a normal incidence holographic grating, and the largest (8” x 8”) microchannel plate detector ever flown in space, covering the 650-1150Å band in medium and low resolution channels. DEUCE will launch on December 1, 2018 as NASA/CU sounding rocket mission 36.331 UG, observing Epsilon Canis Majoris, a B2 II star.

  10. Neutron spectrometry with a monolithic silicon telescope.

    Science.gov (United States)

    Agosteo, S; D'Angelo, G; Fazzi, A; Para, A Foglio; Pola, A; Zotto, P

    2007-01-01

    A neutron spectrometer was set-up by coupling a polyethylene converter with a monolithic silicon telescope, consisting of a DeltaE and an E stage-detector (about 2 and 500 microm thick, respectively). The detection system was irradiated with monoenergetic neutrons at INFN-Laboratori Nazionali di Legnaro (Legnaro, Italy). The maximum detectable energy, imposed by the thickness of the E stage, is about 8 MeV for the present detector. The scatter plots of the energy deposited in the two stages were acquired using two independent electronic chains. The distributions of the recoil-protons are well-discriminated from those due to secondary electrons for energies above 0.350 MeV. The experimental spectra of the recoil-protons were compared with the results of Monte Carlo simulations using the FLUKA code. An analytical model that takes into account the geometrical structure of the silicon telescope was developed, validated and implemented in an unfolding code. The capability of reproducing continuous neutron spectra was investigated by irradiating the detector with neutrons from a thick beryllium target bombarded with protons. The measured spectra were compared with data taken from the literature. Satisfactory agreement was found.

  11. A search for thermal extreme ultraviolet radiation from nearby pulsars

    International Nuclear Information System (INIS)

    Greenstein, G.; Margon, B.

    1977-01-01

    We present the first extreme ultraviolet (100-1000 A) observations of radio pulsars. Using an EUV telescope carried aboard the Apollo-Soyuz mission, data were acquired on the nearby pulsars PSR 1133 + 16, 1451 - 68 and 1929 + 10. The data are interpreted to set limits on the effective temperatures of the neutron stars, yielding T 5 K in the best cases, and the limits compared with theoretical predictions. (orig./BJ) [de

  12. Exploring Galileo's Telescope

    Science.gov (United States)

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  13. Taiwan Automated Telescope Network

    Directory of Open Access Journals (Sweden)

    Dean-Yi Chou

    2010-01-01

    can be operated either interactively or fully automatically. In the interactive mode, it can be controlled through the Internet. In the fully automatic mode, the telescope operates with preset parameters without any human care, including taking dark frames and flat frames. The network can also be used for studies that require continuous observations for selected objects.

  14. The Falcon Telescope Network

    Science.gov (United States)

    Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

    2014-09-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

  15. Deuterium abundance, from ultraviolet to visible

    International Nuclear Information System (INIS)

    Hebrard, Guillaume

    2000-01-01

    In the frame of the standard Big Bang model, the primordial abundance of deuterium is the most sensitive to the baryonic density of the Universe. It was synthesized only during the primordial nucleosynthesis few minutes after the Big Bang and no other standard mechanism is able to produce any further significant amount. On the contrary, since deuterium is burned up within stars, its abundance D/H decreases along cosmic evolution. Thus, D/H measurements constrain Big Bang and galactic chemical evolution models. There are three samples of deuterium abundances: primordial, proto-solar and interstellar. Each of them is representative of a given epoch, respectively about 15 Gyrs past, 4.5 Gyrs past and present epoch. Although the evolution of the deuterium abundance seems to be qualitatively understood, the measurements show some dispersion. Present thesis works are linked to deuterium interstellar abundance measurements. Such measurements are classically obtained from spectroscopic observations of the hydrogen and deuterium Lyman series in absorption in the ultraviolet spectral range, using space observatories. Results presented here were obtained with the Hubble Space Telescope and FUSE, which has recently been launched. Simultaneously, a new way to observe deuterium has been proposed, in the visible spectral range from ground-based telescopes. This has led to the first detections and the identification of the deuterium Balmer series, in emission in HII regions, using CFHT and VLT telescopes. (author) [fr

  16. Algorithms for classification of astronomical object spectra

    Science.gov (United States)

    Wasiewicz, P.; Szuppe, J.; Hryniewicz, K.

    2015-09-01

    Obtaining interesting celestial objects from tens of thousands or even millions of recorded optical-ultraviolet spectra depends not only on the data quality but also on the accuracy of spectra decomposition. Additionally rapidly growing data volumes demands higher computing power and/or more efficient algorithms implementations. In this paper we speed up the process of substracting iron transitions and fitting Gaussian functions to emission peaks utilising C++ and OpenCL methods together with the NOSQL database. In this paper we implemented typical astronomical methods of detecting peaks in comparison to our previous hybrid methods implemented with CUDA.

  17. Extragalactic observations with the MAGIC telescopes

    International Nuclear Information System (INIS)

    Shore, S.N.

    2014-01-01

    The MAGIC imaging atmospheric Cherenkov telescopes, both as a single detector and now used in stereo mode, have been observing a variety of active galaxies and galactic clusters for almost a decade. This review provides a brief summary of some of the most recent results for blazars observed in the energy range > 50 GeV to tens of TeV. The very high energy emission observed with MAGIC is essential for disentangling the various contributions and timescales to the observed spectra and variability. (author)

  18. HUBBLE SPACE TELESCOPE CONSTRAINTS ON THE WINDS AND ASTROSPHERES OF RED GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Brian E. [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States); Müller, Hans-Reinhard [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Harper, Graham M., E-mail: brian.wood@nrl.navy.mil [CASA, University of Colorado, Boulder, CO 80309-0389 (United States)

    2016-10-01

    We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope , focusing on spectra of the Mg ii h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are noncoronal, but possessing strong, chromospheric winds. We find a very tight relation between Mg ii surface flux and photospheric temperature, supporting the notion that all K2-M5 III stars are emitting at a basal flux level. Wind velocities ( V {sub w} ) are generally found to decrease with spectral type, with V {sub w} decreasing from ∼40 km s{sup −1} at K2 III to ∼20 km s{sup −1} at M5 III. We find two new detections of astrospheric absorption, for σ Pup (K5 III) and γ Eri (M1 III). This absorption signature had previously only been detected for α Tau (K5 III). For the three astrospheric detections, the temperature of the wind after the termination shock (TS) correlates with V {sub w} , but is lower than predicted by the Rankine–Hugoniot shock jump conditions, consistent with the idea that red giant TSs are radiative shocks rather than simple hydrodynamic shocks. A full hydrodynamic simulation of the γ Eri astrosphere is provided to explore this further.

  19. PREDICTING Lyα AND Mg II FLUXES FROM K AND M DWARFS USING GALAXY EVOLUTION EXPLORER ULTRAVIOLET PHOTOMETRY

    International Nuclear Information System (INIS)

    Shkolnik, Evgenya L.; Rolph, Kristina A.; Peacock, Sarah; Barman, Travis S.

    2014-01-01

    A star's ultraviolet (UV) emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Lyα emission line at 1216 Å, which dominates the far-ultraviolet (FUV) spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Lyα, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Lyα line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Lyα and GALEX far- and near-ultraviolet (NUV) chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Lyα to the GALEX fluxes reveal how the relative strength of Lyα compared to the broadband fluxes weakens as the FUV and NUV excess flux increase. We also correlate GALEX fluxes with the strong NUV Mg II h+k spectral emission lines formed at lower chromospheric temperatures than Lyα. The reported correlations provide estimates of intrinsic Lyα and Mg II fluxes for the thousands of K and M stars in the archived GALEX all-sky surveys. These will constrain new stellar upper atmosphere models for cool stars and provide realistic inputs to models describing exoplanetary photochemistry and atmospheric evolution in the absence of UV spectroscopy

  20. Experimental investigation on large-area dielectric barrier discharge in atmospheric nitrogen and air assisted by the ultraviolet lamp.

    Science.gov (United States)

    Zhang, Yan; Gu, Biao; Wang, Wenchun; Wang, Dezhen; Peng, Xuwen

    2009-04-01

    In this paper, ultraviolet radiation produced by the ultraviolet lamp is employed to supply pre-ionization for the dielectric barrier discharge in N(2) or air at atmospheric pressure. The effect of the ultraviolet pre-ionization on improving the uniformity of the dielectric barrier discharge is investigated experimentally. The atmospheric pressure glow discharge of the large area (270 mm x 120 mm) is obtained successfully via the ultraviolet pre-ionization in atmospheric DBD in N(2) when the gas gap decrease to 3mm. Based on the emission spectra, the mechanism which ultraviolet pre-ionization improves the uniformity of the dielectric barrier discharge is discussed.

  1. The big data telescope

    International Nuclear Information System (INIS)

    Finkel, Elizabeth

    2017-01-01

    On a flat, red mulga plain in the outback of Western Australia, preparations are under way to build the most audacious telescope astronomers have ever dreamed of - the Square Kilometre Array (SKA). Next-generation telescopes usually aim to double the performance of their predecessors. The Australian arm of SKA will deliver a 168-fold leap on the best technology available today, to show us the universe as never before. It will tune into signals emitted just a million years after the Big Bang, when the universe was a sea of hydrogen gas, slowly percolating with the first galaxies. Their starlight illuminated the fledgling universe in what is referred to as the “cosmic dawn”.

  2. Radio telescope control

    CERN Document Server

    Schraml, J

    1972-01-01

    An on-line computer control process developed for the 100-m radio telescope of the Max-Planck-Institut fur Radioastronomie in Bonn is described. The instrument is the largest fully steerable antenna in the world. Its operation started on May 31st 1972. It is controlled by a Ferranti Argus 500 on-line computer. The first part of the paper deals with the process itself, the radio telescope and its operation, and the demands resulting for the control program. The second part briefly describes the computer and its hardware. The final part introduces the architecture of the executive program in general, which has been tailored to meet the demands of the process and the hardware. The communication between the observer and the system, the format of data on magnetic tape and an on-line reduction of position measurements are considered. (0 refs).

  3. [Galileo and his telescope].

    Science.gov (United States)

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  4. Workshop: Neutrino telescopes

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role

  5. Workshop: Neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-05-15

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role.

  6. Fast Fourier transform telescope

    International Nuclear Information System (INIS)

    Tegmark, Max; Zaldarriaga, Matias

    2009-01-01

    We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore's law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog 2 N rather than N 2 ) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

  7. Biological Action Spectra (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Gruijl, F.R. de

    2000-07-01

    Ultraviolet (UV) radiation induces a wide variety of biological responses: ranging in humans from well-known short-term effects like sunburn to long-term effects like skin cancer. The wavelength dependencies ('action spectra') of the responses can differ significantly, depending on the UV-targeted molecules (their absorption spectra), their localisation (transmission to the target depth) and the photochemical reactions involved (e.g. quantum yields, competing reaction). An action spectrum (e.g. of sunburn) is usually determined in a wavelength by wavelength analysis of the response. This is not always possible (e.g. in case of skin cancer), and an action spectrum may then be extracted mathematically from differences in responses to broadband UV sources of various spectral compositions (yielding 'biological spectral weights'). However, relative spectral weights may shift with exposure levels and contributions from different wavelengths may not always add up. Under these circumstances conventional analyses will yield different action spectra for different experimental conditions. (author)

  8. Ultraviolet radiation and immunosuppression.

    LENUS (Irish Health Repository)

    Murphy, G M

    2009-11-01

    Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

  9. Ultraviolet fire detector

    Science.gov (United States)

    Turnage, J. E.; Linford, R. M. F.; Cornish, S. D.

    1976-01-01

    System is capable of detecting ultraviolet light emitted by match size flame at distance of 10 ft. System is not affected by high energy or particulate radiation and is therefore particularly suited for applications around nuclear plants and X-ray equipment.

  10. Psoriasis and ultraviolet radiation

    International Nuclear Information System (INIS)

    Farber, E.M.; Nall, L.

    1993-01-01

    Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs

  11. Optical Spectra of Candidate International Celestial Reference Frame (ICRF) Flat-spectrum Radio Sources. III

    Energy Technology Data Exchange (ETDEWEB)

    Titov, O.; Stanford, Laura M. [Geoscience Australia, P.O. Box 378, Canberra, ACT 2601 (Australia); Pursimo, T. [Nordic Optical Telescope, Nordic Optical Telescope Apartado 474E-38700 Santa Cruz de La Palma, Santa Cruz de Tenerife (Spain); Johnston, Helen M.; Hunstead, Richard W. [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Jauncey, David L. [CSIRO Astronomy and Space Science, ATNF and Mount Stromlo Observatory, Cotter Road, Weston, ACT 2611 (Australia); Zenere, Katrina A., E-mail: oleg.titov@ga.gov.au [School of Physics, University of Sydney, NSW 2006 (Australia)

    2017-04-01

    In extending our spectroscopic program, which targets sources drawn from the International Celestial Reference Frame (ICRF) Catalog, we have obtained spectra for ∼160 compact, flat-spectrum radio sources and determined redshifts for 112 quasars and radio galaxies. A further 14 sources with featureless spectra have been classified as BL Lac objects. Spectra were obtained at three telescopes: the 3.58 m European Southern Observatory New Technology Telescope, and the two 8.2 m Gemini telescopes in Hawaii and Chile. While most of the sources are powerful quasars, a significant fraction of radio galaxies is also included from the list of non-defining ICRF radio sources.

  12. An Ultraviolet Spectrum of the Tidal Disruption Flare ASASSN-14li

    Science.gov (United States)

    Cenko, S. Bradley; Cucchiara, Antonio; Roth, Nathaniel; Veilleux, Sylvain; Prochaska, J. Xavier; Yan, Lin; Guillochon, James; Maksym, W. Peter; Arcavi, Iair; Butler, Nathaniel R.

    2016-01-01

    We present a Hubble Space Telescope Space Telescope Imaging Spectrograph spectrum of ASASSN-14li, the first rest-frame ultraviolet (UV) spectrum of a tidal disruption flare (TDF). The underlying continuum is well fit by a blackbody with T(sub UV) = 3.5 x 10(exp. 4) K, an order of magnitude smaller than the temperature inferred from X-ray spectra (and significantly more precise than previous efforts based on optical and near-UV photometry).Superimposed on this blue continuum, we detect three classes of features: narrow absorption from the Milky Way (probably a high-velocity cloud), and narrow absorption and broad {approx. 2000-8000 km s(exp. -1)} emission lines at or near the systemic host velocity. The absorption lines are blueshifted with respect to the emission lines by Delta(sub v) = -(250-400) km s(exp. -1). Due both to this velocity offset and the lack of common low-ionization features (Mg II, Fe II), we argue these arise from the same absorbing material responsible for the low-velocity outflow discovered at X-ray wavelengths. The broad nuclear emission lines display a remarkable abundance pattern: N III], N IV], and He II are quite prominent, while the common quasar emission lines of C III] and Mg II are weak or entirely absent. Detailed modeling of this spectrum will help elucidate fundamental questions regarding the nature of the emission processes at work in TDFs, while future UV spectroscopy of ASASSN-14li would help to confirm (or refute) the previously proposed connection between TDFs and N-rich quasars.

  13. Combined ultraviolet studies of astronomical sources. Semiannual Progress report, 1 February-31 July 1986

    International Nuclear Information System (INIS)

    Baliunas, S.L.; Dupree, A.K.; Elvis, M.; Huchra, J.P.; Kenyon, S.; Raymond, J.C.

    1986-10-01

    Topics addressed include: Cygnus Loop; P Cygni profiles in dwarf novae; YY Gem; nova shells; HZ Herculis; activity cycles in cluster giants; Alpha Ori; metal deficient giant stars; ultraviolet spectra of symbiotic stars detected by the Very Large Array; time variability in symbiotic stars; blue galaxies; and quasistellar objects with x-ray spectra

  14. THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Punsly, Brian, E-mail: brian.punsly1@verizon.net [1415 Granvia Altamira, Palos Verdes Estates, CA 90274 (United States); ICRANet, Piazza della Repubblica, I-65100 10 Pescara (Italy)

    2014-12-20

    The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ∼580 Å is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å and 580 Å in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

  15. San Pedro Martir Telescope: Mexican design endeavor

    Science.gov (United States)

    Toledo-Ramirez, Gengis K.; Bringas-Rico, Vicente; Reyes, Noe; Uribe, Jorge; Lopez, Aldo; Tovar, Carlos; Caballero, Xochitl; Del-Llano, Luis; Martinez, Cesar; Macias, Eduardo; Lee, William; Carramiñana, Alberto; Richer, Michael; González, Jesús; Sanchez, Beatriz; Lucero, Diana; Manuel, Rogelio; Segura, Jose; Rubio, Saul; Gonzalez, German; Hernandez, Obed; García, Mary; Lazaro, Jose; Rosales-Ortega, Fabian; Herrera, Joel; Sierra, Gerardo; Serrano, Hazael

    2016-08-01

    The Telescopio San Pedro Martir (TSPM) is a new ground-based optical telescope project, with a 6.5 meters honeycomb primary mirror, to be built in the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN-SPM) located in Baja California, Mexico. The OAN-SPM has an altitude of 2830 meters above sea level; it is among the best location for astronomical observation in the world. It is located 1830 m higher than the atmospheric inversion layer with 70% of photometric nights, 80% of spectroscopic nights and a sky brightness up to 22 mag/arcsec2. The TSPM will be suitable for general science projects intended to improve the knowledge of the universe established on the Official Mexican Program for Science, Technology and Innovation 2014-2018. The telescope efforts are headed by two Mexican institutions in name of the Mexican astronomical community: the Universidad Nacional Autonoma de Mexico and the Instituto Nacional de Astrofisica, Optica y Electronica. The telescope has been financially supported mainly by the Consejo Nacional de Ciencia y Tecnologia (CONACYT). It is under development by Mexican scientists and engineers from the Center for Engineering and Industrial Development. This development is supported by a Mexican-American scientific cooperation, through a partnership with the University of Arizona (UA), and the Smithsonian Astrophysical Observatory (SAO). M3 Engineering and Technology Corporation in charge of enclosure and building design. The TSPM will be designed to allow flexibility and possible upgrades in order to maximize resources. Its optical and mechanical designs are based upon those of the Magellan and MMT telescopes. The TSPM primary mirror and its cell will be provided by the INAOE and UA. The telescope will be optimized from the near ultraviolet to the near infrared wavelength range (0.35-2.5 m), but will allow observations up to 26μm. The TSPM will initially offer a f/5 Cassegrain focal station. Later, four folded Cassegrain and

  16. Solar maximum ultraviolet spectrometer and polarimeter

    Science.gov (United States)

    Tandberg-Hanssen, E.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Hyder, C. L.; Michalitsianos, A. G.; Shine, R. A.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.

    1979-01-01

    The objectives of the UVSP experiment are to study solar ultraviolet radiations, particularly from flares and active regions, and to measure constituents in the terrestrial atmosphere by the extinction of sunlight at satellite dawn and dusk. The instrument is designed to observe the Sun at a variety of spectral and spatial resolutions in the range from 1150 to 3600 A. A Gregorian telescope with effective focal length of 1.8 m is used to feed a 1 m Ebert-Fastie spectrometer. A polarimeter containing rotatable magnesium fluoride waveplates is included behind the spectrometer entrance slit and will allow all four Stokes parameters to be determined. Velocities on the Sun can also be measured. The instrument is controlled by a computer which can interact with the data stream to modify the observing program. The observing modes, including rasters, spectral scans, velocity measurements, and polarimetry, are also described along with plans for mission operations, data handling, and analysis of the observations.

  17. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. III. Optical and UV Spectra of a Blue Kilonova from Fast Polar Ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.; Berger, E.; Kasen, D.; Metzger, B. D.; Elias, J.; Briceño, C.; Alexander, K. D.; Blanchard, P. K.; Chornock, R.; Cowperthwaite, P. S.; Eftekhari, T.; Fong, W.; Margutti, R.; Villar, V. A.; Williams, P. K. G.; Brown, W.; Annis, J.; Bahramian, A.; Brout, D.; Brown, D. A.; Chen, H. -Y.; Clemens, J. C.; Dennihy, E.; Dunlap, B.; Holz, D. E.; Marchesini, E.; Massaro, F.; Moskowitz, N.; Pelisoli, I.; Rest, A.; Ricci, F.; Sako, M.; Soares-Santos, M.; Strader, J.

    2017-10-16

    We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational wave (GW) source, the binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 and 9.5 days post-merger, using the SOAR and Magellan telescopes; the UV spectrum was obtained with the \\textit{Hubble Space Telescope} at 5.5 days. Our data reveal a rapidly-fading blue component ($T\\approx5500$ K at 1.5 days) that quickly reddens; spectra later than $\\gtrsim 4.5$ days peak beyond the optical regime. The spectra are mostly featureless, although we identify a possible weak emission line at $\\sim 7900$ \\AA\\ at $t\\lesssim 4.5$ days. The colours, rapid evolution and featureless spectrum are consistent with a "blue" kilonova from polar ejecta comprised mainly of light $r$-process nuclei with atomic mass number $A\\lesssim 140$. This indicates a sight-line within $\\theta_{\\rm obs}\\lesssim 45^{\\circ}$ of the orbital axis. Comparison to models suggests $\\sim0.03$ M$_\\odot$ of blue ejecta, with a velocity of $\\sim 0.3c$. The required lanthanide fraction is $\\sim 10^{-4}$, but this drops to $<10^{-5}$ in the outermost ejecta. The large velocities point to a dynamical origin, rather than a disk wind, for this blue component, suggesting that both binary constituents are neutron stars (as opposed to a binary consisting of a neutron star and a black hole). For dynamical ejecta, the high mass favors a small neutron star radius of $\\lesssim 12$ km. This mass also supports the idea that neutron star mergers are a major contributor to $r$-process nucleosynthesis.

  18. The Planck Telescope reflectors

    Science.gov (United States)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  19. Deep space telescopes

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo’s telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics throughout the complete electromagnetic spectrum. Such information is there for the taking, from millimiter wavelengths to gamma rays. Forty years astronomy from space, covering now most of the e.m. spectrum, have thus given us a better understanding of our physical Universe then t...

  20. Antares Reference Telescope System

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

    1983-01-01

    Antares is a 24-beam, 40-TW carbon-dioxide laser-fusion system currently nearing completion at the Los Alamos National Laboratory. The 24 beams will be focused onto a tiny target (typically 300 to 1000 μm in diameter) located approximately at the center of a 7.3-m-diameter by 9.3-m-long vacuum (10 - 6 torr) chamber. The design goal is to position the targets to within 10 μm of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares Reference Telescope System is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares Reference Telescope System consists of two similar electro-optical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: (1) a fixed 9X optical imaging subsystem which produces an image of the target at the vidicon; (2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; (3) an adjustable front-lighting subsystem which illuminates the target; and (4) an adjustable back-lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and trade-offs are discussed. The final system chosen (which is being built) and its current status are described in detail

  1. SNAP Telescope Latest Developments

    Science.gov (United States)

    Lampton, M.; SNAP Collaboration

    2004-12-01

    The coming era of precision cosmology imposes new demands on space telescopes with regard to spectrophotometric accuracy and image stability. To meet these requirements for SNAP we have developed an all reflecting two-meter-class space telescope of the three-mirror anastigmat type. Our design features a large flat annular field (1.5 degrees = 580mm diameter) and a telephoto advantage of 6, delivering a 22m focal length within an optical package length of only 3.5 meters. The use of highly stable materials (Corning ULE glass and carbon-fiber reinforced cyanate ester resin for the metering structure) combined with agressive distributed thermal control and an L2 orbit location will lead to unmatched figure stability. Owing to our choice of rigid structure with nondeployable solar panels, finite-element models show no structural resonances below 10Hz. An exhaustive stray light study has been completed. Beginning in 2005, two industry studies will develop plans for fabrication, integration and test, bringing SNAP to a highly realistic level of definition. SNAP is supported by the Office of Science, US DoE, under contract DE-AC03-76SF00098.

  2. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, our completed first mission concept and an introduction to the second concept that will be studied at the study center in 2018. This presentation will also summarize key science drivers and the key study milestones between 2018 and 2020.

  3. Dust Absorption and the Ultraviolet Luminosity Density at z ~ 3 as Calibrated by Local Starburst Galaxies

    Science.gov (United States)

    Meurer, Gerhardt R.; Heckman, Timothy M.; Calzetti, Daniela

    1999-08-01

    We refine a technique to measure the absorption-corrected ultraviolet (UV) luminosity of starburst galaxies using rest-frame UV quantities alone and apply it to Lyman-limit U dropouts at z~3 found in the Hubble Deep Field (HDF). The method is based on an observed correlation between the ratio of far-infrared (FIR) to UV fluxes with spectral slope β (a UV color). A simple fit to this relation allows the UV flux absorbed by dust and reprocessed to the FIR to be calculated, and hence the dust-free UV luminosity to be determined. International Ultraviolet Explorer spectra and Infrared Astronomical Satellite fluxes of local starbursts are used to calibrate the FFIR/F1600 versus β relation in terms of A1600 (the dust absorption at 1600 Å) and the transformation from broadband photometric color to β. Both calibrations are almost completely independent of theoretical stellar-population models. We show that the recent marginal and nondetections of HDF U dropouts at radio and submillimeter wavelengths are consistent with their assumed starburst nature and our calculated A1600. This is also true of recent observations of the ratio of optical emission-line flux to UV flux density in the brightest U dropouts. This latter ratio turns out not to be a good indicator of dust extinction. In U dropouts, absolute magnitude M1600,0 correlates with β: brighter galaxies are redder, as is observed to be the case for local starburst galaxies. This suggests that a mass-metallicity relationship is already in place at z~3. The absorption-corrected UV luminosity function of U dropouts extends up to M1600,0~-24 AB mag, corresponding to a star formation rate ~200 \\Mscrsolar yr-1 (H0=50 km s-1 Mpc-3 and q0=0.5 are assumed throughout). The absorption-corrected UV luminosity density at z~3 is ρ1600,0>=1.4×1027 ergs-1 Hz-1 Mpc-1. It is still a lower limit since completeness corrections have not been done and because only galaxies with A1600dropouts. The luminosity-weighted mean dust

  4. Cost Modeling for Space Telescope

    Science.gov (United States)

    Stahl, H. Philip

    2011-01-01

    Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.

  5. Status of the MAGIC telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Colin, Pierre; Carmona, Emiliano; Schweizer, Thomas; Sitarek, Julian [Max-Planck-Institut fuer Physik, Werner-Heisenberg Institut, Muenchen (Germany)

    2010-07-01

    MAGIC is a system of two 17-m Cherenkov telescopes located on La Palma (Canary islands),sensitive to gamma-rays above 30 GeV. It has been recently upgraded by a second telescope which strongly improves the sensitivity, particularly at low energy. Here we present the status of the MAGIC telescopes and an overview of the recent results obtained in single or stereoscopic mode. We also discuss the real performance of the new stereoscopic system based on Crab Nebula observations.

  6. NEAR-ULTRAVIOLET SPECTROSCOPY OF STAR-FORMING GALAXIES FROM eBOSS: SIGNATURES OF UBIQUITOUS GALACTIC-SCALE OUTFLOWS

    International Nuclear Information System (INIS)

    Zhu, Guangtun Ben; Comparat, Johan; Kneib, Jean-Paul; Delubac, Timothée; Raichoor, Anand; Yèche, Christophe; Dawson, Kyle S.; Newman, Jeffrey; Zhou, Xu; Schneider, Donald P.

    2015-01-01

    We present rest-frame near-ultraviolet (NUV) spectroscopy of star-forming galaxies (SFGs) at 0.6 < z < 1.2 from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) in SDSS-IV. One of the eBOSS programs is to obtain 2″ (about 15 kpc) fiber spectra of about 200,000 emission-line galaxies (ELGs) at redshift z ≳ 0.6. We use the data from the pilot observations of this program, including 8620 spectra of SFGs at 0.6 < z < 1.2. The median composite spectra of these SFGs at 2200 Å < λ < 4000 Å feature asymmetric, preferentially blueshifted non-resonant emission, Fe ii*, and blueshifted resonant absorption, e.g., Fe ii and Mg ii, indicating ubiquitous outflows driven by star formation at these redshifts. For the absorption lines, we find a variety of velocity profiles with different degrees of blueshift. Comparing our new observations with the literature, we do not observe the non-resonant emission in the small-aperture (<40 pc) spectra of local star-forming regions with the Hubble Space Telescope, and find the observed line ratios in the SFG spectra to be different from those in the spectra of local star-forming regions, as well as those of quasar absorption-line systems in the same redshift range. We introduce an outflow model that can simultaneously explain the multiple observed properties and suggest that the variety of absorption velocity profiles and the line ratio differences are caused by scattered fluorescent emission filling in on top of the absorption in the large-aperture eBOSS spectra. We develop an observation-driven, model-independent method to correct the emission infill to reveal the true absorption profiles. Finally, we show that the strengths of both the non-resonant emission and the emission-corrected resonant absorption increase with [O ii] λλ3727, 3730 rest equivalent width and luminosity, with a slightly larger dependence on the former. Our results show that the eBOSS and future dark-energy surveys (e.g., Dark Energy Spectroscopic

  7. Science Enabled by the Ares V: A Large Monolithic Telescope Placed at the Second Sun-Earth Lagrange Point

    Science.gov (United States)

    Hopkins, Randall C.; Stahl, H. Philip

    2007-01-01

    The payload mass and volume capabilities of the planned Ares V launch vehicle provide the science community with unprecedented opportunities to place large science payloads into low earth orbit and beyond. One example, the outcome of a recent study conducted at the NASA Marshall Space Flight Center, is a large, monolithic telescope with a primary mirror diameter of 6.2 meters placed into a halo orbit about the second Sun-Earth Lagrange point, or L2, approximately 1.5 million kin beyond Earth's orbit. Operating in the visible and ultraviolet regions of the electromagnetic spectrum, such a large telescope would allow astronomers to detect bio-signatures and characterize the atmospheres of transiting exoplanets, provide high resolution imaging three or more times better than the Hubble Space Telescope and the James Webb Space Telescope, and observe the ultraviolet light from warm baryonic matter.

  8. Surprise Ultraviolet Party in the Sky

    Science.gov (United States)

    2005-01-01

    Galaxies aren't the only objects filling up the view of NASA's Galaxy Evolution Explorer. Since its launch in 2003, the space telescope -- originally designed to observe galaxies across the universe in ultraviolet light -- has discovered a festive sky blinking with flaring and erupting stars, as well as streaking asteroids, satellites and space debris. A group of six streaking objects -- the identities of which remain unknown -- can be seen here flying across the telescope's sight in this sped-up movie. The two brightest objects appear to perform a sharp turn then travel in the reverse direction. This illusion is most likely the result of the Galaxy Evolution Explorer overtaking the objects as it orbits around Earth. Careful inspection reveals four additional faint objects with the same timing and behavior. These faint objects are easiest to see during the retrograde portion of their paths. Three appear between the two bright sources, and one is above them, near the edge of the field of view. These bonus objects are being collected in to public catalogues for other astronomers to study.

  9. The Evolution of Spacelab Ultraviolet Astronomy Missions from OSS-3 through -7 to Astro-1

    Science.gov (United States)

    Gull, Theodore

    2018-01-01

    In the 1960s and 1970s, NASA was building towards a robust program in space astronomy. An evolutionary step from ground-based astronomy to space astronomy was human operation of space telescopes as astronomy in general evolved from astronomers directly at the telescope to application of computers and long distance communications to control to operate remote telescopes. Today ground-based telescopes and space observatories from cubesats to the Hubble Space Telescope and soon the James Webb Space Telescope are routinely operated remotely.In response to the Spacelab Announcement of Opportunity in the early 1980s, three ultraviolet experiments – the Hopkins Ultraviolet Telescope, the Ultraviolet Imaging Telescope and the Wisconsin Ultraviolet PhotoPolarimetry Experiment -- all instruments derived from multiple sounding rocket flights--were selected to fly as an integrated payload attached to a space shuttle. The justification for professional astronomers, both as Mission Specialists from the astronaut cadre and Payload Specialists from the instrument teams, was built to ensure key technical skills both of the science and the instruments. Bundled together as OSS-3 through -7 flights focused on Comet Halley, the experiments went through many changes and delays as a pathfinder for an anticipated series of attached astronomy payloads.By 1986, the five-flight mission had evolved into two missions, Astro-1 dedicated primarily to observe Halley’s Comet in early March 1986 and Astro-2 to fly about one year later. Due to the Challenger disaster 35 days before scheduled launch of Astro-1, the mission went through an initial cancellation and then re-scheduling once the instrument complement of Astro-1 was expanded to include Broad Band X-ray Telescope with emphasis on studying SN1987A. Ultimately Astro-1 flew in December 1990 partnered with an X-ray experiment focused on SN1987A.The nine-day mission was mostly successful despite multiple technical issues overcome by the NASA

  10. Beta spectra. II-Positron spectra

    International Nuclear Information System (INIS)

    Grau, A.; Garcia-Torano, E.

    1981-01-01

    Using the Fermi theory of beta decay, the beta spectra for 30 positron emitters have been computed, introducing a correction factor for unique forbidden transitions. The spectra are ploted vs. energy, once normalised, and tabulated with the related Fermi functions. The average and median energies are calculated. (author)

  11. Testing of polarimeter UVP layout on telescope AZT-2

    Science.gov (United States)

    Nevodovskyi, P. V.; Vidmachenko, A. P.; Morozhenko, O. V.

    2018-05-01

    Layout of on-board small-sized ultraviolet polarimeter was created. On its basis a ground version of the layout was prepared. It was installed on the AZT-2 telescope for carrying out special tests. With this device we investigated the possibility of determining the degree of polarization of the twilight glow of the Earth's atmosphere, and also worked out the observation methodology required for such work, and the basic principles of the implementation of this method. For this purpose, a special complex of auxiliary equipment was developed.

  12. Silicon Telescope Detectors

    CERN Document Server

    Gurov, Yu B; Sandukovsky, V G; Yurkovski, J

    2005-01-01

    The results of research and development of special silicon detectors with a large active area ($> 8 cm^{2}$) for multilayer telescope spectrometers (fulfilled in the Laboratory of Nuclear Problems, JINR) are reviewed. The detector parameters are listed. The production of totally depleted surface barrier detectors (identifiers) operating under bias voltage two to three times higher than depletion voltage is described. The possibility of fabrication of lithium drifted counters with a very thin entrance window on the diffusion side of the detector (about 10--20 $\\mu$m) is shown. The detector fabrication technique has allowed minimizing detector dead regions without degradation of their spectroscopic characteristics and reliability during long time operation in charge particle beams.

  13. Occupational applications of ultraviolet radiation

    International Nuclear Information System (INIS)

    Eriksen, P.

    1987-01-01

    A large population of workers are exposed to ultraviolet radiation in various occupational environments which often necessitates protection. Since ultraviolet radiation may create other environmental problems an occupational hazard- and protection evaluation can be complicated. Threshold Limit Values adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) on ultraviolet radiation are used in most countries as guidelines for risk assessment and control measures. This review addresses the levels of ultraviolet radiation met in occupational environments, its measurement and evaluation, and discusses different protection methods. Ultraviolet lasers are beginning to find their way into industrial processes but are still limited in number and they will not be covered here. Emphasis is on broad band incoherent radiation in high risk environments such as welding, and on the evaluation of protective eyewear, see-through curtains and plastics. Other occupational risks associated with the emission of ultraviolet radiation are discussed

  14. High-resolution extreme ultraviolet spectroscopy of G191-B2B: structure of the stellar photosphere and the surrounding interstellar medium

    Science.gov (United States)

    Barstow, M. A.; Cruddace, R. G.; Kowalski, M. P.; Bannister, N. P.; Yentis, D.; Lapington, J. S.; Tandy, J. A.; Hubeny, I.; Schuh, S.; Dreizler, S.; Barbee, T. W.

    2005-10-01

    We have continued our detailed analysis of the high-resolution (R= 4000) spectroscopic observation of the DA white dwarf G191-B2B, obtained by the Joint Astrophysical Plasmadynamic Experiment (J-PEX) normal incidence sounding rocket-borne telescope, comparing the observed data with theoretical predictions for both homogeneous and stratified atmosphere structures. We find that the former models give the best agreement over the narrow waveband covered by J-PEX, in conflict with what is expected from previous studies of the lower resolution but broader wavelength coverage Extreme Ultraviolet Explorer spectra. We discuss the possible limitations of the atomic data and our understanding of the stellar atmospheres that might give rise to this inconsistency. In our earlier study, we obtained an unusually high ionization fraction for the ionized HeII present along the line of sight to the star. In the present paper, we obtain a better fit when we assume, as suggested by Space Telescope Imaging Spectrograph results, that this HeII resides in two separate components. When one of these is assigned to the local interstellar cloud, the implied He ionization fraction is consistent with measurements along other lines of sight. However, the resolving power and signal-to-noise available from the instrument configuration used in this first successful J-PEX flight are not sufficient to clearly identify and prove the existence of the two components.

  15. Lunar-based optical telescopes: Planning astronomical tools of the twenty-first century

    Science.gov (United States)

    Hilchey, J. D.; Nein, M. E.

    1995-02-01

    A succession of optical telescopes, ranging in aperture from 1 to 16 m or more, can be deployed and operated on the lunar surface over the next half-century. These candidates to succeed NASA's Great Observatories would capitalize on the unique observational advantages offered by the Moon. The Lunar Telescope Working Group and the LUTE Task Team of the George C. Marshall Space Flight Center (MSFC) have assessed the feasibility of developing and deploying these facilities. Studies include the 16-m Large Lunar Telescope (LLT); the Lunar Cluster Telescope Experiment (LCTE), a 4-m precursor to the LLT; the 2-m Lunar Transit Telescope (LTT); and its precursor, the 1-m Lunar Ultraviolet Telescope Experiment (LUTE). The feasibility of developing and deploying each telescope was assessed and system requirements and options for supporting technologies, subsystems, transportation, and operations were detailed. Influences of lunar environment factors and site selection on telescope design and operation were evaluated, and design approaches and key tradeoffs were established. This paper provides an overview of the study results. Design concepts and brief system descriptions are provided, including subsystem and mission options selected for the concepts.

  16. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  17. Building the Hubble Space Telescope

    International Nuclear Information System (INIS)

    O'dell, C.R.

    1989-01-01

    The development of the design for the Hubble Space Telescope (HST) is discussed. The HST optical system is described and illustrated. The financial and policy issues related to the development of the HST are considered. The actual construction of the HST optical telescope is examined. Also, consideration is given to the plans for the HST launch

  18. 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...

  19. Transparent ultraviolet photovoltaic cells.

    Science.gov (United States)

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  20. LSD-based analysis of high-resolution stellar spectra

    Science.gov (United States)

    Tsymbal, V.; Tkachenko, A.; Van, Reeth T.

    2014-11-01

    We present a generalization of the method of least-squares deconvolution (LSD), a powerful tool for extracting high S/N average line profiles from stellar spectra. The generalization of the method is effected by extending it towards the multiprofile LSD and by introducing the possibility to correct the line strengths from the initial mask. We illustrate the new approach by two examples: (a) the detection of astroseismic signatures from low S/N spectra of single stars, and (b) disentangling spectra of multiple stellar objects. The analysis is applied to spectra obtained with 2-m class telescopes in the course of spectroscopic ground-based support for space missions such as CoRoT and Kepler. Usually, rather high S/N is required, so smaller telescopes can only compete successfully with more advanced ones when one can apply a technique that enables a remarkable increase in the S/N of the spectra which they observe. Since the LSD profiles have a potential for reconstruction what is common in all the spectral profiles, it should have a particular practical application to faint stars observed with 2-m class telescopes and whose spectra show remarkable LPVs.

  1. Key issues of ultraviolet radiation of OH at high altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing [State Key Laboratory of High Temperature Gasdynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-12-09

    Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}Σ{sup +}→X{sup 2}Π ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

  2. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Duan, Lian; Lan, Hui [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Xinbing, E-mail: xbwang@hust.edu.cn; Chen, Ziqi; Zuo, Duluo [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Peixiang [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-05-21

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data.

  3. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    International Nuclear Information System (INIS)

    Chen, Hong; Duan, Lian; Lan, Hui; Wang, Xinbing; Chen, Ziqi; Zuo, Duluo; Lu, Peixiang

    2015-01-01

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data

  4. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    Science.gov (United States)

    Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W. R.; de Mello Neto, J. R. T.; Facal San Luis, P.; Genat, J. F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.; Ramos de Castro, A.; Reyes, L. C.; Richardson, M.; Rouille d'Orfeuil, B.; Santos, E. M.; Wayne, S.; Williams, C.; Zas, E.; Zhou, J.

    2013-08-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4-4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.

  5. Molecular alignment dependent electron interference in attosecond ultraviolet photoionization

    Directory of Open Access Journals (Sweden)

    Kai-Jun Yuan

    2015-01-01

    Full Text Available We present molecular photoionization processes by intense attosecond ultraviolet laser pulses from numerical solutions of time-dependent Schrödinger equations. Simulations preformed on a single electron diatomic H2+ show minima in molecular photoelectron energy spectra resulting from two center interference effects which depend strongly on molecular alignment. We attribute such sensitivity to the spatial orientation asymmetry of the photoionization process from the two nuclei. A similar influence on photoelectron kinetic energies is also presented.

  6. Molecular alignment dependent electron interference in attosecond ultraviolet photoionization

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2015-01-01

    We present molecular photoionization processes by intense attosecond ultraviolet laser pulses from numerical solutions of time-dependent Schrödinger equations. Simulations preformed on a single electron diatomic H2+ show minima in molecular photoelectron energy spectra resulting from two center interference effects which depend strongly on molecular alignment. We attribute such sensitivity to the spatial orientation asymmetry of the photoionization process from the two nuclei. A similar influence on photoelectron kinetic energies is also presented. PMID:26798785

  7. Seismic Imager Space Telescope

    Science.gov (United States)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; hide

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  8. Thirty Years, One Million Spectra: Public Access to the SAO Spectral Archives

    Science.gov (United States)

    Mink, J.; Moran, S.

    2015-09-01

    Over the last 30 years, the SAO Telescope Data Center has reduced and archived over 1,000,000 spectra, consisting of 287,000 spectra from five high dispersion Echelle spectrographs and 717,000 spectra from four low dispersion spectrographs, across three telescopes. 151,000 spectra from six instruments are currently online and publicly available, covering many interesting objects in the northern sky, including most of the galaxies in the Updated Zwicky Catalog which are reachable through NED or Simbad. A majority of the high dispersion spectra will soon be made public, as will more data from the MMT multi-fiber spectrographs. Many objects in the archive have multiple spectra over time, which make them a valuable resource for archival time-domain studies. We are now developing a system to make all of the public spectra more easily searchable and viewable through the Virtual Observatory.

  9. Spectra from foil-excited molybdenum ions

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Cecchi, J.L.; Kruse, T.H.

    1978-01-01

    The extreme-ultraviolet spectra (5 to 55 nm) for foil-excited molybdenum ions have been measured using 22 to 200 MeV beams from the Brookhaven National Laboratory MP tandem Van de Graaff accelerator facility, 20 μg/cm 2 C stripping foils, and a grazing incidence spectrometer. The mean ion charge states (13 to 28) and the narrow distribution widths (about 2 charge states) were accurately predictable from experimental parameters. Where possible, comparisons are given with Mo radiation from tokamaks, vacuum sparks, and laser-excited plasmas

  10. The UV Spectrum of the Ultracool Dwarf LSR J1835+3259 Observed with the Hubble Space Telescope

    Science.gov (United States)

    Saur, Joachim; Fischer, Christian; Wennmacher, Alexandre; Feldman, Paul D.; Roth, Lorenz; Strobel, Darrell F.; Reiners, Ansgar

    2018-05-01

    An interesting question about ultracool dwarfs recently raised in the literature is whether their emission is purely internally driven or partially powered by external processes similar to planetary aurora known from the solar system. In this work, we present Hubble Space Telescope observations of the energy fluxes of the M8.5 ultracool dwarf LSR J1835+3259 throughout the ultraviolet (UV). The obtained spectra reveal that the object is generally UV-fainter compared with other earlier-type dwarfs. We detect the Mg II doublet at 2800 Å and constrain an average flux throughout the near-UV. In the far-UV without Lyα, the ultracool dwarf is extremely faint with an energy output at least a factor of 250 smaller as expected from auroral emission physically similar to that on Jupiter. We also detect the red wing of the Lyα emission. Our overall finding is that the observed UV spectrum of LSR J1835+3259 resembles the spectrum of mid/late-type M-dwarf stars relatively well, but it is distinct from a spectrum expected from Jupiter-like auroral processes.

  11. Tritel: 3D silicon detector telescope used for space dosimetry

    International Nuclear Information System (INIS)

    Pazmandi, T.; Hirn, A.; Deme, S.; Apathy, I.; Csoke, A.; Bodnar, L.

    2006-01-01

    One of the many risks of long-duration space flights is the excessive exposure to cosmic radiation, which has great importance particularly during solar flares and higher solar activity. Radiation weighting factor, which is a function of the linear energy transfer of the radiation, is used to convert absorbed dose to equivalent dose. Since space radiation mainly consists of charged heavy particles, the equivalent dose differs significantly from the absorbed dose. The objectives of this project are to develop and manufacture a three-axis silicon detector telescope (Tritel), and to develop software for data evaluation of the measured energy deposition spectra. The 3 D silicon telescope should be the first such device used for measuring the dose astronauts are subjected to. Research and development began in the K.F.K.I. Atomic Energy Research Institute several years ago. The geometric parameters of the 3 D silicon Let telescope were defined, results of previous measurements were used as a benchmark. Features of various types and sizes of telescopes were analyzed. Elements of the Tritel telescope system, issues of the electronic block diagram, requirements for the mechanical construction and possibilities of data handling and data evaluation are analyzed in this paper. First results of the calibrations are presented as well. (authors)

  12. Observations of Local ISM Emission with the Berkeley EUV/FUV Shuttle Telescope

    Science.gov (United States)

    Martin, C.; Bowyer, S.

    1984-01-01

    The Berkeley extreme ultraviolet/far ultraviolet shuttle telescope (BEST) will be launched on the Space Shuttle as part of the NASA UVX project. The Berkeley spectrometer will make observations of the cosmic diffuse background in the 600 to 1900 A band, with a spectral resolution of 10 A. The sensitivity and spectral resolution of the instrument make it ideal for the study of components of the interstellar medium in the 10 to the 4th power to 10 to the 6th power K range.

  13. A new systems engineering approach to streamlined science and mission operations for the Far Ultraviolet Spectroscopic Explorer (FUSE)

    Science.gov (United States)

    Butler, Madeline J.; Sonneborn, George; Perkins, Dorothy C.

    1994-01-01

    The Mission Operations and Data Systems Directorate (MO&DSD, Code 500), the Space Sciences Directorate (Code 600), and the Flight Projects Directorate (Code 400) have developed a new approach to combine the science and mission operations for the FUSE mission. FUSE, the last of the Delta-class Explorer missions, will obtain high resolution far ultraviolet spectra (910 - 1220 A) of stellar and extragalactic sources to study the evolution of galaxies and conditions in the early universe. FUSE will be launched in 2000 into a 24-hour highly eccentric orbit. Science operations will be conducted in real time for 16-18 hours per day, in a manner similar to the operations performed today for the International Ultraviolet Explorer. In a radical departure from previous missions, the operations concept combines spacecraft and science operations and data processing functions in a single facility to be housed in the Laboratory for Astronomy and Solar Physics (Code 680). A small missions operations team will provide the spacecraft control, telescope operations and data handling functions in a facility designated as the Science and Mission Operations Center (SMOC). This approach will utilize the Transportable Payload Operations Control Center (TPOCC) architecture for both spacecraft and instrument commanding. Other concepts of integrated operations being developed by the Code 500 Renaissance Project will also be employed for the FUSE SMOC. The primary objective of this approach is to reduce development and mission operations costs. The operations concept, integration of mission and science operations, and extensive use of existing hardware and software tools will decrease both development and operations costs extensively. This paper describes the FUSE operations concept, discusses the systems engineering approach used for its development, and the software, hardware and management tools that will make its implementation feasible.

  14. Flare stars of the Orion Nebula - spectra of an outburst

    International Nuclear Information System (INIS)

    Carter, B.D.; O'Mara, B.J.; Ross, J.E.

    1988-01-01

    For the first time, detailed, time-resolved spectra of a flare event of an Orion cluster flare star are presented. These spectra, covering ∼ λλ3600-4600, were obtained by using the Anglo-Australian Telescope with a fibre coupler to simultaneously monitor 23 flare stars in the region of the Orion Nebula. The flare spectra reveal continuous emission which filled in the photospheric Ca I 4226 A absorption, and hydrogen Balmer, Ca II H and K, He I 4026 A and He I 4471 A line emission. Overall, the spectral behaviour indicates similarities to strong outbursts of the classical dMe flare stars. (author)

  15. Lightweighted ZERODUR for telescopes

    Science.gov (United States)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  16. Ultraviolet-visible spectroscopy of graphene oxides

    Directory of Open Access Journals (Sweden)

    Qi Lai

    2012-09-01

    Full Text Available Dispersions of few-layer (1-3 layers, multi-layer (4-10 layers and thick-layer (>10 layers graphene oxide (GO were prepared by a modified Hummers method with different mass ratios of KMnO4 to graphite. Ultraviolet-visible (UV-vis spectroscopic data show that few-layer GO dispersions can be distinguished from multi- and thick-layer dispersions by a more intense peak at 230 nm. Atomic force microscopy (AFM images of few-layer GO contain a single peak, those of multi-layer GO exhibit a shoulder and those of thick-layer GO do not contain a peak or shoulder. These findings allow qualitative analysis of GO dispersions. X-ray photoelectron spectra (XPS show that the change of UV-vis absorption intensity of GO is caused by a conjugative effect related to chromophore aggregation that influences the π-π* plasmon peak.

  17. Advanced UVOIR Mirror Technology Development (AMTD) for Very Large Space Telescopes

    Science.gov (United States)

    Stahl, H. Philip; Smith, W. Scott; Mosier, Gary; Abplanalp, Laura; Arnold, William

    2014-01-01

    ASTRO2010 Decadal stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. AMTD builds on the state of art (SOA) defined by over 30 years of monolithic & segmented ground & space-telescope mirror technology to mature six key technologies. AMTD is deliberately pursuing multiple design paths to provide the science community with op-tions to enable either large aperture monolithic or segmented mirrors with clear engineering metrics traceable to science requirements.

  18. TeV gravity at neutrino telescopes

    International Nuclear Information System (INIS)

    Illana, J.I.; Masip, M.; Meloni, D.

    2005-01-01

    Cosmogenic neutrinos reach the Earth with energies around 10 9 GeV, and their interactions with matter will be measured in upcoming experiments (Auger, IceCube). Models with extra dimensions and the fundamental scale at the TeV could imply signals in these experiments. In particular, the production of microscopic black holes by cosmogenic neutrinos has been extensively studied in the literature. Here we make a complete analysis of gravity-mediated interactions at larger distances, where they can be calculated in the eikonal approximation. In these processes a neutrino of energy E ν interacts elastically with a parton inside a nucleon, loses a small fraction y of its energy, and starts a hadronic shower of energy yE ν ν . We analyze the ultraviolet dependence and the relevance of graviton emission in these processes, and show that they are negligible. We also study the energy distribution of cosmogenic events in AMANDA and IceCube and the possibility of multiple-bang events. For any neutrino flux, the observation of an enhanced rate of neutral current events above 100 TeV in neutrino telescopes could be explained by TeV-gravity interactions. The values of the fundamental scale of gravity that IceCube could reach are comparable to those to be explored at the LHC

  19. Advanced Athermal Telescopes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed innovative athermal telescope design uses advanced lightweight and high-stiffness material of Beryllium-Aluminum (Be-38Al). Peregrine's expertise with...

  20. The JCMT Telescope Management System

    Science.gov (United States)

    Tilanus, Remo P. J.; Jenness, Tim; Economou, Frossie; Cockayne, Steve

    Established telescopes often face a challenge when trying to incorporate new software standards and utilities into their existing real-time control system. At the JCMT we have successfully added important new features such as a Relational Database (the Telescope Management System---TMS), an online data Archive, and WWW based utilities to an, in part, 10-year old system. The new functionality was added with remarkably few alterations to the existing system. We are still actively expanding and exploring these new capabilities.

  1. Alt-Az Spacewatch Telescope

    Science.gov (United States)

    Gehrels, Tom

    1997-01-01

    This grant funded about one third of the cost of the construction of a telescope with an aperture 1.8 meters in diameter to discover asteroids and comets and investigate the statistics of their populations and orbital distributions. This telescope has been built to the PI's specifications and installed in a dome on Kitt Peak mountain in Arizona. Funds for the dome and building were provided entirely by private sources. The dome building and telescope were dedicated in a ceremony at the site on June 7, 1997. The attached abstract describes the parameters of the telescope. The telescope is a new item of capital property. It is permanently located in University of Arizona building number 910 in the Steward Observatory compound on Kitt Peak mountain in the Tohono O'odham Nation, Arizona. fts property tag number is A252107. This grant did not include funds for the coma corrector lens, instrument derotator, CCD detector, detector electronics, or computers to acquire or process the data. It also did not include funds to operate the telescope or conduct research with it. Funds for these items and efforts are pending from NASA and other sources.

  2. The Submillimeter Telescope (SMT) project

    International Nuclear Information System (INIS)

    Martin, R.N.; Baars, J.W.M.

    1990-01-01

    To exploit the potential of submillimeter astronomy, the Submillimeter Telescope (SMT) will be located at an altitude of 3178 meters on Emerald Peak 75 miles northeast of Tucson in Southern Arizona. The instrument is an altazimuth mounted f/13.8 Cassegrain homology telescope with two Nasmyth and bent Cassegrain foci. It will have diffraction limited performance at a wavelength of 300 microns and an operating overall figure accuracy of 15 microns rms. An important feature of the SMT is the construction of the primary and secondary reflectors out of aluminum-core CFRP face sheet sandwich panels, and the reflector backup structure and secondary support out of CFRP structural elements. This modern technology provides both a means for reaching the required precision of the SMT for both night and day operation (basically because of the low coefficient of thermal expansion and high strength-to-weight ratio of CFRP) and a potential route for the realization of lightweight telescopes of even greater accuracy in the future. The SMT will be the highest accuracy radio telescope ever built (at least a factor of 2 more accurate than existing telescopes). In addition, the SMT will be the first 10 m-class submillimeter telescope with a surface designed for efficient measurements at the important 350 microns wavelength atmospheric window. 9 refs

  3. Extreme ultra-violet emission spectroscopy of highly charged gadolinium ions with an electron beam ion trap

    International Nuclear Information System (INIS)

    Ohashi, Hayato; Nakamura, Nobuyuki; Sakaue, Hiroyuki A

    2013-01-01

    We present extreme ultra-violet emission spectra of highly charged gadolinium ions obtained with an electron beam ion trap at electron energies of 0.53–1.51 keV. The electron energy dependence of the spectra in the 5.7–11.3 nm range is compared with calculation with the flexible atomic code. (paper)

  4. STAR FORMATION PROPERTIES IN BARRED GALAXIES (SFB). I. ULTRAVIOLET TO INFRARED IMAGING AND SPECTROSCOPIC STUDIES OF NGC 7479

    International Nuclear Information System (INIS)

    Zhou Zhimin; Meng Xianmin; Wu Hong; Cao Chen

    2011-01-01

    Large-scale bars and minor mergers are important drivers for the secular evolution of galaxies. Based on ground-based optical images and spectra as well as ultraviolet data from the Galaxy Evolution Explorer and infrared data from the Spitzer Space Telescope, we present a multi-wavelength study of star formation properties in the barred galaxy NGC 7479, which also has obvious features of a minor merger. Using various tracers of star formation, we find that under the effects of both a stellar bar and a minor merger, star formation activity mainly takes place along the galactic bar and arms, while the star formation rate changes from the bar to the disk. With the help of spectral synthesis, we find that strong star formation took place in the bar region about 100 Myr ago, and the stellar bar might have been ∼10 Gyr old. By comparing our results with the secular evolutionary scenario from Jogee et al., we suggest that NGC 7479 is possibly in a transitional stage of secular evolution at present, and it may eventually become an earlier type galaxy or a luminous infrared galaxy. We also note that the probable minor merger event happened recently in NGC 7479, and we find two candidates for minor merger remnants.

  5. Crystal-field spectra of fassaite from the Angra dos Reis meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Mao, H K; Bell, P M; Virgo, D [Carnegie Institution of Washington, D.C. (USA)

    1977-06-01

    Fassaitic pyroxene from the Angra dos Reis meteorite has striking spectral properties. The /sup 57/Fe Moessbauer spectra show no Fe/sup 3 +/, and thus the absorption is thought to originate from a complex charge-transfer process. Intense absorption at 480 nm dominates the spectrum of the meteorite and may be important in the interpretation of telescope spectra of objects in space.

  6. Photographic infrared spectra of symbiotic stars

    International Nuclear Information System (INIS)

    Andrillat, Y.; Houziaux, L.

    1982-01-01

    The authors have observed six symbiotic stars during the period 1962-1977 with a grating spectrograph attached to the newtonian focus of the 120-cm telescope at Observatoire de Haute Provence. The reciprocal dispersion is 230 A.mm -1 and the region 5800 to 8800 A has been covered using hypersensitized IN plates. The minimum equivalent width for an emission line to be seen is about 0.5 A. The spectra are displayed and the main spectral characteristics are reviewed briefly. (Auth.)

  7. Spectroscopic Measurements of the Far-Ultraviolet Dust Attenuation Curve at z ˜ 3

    Science.gov (United States)

    Reddy, Naveen A.; Steidel, Charles C.; Pettini, Max; Bogosavljević, Milan

    2016-09-01

    We present the first spectroscopic measurements of the shape of the far-ultraviolet (far-UV; λ =950{--}1500 Å) dust attenuation curve at high redshift (z˜ 3). Our analysis employs rest-frame UV spectra of 933 galaxies at z˜ 3, 121 of which have very deep spectroscopic observations (≳ 7 hr) at λ =850{--}1300 \\mathring{{A}} , with the Low Resolution Imaging Spectrograph on the Keck Telescope. By using an iterative approach in which we calculate the ratios of composite spectra in different bins of continuum color excess, E(B-V), we derive a dust curve that implies a lower attenuation in the far-UV for a given E(B-V) than those obtained with standard attenuation curves. We demonstrate that the UV composite spectra of z˜ 3 galaxies can be modeled well by assuming our new attenuation curve, a high covering fraction of H I, and absorption from the Lyman-Werner bands of {{{H}}}2 with a small (≲ 20 % ) covering fraction. The low covering fraction of {{{H}}}2 relative to that of the {{H}} {{I}} and dust suggests that most of the dust in the ISM of typical galaxies at z˜ 3 is unrelated to the catalysis of {{{H}}}2, and is associated with other phases of the ISM (I.e., the ionized and neutral gas). The far-UV dust curve implies a factor of ≈ 2 lower dust attenuation of Lyman continuum (ionizing) photons relative to those inferred from the most commonly assumed attenuation curves for L* galaxies at z˜ 3. Our results may be utilized to assess the degree to which ionizing photons are attenuated in H II regions or, more generally, in the ionized or low column density (N({{H}} {{I}})≲ {10}17.2 cm-2) neutral ISM of high-redshift galaxies. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W.M. Keck Foundation.

  8. The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, W.B.; /UC, Santa Cruz; Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Anderson, B. /UC, Santa Cruz; Axelsson, M.; /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bartelt, J.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bederede, D.; /DAPNIA, Saclay; Bellardi, F.; /INFN, Pisa; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bignami, G.F.; /Pavia U.; Bisello, D.; /INFN, Padua /Padua U.; Bissaldi, E.; /Garching, Max Planck Inst., MPE; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Pisa /INFN, Pisa /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /INFN, Padua /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /Kalmar U. /Royal Inst. Tech., Stockholm /DAPNIA, Saclay /ASI, Rome /INFN, Pisa /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2009-05-15

    The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view (FoV), high-energy {gamma}-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. The LAT was built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. This paper describes the LAT, its preflight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4 x 4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 (x, y) tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an eight-layer hodoscopic configuration with a total depth of 8.6 radiation lengths, giving both longitudinal and transverse information about the energy deposition pattern. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large FoV (2.4 sr) and ensuring that most pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. Data obtained with the LAT are intended to (1) permit rapid notification of high-energy {gamma}-ray bursts and transients and facilitate monitoring of variable sources, (2) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (3

  9. Alignment and phasing of deployable telescopes

    Science.gov (United States)

    Woolf, N. J.; Ulich, B. L.

    1983-01-01

    The experiences in coaligning and phasing the Multi-Mirror Telescope (MMT), together with studies in setting up radio telescopes, are presented. These experiences are discussed, and on the basis they furnish, schemes are suggested for coaligning and phasing four large future telescopes with complex primary mirror systems. These telescopes are MT2, a 15-m-equivalent MMT, the University of California Ten Meter Telescope, the 10 m sub-mm wave telescope of the University of Arizona and the Max Planck Institute for Radioastronomy, and the Large Deployable Reflector, a future space telescope for far-IR and sub-mm waves.

  10. Reflectance spectra of subarctic lichens

    International Nuclear Information System (INIS)

    Petzold, D.E.; Goward, S.N.

    1988-01-01

    Lichens constitute a major portion of the ground cover of high latitude environments, but little has been reported concerning their in situ solar spectral reflectance properties. Knowledge of these properties is important for the interpretation of remotely sensed observations from high latitude regions, as well as in studies of high latitude ecology and energy balance climatology. The spectral reflectance of common boreal vascular plants is similar to that of vascular plants of the mid latitudes. The dominant lichens, in contrast, display variable reflectance patterns in visible wavelengths. The relative reflectance peak at 0.55 μm, common to green vegetation, is absent or indistinct in spectra of pervasive boreal forest and tundra lichens, despite the presence of chlorophyll in the inner algal cells. Lichens of the dominant genus, Cladina, display strong absorption of ultraviolet energy and short-wavelength blue light relative to their absorption in other visible wavelengths. Since the Cladinae dominate both the surface vegetation in open woodlands of the boreal forest and the low arctic tundra, their unusual spectral reflectance patterns will enable accurate monitoring of the boreal forest-tundra ecotone and detection of its vigor and movement in the future. (author)

  11. Reflectance spectra of subarctic lichens

    Science.gov (United States)

    Petzold, Donald E.; Goward, Samuel N.

    1988-01-01

    Lichens constitute a major portion of the ground cover of high latitude environments, but little has been reported concerning their in situ solar spectral reflectance properties. Knowledge of these properties is important for the interpretation of remotely sensed observations from high latitude regions, as well as in studies of high latitude ecology and energy balance climatology. The spectral reflectance of common boreal vascular plants is similar to that of vascular plants of the midlatitudes. The dominant lichens, in contrast, display variable reflectance patterns in visible wavelengths. The relative reflectance peak at 0.55 microns, common to green vegetation, is absent or indistinct in spectra of pervasive boreal forest and tundra lichens, despite the presence of chlorophyll in the inner algal cells. Lichens of the dominant genus, Cladina, display strong absorption of ultraviolet energy and short-wavelength blue light relative to their absorption in other visible wavelengths. Since the Cladinae dominate both the surface vegetation in open woodlands of the boreal forest and the low arctic tundra, their unusual spectral reflectance patterns will enable accurate monitoring of the boreal forest-tundra ecotone and detection of its vigor and movement in the future.

  12. Flares on dMe stars: IUE and optical observations of At Mic, and comparison of far-ultraviolet stellar and solar flares

    International Nuclear Information System (INIS)

    Bromage, G.E.; Phillips, K.J.H.; Dufton, P.L.; Kingston, A.E.

    1986-01-01

    The paper concerns observations of a large flare event on the dMe star At Mic, detected by the International Ultraviolet Explorer. The far-ultraviolet spectra of the flare is compared with those of other stellar flares, and also with a large solar flare recorded by the Skylab mission in 1973. The quiescent-phase optical and ultraviolet spectrum of the same dMe flare star is discussed. (U.K.)

  13. Ultraviolet photovoltaics: Share the spectrum

    Science.gov (United States)

    Milliron, Delia J.

    2017-08-01

    Electrically controlled windows require power to switch between transparent and tinted states. Now, an ultraviolet light-harvesting solar cell can power smart windows without compromising their control over heat and light.

  14. Solar ultraviolet radiation cataract.

    Science.gov (United States)

    Löfgren, Stefan

    2017-03-01

    Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

  15. Ultraviolet radiation and cyanobacteria.

    Science.gov (United States)

    Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun

    2014-12-01

    Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1996-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  17. Ultraviolet radiation: the eye

    International Nuclear Information System (INIS)

    Cesarini, J.P.; Sliney, D.H.

    1996-01-01

    Under most conditions, the eye is well adapted to protect itself against ultraviolet radiation encountered in the outdoor environment as a result of the exposure geometry of the sun. Only when snow is on the ground does one experience acute effects of UV sunlight exposure (i.e. snow blindness, or photokeratitis). With regard to artificial sources, there are many occasions where one views bright light sources such as tungsten-halogen lamps, arc lamps and welding arcs. Such viewing is normally only momentary because of the aversion response to bright light and due to discomfort glare. However, such an aversion does not take place for germicidal lamps and other UV lamps which do not contain a strong visible component in their spectrum. The adverse effects from viewing such sources has been studied for decades and during the last two decades guidelines for limiting exposure to protect the eye have been developed. The guidelines were fostered to a large extent by the growing use of lasers and the quickly recognized hazard posed by viewing laser sources. (author)

  18. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P; Koskela, T; Damski, J; Supperi, A [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1997-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  19. Ultraviolet Communication for Medical Applications

    Science.gov (United States)

    2015-06-01

    DEI procured several UVC phosphors and tested them with vacuum UV (VUV) excitation. Available emission peaks include: 226 nm, 230 nm, 234 nm, 242...SUPPLEMENTARY NOTES Report contains color. 14. ABSTRACT Under this Phase II SBIR effort, Directed Energy Inc.’s (DEI) proprietary ultraviolet ( UV ...15. SUBJECT TERMS Non-line-of-sight (NLOS), networking, optical communication, plasma-shells, short range, ultraviolet ( UV ) light 16. SECURITY

  20. ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION

    OpenAIRE

    Guedes, AMM; Novello, D; Mendes, GMD; Cristianini, M

    2009-01-01

    ULTRAVIOLET TECHNOLOGY FOR FOOD PRESERVATION This literature review article had as objective to gather information about ultraviolet (UV) technology utilization on the food industry, its effects and potential application. Aspects as the origin, concept and applications of the technology on the equipment industry and running mechanisms were approached. The application of UV radiation on food decontamination is still little used due its low penetration, but it is known that it can be easily app...

  1. Spectra of Graphs

    NARCIS (Netherlands)

    Brouwer, A.E.; Haemers, W.H.

    2012-01-01

    This book gives an elementary treatment of the basic material about graph spectra, both for ordinary, and Laplace and Seidel spectra. The text progresses systematically, by covering standard topics before presenting some new material on trees, strongly regular graphs, two-graphs, association

  2. ESA innovation rescues Ultraviolet Observatory

    Science.gov (United States)

    1995-10-01

    Astrophysicist Freeman J. Dyson from the Institute for Advanced Studies in Princeton characterizes IUE as "A little half-meter mirror sitting in the sky, unnoticed by the public, pouring out results". By use of the IUE satellite, astronomers obtain access to the ultraviolet radiation of celestial bodies in unique ways not available by any other means, neither from the ground nor by any other spacecraft currently in orbit. IUE serves a wide community of astronomers all over Europe, the United States and many other parts of the world. It allows the acquisition of critical data for fundamental studies of comets and their evaporation when they approach the Sun, of the mechanisms driving the stellar winds which make many stars lose a significant fraction of their mass (before they die slowly as White Dwarfs or in sudden Supernova explosions), as well as in the search to understand the ways in which black holes possibly power the violent nuclei of Active galaxies. One year ago the project was threatened with termination and serious concern was expressed by astronomers about the potential loss of IUE's capabilities, as a result of NASA not continuing to operate the spacecraft. Under the leadership of ESA, the three Agencies involved in the operations of IUE (ESA, NASA and the United Kingdom's Particle Physics and Astronomy Research Council, PPARC), reviewed the operations agreements of the Project. A minor investment allowing the implementation of modern management and engineering techniques as well as a complete revision of the communication infrastructure of the project and continuous improvements in efficiency in the ESA management, also taking advantage of today's technologies, both in computing and communications, have made it possible to continue IUE operations within the financial means available, with ESA taking up most of NASA's share in the operations. According to Dr. Willem Wamsteker, ESA's Dutch IUE Project Scientist, "it was a extremely interesting

  3. VizieR Online Data Catalog: BD+46 442 optical spectra (Bollen+, 2017)

    Science.gov (United States)

    Bollen, D.; van Winckel, H.; Kamath, D.

    2017-08-01

    Reduced high-resolution (R~85000) optical spectra of BD+46 442. These 104 spectra were obtained between July 2009 and January 2016 from the HERMES spectrograph, mounted on the 1.2m Flemish Mercator telescope at La Palma, Canary Islands, Spain. The spectra cover a wavelength range from 3770 to 9000 angstrom in logscale. The flux is given in arbitrary units. The spectra are collected as FITS files. The numbering of the spectra corresponds to the numbering in Table B.1 in the article (e.g. spec_15.fits corresponds to N=15). (2 data files).

  4. SIMULTANEOUS ULTRAVIOLET AND OPTICAL EMISSION-LINE PROFILES OF QUASARS: IMPLICATIONS FOR BLACK HOLE MASS DETERMINATION

    International Nuclear Information System (INIS)

    Ho, Luis C.; Dong Xiaobo; Goldoni, Paolo; Ponti, Gabriele; Greene, Jenny E.

    2012-01-01

    The X-shooter instrument on the Very Large Telescope was used to obtain spectra of seven moderate-redshift quasars simultaneously covering the spectral range ∼3000 Å to 2.5 μm. At z ≈ 1.5, most of the prominent broad emission lines in the ultraviolet to optical region are captured in their rest frame. We use this unique data set, which mitigates complications from source variability, to intercompare the line profiles of C IV λ1549, C III] λ1909, Mg II λ2800, and Hα and evaluate their implications for black hole (BH) mass estimation. We confirm that Mg II and the Balmer lines share similar kinematics and that they deliver mutually consistent BH mass estimates with minimal internal scatter (∼<0.1 dex) using the latest virial mass estimators. Although no virial mass formalism has yet been calibrated for C III], this line does not appear promising for such an application because of the large spread of its velocity width compared to lines of both higher and lower ionization; part of the discrepancy may be due to the difficulty of deblending C III] from its neighboring lines. The situation for C IV is complex and, because of the limited statistics of our small sample, inconclusive. On the one hand, slightly more than half of our sample (4/7) have C IV line widths that correlate reasonably well with Hα line widths, and their respective BH mass estimates agree to within ∼0.15 dex. The rest, on the other hand, exhibit exceptionally broad C IV profiles that overestimate virial masses by factors of 2-5 compared to Hα. As C IV is widely used to study BH demographics at high redshifts, we urgently need to revisit our analysis with a larger sample.

  5. Ultraviolet extinction in M-supergiant circumstellar envelopes

    International Nuclear Information System (INIS)

    Buss, R.H. Jr.; Snow, T.P. Jr.

    1986-01-01

    Using International Ultraviolet (IUS) archival low-dispersion spectra, ultraviolet spectral extinctions were derived for the circumstellar envelopes of two M supergiants: HD 60414 and HD 213310. The observed stellar systems belong to a class of widely-separated spectroscopic binaries that are called VV Cephei stars. The total extinction was calculated by dividing the reddened fluxes with unreddened comparison fluxes of similar stars (g B2.5 for HD 213310 and a normalized s+B3 for HD 60414) from the reference atlas. After substracting the interstellar extinctions, which were estimated from the E(B-V) reddening of nearby stars, the resultant circumstellar extinctions were normalized at about 3.5 inverse microns. Not only is the 2175 A extinction bump absent in the circumstellar extinctions, but the far-ultraviolet extinction rise is also absent. The rather flat, ultraviolet extinction curves were interpreted as signatures of a population of noncarbonaceous, oxygen-rich grains with diameters larger than the longest observed wavelength

  6. Trick or Treat and Telescopes

    Science.gov (United States)

    Buratti, Bonnie J.; Meinke, Bonnie K.; Schmude, Richard W.

    2017-10-01

    Based on an activity that DPS member Richard Schmude Jr. has been doing for years, with over 5000 children reached, DPS initiated in 2016 a pilot program entitled “Trick-or-Treat and Telescopes.” DPS encouraged its members to put out their telescopes during trick-or-treat time on Halloween, in their own lawns or in a neighbor’s lawn with better viewing (or more traffic). The program will be continued in 2017. This year should offer good viewing with a waxing gibbous moon and Saturn visible. The program was also advertised though the Night Sky Network, a consortium of astronomy clubs. The following website gives advice and connections to resources.https://dps.aas.org/education/trick-or-treat-and-telescopes acknowledged.

  7. Scientific management of Space Telescope

    Science.gov (United States)

    Odell, C. R.

    1981-01-01

    A historical summay is given on the science management of the Space Telescope, the inception of which began in 1962, when scientists and engineers first recommended the development of a nearly diffraction limited substantial-size optical telescope. Phase A, the feasibility requirements generation phase, began in 1971 and consisted largely of NASA scientists and a NASA design. Phase B, the preliminary design phase, established a tiered structure of scientists, led by the Large Space Telescope operations and Management Work Group. A Mission Operations Working Group headed six instrument definition teams to develop the essential instrument definitions. Many changes took place during Phase B, before design and development, which began in 1978 and still continues today.

  8. Space Telescope maintenance and refurbishment

    Science.gov (United States)

    Trucks, H. F.

    1983-01-01

    The Space Telescope (ST) represents a new concept regarding spaceborne astronomical observatories. Maintenance crews will be brought to the orbital worksite to make repairs and replace scientific instruments. For major overhauls the telescope can be temporarily returned to earth with the aid of the Shuttle. It will, thus, be possible to conduct astronomical studies with the ST for two decades or more. The five first-generation scientific instruments used with the ST include a wide field/planetary camera, a faint object camera, a faint object spectrograph, a high resolution spectrograph, and a high speed photometer. Attention is given to the optical telescope assembly, the support systems module, aspects of mission and science operations, unscheduled maintenance, contingency orbital maintenance, planned on-orbit maintenance, ground maintenance, ground refurbishment, and ground logistics.

  9. VizieR Online Data Catalog: Space telescope RM project. V. NGC5548 sp. monitoring (Pei+, 2017)

    Science.gov (United States)

    Pei, L.; Fausnaugh, M. M.; Barth, A. J.; Peterson, B. M.; Bentz, M. C.; De Rosa, G.; Denney, K. D.; Goad, M. R.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Pogge, R. W.; Bennert, V. N.; Brotherton, M.; Clubb, K. I.; Dalla Bonta, E.; Filippenko, A. V.; Greene, J. E.; Grier, C. J.; Vestergaard, M.; Zheng, W.; Adams, S. M.; Beatty, T. G.; Bigley, A.; Brown, J. E.; Brown, J. S.; Canalizo, G.; Comerford, J. M.; Coker, C. T.; Corsini, E. M.; Croft, S.; Croxall, K. V.; Deason, A. J.; Eracleous, M.; Fox, O. D.; Gates, E. L.; Henderson, C. B.; Holmbeck, E.; Holoien, T. W.-S.; Jensen, J. J.; Johnson, C. A.; Kelly, P. L.; Kim, S.; King, A.; Lau, M. W.; Li, M.; Lochhaas, C.; Ma, Z.; Manne-Nicholas, E. R.; Mauerhan, J. C.; Malkan, M. A.; McGurk, R.; Morelli, L.; Mosquera, A.; Mudd, D.; Sanchez, F. M.; Nguyen, M. L.; Ochner, P.; Ou-Yang, B.; Pancoast, A.; Penny, M. T.; Pizzella, A.; Poleski, R.; Runnoe, J.; Scott, B.; Schimoia, J. S.; Shappee, B. J.; Shivvers, I.; Simonian, G. V.; Siviero, A.; Somers, G.; Stevens, D. J.; Strauss, M. A.; Tayar, J.; Tejos, N.; Treu, T.; van Saders, J.; Vican, L.; Villanueva, S.; Yuk, H.; Zakamska, N. L.; Zhu, W.; Anderson, M. D.; Arevalo, P.; Bazhaw, C.; Bisogni, S.; Borman, G. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Cackett, E. M.; Carini, M. T.; Crenshaw, D. M.; de Lorenzo-Caceres, A.; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Ferland, G. J.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Grupe, D.; Gupta, A.; Hall, P. B.; Hicks, S.; Horenstein, D.; Horne, K.; Hutchison, T.; Im, M.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira, P.; Macinnis, F.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Netzer, H.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J.-U.; Rafter, S. E.; Rix, H.-W.; Saylor, D. A.; Schnulle, K.; Sergeev, S. G.; Siegel, M.; Skielboe, A.; Spencer, M.; Starkey, D.; Sung, H.-I.; Teems, K. G.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J.-H.; Yan, H.; Young, S.; Zu, Y.

    2017-10-01

    Spectroscopic data were obtained from five telescopes: the McGraw-Hill 1.3m telescope at the MDM Observatory (4225-5775Å; median S/N=118), the Shane 3m telescope at the Lick Observatory (Kast Double Spectrograph: 3250-7920Å; median S/N=194), the 1.22m Galileo telescope at the Asiago Astrophysical Observatory (3250-7920Å; median S/N=160), the 3.5m telescope at Apache Point Observatory (APO; Dual Imaging Spectrograph: 4180-5400Å, median S/N =160), and the 2.3m telescope at the Wyoming Infrared Observatory (WIRO; 5599-4399Å; median S/N=217). The optical spectroscopic monitoring targeting NGC 5548 began on 2014 January 4 and continued through 2014 July 6 with approximately daily cadence. MDM contributed the largest number of spectra with 143 epochs. (1 data file).

  10. LSST telescope and site status

    Science.gov (United States)

    Gressler, William J.

    2016-07-01

    The Large Synoptic Survey Telescope (LSST) Project1 received its construction authorization from the National Science Foundation in August 2014. The Telescope and Site (T and S) group has made considerable progress towards completion in subsystems required to support the scope of the LSST science mission. The LSST goal is to conduct a wide, fast, deep survey via a 3-mirror wide field of view optical design, a 3.2-Gpixel camera, and an automated data processing system. The summit facility is currently under construction on Cerro Pachón in Chile, with major vendor subsystem deliveries and integration planned over the next several years. This paper summarizes the status of the activities of the T and S group, tasked with design, analysis, and construction of the summit and base facilities and infrastructure necessary to control the survey, capture the light, and calibrate the data. All major telescope work package procurements have been awarded to vendors and are in varying stages of design and fabrication maturity and completion. The unique M1M3 primary/tertiary mirror polishing effort is completed and the mirror now resides in storage waiting future testing. Significant progress has been achieved on all the major telescope subsystems including the summit facility, telescope mount assembly, dome, hexapod and rotator systems, coating plant, base facility, and the calibration telescope. In parallel, in-house efforts including the software needed to control the observatory such as the scheduler and the active optics control, have also seen substantial advancement. The progress and status of these subsystems and future LSST plans during this construction phase are presented.

  11. The ultraviolet galactic background from TD-1 satellite observations

    International Nuclear Information System (INIS)

    Morgan, D.H.; Nandy, K.; Thompson, G.I.

    1976-01-01

    The background data from the S2/68 ultraviolet telescope on the TD-I satellite have been analysed. Using statistical tests those data contaminated by noise due to charged particles in the atmosphere have been discarded, and the remainder have been arranged to form ultraviolet profiles of the Galaxy. These profiles have been constructed at 2740 and 2350 A. The zodiacal light components of the total radiation field have been separated from the galactic components to give the intensity of the zodiacal light at elongation 90 0 as function of ecliptic latitude. The spectrum of the zodiacal light in the near ultraviolet is found to be redder than that of the Sun. The intensity of the diffuse galactic light as a function of galactic latitude has been obtained by subtraction of the zodiacal light and contributions due to faint stars calculated using an axi-symmetric model of the Galaxy. On comparison with predictions of the diffuse galactic light from a radiative transfer model it is found that the ratio of the albedos at 2350 and 2740 A is relatively insensitive to the model used, and is 0.73 +- 0.1. The albedo at 2740 A is found to be 0.65 +- 0.1 when g is assumed to be 0.75. (author)

  12. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    International Nuclear Information System (INIS)

    Brown, Peter J.

    2014-01-01

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the Type Ia supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observed—more than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 × 10 13 cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia

  13. A monolithic silicon detector telescope

    International Nuclear Information System (INIS)

    Cardella, G.; Amorini, F.; Cabibbo, M.; Di Pietro, A.; Fallica, G.; Franzo, G.; Figuera, P.; Papa, M.; Pappalardo, G.; Percolla, G.; Priolo, F.; Privitera, V.; Rizzo, F.; Tudisco, S.

    1996-01-01

    An ultrathin silicon detector (1 μm) thick implanted on a standard 400 μm Si-detector has been built to realize a monolithic telescope detector for simultaneous charge and energy determination of charged particles. The performances of the telescope have been tested using standard alpha sources and fragments emitted in nuclear reactions with different projectile-target colliding systems. An excellent charge resolution has been obtained for low energy (less than 5 MeV) light nuclei. A multi-array lay-out of such detectors is under construction to charge identify the particles emitted in reactions induced by low energy radioactive beams. (orig.)

  14. Artificial Intelligence in Autonomous Telescopes

    Science.gov (United States)

    Mahoney, William; Thanjavur, Karun

    2011-03-01

    Artificial Intelligence (AI) is key to the natural evolution of today's automated telescopes to fully autonomous systems. Based on its rapid development over the past five decades, AI offers numerous, well-tested techniques for knowledge based decision making essential for real-time telescope monitoring and control, with minimal - and eventually no - human intervention. We present three applications of AI developed at CFHT for monitoring instantaneous sky conditions, assessing quality of imaging data, and a prototype for scheduling observations in real-time. Closely complementing the current remote operations at CFHT, we foresee further development of these methods and full integration in the near future.

  15. Ultraviolet inactivation of papain

    International Nuclear Information System (INIS)

    Baugher, J.F.; Grossweiner, L.I.

    1975-01-01

    Flash photolysis transient spectra (lambda > 250 nm) of aqueous papain showed that the initial products are the neutral tryptophan radical Trp (lambdasub(max) 510 nm), the tryptophan triplet state 3 Trp (lambdasub(max) 460 nm), the disulfide bridge electron adduct -SS - - (lambdasub(max) 420 nm) and the hydrated electron esub(aq) - . The -SS - - yield was not altered by nitrous oxide or air, indicating that the formation of this product does not involve electrons in the external medium. The original papain preparation was activated by irradiating under nitrogen. The action spectrum supports previous work attributing the low initial activity to blocking of cysteinyl site 25 with a mixed disulfide. Flask lamp irradiation in nitrogen led to activation at low starting activities and inactivation at higher starting activities, while only inactivation at the same quantum yield was observed with air saturation. The results are consistent with photoionization of an essential tryptophyl residue as the key inactivating step. (author)

  16. Ultraviolet photodissociation dynamics of the benzyl radical.

    Science.gov (United States)

    Song, Yu; Zheng, Xianfeng; Lucas, Michael; Zhang, Jingsong

    2011-05-14

    Ultraviolet (UV) photodissociation dynamics of jet-cooled benzyl radical via the 4(2)B(2) electronically excited state is studied in the photolysis wavelength region of 228 to 270 nm using high-n Rydberg atom time-of-flight (HRTOF) and resonance enhanced multiphoton ionization (REMPI) techniques. In this wavelength region, H-atom photofragment yield (PFY) spectra are obtained using ethylbenzene and benzyl chloride as the precursors of benzyl radical, and they have a broad peak centered around 254 nm and are in a good agreement with the previous UV absorption spectra of benzyl. The H + C(7)H(6) product translational energy distributions, P(E(T))s, are derived from the H-atom TOF spectra. The P(E(T)) distributions peak near 5.5 kcal mol(-1), and the fraction of average translational energy in the total excess energy, , is ∼0.3. The P(E(T))s indicate the production of fulvenallene + H, which was suggested by recent theoretical studies. The H-atom product angular distribution is isotropic, with the anisotropy parameter β ≈ 0. The H/D product ratios from isotope labeling studies using C(6)H(5)CD(2) and C(6)D(5)CH(2) are reasonably close to the statistical H/D ratios, suggesting that the H/D atoms are scrambled in the photodissociation of benzyl. The dissociation mechanism is consistent with internal conversion of the electronically excited benzyl followed by unimolecular decomposition of the hot benzyl radical on the ground state.

  17. The use of an ultra-violet camera in the atmospheric Cherenkov technique

    International Nuclear Information System (INIS)

    Urban, M.; Fleury, P.; Kerrick, A.D.; Pare, E.; Vacanti, G.

    1996-01-01

    The atmospheric Cherenkov technique for gamma ray astronomy is shown to be feasible using an ultraviolet (UV) camera on moon-lit-nights. The Whipple telescope has been used as the reflector and the CRab Nebula as the standard gamma ray beam. Our energy threshold is 1.2 TeV which is compared to 0.4 TeV in the visible. (orig.)

  18. The Lunar Transit Telescope (LTT) - An early lunar-based science and engineering mission

    Science.gov (United States)

    Mcgraw, John T.

    1992-01-01

    The Sentinel, the soft-landed lunar telescope of the LTT project, is described. The Sentinel is a two-meter telescope with virtually no moving parts which accomplishes an imaging survey of the sky over almost five octaves of the electromagnetic spectrum from the ultraviolet into the infrared, with an angular resolution better than 0.1 arsec/pixel. The Sentinel will incorporate innovative techniques of interest for future lunar-based telescopes and will return significant engineering data which can be incorporated into future lunar missions. The discussion covers thermal mapping of the Sentinel, measurement of the cosmic ray flux, lunar dust, micrometeoroid flux, the lunar atmosphere, and lunar regolith stability and seismic activity.

  19. Portable triple silicon detector telescope spectrometer for skin dosimetry

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Larsen, H.E.; Christensen, P.

    1999-01-01

    The features of a newly developed portable beta telescope spectrometer are described. The detector probe uses three silicon detectors with the thickness: 50 mu m/150 mu m/7000 mu m covered by a 2 mu m thick titanium window. Rejection of photon contributions from mixed beta/photon exposures...... is achieved by coincidence requirements between the detector signals. The silicon detectors, together with cooling aggregate, bias supplies, preamplifiers and charge generation for calibration are contained in a handy detector probe. Through a 3- or 10-m cable the detector unit is connected to a compact...... detectors. The LabVIEW(TM) software distributed by National Instruments was used for all program developments for the spectrometer, comprising also the capability of evaluating the absorbed dose rates from the measured beta spectra. The report describes the capability of the telescope spectrometer...

  20. The Phobos low energy telescope charged particle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

    1990-05-01

    The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

  1. Ultraviolet-resonance femtosecond stimulated Raman study of the initial events in photoreceptor chromophore

    Directory of Open Access Journals (Sweden)

    Tahara T.

    2013-03-01

    Full Text Available Newly-developed ultraviolet-resonance femtosecond stimulated-Raman spectroscopy was utilized to study the initial structural evolution of photoactive yellow protein chromophore in solution. The obtained spectra changed drastically within 1 ps, demonstrating rapid in-plane deformations of the chromophore.

  2. Harmful effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

  3. Future Directions in Ultraviolet Spectroscopy

    Science.gov (United States)

    Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

    2009-01-01

    The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

  4. Neutrino telescopes in the World

    International Nuclear Information System (INIS)

    Ernenwein, J.-P.

    2007-01-01

    Neutrino astronomy has rapidly developed these last years, being the only way to get specific and reliable information about astrophysical objects still poorly understood.Currently two neutrino telescopes are operational in the World: BAIKAL, in the lake of the same name in Siberia, and AMANDA, in the ices of the South Pole. Two telescopes of the same type are under construction in the Mediterranean Sea: ANTARES and NESTOR. All these telescopes belong to a first generation, with an instrumented volume smaller or equal to 0.02 km3. Also in the Mediterranean Sea, the NEMO project is just in its starting phase, within the framework of a cubic kilometer size neutrino telescope study. Lastly, the ICECUBE detector, with a volume reaching about 1 km3, is under construction on the site of AMANDA experiment, while an extension of the BAIKAL detector toward km3 is under study. We will present here the characteristics of these experiments, as well as the results of their observations

  5. Push-To Telescope Mathematics

    Science.gov (United States)

    Teets, Donald

    2012-01-01

    Two coordinate systems are related here, one defined by the earth's equator and north pole, the other by the orientation of a telescope at some location on the surface of the earth. Applying an interesting though somewhat obscure property of orthogonal matrices and using the cross-product simplifies this relationship, revealing that a surprisingly…

  6. GISOT: a giant solar telescope

    Science.gov (United States)

    Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil, Felix C.; Jägers, Aswin P.; Snik, Frans

    2004-10-01

    A concept is presented for an extremely large high-resolution solar telescope with an aperture of 11 m and diffraction limited for visual wavelengths. The structure of GISOT will be transparent to wind and placed on a transparent stiff tower. For efficient wind flushing, all optics, including the primary mirror, will be located above the elevation axis. The aperture will be of the order of 11 m, not rotatively symmetrical, but of an elongated shape with dimensions 11 x 4 m. It consists of a central on-axis 4 m mirror with on both sides 3 pieces of 2 m mirrors. The optical layout will be kept simple to guarantee quality and minimize stray light. A Coudé room for instruments is planned below the telescope. The telescope will not be housed in a dome-like construction, which interferes with the open principle. Instead the telescope will be protected by a foldable tent construction with a diameter of the order of 30 m, which doesn"t form any obstruction during observations, but can withstand the severe weather circumstances on mountain sites. Because of the nature of the solar scene, extremely high resolution in only one dimension is sufficient to solve many exciting problems in solar physics and in this respect the concept of GISOT is very promising.

  7. The Thirty-Meter Telescope

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The Thirty-Meter Telescope international observatory will enable transformational observations over the full cosmic timeline all the way from the first luminous objects in the Universe to the planets and moons of our own solar system. To realize its full scientific potential, TMT will be equipped with a powerful ...

  8. Monster telescope hunts blue planets

    CERN Multimedia

    Leake, J

    2003-01-01

    BRITAIN is to back a project to build the world's biggest telescope - so powerful that it could see life-bearing planets in other solar systems. It will need the largest mirror ever built at about 100 metres in diameter (1/2 page).

  9. Hubble Space Telescope Image of Omega Nebula

    Science.gov (United States)

    2002-01-01

    This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

  10. Grism and immersion grating for space telescope

    Science.gov (United States)

    Ebizuka, Noboru; Oka, Kiko; Yamada, Akiko; Ishikawa, Mami; Kashiwagi, Masako; Kodate, Kashiko; Hirahara, Yasuhiro; Sato, Shuji; Kawabata, Koji S.; Wakaki, Moriaki; Morita, Shin-ya; Simizu, Tomoyuki; Yin, Shaohui; Omori, Hitoshi; Iye, Masanori

    2017-11-01

    The grism is a versatile dispersion element for an astronomical instrument ranging from ultraviolet to infrared. Major benefit of using a grism in a space application, instead of a reflection grating, is the size reduction of optical system because collimator and following optical elements could locate near by the grism. The surface relief (SR) grism is consisted a transmission grating and a prism, vertex angle of which is adjusted to redirect the diffracted beam straight along the direct vision direction at a specific order and wavelength. The volume phase holographic (VPH) grism consists a thick VPH grating sandwiched between two prisms, as specific order and wavelength is aligned the direct vision direction. The VPH grating inheres ideal diffraction efficiency on a higher dispersion application. On the other hand, the SR grating could achieve high diffraction efficiency on a lower dispersion application. Five grisms among eleven for the Faint Object Camera And Spectrograph (FOCAS) of the 8.2m Subaru Telescope with the resolving power from 250 to 3,000 are SR grisms fabricated by a replication method. Six additional grisms of FOCAS with the resolving power from 3,000 to 7,000 are VPH grisms. We propose "Quasi-Bragg grism" for a high dispersion spectroscopy with wide wavelength range. The germanium immersion grating for instance could reduce 1/64 as the total volume of a spectrograph with a conventional reflection grating since refractive index of germanium is over 4.0 from 1.6 to 20 μm. The prototype immersion gratings for the mid-InfraRed High dispersion Spectrograph (IRHS) are successfully fabricated by a nano-precision machine and grinding cup of cast iron with electrolytic dressing method.

  11. Overdenture dengan Pegangan Telescopic Crown

    Directory of Open Access Journals (Sweden)

    Pambudi Santoso

    2014-06-01

    Full Text Available Kaitan presisi merupakan alat retensi mekanis yang menghubungkan antara satu atau lebih pegangan gigi tiruan, yang bertujuan untuk menambah retensi dan/atau stabilisasi. Kaitan presisi dapat digunakan secara luas pada gigi tiruan cekat, gigi tiruan sebagian lepasan, overdenture, implant untuk retensi overdenture, dan protesa maksilo fasial. Overdenture dengan kaitan presisi dapat membantu dalam pembagian beban kunyah, meminimalkan trauma pada gigi pegangan dan jaringan lunak, meminimalkan resorbsi tulang, dan meningkatkan estetik dan pengucapan suara. Salah satu jenis dari kaitan presisi adalah telescopic crown, terdiri dari 2 macam mahkota, yaitu mahkota primer yang melekat secara permanen pada gigi penyangga, dan mahkota sekunder yang melekat pada gigi tiruan. Tujuan pemaparan kasus ini adalah untuk memberikan informasi tentang rehabilitasi pasien edentulous sebagian rahang atas dengan telescopic crown..  Pasien wanita berusia 45 tahun datang ke klinik prostodonsia RSGM Prof.Soedomo dengan keluhan ingin dibuatkan gigi tiruan. Pasien kehilangan gigi 11 12 15 16 17 21 22 24 25 26 dan 27 yang diindikasikan untuk pembuatan overdenture gigi tiruan sebagian lepasan (GTS kerangka logam dengan pegangan telescopic crown pada gigi 13 dan 14 dengan sistem parallel-sided crown. Tahap-tahap pembuatan telescopic crown yaitu mencetak model study dengan catatan gigit pendahuluan. Perawatan saluran dilakukan pada akar gigi 13, dilanjutkan pemasangan pasak fiber serta rewalling dinding bukal. Gigi 13 dan 14 dilakukan preparasi mahkota penuh, dilanjutkan dengan pencetakan model kerja untuk coping primer dan kerangka logam dengan metode double impression. Coping primer disementasi pada gigi penyangga, dilanjutkan pasang coba coping sekunder beserta kerangka logam. Selanjutnya dilakukan pencatatan gigit, pencetakan model kerja, penyusunan gigi dan pasang coba penyusunan gigi pada pasien. Prosedur dilanjutkan dengan proses di laboratorium, serta insersi pada

  12. Characterizing Sky Spectra Using SDSS BOSS Data

    Science.gov (United States)

    Florez, Lina Maria; Strauss, Michael A.

    2018-01-01

    In the optical/near-infrared spectra gathered by a ground-based telescope observing very faint sources, the strengths of the emission lines due to the Earth’s atmosphere can be many times larger than the fluxes of the sources we are interested in. Thus the limiting factor in faint-object spectroscopy is the degree to which systematics in the sky subtraction can be minimized. Longwards of 6000 Angstroms, the night-sky spectrum is dominated by multiple vibrational/rotational transitions of the OH radical from our upper atmosphere. While the wavelengths of these lines are the same in each sky spectrum, their relative strengths vary considerably as a function of time and position on the sky. The better we can model their strengths, the better we can hope to subtract them off. We expect that the strength of lines from common upper energy levels will be correlated with one another. We used flux-calibrated sky spectra from the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (SDSS BOSS) to explore these correlations. Our aim is to use these correlations for creating improved sky subtraction algorithms for the Prime Focus Spectrograph (PFS) on the 8.2-meter Subaru Telescope. When PFS starts gathering data in 2019, it will be the most powerful multi-object spectrograph in the world. Since PFS will be gathering data on sources as faint as 24th magnitude and fainter, it's of upmost importance to be able to accurately measure and subtract sky spectra from the data that we receive.

  13. Variability of the BL Lacertae objects PKS 2155 - 304 and OJ 287 in the far-ultraviolet

    International Nuclear Information System (INIS)

    Maraschi, L.; Treves, A.; Tagliaferri, G.; Tanzi, E.G.; CNR, Istituto di Fisica Cosmica, Milan, Italy)

    1986-01-01

    All the ultraviolet spectra of the two bright BL Lacertae objects PKS 2155 - 304 and OJ 287 taken with the International Ultraviolet Explorer in the period 1978-1984 are examined. For each spectrum the best-fitting power law is determined and a correlation between spectral slope and intensity is searched for. The correlation, if present, is weak. This is discussed in terms of models of the continuum emission of active galactic nuclei. 31 references

  14. Variability of the BL Lacertae objects PKS 2155 - 304 and OJ 287 in the far-ultraviolet

    Energy Technology Data Exchange (ETDEWEB)

    Maraschi, L.; Treves, A.; Tagliaferri, G.; Tanzi, E.G.

    1986-05-01

    All the ultraviolet spectra of the two bright BL Lacertae objects PKS 2155 - 304 and OJ 287 taken with the International Ultraviolet Explorer in the period 1978-1984 are examined. For each spectrum the best-fitting power law is determined and a correlation between spectral slope and intensity is searched for. The correlation, if present, is weak. This is discussed in terms of models of the continuum emission of active galactic nuclei. 31 references.

  15. The Dutch Open Telescope: History, Status, Prospects

    NARCIS (Netherlands)

    Rutten, R.J.

    1999-01-01

    After many years of persistent telescope design and telescope construction, R.H. Hammerschlag has installed his Dutch Open Telescope (DOT) on La Palma. I brie y review its history and design. The future of optical solar physics at Utrecht hinges on a recently-funded three- year DOT science

  16. Results from the ANTARES neutrino telescope

    Directory of Open Access Journals (Sweden)

    Losa Agustín Sánchez

    2017-01-01

    Full Text Available The ANTARES detector is an underwater neutrino telescope, the largest in the Northern Hemisphere and the first one ever built under the sea, located in the Mediterranean Sea 40 km off the Southern coast of France, at a depth of 2.5 km. It comprises 885 photomultiplier tubes distributed along twelve detection lines. The signal due to neutrinos is searched by reconstructing the tracks of secondary particles produced in the surroundings of the detector. The detector is in data taking with its final configuration since 2008. It is aimed at identifying the sources, either steady or flaring, of cosmic neutrinos, and is also suitable for detection of dark matter within the Sun and/or Galactic Centre. ANTARES can contribute in the confirmation of the cosmic neutrino flux observed by IceCube, being particularly competitive for the Galactic Centre, and in general for galactic sources, due its latitude and at lower energies and softer spectra due its configuration. Several multi-messenger analyses have been also attempted, including the search of coincidence signals of neutrinos with gravitational-waves. Additional topics include neutrino oscillations or the search of exotic particles, like nuclearites and magnetic monopoles. Results from the latest analyses are presented.

  17. DynamiX, numerical tool for design of next-generation x-ray telescopes.

    Science.gov (United States)

    Chauvin, Maxime; Roques, Jean-Pierre

    2010-07-20

    We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

  18. DynamiX, numerical tool for design of next-generation x-ray telescopes

    International Nuclear Information System (INIS)

    Chauvin, Maxime; Roques, Jean-Pierre

    2010-01-01

    We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

  19. DynamiX, numerical tool for design of next-generation x-ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Chauvin, Maxime; Roques, Jean-Pierre

    2010-07-20

    We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

  20. Solar Energetic Particle Spectra

    Science.gov (United States)

    Ryan, J. M.; Boezio, M.; Bravar, U.; Bruno, A.; Christian, E. R.; de Nolfo, G. A.; Martucci, M.; Mergè, M.; Munini, R.; Ricci, M.; Sparvoli, R.; Stochaj, S.

    2017-12-01

    We report updated event-integrated spectra from several SEP events measured with PAMELA. The measurements were made from 2006 to 2014 in the energy range starting at 80 MeV and extending well above the neutron monitor threshold. The PAMELA instrument is in a high inclination, low Earth orbit and has access to SEPs when at high latitudes. Spectra have been assembled from these high-latitude measurements. The field of view of PAMELA is small and during the high-latitude passes it scans a wide range of asymptotic directions as the spacecraft orbits. Correcting for data gaps, solid angle effects and improved background corrections, we have compiled event-integrated intensity spectra for twenty-eight SEP events. Where statistics permit, the spectra exhibit power law shapes in energy with a high-energy exponential roll over. The events analyzed include two genuine ground level enhancements (GLE). In those cases the roll-over energy lies above the neutron monitor threshold ( 1 GV) while the others are lower. We see no qualitative difference between the spectra of GLE vs. non-GLE events, i.e., all roll over in an exponential fashion with rapidly decreasing intensity at high energies.

  1. The Atacama Cosmology Telescope: cross correlation with Planck maps

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Thibaut; Calabrese, Erminia; Dunkley, Joanna; Næss, Sigurd [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Addison, Graeme E.; Hincks, Adam D. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hasselfield, Matthew; Hlozek, Renée [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Bond, J. Richard; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [Argonne National Laboratory, 9700 S. Cass Ave., Lemont, IL 60439 (United States); Devlin, Mark J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, U.S.A (United States); Dünner, Rolando; Infante, Leopoldo [Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Gralla, Megan; Marriage, Tobias A. [Dept. of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Huffenberger, Kevin [Department of Physics, Florida State University, Keen Physics Building, 77 Chieftan Way, Tallahassee, Florida (United States); Kosowsky, Arthur [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban, 4041 (South Africa); Niemack, Michael D., E-mail: Thibaut.Louis@astro.ox.ac.uk [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); and others

    2014-07-01

    We present the temperature power spectrum of the Cosmic Microwave Background obtained by cross-correlating maps from the Atacama Cosmology Telescope (ACT) at 148 and 218 GHz with maps from the Planck satellite at 143 and 217 GHz, in two overlapping regions covering 592 square degrees. We find excellent agreement between the two datasets at both frequencies, quantified using the variance of the residuals between the ACT power spectra and the ACT × Planck cross-spectra. We use these cross-correlations to measure the calibration of the ACT data at 148 and 218 GHz relative to Planck, to 0.7% and 2% precision respectively. We find no evidence for anisotropy in the calibration parameter. We compare the Planck 353 GHz power spectrum with the measured amplitudes of dust and cosmic infrared background (CIB) of ACT data at 148 and 218 GHz. We also compare planet and point source measurements from the two experiments.

  2. Focusing Telescopes in Nuclear Astrophysics

    CERN Document Server

    Ballmoos, Peter von

    2007-01-01

    This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

  3. The Atacama Cosmology Telescope: Instrument

    Science.gov (United States)

    Thornton, Robert J.; Atacama Cosmology Telescope Team

    2010-01-01

    The 6-meter Atacama Cosmology Telescope (ACT) is making detailed maps of the Cosmic Microwave Background at Cerro Toco in northern Chile. In this talk, I focus on the design and operation of the telescope and its commissioning instrument, the Millimeter Bolometer Array Camera. The camera contains three independent sets of optics that operate at 148 GHz, 217 GHz, and 277 GHz with arcminute resolution, each of which couples to a 1024-element array of Transition Edge Sensor (TES) bolometers. I will report on the camera performance, including the beam patterns, optical efficiencies, and detector sensitivities. Under development for ACT is a new polarimeter based on feedhorn-coupled TES devices that have improved sensitivity and are planned to operate at 0.1 K.

  4. Backyard Telescopes Watch an Expanding Binary

    Science.gov (United States)

    Kohler, Susanna

    2018-01-01

    What can you do with a team of people armed with backyard telescopes and a decade of patience? Test how binary star systems evolve under Einsteins general theory of relativity!Unusual VariablesCataclysmic variables irregularly brightening binary stars consisting of an accreting white dwarf and a donor star are a favorite target among amateur astronomers: theyre detectable even with small telescopes, and theres a lot we can learn about stellar astrophysics by observing them, if were patient.Diagram of a cataclysmic variable. In an AM CVn, the donor is most likely a white dwarf as well, or a low-mass helium star. [Philip D. Hall]Among the large family of cataclysmic variables is one unusual type: the extremely short-period AM Canum Venaticorum (AM CVn) stars. These rare variables (only 40 are known) are unique in having spectra dominated by helium, suggesting that they contain little or no hydrogen. Because of this, scientists have speculated that the donor stars in these systems are either white dwarfs themselves or very low-mass helium stars.Why study AM CVn stars? Because their unusual configuration allows us to predict the behavior of their orbital evolution. According to the general theory of relativity, the two components of an AM CVn will spiral closer and closer as the system loses angular momentum to gravitational-wave emission. Eventually they will get so close that the low-mass companion star overflows its Roche lobe, beginning mass transfer to the white dwarf. At this point, the orbital evolution will reverse and the binary orbit will expand, increasing its period.CBA member Enrique de Miguel, lead author on the study, with his backyard telescope in Huelva, Spain. [Enrique de Miguel]Backyard Astronomy Hard at WorkMeasuring the evolution of an AM CVns orbital period is the best way to confirm this model, but this is no simple task! To observe this evolution, we first need a system with a period that can be very precisely measured best achieved with an

  5. Ultraviolet light and cutaneous lupus

    NARCIS (Netherlands)

    Bijl, Marc; Kallenberg, Cees G. M.

    2006-01-01

    Exposure to ultraviolet (UV) light is one of the major factors known to trigger cutaneous disease activity in (systemic) lupus erythematosus patients. UV light, UVB in particular, is a potent inducer of apoptosis. Currently, disturbed clearance of apoptotic cells is one of the concepts explaining

  6. RHCV Telescope System Operations Manual

    Science.gov (United States)

    2018-01-05

    KRISTOFFER A. SMITH-RODRIGUEZ, LTCOL, USAF Chief, Warfighter Interface Division Airman Systems Directorate This report is published in the...other system components via ASCOM protocols. 1. Start the MaxImDL application using the desktop shortcut (a) Start Observatory dialog, (b...the desktop shortcut (a) Select “Connect Telescope” from Startup menu in Telescope tab (b) Select “Look Up” icon on ribbon menu at the top right of

  7. Telescopic Overdenture: A Case Report

    OpenAIRE

    Shruthi, C. S.; Poojya, R.; Ram, Swati; Anupama,

    2017-01-01

    Patient: This report describes the case of a 68 year old female patient who presented with the chief complaint of difficulty in chewing and poor aesthetics due to missing teeth. The patient was interested in saving the remaining natural teeth and desired minimal tissue coverage from the prosthesis. After consideration of all the factors involved, it was deemed advisable to resort to a palate free maxillary telescopic complete denture and a mandibular removable partial denture. Discussion: Con...

  8. Telescopic mine roof-support

    Energy Technology Data Exchange (ETDEWEB)

    Piscitelli, A

    1989-05-17

    A mining roof support which includes a main body consisting of a pair of telescopically associated elongated members and which slide relative to each other to extend the support, engaging one of the members. A locking plate which is movable into engagement with the member by means of a lever operated cam causes tilting of the plate to engage the member and then to raise the member and lock it in the raised position. 1 fig.

  9. Telescopic Overdenture: A Case Report

    Science.gov (United States)

    Shruthi, C. S.; Poojya, R.; Ram, Swati; Anupama

    2017-01-01

    Patient: This report describes the case of a 68 year old female patient who presented with the chief complaint of difficulty in chewing and poor aesthetics due to missing teeth. The patient was interested in saving the remaining natural teeth and desired minimal tissue coverage from the prosthesis. After consideration of all the factors involved, it was deemed advisable to resort to a palate free maxillary telescopic complete denture and a mandibular removable partial denture. Discussion: Considering the age of the patient and the cost involved, implant supported prosthesis was ruled out as a treatment option for the patient. A telescopic denture was chosen as a favourable treatment option since it overcomes many of the problems posed by conventional complete dentures like progressive bone loss, lower stability and retention, loss of periodontal proprioception and low masticatory efficiency. It also provides minimal tissue coverage and better distribution of forces. Evaluation of occlusion, esthetics, phonetics and comfort after 24 hours, 1 week and 1 month of treatment showed that the patient was happy with the prosthesis and was able to speak and chew well. Conclusion: Telescopic overdentures have better retention and stability as compared to conventional complete dentures. They improve the chewing efficiency, patient comfort and also decrease the alveolar bone resorption. As such they are an excellent alternative to conventional complete denture treatment. PMID:28533736

  10. Black holes at neutrino telescopes

    International Nuclear Information System (INIS)

    Kowalski, M.; Ringwald, A.; Tu, H.

    2002-01-01

    In scenarios with extra dimensions and TeV-scale quantum gravity, black holes are expected to be produced in the collision of light particles at center-of-mass energies above the fundamental Planck scale with small impact parameters. Black hole production and evaporation may thus be studied in detail at the large hadron collider (LHC). But even before the LHC starts operating, neutrino telescopes such as AMANDA/IceCube, ANTARES, Baikal, and RICE have an opportunity to search for black hole signatures. Black hole production in the scattering of ultrahigh energy cosmic neutrinos on nucleons in the ice or water may initiate cascades and through-going muons with distinct characteristics above the Standard Model rate. In this Letter, we investigate the sensitivity of neutrino telescopes to black hole production and compare it to the one expected at the Pierre Auger Observatory, an air shower array currently under construction, and at the LHC. We find that, already with the currently available data, AMANDA and RICE should be able to place sensible constraints in black hole production parameter space, which are competitive with the present ones from the air shower facilities Fly's Eye and AGASA. In the optimistic case that a ultrahigh energy cosmic neutrino flux significantly higher than the one expected from cosmic ray interactions with the cosmic microwave background radiation is realized in nature, one even has discovery potential for black holes at neutrino telescopes beyond the reach of LHC. (orig.)

  11. Academic Training: Deep Space Telescopes

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22, 23, 24 February from 11:00 to 12:00 - Council Chamber on 20, 21, 23, 24 February, TH Auditorium, bldg 4 - 3-006, on 22 February Deep Space Telescopes G. BIGNAMI / CNRS, Toulouse, F & Univ. di Pavia, I The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo's telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics thro...

  12. EUSO-TA prototype telescope

    Energy Technology Data Exchange (ETDEWEB)

    Bisconti, Francesca, E-mail: francesca.bisconti@kit.edu

    2016-07-11

    EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

  13. The NASA Spitzer Space Telescope.

    Science.gov (United States)

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  14. Telescopic Overdenture: A Case Report.

    Science.gov (United States)

    Shruthi, C S; Poojya, R; Ram, Swati; Anupama

    2017-03-01

    This report describes the case of a 68 year old female patient who presented with the chief complaint of difficulty in chewing and poor aesthetics due to missing teeth. The patient was interested in saving the remaining natural teeth and desired minimal tissue coverage from the prosthesis. After consideration of all the factors involved, it was deemed advisable to resort to a palate free maxillary telescopic complete denture and a mandibular removable partial denture. Considering the age of the patient and the cost involved, implant supported prosthesis was ruled out as a treatment option for the patient. A telescopic denture was chosen as a favourable treatment option since it overcomes many of the problems posed by conventional complete dentures like progressive bone loss, lower stability and retention, loss of periodontal proprioception and low masticatory efficiency. It also provides minimal tissue coverage and better distribution of forces. Evaluation of occlusion, esthetics, phonetics and comfort after 24 hours, 1 week and 1 month of treatment showed that the patient was happy with the prosthesis and was able to speak and chew well. Telescopic overdentures have better retention and stability as compared to conventional complete dentures. They improve the chewing efficiency, patient comfort and also decrease the alveolar bone resorption. As such they are an excellent alternative to conventional complete denture treatment.

  15. EUSO-TA prototype telescope

    Science.gov (United States)

    Bisconti, Francesca; JEM-EUSO Collaboration

    2016-07-01

    EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

  16. A climatology of visible surface reflectance spectra

    International Nuclear Information System (INIS)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-01-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290–740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment–2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes. - Highlights: • Our goals was visible surface reflectance for satellite trace gas measurements. • Captured the range of surface reflectance spectra through EOF analysis. • Used satellite surface reflectance products for each given scene to anchor EOFs. • Generated a climatology of time/geometry dependent surface reflectance spectra. • Demonstrated potential to

  17. New advances in protection against solar ultraviolet radiation in textiles for summer clothing.

    Science.gov (United States)

    Aguilera, José; de Gálvez, María Victoria; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

    2014-01-01

    Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection. © 2014 The American Society of Photobiology.

  18. Twin-Telescope Wettzell (TTW)

    Science.gov (United States)

    Hase, H.; Dassing, R.; Kronschnabl, G.; Schlüter, W.; Schwarz, W.; Lauber, P.; Kilger, R.

    2007-07-01

    Following the recommendations made by the VLBI2010 vision report of the IVS, a proposal has been made to construct a Twin Telescope for the Fundamental Station Wettzell in order to meet the future requirements of the next VLBI generation. The Twin Telescope consists of two identical radiotelescopes. It is a project of the Federal Agency for Cartography and Geodesy (BKG). This article summarizes the project and some design ideas for the Twin-Telescope. %ZALMA (2005). Technical Specification for Design, Manufacturing, Transport and Integration on Site of the ALMA ANTENNAS, Doc. ALMA-34.00.00.00.006-BSPE. Behrend, D. (2006). VLBI2010 Antenna Specs, Data sheet. DeBoer, D. (2001). The ATA Offset Gregorian Antenna, ATA Memo #16, February 10. Imbriale, W.A. (2006). Design of a Wideband Radio Telescope, Jet Propulsion Laboratory and S. Weinreb and H. Mandi, California Institute of Technology. Kilger, R. (2007). TWIN-Design studies, Presentation for the IVS board members (internal document),Wettzell. Kronschnabl, G. (2006). Subject: Memo from Bill Petrachenko, E-mail to the Twin-Working Group (in German), July. Lindgren, ETS-Lindgren (2005). The Model 3164-05 Open Boundary Quadridge Horn, Data Sheet. Niell, A., A. Whitney, W. Petrachenko, W. Schlüter, N. Vandenberg, H.Hase, Y. Koyama, C. Ma, H. Schuh, G. Tucari (2006). in: IVS Annual Report 2005, pg. 13-40, NASA/TP-2006-214136, April. Olsson, R., Kildal, P.-S., and Weinreb, S. (2006). IEEE Transactions on Antennas and Propagation, Vol. 54, No. 2, February. Petrachenko, B. (2006). The Case For and Against Multiple Antennas at a Site, IVS Memorandum, 2006-019v01. Petrachenko, B. (2006). IVS Memorandum, 2006-016v01. RFSpin (2004). Double Ridged Waveguide Horn-Model DRH20, Antenna Specifications, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Crossed Log- Periodic Antennas HL024A1/S1, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Log-Periodic Antennas HL050/HL050S1, Data Sheet. Rogers, A.E.E. (2006). Simulations of broadband

  19. Those Crafty Cepheids: Surprises From Ground-Based Photometry and HST-COS FUV Spectra

    Science.gov (United States)

    Engle, Scott G.; Guinan, E. F.; Neilson, H.; Wasatonic, R. P.; Harper, G.

    2013-06-01

    Several years ago the Secret Lives of Cepheids (SLiC) program was initiated to look for unexpected or exotic behaviors from Cepheids. Regular photometric monitoring of Cepheids already possessing robust historical datasets was started to better understand long-term pulsation period changes, but to look for possible amplitude changes as well. At the time, only two “unusual” Cepheids were known to have undergone amplitude changes - Polaris and V473 Lyr. To date, however, the SLiC program has found evidence for amplitude changes in seven other Cepheids, raising the possibility that a "Blazhko effect" could be at work in certain Cepheids, as exists in a subset of RR Lyr stars. As the program expanded, we found that previous International Ultraviolet Exporer (IUE) studies showed certain Cepheids to have UV emissions from warm-to-hot stellar atmospheres. On top of that, the emissions were variable and well-phased to the stellar pulsation period, indicating that the mechanism heating the Cepheid atmosphere was influenced by these pulsations, if not linked to them. With the installation of the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST), a modern, high-quality UV spectrograph was now operating that could efficiently obtain high-resolution spectra of the Cepheids. We have been fortunate to observe four Cepheids to date with COS, and the results are well beyond anything IUE had led us to expect. Here we will present the current optical and UV results of the SLiC program, the implications of the results, and the future direction and expansion of the program. We gratefully acknowledge support for this program from HST grants HST-GO-11726.01-A, HST-GO-12302.01-A and HST-GO-13019.01-A, as well as NSF/RUI grant AST-1009903.

  20. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  1. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    International Nuclear Information System (INIS)

    Shin, Joong-Won; Bernstein, Elliot R.

    2014-01-01

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5 ′ -monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results

  2. Parameterization of rotational spectra

    International Nuclear Information System (INIS)

    Zhou Chunmei; Liu Tong

    1992-01-01

    The rotational spectra of the strongly deformed nuclei with low rotational frequencies and weak band mixture are analyzed. The strongly deformed nuclei are commonly encountered in the rare-earth region (e. g., 150 220). A lot of rotational band knowledge are presented

  3. Atomic Spectra Database (ASD)

    Science.gov (United States)

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  4. Configuration interaction in charge exchange spectra of tin and xenon

    Science.gov (United States)

    D'Arcy, R.; Morris, O.; Ohashi, H.; Suda, S.; Tanuma, H.; Fujioka, S.; Nishimura, H.; Nishihara, K.; Suzuki, C.; Kato, T.; Koike, F.; O'Sullivan, G.

    2011-06-01

    Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

  5. Far-ultraviolet observations of comet C/2012 S1 (ISON) with a sounding-rocket-borne instrument

    Science.gov (United States)

    Feldman, P.; McCandliss, S.; Weaver, H.; Fleming, B.; Redwine, K.; Li, M.; Kutyrev, A.; Moseley, S.

    2014-07-01

    We report on a far-ultraviolet observation of comet C/2012 S1 (ISON) made from a Black Brant IX sounding rocket that was launched on 20 November 2013 at 04:40 MST from the White Sands Missile Range, New Mexico, when the comet was 0.44 au from the Sun, 0.86 au from the Earth, and at a solar elongation of 26.3 degrees pre-perihelion. At the time of launch the comet was 0.1 degrees below ground horizon. The payload reached an apogee of 279 km and the total time pointed at the comet was 353 s. The sounding rocket borne instrument was our wide-field multi-object spectro-telescope called FORTIS (Far-UV Off Rowland-circle Telescope for Imaging and Spectroscopy), which is a Gregorian telescope (concave primary and secondary optics) with a triaxial figured diffractive secondary that provides an on-axis imaging channel and two off-axis spectral channels in a common focal plane. A multi-object spectroscopic capability is provided by an array of microshutters placed at the prime focus of the telescope. Our microshutter array (MSA) is based on prototype devices of the large area arrays developed at Goddard Space Flight Center (GSFC) for use in the Near Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST). The imaging channel on FORTIS has a field-of-view (FOV) of 0.5 degrees square. The MSA allows selection of up to 43 individual regions, each with a solid angle of 12.4'' × 36.9'', for spectral acquisition over the 800--1950 Ångstroms bandpass at a resolution of 6 Ångstroms. However a problem with addressing the MSA prevented the acquisition of spectra through individual slits. Nonetheless spectrally confused images, dominated by Lyman-alpha emission from the comet, were acquired in both off-axis spectral channels. The imaging channel uses a CaF_2/MgF_2 cylindrical doublet to correct for astigmatism introduced by the triaxial secondary, which restricts the bandpass to wavelengths longward of 1280 Ångstroms. The corrected imaging resolution is

  6. A NEW CONCEPT FOR SPECTROPHOTOMETRY OF EXOPLANETS WITH SPACE-BORNE TELESCOPES

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Taro; Itoh, Satoshi; Shibai, Hiroshi; Sumi, Takahiro [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1, Machikaneyamacho, Toyonaka, Osaka 560-0043 (Japan); Yamamuro, Tomoyasu [Optocraft, 3-16-8-101, Higashi Hashimoto, Midori-ku, Sagamihara, Kanagawa 252-0144 (Japan)

    2016-06-01

    We propose a new concept for the spectral characterization of transiting exoplanets with future space-based telescopes. This concept, called densified pupil spectroscopy, allows us to perform high, stable spectrophotometry against telescope pointing jitter and deformation of the primary mirror. This densified pupil spectrometer comprises the following three roles: division of a pupil into a number of sub-pupils, densification of each sub-pupil, and acquisition of the spectrum of each sub-pupil with a conventional spectrometer. Focusing on the fact that the divided and densified sub-pupil can be treated as a point source, we discovered that a simplified spectrometer allows us to acquire the spectra of the densified sub-pupils on the detector plane−an optical conjugate with the primary mirror−by putting the divided and densified sub-pupils on the entrance slit of the spectrometer. The acquired multiple spectra are not principally moved on the detector against low-order aberrations such as the telescope pointing jitter and any deformation of the primary mirror. The reliability of the observation result is also increased by statistically treating them. Our numerical calculations show that because this method suppresses the instrumental systematic errors down to 10 ppm under telescopes with modest pointing accuracy, next generation space telescopes with more than 2.5 m diameter potentially provide opportunities to characterize temperate super-Earths around nearby late-type stars through the transmission spectroscopy and secondary eclipse.

  7. A Fourier transform spectrometer for visible and near ultra-violet measurements of atmospheric absorption

    Science.gov (United States)

    Parsons, C. L.; Gerlach, J. C.; Whitehurst, M.

    1982-01-01

    The development of a prototype, ground-based, Sun-pointed Michelson interferometric spectrometer is described. Its intended use is to measure the atmospheric amount of various gases which absorb in the near-infrared, visible, and near-ultraviolet portions of the electromagnetic spectrum. Preliminary spectra which contain the alpha, 0.8 micrometer, and rho sigma tau water vapor absorption bands in the near-infrared are presented to indicate the present capability of the system. Ultimately, the spectrometer can be used to explore the feasible applications of Fourier transform spectroscopy in the ultraviolet where grating spectrometers were used exclusively.

  8. Swelling and functional disorders of isolated liver mitochondria induced by ultraviolet light exposure

    International Nuclear Information System (INIS)

    Sayanagi, Hideaki

    1977-01-01

    Biochemical and morphological disruption of liver mitochondria exposed to ultraviolet light were discussed. The mitochondria was prepared from rat liver, and the suspension was exposed to a broad spectrum ultraviolet light. The ultraviolet exposure of isolated rat liver mitochondria prepared from group 1 (regular laboratory chow), caused the great acceleration of swelling of mitochondria and the loss of the ability to couple the phosphorylation with respiration chain. The irradiated mitochondria produced an increase of lipid peroxide which was proportional to the dose of ultraviolet energy. By the use of a difference spectra technic, the absorption bands of cytochrome b, c (c 1 ), and flavoprotein were found to decrease in absorption after ultraviolet exposure. However, mitochondrial suspension prepared from rat in group 2 (regular chow supplemented with 3 mg% riboflavin free form), 3 (with 3 mg% riboflavin tetrabutyrate), 4 (with 5 mg% glutathione (GSH)), provided some degree of protection against the above deleterious effects of ultraviolet radiation. The irradiation effects could be reduced in the irradiated mitochondrial suspension which was incubated with riboflavin and GSH respectively after exposure. Riboflavin B 2 tetrabutyrate was found to show the significant effect of anti-oxidation. Riboflavin free-form was also active in this respect but to a lesser extent. (auth.)

  9. Simultaneous detection and analysis of optical and ultraviolet broad emission lines in quasars at z 2.2

    Science.gov (United States)

    Bisogni, S.; di Serego Alighieri, S.; Goldoni, P.; Ho, L. C.; Marconi, A.; Ponti, G.; Risaliti, G.

    2017-06-01

    We studied the spectra of six z 2.2 quasars obtained with the X-shooter spectrograph at the Very Large Telescope. The redshift of these sources and the X-shooter's spectral coverage allow us to cover the rest of the spectral range 1200-7000 Å for the simultaneous detection of optical and ultraviolet lines emitted by the broad-line region. Simultaneous measurements, avoiding issues related to quasars variability, help us understand the connection between the different broad-line region line profiles generally used as virial estimators of black hole masses in quasars. The goal of this work is to compare the different emission lines for each object to check on the reliability of Hα, Mg II and C iv with respect to Hβ. Hα and Mg II linewidths correlate well with Hβ, while C iv shows a poorer correlation, due to the presence of strong blueshifts and asymmetries in the profile. We compared our sample with the only other two whose spectra were taken with the same instrument and for all examined lines our results are in agreement with the ones obtained with X-shooter at z 1.5-1.7. We finally evaluate C III] as a possible substitute of C iv in the same spectral range and find that its behaviour is more coherent with those of the other lines: we believe that, when a high quality spectrum such as the ones we present is available and a proper modelization with the Fe II and Fe III emissions is performed, it is more appropriate to use this line than that of C iv if not corrected for the contamination by non-virialized components. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under programme 086.B-0320(A).The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/A1

  10. The Northwest Indiana Robotic Telescope

    Science.gov (United States)

    Slavin, Shawn D.; Rengstorf, A. W.; Aros, J. C.; Segally, W. B.

    2011-01-01

    The Northwest Indiana Robotic (NIRo) Telescope is a remote, automated observing facility recently built by Purdue University Calumet (PUC) at a site in Lowell, IN, approximately 30 miles from the PUC campus. The recently dedicated observatory will be used for broadband and narrowband optical observations by PUC students and faculty, as well as pre-college students through the implementation of standards-based, middle-school modules developed by PUC astronomers and education faculty. The NIRo observatory and its web portal are the central technical elements of a project to improve astronomy education at Purdue Calumet and, more broadly, to improve science education in middle schools of the surrounding region. The NIRo Telescope is a 0.5-meter (20-inch) Ritchey-Chrétien design on a Paramount ME robotic mount, featuring a seven-position filter wheel (UBVRI, Hα, Clear), Peltier (thermoelectrically) cooled CCD camera with 3056 x 3056, square, 12 μm pixels, and off-axis guiding. It provides a coma-free imaging field of 0.5 degrees square, with a plate scale of 0.6 arcseconds per pixel. The observatory has a wireless internet connection, local weather station which publishes data to an internet weather site, and a suite of CCTV security cameras on an IP-based, networked video server. Control of power to every piece of instrumentation is maintained via internet-accessible power distribution units. The telescope can be controlled on-site, or off-site in an attended fashion via an internet connection, but will be used primarily in an unattended mode of automated observation, where queued observations will be scheduled daily from a database of requests. Completed observational data from queued operation will be stored on a campus-based server, which also runs the web portal and observation database. Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0736592.

  11. History of Robotic and Remotely Operated Telescopes

    Science.gov (United States)

    Genet, Russell M.

    2011-03-01

    While automated instrument sequencers were employed on solar eclipse expeditions in the late 1800s, it wasn't until the 1960s that Art Code and associates at Wisconsin used a PDP minicomputer to automate an 8-inch photometric telescope. Although this pioneering project experienced frequent equipment failures and was shut down after a couple of years, it paved the way for the first space telescopes. Reliable microcomputers initiated the modern era of robotic telescopes. Louis Boyd and I applied single board microcomputers with 64K of RAM and floppy disk drives to telescope automation at the Fairborn Observatory, achieving reliable, fully robotic operation in 1983 that has continued uninterrupted for 28 years. In 1985 the Smithsonian Institution provided us with a suburb operating location on Mt. Hopkins in southern Arizona, while the National Science Foundation funded additional telescopes. Remote access to our multiple robotic telescopes at the Fairborn Observatory began in the late 1980s. The Fairborn Observatory, with its 14 fully robotic telescopes and staff of two (one full and one part time) illustrates the potential for low operating and maintenance costs. As the information capacity of the Internet has expanded, observational modes beyond simple differential photometry opened up, bringing us to the current era of real-time remote access to remote observatories and global observatory networks. Although initially confined to smaller telescopes, robotic operation and remote access are spreading to larger telescopes as telescopes from afar becomes the normal mode of operation.

  12. Ultraviolet extensions of particle physics

    DEFF Research Database (Denmark)

    Berthier, Laure Gaëlle

    The discovery of the Higgs boson in 2012 at the Large Hadron Collider completed the Standard Model field content. Many questions though remain unanswered by the Standard Model triggering a search for new physics. New physics could manifest itself at the Large Hadron Collider by the discovery of new...... particles. However, the lack of new resonances might suggest that these new particles are still out of reach which leaves us with few options. Two possibilities are explored in this thesis. The first is to study precision measurements which might indicate new physics as small deviations from the Standard...... are expressed as power series with missing higher order terms. We also show how to connect ultraviolet models of new physics to the Standard Model effective field theory and calculate bounds on them using the Standard Model effective field theory fit results. Finally, we study a nonrelativistic ultraviolet...

  13. New discoveries with radio telescopes

    International Nuclear Information System (INIS)

    Schmidt, J.

    1985-01-01

    The author describes in a simple fashion the results obtained by astronomers from ETH Zurich using the broadband 7-m radio telescope in Switzerland to observe the sun over a period of six years. He explains the results in terms of our present understanding of the sun's workings. The astronomers found that a solar eruption is not a single event but consists of tens of thousands of small eruptions or spikes each only 200 km high and producing a burst of radio waves 10-100 times as intense as the background. (T.J.R.A.)

  14. Imaging monolithic silicon detector telescopes

    International Nuclear Information System (INIS)

    Amorini, F.; Sipala, V.; Cardella, G.; Boiano, C.; Carbone, B.; Cosentino, L.; Costa, E.; Di Pietro, A.; Emanuele, U.; Fallica, G.; Figuera, P.; Finocchiaro, P.; La Guidara, E.; Marchetta, C.; Pappalardo, A.; Piazza, A.; Randazzo, N.; Rizzo, F.; Russo, G.V.; Russotto, P.

    2008-01-01

    We show the results of some test beams performed on a new monolithic strip silicon detector telescope developed in collaboration with the INFN and ST-microelectronics. Using an appropriate design, the induction on the ΔE stages, generated by the charge released in the E stage, was used to obtain the position of the detected particle. The position measurement, together with the low threshold for particle charge identification, allows the new detector to be used for a large variety of applications due to its sensitivity of only a few microns measured in both directions

  15. X-ray absorption spectra and emission spectra of plasmas

    International Nuclear Information System (INIS)

    Peng Yonglun; Yang Li; Wang Minsheng; Li Jiaming

    2002-01-01

    The author reports a theoretical method to calculate the resolved absorption spectra and emission spectra (optically thin) of hot dense plasmas. Due to its fully relativistic treatment incorporated with the quantum defect theory, it calculates the absorption spectra and emission spectra for single element or multi-element plasmas with little computational efforts. The calculated absorption spectra of LTE gold plasmas agree well with the experimental ones. It also calculates the optical thin emission spectra of LTE gold plasmas, which is helpful to diagnose the plasmas of relevant ICF plasmas. It can also provide the relevant parameters such as population density of various ionic stages, precise radiative properties for ICF studies

  16. International Conference “Ultraviolet Properties of Evolved Stellar Populations

    CERN Document Server

    Chavez Dagostino, Miguel

    2009-01-01

    This book presents an up-to-date collection of reviews and contributed articles in the field of ultraviolet astronomy. Its content has been mainly motivated by the recent access to the rest frame UV light of distant red galaxies, gained through large optical facilities. This driveway has derived in a renewed interest on the stars that presumably dominate or have important effects on the integrated UV properties of evolved systems of the nearby and faraway Universe. The topics included in this volume extend from the fresh spectroscopic analyses of high redshift early-type galaxies observed with the 8-10m class telescopes to the fundamental outcomes from various satellites, from the long-lived International Ultraviolet Explorer to current facilities, such as the Galaxy Evolution Explorer. This is one of the few volumes published in recent years devoted to UV astronomical research and the only one dedicated to the properties of evolved stellar populations at these wavelengths. This contemporary panorama will be ...

  17. Lattice vibration spectra. 16

    International Nuclear Information System (INIS)

    Lutz, H.D.; Willich, P.

    1977-01-01

    The FIR absorption spectra of pyrite type compounds RuS 2 , RuSsub(2-x)Sesub(x), RuSe 2 , RuTe 2 , OsS 2 , OsSe 2 , and PtP 2 as well as loellingite type phosphides FeP 2 , RuP 2 , and OsP 2 are reported. For RuS 2 , RuSe 2 , RuTe 2 , OsS 2 , and PtP 2 all of the five infrared allowed modes (k = 0) are observed. As a first result of a numerical normal coordinate treatment vibration forms of pyrite structure are communicated. The spectra show that lattice forces of corresponding sulfides, tellurides, and phosphides are about the same strength, but increase strongly by substitution of iron by ruthenium and especially of ruthenium by osmium. The lattice constants of the RuSsub(2-x)Sesub(x) solid solution obey Vegard's rule. (author)

  18. Deconvoluting double Doppler spectra

    International Nuclear Information System (INIS)

    Ho, K.F.; Beling, C.D.; Fung, S.; Chan, K.L.; Tang, H.W.

    2001-01-01

    The successful deconvolution of data from double Doppler broadening of annihilation radiation (D-DBAR) spectroscopy is a promising area of endeavour aimed at producing momentum distributions of a quality comparable to those of the angular correlation technique. The deconvolution procedure we test in the present study is the constrained generalized least square method. Trials with computer simulated DDBAR spectra are generated and deconvoluted in order to find the best form of regularizer and the regularization parameter. For these trials the Neumann (reflective) boundary condition is used to give a single matrix operation in Fourier space. Experimental D-DBAR spectra are also subject to the same type of deconvolution after having carried out a background subtraction and using a symmetrize resolution function obtained from an 85 Sr source with wide coincidence windows. (orig.)

  19. Spectra, Winter 2014

    Science.gov (United States)

    2014-01-01

    additional copies or more information, please email spectra@nrl.navy.mil. LEADINGEDGE 1 Contents 30 Navy Launches UAV from Submerged Submarine 31... multitasking have become mainstream concerns. For example, the New York Times in 2005 and Time magazine in 2006 both reported stories about...interruptions and multitasking , and how they affect performance by increasing human er- ror. In 2005, the information technol- ogy research firm Basex

  20. Thermoluminescence spectra of amethyst

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q. [Suzhou Railway Teachers College (China). Dept. of Physics; Yang, B. [Beijing Normal University (China). Dept. of Physics; Wood, R.A.; White, D.R.R.; Townsend, P.D.; Luff, B.J. [Sussex Univ., Brighton (United Kingdom). School of Mathematical and Physical Sciences

    1994-04-01

    Thermoluminescence and cathodoluminescence data from natural and synthetic amethyst and synthetic quartz samples are compared. The spectra include features from the quartz host lattice and from impurity-generated recombination sites. Emission features exist throughout the wavelength range studied, 250-800 nm. The near infrared emission at 740-750 nm appears to be characteristic of the amethyst and is proposed to be due to Fe ion impurity. (Author).

  1. Auger spectra of alkanes

    International Nuclear Information System (INIS)

    Rye, R.R.; Jennison, D.R.; Houston, J.E.

    1980-01-01

    The gas-phase Auger line shapes of the linear alkanes C 1 through C 6 and of neopentane are presented and analyzed. The general shape of the spectra are characteristic of carbon in a tetrahedral environment with the major feature in all cases occurring at approx.249 eV. The relatively large spectral changes found between methane and ethane results from the direct interaction of the terminal methyl groups in ethane, and the spectra of the higher alkanes are shown to be a composite of contributions from terminal methyl and interior methylene group carbon atoms. Theoretical analysis based on a one-electron approximation is shown to be capable of making a molecular orbital assignment by comparing calculated vertical transitions to features in the Auger spectra of ethane and propane, and, in the case of ethane, of differentiating between the 2 E/sub g/ and 2 A/sub 1g/ assignment of the ground state of (C 2 H 6 ) + . A one-electron based molecular orbital treatment, however, is shown to partially break down in propane and neopentane. Analysis of neopentane and the observed absence of any noticeable major peak energy shift with increasing molecular size (as predicted by the one-electron treatment) suggests that some Auger final states occur in which both valence holes are localized on the same subunit of the molecule

  2. Pattern recognition in spectra

    International Nuclear Information System (INIS)

    Gebran, M; Paletou, F

    2017-01-01

    We present a new automated procedure that simultaneously derives the effective temperature T eff , surface gravity log g , metallicity [ Fe/H ], and equatorial projected rotational velocity v e sin i for stars. The procedure is inspired by the well-known PCA-based inversion of spectropolarimetric full-Stokes solar data, which was used both for Zeeman and Hanle effects. The efficiency and accuracy of this procedure have been proven for FGK, A, and late type dwarf stars of K and M spectral types. Learning databases are generated from the Elodie stellar spectra library using observed spectra for which fundamental parameters were already evaluated or with synthetic data. The synthetic spectra are calculated using ATLAS9 model atmospheres. This technique helped us to detect many peculiar stars such as Am, Ap, HgMn, SiEuCr and binaries. This fast and efficient technique could be used every time a pattern recognition is needed. One important application is the understanding of the physical properties of planetary surfaces by comparing aboard instrument data to synthetic ones. (paper)

  3. Advances in telescope mirror cleaning

    Science.gov (United States)

    Blanken, Maarten F.; Chopping, Alan K.; Dee, Kevin M.

    2004-09-01

    Metrology and cleaning techniques for telescope mirrors are generally well established. CO2 cleaning and water washing are mainly used. Water washing has proven to be the best method of removing oil and water stains and restoring the aluminium to nearly fresh values. The risk of water getting to unwanted places such as electronics or other optics prevents this method from being employed more often. Recently the Isaac Newton Group introduced a new cleaning technique for their telescope mirrors, which reduces the risks discussed above. This technique uses water vapour instead of water to wash the mirror. The advantage of this method is that the amount of water needed is drastically reduced. In addition the pressure of the vapour will blow away any large dust particles on the mirror and the temperature shock between the vapour and the mirror will help to de-bond the dust particles. Adding a soapy solution will help to clean oil and watermarks of the mirror. This paper describes the vapour cleaning method, tests that have been done and the overall findings.

  4. Origins Space Telescope: Study Plan

    Science.gov (United States)

    Nayyeri, Hooshang; Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, the OST Study Team based at NASA Goddard Space Flight Center, study partners, and the advisory panel to the study. This presentation will also summarize recent activities, including the process used to reach a decision on the mission architecture, the identification of key science drivers, and the key study milestones between 2017 and 2020.

  5. Telescoping phenomenon in pathological gambling

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Mooney, Marc E

    2012-01-01

    The course of pathological gambling (PG) in women has been described as having a later age of initiation but a shorter time to problematic gambling ("telescoped"). This study examined evidence for telescoping and its relationship with comorbidities. Seventy-one treatment-seeking individuals with PG...... underwent a diagnostic interview to examine gambling behaviors, age at initiation of gambling, and time from initiation to meeting criteria for PG. The women had a higher mean age at gambling initiation compared with that of the men (mean [SD] age, 31.3 [13.0] years, compared with 22.4 [7.9] years; p = 0.......0003) and a significantly shorter time from initiation of gambling to meeting the criteria for PG (8.33 [8.7] years compared with 11.97 [9.1] years; p = 0.0476) after controlling for demographic and clinical variables. This study presents evidence for a gender-specific course of PG unrelated to psychiatric comorbidities...

  6. ANTARES: An Undersea Neutrino telescope

    CERN Multimedia

    2002-01-01

    The ANTARES (Astronomy with a Neutrino Telescope and ${Abyss}$ environmental RESearch) deep-sea neutrino telescope is designed to search for neutrinos of astrophysical origin. Neutrinos are unique probes of the high energy universe; being neutral they are not deflected by magnetic fields and interacting weakly they can readily escape from the densest regions of the universe. Potential sources of neutrino are galactic (e.g supernova remnants, micro-quasars) and extra-galactic (e.g active galactic nuclei, gamma-ray bursters). Annihilation of dark matter particles in the Sun or Galactic Centre is another well motivated potential source of extra terrestrial neutrinos. The ANTARES detector is located 40 km off the coast of Toulon (France) at a depth of 2475m in the Mediterranean Sea. Being located in the Northern hemisphere it studies the Southern sky and in particular has the Galactic Centre in its field of view. Since 2006, the detector has operated continuously in a partial configuration. The detector was compl...

  7. Merz telescopes a global heritage worth preserving

    CERN Document Server

    2017-01-01

    This book comprises a fascinating collection of contributions on the Merz telescopes in Italy that collectively offer the first survey on historical large refracting telescopes in the country, drawing on original documents and photographs. It opens with a general introduction on the importance of Merz telescopes in the history of astronomy and analyses of the local and international contexts in which the telescopes were made. After examination of an example of the interaction between the maker and the astronomer in the construction and maintenance of these refractors, the history of the Merz telescopes at the main Italian observatories in the nineteenth century is described in detail. Expert testimony is also provided on how these telescopes were successfully used until the second half of the twentieth century for research purposes, thus proving their excellent optical qualities.

  8. THE CBS SPECTRA INVESTIGATION AS METHOD OF THE PN CHEMICAL COMPOSITION ANALYSIS

    OpenAIRE

    Shimanskaya, N. N.; Shimansky, V. V.; Bikmaev, I. F.; Sakhibullin, N. A.; Zhuchkov, R. Ya.

    2007-01-01

    We report the results of the investigations of chemical composition of close binaries which had gone through the stage of common envelope and which are the remnants of planetary nebular cores. High resolution spectra for different phases of orbital period of V471 Tau were taken by RTT-150 telescope and were investigated by the modified SYNTH-K program. It was found that the spectra show noticeable variability with appearance of emission components depended on the orbital period phase. For che...

  9. Development of the Phase-up Technology of the Radio Telescopes: 6.7 GHz Methanol Maser Observations with Phased Hitachi 32 m and Takahagi 32 m Radio Telescopes

    Science.gov (United States)

    Takefuji, K.; Sugiyama, K.; Yonekura, Y.; Saito, T.; Fujisawa, K.; Kondo, T.

    2017-11-01

    For the sake of high-sensitivity 6.7 GHz methanol maser observations, we developed a new technology for coherently combining the two signals from the Hitachi 32 m radio telescope and the Takahagi 32 m radio telescope of the Japanese Very long baseline interferometer Network (JVN), where the two telescopes were separated by about 260 m. After the two telescopes were phased as a twofold larger single telescope, the mean signal-to-noise ratio (S/N) of the 6.7 GHz methanol masers observed by the phased telescopes was improved to 1.254-fold higher than that of the single dish, through a very long baseline interferometry (VLBI) experiment on the 50 km baseline of the Kashima 34 m telescope and the 1000 km baseline of the Yamaguchi 32 m telescope. Furthermore, we compared the S/Ns of the 6.7 GHz maser spectra for two methods. One is a VLBI method and the other is the newly developed digital position switching that is a similar technology to that used in noise-canceling headphones. Finally, we confirmed that the mean S/N of method of the digital position switching (ON-OFF) was 1.597-fold higher than that of the VLBI method.

  10. The MUSCLES Treasury Survey. IV. Scaling Relations for Ultraviolet, Ca II K, and Energetic Particle Fluxes from M Dwarfs

    Science.gov (United States)

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke; Brown, Alexander; Mason, James P.; Schneider, P. Christian; Tilley, Matt A.; Berta-Thompson, Zachory K.; Buccino, Andrea; Froning, Cynthia S.; Hawley, Suzanne L.; Linsky, Jeffrey; Mauas, Pablo J. D.; Redfield, Seth; Kowalski, Adam; Miguel, Yamila; Newton, Elisabeth R.; Rugheimer, Sarah; Segura, Antígona; Roberge, Aki; Vieytes, Mariela

    2017-07-01

    Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet’s potential habitability, particularly for M dwarfs, as they are prime targets for current and near-term exoplanet characterization efforts and atmospheric models predict that their UV radiation can produce photochemistry on habitable zone planets different from that on Earth. To derive ground-based proxies for UV emission for use when Hubble Space Telescope (HST) observations are unavailable, we have assembled a sample of 15 early to mid-M dwarfs observed by HST and compared their nonsimultaneous UV and optical spectra. We find that the equivalent width of the chromospheric Ca II K line at 3933 Å, when corrected for spectral type, can be used to estimate the stellar surface flux in ultraviolet emission lines, including H I Lyα. In addition, we address another potential driver of habitability: energetic particle fluxes associated with flares. We present a new technique for estimating soft X-ray and >10 MeV proton flux during far-UV emission line flares (Si IV and He II) by assuming solar-like energy partitions. We analyze several flares from the M4 dwarf GJ 876 observed with HST and Chandra as part of the MUSCLES Treasury Survey and find that habitable zone planets orbiting GJ 876 are impacted by large Carrington-like flares with peak soft X-ray fluxes ≥10-3 W m-2 and possible proton fluxes ˜102-103 pfu, approximately four orders of magnitude more frequently than modern-day Earth.

  11. The MUSCLES Treasury Survey. IV. Scaling Relations for Ultraviolet, Ca ii K, and Energetic Particle Fluxes from M Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke; Mason, James P. [Laboratory for Atmospheric and Space Physics, University of Colorado, 600 UCB, Boulder, CO 80309 (United States); Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Schneider, P. Christian [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Tilley, Matt A. [Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195 (United States); Berta-Thompson, Zachory K.; Kowalski, Adam [Department of Astrophysical and Planetary Sciences, University of Colorado, 2000 Colorado Ave., Boulder, CO 80305 (United States); Buccino, Andrea; Mauas, Pablo J. D. [Dpto. de Física, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires (UBA), Buenos Aires (Argentina); Froning, Cynthia S. [Department of Astronomy/McDonald Observatory, C1400, University of Texas at Austin, Austin, TX 78712 (United States); Hawley, Suzanne L. [Astronomy Department, Box 351580, University of Washington, Seattle, WA 98195 (United States); Linsky, Jeffrey [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States); Redfield, Seth [Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459 (United States); Miguel, Yamila [Observatoire de la Cote d’Azur, Boulevard de l’Observatoire, CS 34229 F-06304 NICE Cedex 4 (France); Newton, Elisabeth R. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02138 (United States); Rugheimer, Sarah, E-mail: allison.youngblood@colorado.edu [School of Earth and Environmental Sciences, University of St. Andrews, Irvine Building, North Street, St. Andrews, KY16 9AL (United Kingdom); and others

    2017-07-01

    Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet’s potential habitability, particularly for M dwarfs, as they are prime targets for current and near-term exoplanet characterization efforts and atmospheric models predict that their UV radiation can produce photochemistry on habitable zone planets different from that on Earth. To derive ground-based proxies for UV emission for use when Hubble Space Telescope ( HST ) observations are unavailable, we have assembled a sample of 15 early to mid-M dwarfs observed by HST and compared their nonsimultaneous UV and optical spectra. We find that the equivalent width of the chromospheric Ca ii K line at 3933 Å, when corrected for spectral type, can be used to estimate the stellar surface flux in ultraviolet emission lines, including H i Ly α . In addition, we address another potential driver of habitability: energetic particle fluxes associated with flares. We present a new technique for estimating soft X-ray and >10 MeV proton flux during far-UV emission line flares (Si iv and He ii) by assuming solar-like energy partitions. We analyze several flares from the M4 dwarf GJ 876 observed with HST and Chandra as part of the MUSCLES Treasury Survey and find that habitable zone planets orbiting GJ 876 are impacted by large Carrington-like flares with peak soft X-ray fluxes ≥10{sup −3} W m{sup −2} and possible proton fluxes ∼10{sup 2}–10{sup 3} pfu, approximately four orders of magnitude more frequently than modern-day Earth.

  12. The MUSCLES Treasury Survey. IV. Scaling Relations for Ultraviolet, Ca ii K, and Energetic Particle Fluxes from M Dwarfs

    International Nuclear Information System (INIS)

    Youngblood, Allison; France, Kevin; Loyd, R. O. Parke; Mason, James P.; Brown, Alexander; Schneider, P. Christian; Tilley, Matt A.; Berta-Thompson, Zachory K.; Kowalski, Adam; Buccino, Andrea; Mauas, Pablo J. D.; Froning, Cynthia S.; Hawley, Suzanne L.; Linsky, Jeffrey; Redfield, Seth; Miguel, Yamila; Newton, Elisabeth R.; Rugheimer, Sarah

    2017-01-01

    Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet’s potential habitability, particularly for M dwarfs, as they are prime targets for current and near-term exoplanet characterization efforts and atmospheric models predict that their UV radiation can produce photochemistry on habitable zone planets different from that on Earth. To derive ground-based proxies for UV emission for use when Hubble Space Telescope ( HST ) observations are unavailable, we have assembled a sample of 15 early to mid-M dwarfs observed by HST and compared their nonsimultaneous UV and optical spectra. We find that the equivalent width of the chromospheric Ca ii K line at 3933 Å, when corrected for spectral type, can be used to estimate the stellar surface flux in ultraviolet emission lines, including H i Ly α . In addition, we address another potential driver of habitability: energetic particle fluxes associated with flares. We present a new technique for estimating soft X-ray and >10 MeV proton flux during far-UV emission line flares (Si iv and He ii) by assuming solar-like energy partitions. We analyze several flares from the M4 dwarf GJ 876 observed with HST and Chandra as part of the MUSCLES Treasury Survey and find that habitable zone planets orbiting GJ 876 are impacted by large Carrington-like flares with peak soft X-ray fluxes ≥10 −3 W m −2 and possible proton fluxes ∼10 2 –10 3 pfu, approximately four orders of magnitude more frequently than modern-day Earth.

  13. Extreme ultraviolet spectral irradiance measurements since 1946

    Science.gov (United States)

    Schmidtke, G.

    2015-03-01

    In the physics of the upper atmosphere the solar extreme ultraviolet (EUV) radiation plays a dominant role controlling most of the thermospheric/ionospheric (T/I) processes. Since this part of the solar spectrum is absorbed in the thermosphere, platforms to measure the EUV fluxes became only available with the development of rockets reaching altitude levels exceeding 80 km. With the availability of V2 rockets used in space research, recording of EUV spectra started in 1946 using photographic films. The development of pointing devices to accurately orient the spectrographs toward the sun initiated intense activities in solar-terrestrial research. The application of photoelectric recording technology enabled the scientists placing EUV spectrometers aboard satellites observing qualitatively strong variability of the solar EUV irradiance on short-, medium-, and long-term scales. However, as more measurements were performed more radiometric EUV data diverged due to the inherent degradation of the EUV instruments with time. Also, continuous recording of the EUV energy input to the T/I system was not achieved. It is only at the end of the last century that there was progress made in solving the serious problem of degradation enabling to monitore solar EUV fluxes with sufficient radiometric accuracy. The data sets available allow composing the data available to the first set of EUV data covering a period of 11 years for the first time. Based on the sophisticated instrumentation verified in space, future EUV measurements of the solar spectral irradiance (SSI) are promising accuracy levels of about 5% and less. With added low-cost equipment, real-time measurements will allow providing data needed in ionospheric modeling, e.g., for correcting propagation delays of navigation signals from space to earth. Adding EUV airglow and auroral emission monitoring by airglow cameras, the impact of space weather on the terrestrial T/I system can be studied with a spectral terrestrial

  14. ANTARES: The first undersea neutrino telescope

    Science.gov (United States)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Cârloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th.; Charvis, Ph.; Chauchot, P.; Chiarusi, T.; Circella, M.; Compère, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; de Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J.-J.; di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J.-L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J.-F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatá, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gómez-González, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J.-C.; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Levansuu, A.; Lefèvre, D.; Legou, T.; Lelaizant, G.; Lévéque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazéas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Palioselitis, D.; Papaleo, R.; Păvălaş, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J.-F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; van Wijk, R.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

    2011-11-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.

  15. ANTARES: The first undersea neutrino telescope

    International Nuclear Information System (INIS)

    Ageron, M.; Aguilar, J.A.; Al Samarai, I.; Albert, A.; Ameli, F.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Assis Jesus, A.C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Baret, B.

    2011-01-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.

  16. Investigating nearby star-forming galaxies in the ultraviolet with HST/COS spectroscopy. I. Spectral analysis and interstellar abundance determinations

    International Nuclear Information System (INIS)

    James, B. L.; Aloisi, A.; Sohn, S. T.; Wolfe, M. A.; Heckman, T.

    2014-01-01

    This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of nine nearby star-forming galaxies. The goal is to assess the (in)homogeneities of the multiphase ISM in galaxies where the bulk of metals can be hidden in the neutral phase, yet the metallicity is inferred from the ionized gas in the H II regions. The sample, spanning a wide range in physical properties, is to date the best suited to investigate the metallicity behavior of the neutral gas at redshift z = 0. ISM absorption lines were detected against the far-ultraviolet spectra of the brightest star-forming region(s) within each galaxy. Here we report on the observations, data reduction, and analysis of these spectra. Column densities were measured by a multicomponent line-profile fitting technique, and neutral-gas abundances were obtained for a wide range of elements. Several caveats were considered, including line saturation, ionization corrections, and dust depletion. Ionization effects were quantified with ad hoc CLOUDY models reproducing the complex photoionization structure of the ionized and neutral gas surrounding the UV-bright sources. An 'average spectrum of a redshift z = 0 star-forming galaxy' was obtained from the average column densities of unsaturated profiles of neutral-gas species. This template can be used as a powerful tool for studies of the neutral ISM at both low and high redshift.

  17. European Extremely Large Telescope: progress report

    Science.gov (United States)

    Tamai, R.; Spyromilio, J.

    2014-07-01

    The European Extremely Large Telescope is a project of the European Southern Observatory to build and operate a 40-m class optical near-infrared telescope. The telescope design effort is largely concluded and construction contracts are being placed with industry and academic/research institutes for the various components. The siting of the telescope in Northern Chile close to the Paranal site allows for an integrated operation of the facility providing significant economies. The progress of the project in various areas is presented in this paper and references to other papers at this SPIE meeting are made.

  18. GRANITE- A steroscopic imaging Chernkov telescope system

    International Nuclear Information System (INIS)

    Shubnell, M.; Akerlof, C.W.; Cawley, M.F.; Chantell, M.; Fegan, D.J.; Fennell, S.; O'Flaherty, K.S.; Freeman, S.; Frishman, D.; Gaidos, J.A.; Hagan, J.; Harris, K.; Hillas, A.M.; Kerrick, A.D.; Lamb, R.C.; Lappin, T.; Lawrence, M.A.; Levy, H.; Lewis, D.A.; Meyer, D.I.; Mohanty, G.; Punch, M.; Reynolds, P.T.; Rovero, A.C.; Sembroski, G.; Weaverdyck, C.; Weekes, T.C.; Whitaker, T.; Wilson, C.

    1993-01-01

    A second 10 meter class imaging telescope was constructed on Mt. Hopkins, Arizona, the site of the original 10 meter Whipple Cherenkov telescope. The twin telescope system with a 140 meter base line will allow both a reduction in the energy threshold and an improvement in the rejection of the hardonic background. The new telescope started operation in December 1991. With the final completion of the first installation stage (GRANITE I) during spring 92, it is now operating simultaneously with the orginal reflector. We describe in this paper design and construction of the new instrument and demonstrate the capability of the experiment to record coincident events

  19. Preliminary Cost Model for Space Telescopes

    Science.gov (United States)

    Stahl, H. Philip; Prince, F. Andrew; Smart, Christian; Stephens, Kyle; Henrichs, Todd

    2009-01-01

    Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. However, great care is required. Some space telescope cost models, such as those based only on mass, lack sufficient detail to support such analysis and may lead to inaccurate conclusions. Similarly, using ground based telescope models which include the dome cost will also lead to inaccurate conclusions. This paper reviews current and historical models. Then, based on data from 22 different NASA space telescopes, this paper tests those models and presents preliminary analysis of single and multi-variable space telescope cost models.

  20. Measurements of impurity spectra using UV/visible spectroscopic system in a GAMMA 10 plasma

    International Nuclear Information System (INIS)

    Matama, K.; Yoshikawa, M.; Kobayashi, T.; Kubota, Y.; Cho, T.

    2006-01-01

    Impurity spectra have been measured and identified using a newly designed ultraviolet and visible (UV/visible) spectroscopic system in the tandem mirror GAMMA 10. It is constructed using two spectrometers to obtain an entire wavelength range of UV/visible impurity spectra with a high wavelength resolution in one plasma shot. We successfully obtained the emission intensities of the radiation spectra in detail and information on the time-varying population densities of the impurities. We evaluate radiation loss from the GAMMA 10 plasma in the UV/visible range; further we estimate the electron density and temperature after applying the measured spectral intensity to a collisional-radiative model

  1. EARLY ULTRAVIOLET OBSERVATIONS OF A TYPE IIn SUPERNOVA (2007pk)

    International Nuclear Information System (INIS)

    Pritchard, T. A.; Roming, P. W. A.; Brown, P. J.; Kuin, N. P. M.; Oates, S. R.; Bayless, Amanda J.; Holland, S. T.; Immler, S.; Milne, P.

    2012-01-01

    We present some of the earliest UV observations of a Type IIn supernova (SN)—SN 2007pk, where UV and optical observations using Swift's Ultra-Violet/Optical Telescope began 3 days after discovery or ∼5 days after shock breakout. The SN observations commence at approximately maximum light in the UV and u-band filters, suggesting that the UV light curve peaks begin very rapidly after the initial explosion, and subsequently exhibit a linear decay of 0.20, 0.21, 0.16 mag day –1 in the UVOT uvw2, uvm2, uvw1 (λ c = 1928, 2246, 2600 Å) filters. Meanwhile the b- and v-band light curves begin approximately seven days before v-band peak and exhibit a shallow rise followed by a subsequent decay. A series of optical/near-IR spectra taken with the Hobby-Eberly Telescope at days 3-26 after discovery show spectra similar to that of the peculiar Type IIn 1998S. The emission from 2007pk falls below detection ∼20 days after discovery in the UV and 50 days in the optical, showing no sign of the long duration emission seen in other Type IIn SNe. We examine the physical and spectral characteristics of 2007pk and compare its UV light curve and decay rate with other Type II SNe.

  2. Analysis of the FF Aqr spectra

    Science.gov (United States)

    Shimanskaya, N. N.; Bikmaev, I. F.; Shimansky, V. V.

    2011-07-01

    We determine the atmospheric parameters of the secondary in the close binary system FF Aqr and analyze its chemical composition. A series of high-resolution spectra are taken at different orbital phases using the coude echelle spectrometer of the 1.5-m Russian-Turkish Telescope (RTT150). We show that the absorption line intensity of heavy elements varies with phase due to the spotty nature of the cool component. We determine the abundances of heavy elements in the star's atmosphere by modelling the synthetic spectra and performing a differential analysis of the chemical composition of FF Aqr relative to the solar composition. Our analysis of the averaged spectrum of FF Aqr yielded 539 abundance estimates for 21 chemical elements. We found the metallicity of the star ([ Fe/H] = -0.11 ± 0.08) to be close solar, in agreement with the hypothesis that FF Aqr should belong to the Galactic disk. The inferred chemical composition of the objects exhibits no anomalous abundances of the α-, r-, and s-process elements like those earlier found in other systems (IN Com, LW Hya, V471 Tau). The lack of such anomalies in FF Aqr must be due to the fact that the elements heavier than 16 O cannot be synthesized in the core of the primary during the last stages of its evolution.

  3. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    Science.gov (United States)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  4. Deconvolution of Positrons' Lifetime spectra

    International Nuclear Information System (INIS)

    Calderin Hidalgo, L.; Ortega Villafuerte, Y.

    1996-01-01

    In this paper, we explain the iterative method previously develop for the deconvolution of Doppler broadening spectra using the mathematical optimization theory. Also, we start the adaptation and application of this method to the deconvolution of positrons' lifetime annihilation spectra

  5. Deuterium Abundance Toward G191-B2B: Results from the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission

    Science.gov (United States)

    Lemoine, M.; Vidal-Madjar, A.; Hebrard, G.; Desert, J.-M.; Ferlet, R.; LecavelierdesEtangs, A.; Howk, J. C.; Andre, M.; Blair, W. P.; Friedman, S. D.; hide

    2002-01-01

    High-resolution spectra of the hot white dwarf G191-B2B covering the wavelength region 905-1187A were obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). This data was used in conjunction with existing high-resolution Hubble Space Telescope STIS observations to evaluate the total H(sub I), D(sub I), O(sub I) and N(sub I) column densities along the line of sight. Previous determinations of N(D(sub I)) based upon GHRS (Goddard High Resolution Spectrograph) and STIS (Space Telescope Imaging Spectrograph) observations were controversial due to the saturated strength of the D(sub I) Lyman alpha line. In the present analysis the column density of D(sub I) has been measured using only the unsaturated Lyman beta and Lyman gamma lines observed by FUSE. A careful inspection of possible systematic uncertainties tied to the modeling of the stellar continuum or to the uncertainties in the FUSE instrumental character series has been performed. The column densities derived are: log N(D(sub I)) = 13.40+/-0.07, log N(O(sub I)) = 14.86+/-0.07, and log N(N(sub I)) = 13.87+/-0.07 quoted with 2sigma, uncertainties. The measurement of the H(sub I) column density by profile fitting of the Lyman alpha line has been found to be unsecure. If additional weak hot interstellar components are added to the three detected clouds along the line of sight, the H(sub I)) column density can be reduced quite significantly, even though the signal-to-noise ratio and spectral resolution at Lyman alpha are excellent. The new estimate of N(H(sub I)) toward G191-B2B reads: logN(H (sub I)) = 18.18+/-0.18 (2sigma uncertainty), so that the average (D/H) ratio on the line of sight is: (D/H)= 1.66(+0.9/-0.6) x 10(exp -5) (2sigma uncertainty).

  6. Vibrational spectra of aminoacetonitrile

    International Nuclear Information System (INIS)

    Bak, B.; Hansen, E.L.; Nicolaisen, F.M.; Nielsen, O.F.

    1975-01-01

    The preparation of pure, stable aminoacetonitrile(1-amino, 1'-cyanomethane)CH 2 NH 2 CN (1) is described. The Raman spectrum, now complete, and a novel infrared spectrum extending over the 50-3600 cm -1 region are reported. A tentative normal vibration analysis is presented and supported by Raman and infrared data from the spectra of CH 2 NHDCN (2) and CH 2 ND 2 CN (3). The predominance of the trans rotamer may be attributed to intramolecular hydrogen bonding but this is too unimportant to influence the vibrational frequencies of gaseous 1, 2, and 3. However, large gas/liquid frequency shifts occur. (author)

  7. Diffractive X-Ray Telescopes

    International Nuclear Information System (INIS)

    Skinner, G.K.; Skinner, G.K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro arc seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed atmospheric absorption

  8. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  9. NESTOR Deep Sea Neutrino Telescope

    International Nuclear Information System (INIS)

    Aggouras, G.; Anassontzis, E.G.; Ball, A.E.; Bourlis, G.; Chinowsky, W.; Fahrun, E.; Grammatikakis, G.; Green, C.; Grieder, P.; Katrivanos, P.; Koske, P.; Leisos, A.; Markopoulos, E.; Minkowsky, P.; Nygren, D.; Papageorgiou, K.; Przybylski, G.; Resvanis, L.K.; Siotis, I.; Sopher, J.; Staveris-Polikalas, A.; Tsagli, V.; Tsirigotis, A.; Tzamarias, S.; Zhukov, V.A.

    2006-01-01

    One module of NESTOR, the Mediterranean deep-sea neutrino telescope, was deployed at a depth of 4000m, 14km off the Sapienza Island, off the South West coast of Greece. The deployment site provides excellent environmental characteristics. The deployed NESTOR module is constructed as a hexagonal star like latticed titanium star with 12 Optical Modules and an one-meter diameter titanium sphere which houses the electronics. Power and data were transferred through a 30km electro-optical cable to the shore laboratory. In this report we describe briefly the detector and the detector electronics and discuss the first physics data acquired and give the zenith angular distribution of the reconstructed muons

  10. Ultraviolet divergences and supersymmetric theories

    International Nuclear Information System (INIS)

    Sagnotti, A.

    1984-09-01

    This article is closely related to the one by Ferrara in these same Proceedings. It deals with what is perhaps the most fascinating property of supersymmetric theories, their improved ultraviolet behavior. My aim here is to present a survey of the state of the art as of August, 1984, and a somewhat more detailed discussion of the breakdown of the superspace power-counting beyond N = 2 superfields. A method is also described for simplifying divergence calculations that uses the locality of subtracted Feynman integrals. 74 references

  11. Ultraviolet disinfection of potable water

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, R. L. [Metropolitan Water District of Southern California, Los Angeles, CA (United States)

    1990-06-15

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection.

  12. Ultraviolet disinfection of potable water

    International Nuclear Information System (INIS)

    Wolfe, R.L.

    1990-01-01

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection

  13. Ultraviolet divergences of Einstein gravity

    International Nuclear Information System (INIS)

    Goroff, M.H.

    1986-01-01

    The author discuss a two-loop calculation showing that the S matrix of Einstein's theory of gravity contains nonrenormalizable ultraviolet divergences in four dimension. The author discusses the calculation in both background field and normal field theory. The author describes a new method for dealing with ghost fields in gauge theories by combining them with suitable extensions of the gauge fields in higher dimensions. The author shows how using subtracted integrals in the calculation of higher loop graphs simplifies the calculation in the background field method by eliminating the need for mixed counterterms. Finally, the author makes some remarks about the implications of the result for supergravity theories

  14. Ultraviolet laser technology and applications

    CERN Document Server

    Elliott, David L

    1995-01-01

    Ultraviolet Laser Technology and Applications is a hands-on reference text that identifies the main areas of UV laser technology; describes how each is applied; offers clearly illustrated examples of UV opticalsystems applications; and includes technical data on optics, lasers, materials, and systems. This book is unique for its comprehensive, in-depth coverage. Each chapter deals with a different aspect of the subject, beginning with UV light itself; moving through the optics, sources, and systems; and concluding with detailed descriptions of applications in various fields.The text enables pr

  15. Photoelectron spectroscopy an introduction to ultraviolet photoelectron spectroscopy in the gas phase

    CERN Document Server

    Eland, J H D

    2013-01-01

    Photoelectron Spectroscopy: An Introduction to Ultraviolet Photoelectronspectroscopy in the Gas Phase, Second Edition Photoelectron Spectroscopy: An Introduction to Ultraviolet PhotoelectronSpectroscopy in the Gas Phase, Second Edition aims to give practical approach on the subject of photoelectron spectroscopy, as well as provide knowledge on the interpretation of the photoelectron spectrum. The book covers topics such as the principles and literature of photoelectron microscopy; the main features and analysis of photoelectron spectra; ionization techniques; and energies from the photoelectron spectra. Also covered in the book are topics suc as photoelectron band structure and the applications of photoelectron spectroscopy in chemistry. The text is recommended for students and practitioners of chemistry who would like to be familiarized with the concepts of photoelectron spectroscopy and its importance in the field.

  16. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Amaral Soares, E. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Berlin, A.; Bogdan, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Boháčová, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Bonifazi, C. [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Carvalho, W.R. [Universidad de Santiago de Compostela, Departamento de Física de Partículas, Campus Sur, Universidad, E-15782 Santiago de Compostela (Spain); Mello Neto, J.R.T. de [Universidade Federal do Rio de Janeiro, Instituto de Física, Cidade Universitaria, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Facal San Luis, P., E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); and others

    2013-08-11

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique.

  17. The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    Alvarez-Muñiz, J.; Amaral Soares, E.; Berlin, A.; Bogdan, M.; Boháčová, M.; Bonifazi, C.; Carvalho, W.R.; Mello Neto, J.R.T. de; Facal San Luis, P.; Genat, J.F.; Hollon, N.; Mills, E.; Monasor, M.; Privitera, P.

    2013-01-01

    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4–4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope – to validate the telescope design, and to demonstrate a large detector duty cycle – were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory. -- Highlights: • The MIDAS objective is to detect ultra high energy cosmic rays using microwaves. • GHz radiation could provide a powerful alternative to current detection methods. • The MIDAS prototype explores the potential of the microwave technique

  18. Spectral analysis of the Crab Pulsar and Nebula with the Fermi Large Area Telescope

    International Nuclear Information System (INIS)

    Loparco, F.

    2011-01-01

    The Crab Pulsar is a relatively young neutron star. The Pulsar is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was observed on Earth in the year 1054. The Crab Pulsar has been extensively observed in the gamma-ray energy band by the Large Area Telescope (LAT), the main instrument onboard the Fermi gamma-ray space telescope, during its first months of data taking. The LAT data have been used to reconstruct the fluxes and the energy spectra of the pulsed gamma-ray component and of the gamma-rays from the Nebula. The results on the pulsed component are in good agreement with the previous measurement from EGRET, while the results on the Nebula are consistent with the observations from Earth based telescopes.

  19. Modelling ultraviolet-line diagnostics of stars, the ionized and the neutral interstellar medium in star-forming galaxies

    Science.gov (United States)

    Vidal-García, A.; Charlot, S.; Bruzual, G.; Hubeny, I.

    2017-09-01

    We combine state-of-the-art models for the production of stellar radiation and its transfer through the interstellar medium (ISM) to investigate ultraviolet-line diagnostics of stars, the ionized and the neutral ISM in star-forming galaxies. We start by assessing the reliability of our stellar population synthesis modelling by fitting absorption-line indices in the ISM-free ultraviolet spectra of 10 Large Magellanic Cloud clusters. In doing so, we find that neglecting stochastic sampling of the stellar initial mass function in these young (∼10-100 Myr), low-mass clusters affects negligibly ultraviolet-based age and metallicity estimates but can lead to significant overestimates of stellar mass. Then, we proceed and develop a simple approach, based on an idealized description of the main features of the ISM, to compute in a physically consistent way the combined influence of nebular emission and interstellar absorption on ultraviolet spectra of star-forming galaxies. Our model accounts for the transfer of radiation through the ionized interiors and outer neutral envelopes of short-lived stellar birth clouds, as well as for radiative transfer through a diffuse intercloud medium. We use this approach to explore the entangled signatures of stars, the ionized and the neutral ISM in ultraviolet spectra of star-forming galaxies. We find that, aside from a few notable exceptions, most standard ultraviolet indices defined in the spectra of ISM-free stellar populations are prone to significant contamination by the ISM, which increases with metallicity. We also identify several nebular-emission and interstellar-absorption features, which stand out as particularly clean tracers of the different phases of the ISM.

  20. Emission spectra of yttrium vanadate doped with bismuth and dysprosium

    International Nuclear Information System (INIS)

    Pawar, B.V.; Patil, R.N.

    1975-01-01

    The fluorescence spectra of YVO 4 :Bi and YVO 4 :Bi:Dy phosphors under X-rays and ultra-violet radiation have been studied. The observations on the phosphors with constant Bi 3+ and varying Dy 3+ concentration can be attributed to radiationless transfer of energy from Bi 3+ to Dy 3+ coupled with non-radiative losses due to self-quenching at higher level of Dy 3+ concentration. While the observations on the phosphors with constant Dy 3+ and varying Bi 3+ concentration indicate that there is radiationless transfer from Bi 3+ to Dy 3+ under X-ray or UV irradiation. (author)

  1. Proxy magnetometry with the Dutch Open Telescope

    NARCIS (Netherlands)

    Rutten, R.J.; Hammerschlag, R.H.; Sütterlin, P.; Bettonvil, F.C.M.

    1999-01-01

    Superb movies from the Dutch Open Telescope (DOT) on La Palma have proven the validity of the open concept of this innovative telescope for high-resolution imaging of the solar atmosphere. A five- camera speckle-burst registration system is being installed that should permit consistent and

  2. ANTARES : The first undersea neutrino telescope

    NARCIS (Netherlands)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Jesus, A. C. Assis; Astraatmadja, T.; Aubert, J. -J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Carloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th; Charvis, Ph; Chauchot, P.; Chiarusi, T.; Circella, M.; Compere, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; De Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J. -J.; Di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J. -L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J. -F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J. -P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J. -L.; Galata, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gomez-Gonzalez, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernandez-Rey, J. J.; Herold, B.; Hoessl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J-C; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; LeVanSuu, A.; Lefevre, D.; Legou, T.; Lelaizant, G.; Leveque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazeas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Patioselitis, D.; Papaleo, R.; Pavalas, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Rethore, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J. -F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schoeck, F.; Schuller, J. -P.; Schuessler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zuniga, J.; van Wijk, R.

    2011-01-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the

  3. Hard x-ray telescope mission

    DEFF Research Database (Denmark)

    Gorenstein, P.; Worrall, D.; Joensen, K.D.

    1996-01-01

    The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

  4. The Gemini 8-Meter Telescopes Project

    Science.gov (United States)

    Boroson, Todd A.

    1995-05-01

    The Gemini 8-Meter Telescopes Project is an international partnership to build and operate two 8-meter telescopes, one on Mauna Kea, Hawaii, and one on Cerro Pachon, Chile. The telescopes will be international facilities, open to the scientific communities of the six member countries, the United States (50%), the United Kingdom (25%), Canada (15%), Chile (5%), Argentina (2.5%), and Brazil (2.5%). The telescopes are designed to exploit the best atmospheric conditions at these excellent sites. Near diffraction limited performance will be delivered at 2.2 microns and longward, with minimal degradation of the best seeing conditions at shorter wavelengths. The telescopes and facilities are designed to achieve emissivity opportunity. First light for the Mauna Kea telescope is expected in late 1998, and for the Cerro Pachon telescope in mid-2000. This talk will report on construction progress, the instrumental capabilities, and operations strategies being considered. The Gemini 8-meter Telescopes Project is managed by the Association of Universities for Research in Astronomy (AURA), Inc. under a cooperative agreement with the National Science Foundation which serves as executive agency for the Gemini partner countries. U.S. participation in the project is through the U.S. Gemini Program, a division of the National Optical Astronomy Observatories. NOAO is operated by AURA, Inc. under cooperative agreement with the National Science Foundation.

  5. Young Astronomers' Observe with ESO Telescopes

    Science.gov (United States)

    1995-11-01

    are described, but in the end it is appears that only infrared astrometry and astrometry would allow to detect the presence of the planets around this star. Denmark: Mr. Joern C. Olsen, Mr. Henrik Struckmann, Mr. Uffe A. Hansen, Mr. Mogens Winther (Teacher) (Soenderborg Amtsgymnasium) This team performed extensive CCD-observations with the school telescope of three stellar clusters. The goal was to determine their HR-diagrammes (colour-magnitude) and other characteristics. Among others, the team succeeded to measure quite accurate B (blue) and V (green-yellow) colours of 40, 12-16-magnitude stars in the open stellar cluster NGC 6939. This allowed a determination of the distance (2500 parsec) to this cluster and its age (1800 million years), quite similar to the `professionally' determined values. As a side-result, and illustrating the faintness of starlight, a calculation showed that it would take no less than 437,236 years for the brightest star in the sky, Sirius, to heat a cup of coffee to the boiling point ! Finland: Mr. Reima EresmA, Ms. Laura Elina Nykyri, Ms. Reetamaija Janhonen (Cygnaeues-Lukeo, Jyvaeskylae and Jyvaeskylae Lyseon Lukeo) This group used a 50-cm amateur telescope in their home town to observe the spectra of galaxies. A CCD spectrograph recorded the data which were then image-processed in the computer. For this programme, five galaxy pairs were selected and their velocities were measured. This allowed to calculate the distance to the galaxies by means of Hubble's law and also to determine the velocity difference between the two galaxies in a binary system. This in turn makes it possible to estimate the galaxies' total mass. When comparing these numbers with the mass of the visible objects, the group finally determined that the visible mass is only about 8 percent of the total mass, i.e. there must be much `dark matter' in these galaxies. France: Mr. Rene Cavaroz (Teacher), Mr. Vincent Hardy, Mr. Antoine Lesuffleur (Lycee Chartier, Bayeux) This

  6. Ultraviolet spectral reflectance of carbonaceous materials

    Science.gov (United States)

    Applin, Daniel M.; Izawa, Matthew R. M.; Cloutis, Edward A.; Gillis-Davis, Jeffrey J.; Pitman, Karly M.; Roush, Ted L.; Hendrix, Amanda R.; Lucey, Paul G.

    2018-06-01

    A number of planetary spacecraft missions have carried instruments with sensors covering the ultraviolet (UV) wavelength range. However, there exists a general lack of relevant UV reflectance laboratory data to compare against these planetary surface remote sensing observations in order to make confident material identifications. To address this need, we have systematically analyzed reflectance spectra of carbonaceous materials in the 200-500 nm spectral range, and found spectral-compositional-structural relationships that suggest this wavelength region could distinguish between otherwise difficult-to-identify carbon phases. In particular (and by analogy with the infrared spectral region), large changes over short wavelength intervals in the refractive indices associated with the trigonal sp2π-π* transition of carbon can lead to Fresnel peaks and Christiansen-like features in reflectance. Previous studies extending to shorter wavelengths also show that anomalous dispersion caused by the σ-σ* transition associated with both the trigonal sp2 and tetrahedral sp3 sites causes these features below λ = 200 nm. The peak wavelength positions and shapes of π-π* and σ-σ* features contain information on sp3/sp2, structure, crystallinity, and powder grain size. A brief comparison with existing observational data indicates that the carbon fraction of the surface of Mercury is likely amorphous and submicroscopic, as is that on the surface of the martian satellites Phobos and Deimos, and possibly comet 67P/Churyumov-Gerasimenko, while further coordinated observations and laboratory experiments should refine these feature assignments and compositional hypotheses. The new laboratory diffuse reflectance data reported here provide an important new resource for interpreting UV reflectance measurements from planetary surfaces throughout the solar system, and confirm that the UV can be rich in important spectral information.

  7. Ultraviolet Radiations: Skin Defense-Damage Mechanism.

    Science.gov (United States)

    Mohania, Dheeraj; Chandel, Shikha; Kumar, Parveen; Verma, Vivek; Digvijay, Kumar; Tripathi, Deepika; Choudhury, Khushboo; Mitten, Sandeep Kumar; Shah, Dilip

    2017-01-01

    UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Based on wavelength, UV rays are subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Ultraviolet rays can have both harmful and beneficial effects. UV-C has the property of ionization thus acting as a strong mutagen, which can cause immune-mediated disease and cancer in adverse cases. Numbers of genetic factors have been identified in human involved in inducing skin cancer from UV-radiations. Certain heredity diseases have been found susceptible to UV-induced skin cancer. UV radiations activate the cutaneous immune system, which led to an inflammatory response by different mechanisms. The first line of defense mechanism against UV radiation is melanin (an epidermal pigment), and UV absorbing pigment of skin, which dissipate UV radiation as heat. Cell surface death receptor (e.g. Fas) of keratinocytes responds to UV-induced injury and elicits apoptosis to avoid malignant transformation. In addition to the formation of photo-dimers in the genome, UV also can induce mutation by generating ROS and nucleotides are highly susceptible to these free radical injuries. Melanocortin 1 receptor (MC1R) has been known to be implicated in different UV-induced damages such as pigmentation, adaptive tanning, and skin cancer. UV-B induces the formation of pre-vitamin D3 in the epidermal layer of skin. UV-induced tans act as a photoprotection by providing a sun protection factor (SPF) of 3-4 and epidermal hyperplasia. There is a need to prevent the harmful effects and harness the useful effects of UV radiations.

  8. The earthshine s spectra

    Science.gov (United States)

    Montanes Rodriguez, P.; Palle, E.; Goode, P.; Koonin, S.; Hickey, J.; Qiu, J.; Yurchysyn, V.

    The Earthshine project, was run by California Institute of Technology (Caltech) between 1993 and 1995. Since 1998, it has been a collaborative effort between Caltech and Big Bear Solar Observatory (BBSO)/New Jersey Institute of Technology (NJIT). Our primary goal is the precise determination of a global and absolutely calibrated Earth's albedo and its synoptic, seasonal, and annual variability; as well as the measurement and investigation of the resolved reflected spectrum of the integrated Earth in the infrared region. The absorption in the infrared region, mainly due to rotational and vibrational transitions of the molecules, show the absorption bands of various telluric and solar components allowing the analysis of the Earth's spectrum such as it would be observed from the outer space. In this paper we present preliminary results of spectroscopic observations, made at Palomar Observatory with the 60-inch telescope's echelle spectrograph. They targeted the visible and near infrared region of the electromagnetic spectrum, and were performed in the spectral range (typically terrestrial molecular bands. The fourth line, H, is a solar line, used mainly for spectral calibration.

  9. A virtual reality environment for telescope operation

    Science.gov (United States)

    Martínez, Luis A.; Villarreal, José L.; Ángeles, Fernando; Bernal, Abel

    2010-07-01

    Astronomical observatories and telescopes are becoming increasingly large and complex systems, demanding to any potential user the acquirement of great amount of information previous to access them. At present, the most common way to overcome that information is through the implementation of larger graphical user interfaces and computer monitors to increase the display area. Tonantzintla Observatory has a 1-m telescope with a remote observing system. As a step forward in the improvement of the telescope software, we have designed a Virtual Reality (VR) environment that works as an extension of the remote system and allows us to operate the telescope. In this work we explore this alternative technology that is being suggested here as a software platform for the operation of the 1-m telescope.

  10. Remote secure observing for the Faulkes Telescopes

    Science.gov (United States)

    Smith, Robert J.; Steele, Iain A.; Marchant, Jonathan M.; Fraser, Stephen N.; Mucke-Herzberg, Dorothea

    2004-09-01

    Since the Faulkes Telescopes are to be used by a wide variety of audiences, both powerful engineering level and simple graphical interfaces exist giving complete remote and robotic control of the telescope over the internet. Security is extremely important to protect the health of both humans and equipment. Data integrity must also be carefully guarded for images being delivered directly into the classroom. The adopted network architecture is described along with the variety of security and intrusion detection software. We use a combination of SSL, proxies, IPSec, and both Linux iptables and Cisco IOS firewalls to ensure only authenticated and safe commands are sent to the telescopes. With an eye to a possible future global network of robotic telescopes, the system implemented is capable of scaling linearly to any moderate (of order ten) number of telescopes.

  11. A telescope with augmented reality functions

    Science.gov (United States)

    Hou, Qichao; Cheng, Dewen; Wang, Qiwei; Wang, Yongtian

    2016-10-01

    This study introduces a telescope with virtual reality (VR) and augmented reality (AR) functions. In this telescope, information on the micro-display screen is integrated to the reticule of telescope through a beam splitter and is then received by the observer. The design and analysis of telescope optical system with AR and VR ability is accomplished and the opto-mechanical structure is designed. Finally, a proof-of-concept prototype is fabricated and demonstrated. The telescope has an exit pupil diameter of 6 mm at an eye relief of 19 mm, 6° field of view, 5 to 8 times visual magnification , and a 30° field of view of the virtual image.

  12. Simulation and Track Reconstruction for Beam Telescopes

    CERN Document Server

    Maqbool, Salman

    2017-01-01

    Beam telescopes are an important tool to test new detectors under development in a particle beam. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, its predicted position on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them do not account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framework along with the General Broken ...

  13. PEPSI deep spectra. I. The Sun-as-a-star

    Science.gov (United States)

    Strassmeier, K. G.; Ilyin, I.; Steffen, M.

    2018-04-01

    Context. Full-disk solar flux spectra can be directly compared to stellar spectra and thereby serve as our most important reference source for, for example stellar chemical abundances, magnetic activity phenomena, radial-velocity signatures or global pulsations. Aim. As part of the first Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) key-science project, we aim to provide well-exposed and average-combined (viz. deep) high-resolution spectra of representative stellar targets. Such deep spectra contain an overwhelming amount of information, typically much more than what could be analyzed and discussed within a single publication. Therefore, these spectra will be made available in form of (electronic) atlases. The first star in this series of papers is our Sun. It also acts as a system-performance cornerstone. Methods: The Sun was monitored with PEPSI at the Large Binocular Telescope (LBT). Instead of the LBT we used a small robotic solar disk integration (SDI) telescope. The deep spectra in this paper are the results of combining up to ≈100 consecutive exposures per wavelength setting and are compared with other solar flux atlases. Results: Our software for the optimal data extraction and reduction of PEPSI spectra is described and verified with the solar data. Three deep solar flux spectra with a spectral resolution of up to 270 000, a continuous wavelength coverage from 383 nm to 914 nm, and a photon signal to noise ratio (S/N) of between 2000-8000:1 depending on wavelength are presented. Additionally, a time-series of 996 high-cadence spectra in one cross disperser is used to search for intrinsic solar modulations. The wavelength calibration based on Th-Ar exposures and simultaneous Fabry-Pérot combs enables an absolute wavelength solution within 10 m s-1 (rms) with respect to the HARPS laser-comb solar atlas and a relative rms of 1.2 m s-1 for one day. For science demonstration, we redetermined the disk-average solar Li abundance to 1.09

  14. Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space

    Directory of Open Access Journals (Sweden)

    Niu Qinglin

    2016-10-01

    Full Text Available A systemic and validated model was developed to predict ultraviolet spectra features from the shock layer of near-space hypersonic vehicles in the “solar blind” band region. Computational procedures were performed with 7-species thermal non-equilibrium fluid mechanics, finite rate chemistry, and radiation calculations. The thermal non-equilibrium flow field was calculated with a two-temperature model by the finite volume technique and verified against the bow-shock ultra-violet (BSUV flight experiments. The absorption coefficient of the mixture gases was evaluated with a line-by-line method and validated through laboratory shock tube measurements. Using the line of sight (LOS method, radiation was calculated from three BSUV flights at altitudes of 38, 53.5 and 71 km. The investigation focused on the level and structure of ultraviolet spectra radiated from a NO band system in wavelengths of 200–400 nm. Results predicted by the current model show qualitative spatial agreement with the measured data. At a velocity of 3.5 km/s (about Mach 11, the peak absolute intensity at an altitude of 38 km is two orders of magnitude higher than that at 53.5 km. Under the same flight conditions, the spectra structures have quite a similar distribution at different viewing angles. The present computational model performs well in the prediction of the ultraviolet spectra emitted from the shock layer and will contribute to the investigation and analysis of radiative features of hypersonic vehicles in near space.

  15. Dose modeling in ultraviolet phototherapy

    International Nuclear Information System (INIS)

    Grimes, David Robert; Robbins, Chris; O'Hare, Neil John

    2010-01-01

    Purpose: Ultraviolet phototherapy is widely used in the treatment of numerous skin conditions. This treatment is well established and largely beneficial to patients on both physical and psychological levels; however, overexposure to ultraviolet radiation (UVR) can have detrimental effects, such as erythemal responses and ocular damage in addition to the potentially carcinogenic nature of UVR. For these reasons, it is essential to control and quantify the radiation dose incident upon the patient to ensure that it is both biologically effective and has the minimal possible impact on the surrounding unaffected tissue. Methods: To date, there has been little work on dose modeling, and the output of artificial UVR sources is an area where research has been recommended. This work characterizes these sources by formalizing an approach from first principles and experimentally examining this model. Results: An implementation of a line source model is found to give impressive accuracy and quantifies the output radiation well. Conclusions: This method could potentially serve as a basis for a full computational dose model for quantifying patient dose.

  16. Evolution of solar ultraviolet luminosity

    International Nuclear Information System (INIS)

    Zahnle, K.J.; Walker, J.C.G.

    1982-01-01

    In view of the major role of the sun in defining the properties of planetary atmospheres, their evolution cannot be fully understood outside the context of an evolving sun. The ultraviolet radiation is especially interesting because of its strong interaction with planetary atmospheres. We use astronomical observation of stars that are analogous to the sun in order to reconstruct a tentative account of the evolution of solar UV luminosity. A wealth of evidence indicates that the young sun was a much more powerful source of energetic particles and radiation than it is today. While on the main sequence, solar activity has declined as an inverse power law of age (between t -5 and t/sup -1.2/) as a consequence of angular momentum loss to the solar wind. Recent IUE satellite observations of premain sequence stars suggest that before the sun reached the main sequence (at an age of about 50 m.y.), it may have emitted as much as 10 4 times as much ultraviolet radiation (γ<2000 A) than it does today. These results could impact our understanding of the photochemistry and escape of constituents of primordial planetary atmospheres

  17. ALMA Telescope Reaches New Heights

    Science.gov (United States)

    2009-09-01

    ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array

  18. FULVUE: Far Ultraviolet Universal Explorer

    Science.gov (United States)

    White, David L.; Cross, Eugene W.

    1997-10-01

    This is a concept study for a proposal to NASA/GSFC for a medium class Explorer Mission. It is designed to replace a prior SBIR Phase I design for NASA/MSFC for a Lunar far-UV survey telescope done in 1994 - 1995 for the Pathfinder Program (by the authors for I.S.E., under M. E. Nein, MSFC). A full investigation by project scientist D. L. White as to the most desirable mission science for a Lunar-based UV telescope, resulted in the decision to do a universal survey of the most interesting lines in the Lyman alpha forest, especially the O VI doublet lines around 103.2/103.8 nm. A telescope was designed by the authors incorporating a multiple instrument pod (MEDUSA), and a unique optical train featuring a selectable element secondary mirror module, with a special high resolution mode debuting a new optical design, all by chief optical engineer E. W. Cross. Special thanks go to chief spacecraft engineer T. L. Kessler for all packaging and integration of the telescope, its attendant systems, and the entire mission, including the launch interface and all presentations. In this incarnation, the basic concept has been converted by D. L. White into a free flyer designed for at least a LEO. In reconfiguring the original concept in the order to accomplish the original mission science goals, it has been necessary to take a fresh approach in order to fit the largest feasible Explorer Class Fairing (10L). In addition, the reconsideration of the mission science and the performance level available from the prior mission's optics, the authors decided to push the limits of the possible in the pursuit of excellence and choose two exceptional optical designs, augment them, and integrate them into the same limited envelope, while not sacrificing performance, communications, power, control, or serviceability. This we have kept close to focus throughout our pursuit of the mission science, which we hold foremost. We see a great need to bring the lessons learned at other portions of the

  19. Perfomance of a high purity germanium multi-detector telescope for long range particles

    International Nuclear Information System (INIS)

    Riepe, G.; Protic, D.; Suekoesd, C.; Didelez, J.P.; Frascaria, N.; Gerlic, E.; Hourani, E.; Morlet, M.

    1980-01-01

    A telescope of stacked high purity germanium detectors designed for long range charged particles was tested using medium energy protons. Particle identification and the rejection of the low energy tail could be accomplished on-line allowing the measurement of complex spectra. The efficiency of the detector stack for protons was measured up to 156 MeV incoming energy. The various factors affecting the energy resolution are discussed and their estimated contributions are compared with the experimental results

  20. Vacuum-ultraviolet circular dichroism spectrophotometer using synchrotron radiation

    International Nuclear Information System (INIS)

    Matsuo, K.; Fukuyama, T.; Yonehara, R.; Namatame, H.; Taniguchi, M.; Gekko, K.

    2005-01-01

    We have constructed a vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer using a synchrotron radiation and an assembled-type MgF 2 cell endurable under a high vacuum, to measure the CD spectra of biomaterials in aqueous solutions from 310 to 140 nm. To avoid the absorption of light by air and water vapor, all optical devices of the spectrophotometer were set up under a high vacuum (10 -4 Pa). A path length of the optical cell can be adjusted by various Teflon spacers in the range from 1.3 to 50 μm and its temperature can be controlled to an accuracy of ±1 deg. C over the range from -30 to 70 deg. C by a temperature-control unit using a Peltier thermoelectric element. The performance of the spectrophotometer and the optical cell constructed was tested by measuring the CD spectra of ammonium d-camphor-10-sulfonate, D- and L-isomers of amino acids, and myoglobin in aqueous solutions. The spectra obtained demonstrate that the optical system and the sample cell constructed operate normally under a high vacuum and provide useful information on the structure of biomolecules based on the higher energy chromophores

  1. SEURAT: SPH scheme extended with ultraviolet line radiative transfer

    Science.gov (United States)

    Abe, Makito; Suzuki, Hiroyuki; Hasegawa, Kenji; Semelin, Benoit; Yajima, Hidenobu; Umemura, Masayuki

    2018-05-01

    We present a novel Lyman alpha (Ly α) radiative transfer code, SEURAT (SPH scheme Extended with Ultraviolet line RAdiative Transfer), where line scatterings are solved adaptively with the resolution of the smoothed particle hydrodynamics (SPH). The radiative transfer method implemented in SEURAT is based on a Monte Carlo algorithm in which the scattering and absorption by dust are also incorporated. We perform standard test calculations to verify the validity of the code; (i) emergent spectra from a static uniform sphere, (ii) emergent spectra from an expanding uniform sphere, and (iii) escape fraction from a dusty slab. Thereby, we demonstrate that our code solves the {Ly} α radiative transfer with sufficient accuracy. We emphasize that SEURAT can treat the transfer of {Ly} α photons even in highly complex systems that have significantly inhomogeneous density fields. The high adaptivity of SEURAT is desirable to solve the propagation of {Ly} α photons in the interstellar medium of young star-forming galaxies like {Ly} α emitters (LAEs). Thus, SEURAT provides a powerful tool to model the emergent spectra of {Ly} α emission, which can be compared to the observations of LAEs.

  2. The eclipse of CI Cygni in 1980 on the objective prism spectra

    International Nuclear Information System (INIS)

    Mikolajewska, J.; Mikolajewski, M.

    1982-01-01

    The observations of CI Cyg were carried out with the Torun 60/90 cm Schmidt telescope with the objective prism giving a dispersion of 250 A/mm at H-gamma. Intensity traces of 20 selected spectra, made on the Kodak IIa-O plates, were made. The results were corrected for all instrumental effects and the interstellar extinction. The relative emission lines intensities have been obtained from the tracings after normalization to H-beta = 100. The spectra were typical for the quiet symbiotic star. So, all changes in the spectrum were caused by geometrical effects (eclipse). A preliminary analysis of the obtained spectra is presented. (Auth.)

  3. Catalogue of neutron spectra

    International Nuclear Information System (INIS)

    Buxerolle, M.; Massoutie, M.; Kurdjian, J.

    1987-09-01

    Neutron dosimetry problems have arisen as a result of developments in the applications of nuclear energy. The largest number of possible irradiation situations has been collected: they are presented in the form of a compilation of 44 neutron spectra. Diagrams show the variations of energy fluence and energy fluence weighted by the dose equivalent/fluence conversion factor, with the logarithm of the corresponding energy. The equivalent dose distributions are presented as percentages for the following energy bins: 0.01 eV/0.5 eV/50 keV/1 MeV/5 MeV/15 MeV. The dose equivalent, the mean energy and the effective energy for the dose equivalent for 1 neutron cm -2 are also given [fr

  4. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  5. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  6. Optical Characteristics of the Marshall Space Flight Center Solar Ultraviolet Magnetograph

    Science.gov (United States)

    West, E. A.; Porter, J. G.; Davis, J. M.; Gary, G. A.; Adams, M.; Smith, S.; Hraba, J. F.

    2001-01-01

    This paper will describe the scientific objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. In order to test the scientific feasibility of measuring magnetic fields in the UV, a sounding rocket payload is being developed. This paper will discuss: (1) the scientific measurements that will be made by the SUMI sounding rocket program, (2) how the optics have been optimized for simultaneous measurements of two magnetic lines CIV (1550 Angstroms) and MgII (2800 Angstroms), and (3) the optical, reflectance, transmission and polarization measurements that have been made on the SUMI telescope mirror and polarimeter.

  7. Ni-doped zinc oxide nanocombs and phonon spectra properties

    International Nuclear Information System (INIS)

    Zhang Bin; Zhang Xingtang; Gong Hechun; Wu Zhishen; Zhou Shaomin; Du Zuliang

    2008-01-01

    Ni-doped comb-like zinc oxide (ZnO) semiconductor nanostructures have been synthesized by a simple chemical vapor-deposition method (CVD) at relatively low temperature. The as-synthesized ZnO nanocombs consist of an array of very uniform, perfectly aligned, evenly spaced and long single-crystalline nanobelts (nanowires) with periods of about several tens of nanometers. X-ray diffraction and Raman spectra results provide the evidence that Ni is incorporated into the ZnO lattice at Zn site. Photoluminescence spectra of the as-obtained samples have been detected, in which the incorporation of donor Ni leads to the increases of the ultraviolet emission intensity and a blueshift of emission peak. This technique can be used to prepare other semiconductors and morphology-controlled doping nanocombs

  8. Preliminary report on the IUE spectra of Mu(1) Scorpii

    Energy Technology Data Exchange (ETDEWEB)

    Sahade, J; Garcia, L G

    1981-12-01

    IUE ultraviolet spectra of the eclipsing binary Mu(1) Scorpii are examined. The available spectra correspond to primary eclipse and to one of the quadratures, and only display absorption lines. Many lines arising from resonance transitions are apparent and can be placed into groups. These include: sharp and deep lines identified with elements like O I, N I, C II, Si II, Al II, Fe II, Mg II which are probably circumstellar and interstellar lines that have about 1.5 FWHM identified with elements like Si III and Al III lines about 2 A FWHM identified as Si IV low excitation, relatively deep lines of about 1 A FWHM of C II, Si II, Si III, and Ti III and higher excitation, relatively broad and shallow lines of C III. The resonance lines of Si IV are characterized by a fine structure of as many as nine components which suggest velocity values ranging from -180 to about +150 km/s.

  9. Low energy pion detection by a silicon surface barrier telescope

    International Nuclear Information System (INIS)

    Sealock, R.M.; Caplan, H.S.; Leung, M.K.

    1978-01-01

    Four telescopes of three (2-ΔE, 1-E) silicon surface barrier detectors each, mounted in the focal plane of a magnetic spectrometer, have been used to detect positive pions in the energy range from 4.7-17.9 MeV and negative pions from 14.1-17.9 MeV. Positive pions from 4.7-12.7 MeV were stopped in the third detector while positive and negative pions from 14.1-17.9 MeV were detected in transmission. For energies greater than 7.4 MeV aluminum moderators were placed in front of the first detector to degrade the pion energy. Energy spectra show well resolved pion peaks with extremely low background. Double differential cross sections for the 12 C(e,π + ) 12 B,e' reaction have been measured. (Auth.)

  10. Ultraviolet safety assessments of insect light traps.

    Science.gov (United States)

    Sliney, David H; Gilbert, David W; Lyon, Terry

    2016-01-01

    Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to ultraviolet radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic ultraviolet safety standards for ILT products.

  11. Hand protection from ultraviolet exposure

    International Nuclear Information System (INIS)

    Khazova, M.; O'Hagan, J.B.

    2006-01-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of ∼ 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  12. Hand protection from ultraviolet exposure

    Energy Technology Data Exchange (ETDEWEB)

    Khazova, M.; O' Hagan, J.B. [Health Protection Agency, Radiation Protection Division, Chilton, Did cot (United Kingdom)

    2006-07-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of {approx} 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  13. The Origins Space Telescope (OST)

    Science.gov (United States)

    Staguhn, Johannes

    2018-01-01

    The Origins Space Telescope is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies to be submitted by NASA Headquarters to the 2020 Astronomy and Astrophysics Decadal survey. The observatory will provide orders of magnitude improvements in sensitivity over prior missions, in particular for spectroscopy, enabling breakthrough science across astrophysics. The observatory will cover a wavelength range between 5 μm and 600 μm in order to enable the study of the formation of proto-planetary disks, detection of bio-signatures from extra-solar planet's atmospheres, characterization of the first galaxies in the universe, and many more. The five instruments that are currently studied are two imaging far-infrared spectrometers using incoherent detectors, providing up to R 10^5 spectral resolution, one far-infrared infrared heterodyne instrument for even higher spectral resolving powers, one far-infrared continuum imager and polarimeter, plus a mid-infrared coronagraph with imaging and spectroscopy mode. I will describe the scientific and technical capabilities of the observatory with focus on the expected synergies with AtLAST.

  14. Prospects for γ-ray imaging telescopes

    International Nuclear Information System (INIS)

    Carter, J.N.; Dean, A.J.; Ramsden, D.

    1981-01-01

    Apart from the requirement for a new, high angular-resolution gamma-ray telescope for the more precise location of known COS-B gamma-ray sources, there is also a need for another instrument that can be used in a search for the gamma-ray emission from specific X-ray-emitting objects. If there is to be any hope of relating gamma ray emission to specific candidate X-ray objects, then an angular resolution of typically a few minutes of arc is required to resolve adjacent sources in crowded regions of the sky such as the galactic centre. Efforts to improve the angular resolution of track-chamber telescopes are compared. For energies close to 1 MeV telescopes have either used collimators to restrict the field of view or have made use of the kinematics of the Compton scattering process to determine the direction of the incident photon. The use of coded aperture techniques in high angular resolution X-ray astronomy telescopes is reviewed. A practical telescope for astronomy at high energies described by Carter is mentioned. At low energies an imaging telescope could be constructed by making use of position-sensitive detectors initially developed for use in medical physics. Such a telescope is outlined in general terms and its benefits and uses given. (U.K.)

  15. Parametric Cost Models for Space Telescopes

    Science.gov (United States)

    Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtney

    2010-01-01

    Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

  16. Parametric cost models for space telescopes

    Science.gov (United States)

    Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtnay

    2017-11-01

    Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

  17. Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

    Science.gov (United States)

    Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

    1999-01-01

    Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

  18. Swift Burst Alert Telescope Data Products and Analysis Software

    International Nuclear Information System (INIS)

    Krimm, Hans A.; Barbier, Louis M.; Barthelmy, Scott D.; Cummings, Jay R.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Fenimore, Edward E.; Palmer, David M.; Hullinger, Derek D.; Markwardt, Craig B.

    2004-01-01

    The Burst Alert Telescope (BAT) on the Swift gamma-ray burst mission serves as the GRB trigger for Swift as well as a sensitive imaging telescope for the energy range of 15-150 keV. All BAT data products will be available to the astronomical community along with a complete set of analysis tools. Gamma-ray burst data products include rapid discovery messages delivered immediately via the GRB Coordinates Network, and event-by-event data from which light curves and spectra of the burst are generated. During nominal operations, the instrument provides accumulated survey histograms with 5-minute time sampling and appropriate energy resolution. These survey accumulations are analyzed in a pipeline to detect new sources and derive light curves of known sources. The 5-minute surveys will also be combined to produce the BAT all sky hard X-ray survey. In addition, the instrument accumulates high time resolution light curves of the brightest BAT sources in multiple energy bands, which are merged into a source light curve database on the ground. The BAT science data products and analysis tools will be described in this paper

  19. DMD-based multi-object spectrograph on Galileo telescope

    Science.gov (United States)

    Zamkotsian, Frederic; Spano, Paolo; Lanzoni, Patrick; Bon, William; Riva, Marco; Nicastro, Luciano; Molinari, Emilio; Di Marcantonio, Paolo; Zerbi, Filippo; Valenziano, Luca

    2013-03-01

    Next-generation infrared astronomical instrumentation for ground-based and space telescopes could be based on MOEMS programmable slit masks for multi-object spectroscopy (MOS). This astronomical technique is used extensively to investigate the formation and evolution of galaxies. We propose to develop a 2048x1080 DMD-based MOS instrument to be mounted on the Galileo telescope and called BATMAN. A two-arm instrument has been designed for providing in parallel imaging and spectroscopic capabilities. The two arms with F/4 on the DMD are mounted on a common bench, and an upper bench supports the detectors thanks to two independent hexapods. Very good optical quality on the DMD and the detectors will be reached. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. It permits to determine the instrument integration procedure, including optics and mechanics integration, alignment procedure and optical quality. First images have been obtained and measured. A DMD pattern manager has been developed in order to generate any slit mask according to the list of objects to be observed; spectra have been generated and measured. Observation strategies will be studied and demonstrated for the scientific optimization strategy over the whole FOV. BATMAN on the sky is of prime importance for characterizing the actual performance of this new family of MOS instruments, as well as investigating the operational procedures on astronomical objects. This instrument will be placed on the Telescopio Nazionale Galileo at the beginning of next year, in 2014.

  20. Particle Beam Tests of the Calorimetric Electron Telescope

    CERN Document Server

    Tamura, Tadahisa

    The Calorimetric Electron Telescope (CALET) is a new mission addressing outstanding astrophysics questions including the nature of dark matter, the sources of high-energy particles and photons, and the details of particle acceleration and transport in the galaxy by measuring the high-energy spectra of electrons, nuclei, and gamma-rays. It will launch on HTV-5 (H-II Transfer Vehicle 5) in 2014 for installation on the Japanese Experiment Module–Exposed Facility (JEM-EF) of the International Space Station. The CALET collaboration is led by JAXA and includes researchers from Japan, the U.S. and Italy. The CALET Main Telescope uses a plastic scintillator charge detector followed by a 30 radiation-length (X0) deep particle calorimeter divided into a 3 X0 imaging calorimeter, with scintillating optical fibers interleaved with thin tungsten sheets, and a 27 X0 fully-active total-absorption calorimeter made of lead tungstate scintillators. CALET prototypes were tested at the CERN (European Laboratory for Particle Ph...

  1. The Infrared-Optical Telescope (IRT) of the Exist Observatory

    Science.gov (United States)

    Kutyrev, Alexander; Bloom, Joshua; Gehrels, Neil; Golisano, Craig; Gong, Quan; Grindlay, Jonathan; Moseley, Samuel; Woodgate, Bruce

    2010-01-01

    The IRT is a 1.1m visible and infrared passively cooled telescope, which can locate, identify and obtain spectra of GRB afterglows at redshifts up to z 20. It will also acquire optical-IR, imaging and spectroscopy of AGN and transients discovered by the EXIST (The Energetic X-ray Imaging Survey Telescope). The IRT imaging and spectroscopic capabilities cover a broad spectral range from 0.32.2m in four bands. The identical fields of view in the four instrument bands are each split in three subfields: imaging, objective prism slitless for the field and objective prism single object slit low resolution spectroscopy, and high resolution long slit on single object. This allows the instrument, to do simultaneous broadband photometry or spectroscopy of the same object over the full spectral range, thus greatly improving the efficiency of the observatory and its detection limits. A prompt follow up (within three minutes) of the transient discovered by the EXIST makes IRT a unique tool for detection and study of these events, which is particularly valuable at wavelengths unavailable to the ground based observatories.

  2. CTA-A project for a new generation of Cherenkov telescopes

    International Nuclear Information System (INIS)

    Doro, Michele

    2011-01-01

    Gamma-rays provide a powerful insight into the non-thermal universe and perhaps a unique probe for new physics beyond the standard model. Current experiments are already giving results in the physics of acceleration of cosmic rays in supernova remnants, pulsar and active galactic nuclei with a 100 sources detected at very-high-energies so far. Despite its relatively recent appearance, very high-energy gamma-ray astronomy has proven to have reached a mature technology with fast assembling, relatively cheap and reliable telescopes. The goal of future installation is to increase the sensitivity by a factor 10 compared to current installations, and enlarge the energy domain from few 10s of GeV to a 100 TeV. Gamma-ray spectra of astrophysical origin are rather soft thus hardly one single size telescope can cover more than 1.5 decades in energy, therefore an array of telescopes of 2-3 different sizes is required. Hereafter, we present design considerations for a Cherenkov Telescope Array (CTA), a project for a new generation of highly automated telescopes for gamma-ray astronomy. The status of the project, technical solutions and an insight in the involved physics will be presented.

  3. Spectra of the Wolf-Rayet stars in 30 Doradus

    International Nuclear Information System (INIS)

    Conti, P.S.

    1982-01-01

    The central cluster of the 30 Doradus complex in the Large Magellanic Cloud (LMC) contains at least a dozen Wolf-Rayet (W-R) stars of the nitrogen sequence according to Melnick (1978). In addition to the six stars previously identified by Feast, Thackeray and Wesselinck (1960), Melnick identified an additional six using an Echele spectrograph on the 1.52 m telescope at La Silla. The author has obtained high resolution spectra of ten of these stars and discusses the spectral types. (Auth.)

  4. Model independent method to deconvolve hard X-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

    1984-07-01

    A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented.

  5. Galactic Astronomy in the Ultraviolet

    Science.gov (United States)

    Rastorguev, A. S.; Sachkov, M. E.; Zabolotskikh, M. V.

    2017-12-01

    We propose a number of prospective observational programs for the ultraviolet space observatory WSO-UV, which seem to be of great importance to modern galactic astronomy. The programs include the search for binary Cepheids; the search and detailed photometric study and the analysis of radial distribution of UV-bright stars in globular clusters ("blue stragglers", blue horizontal-branch stars, RR Lyrae variables, white dwarfs, and stars with UV excesses); the investigation of stellar content and kinematics of young open clusters and associations; the study of spectral energy distribution in hot stars, including calculation of the extinction curves in the UV, optical and NIR; and accurate definition of the relations between the UV-colors and effective temperature. The high angular resolution of the observatory allows accurate astrometric measurements of stellar proper motions and their kinematic analysis.

  6. Additive effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A xenon-mercury high pressure lamp and a double monochromator were used to produce ultraviolet (uv) radiation at 295 nm. Pigmented rabbit eyes were irradiated and evaluated by slitlamp biomicroscopy. Corneal threshold (Hc) was 0.05 J.cm-2 and lens threshold (hL) was 0.75 J.cm-2. Other eyes were irradiated with 2 Hc and evaluated from 4 to 24 h at 4 h intervals. Corneal damage was only greater than that expected from a single Hc exposure if the separation between the two Hc exposures did not exceed 8 h. The most repeatable and reliable corneal response to these levels of uv was the development of corneal epithelial granules

  7. Ultraviolet, Visible, and Fluorescence Spectroscopy

    Science.gov (United States)

    Penner, Michael H.

    Spectroscopy in the ultraviolet-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.

  8. Telescoping cylindrical piezoelectric fiber composite actuator assemblies

    Science.gov (United States)

    Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)

    2010-01-01

    A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

  9. Ground-Based Telescope Parametric Cost Model

    Science.gov (United States)

    Stahl, H. Philip; Rowell, Ginger Holmes

    2004-01-01

    A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

  10. Optical Property Retention Methods for the T-170M Space Telescope Mirrors Surface in the Project «Spektr-UF» at the Preflight Preparation Stage

    Directory of Open Access Journals (Sweden)

    F L. Chubarov

    2017-01-01

    Full Text Available Astrophysical observations in the ultraviolet band have many advantages. At present, the «Spektr-UF» project is under implementation to create a large space observatory for operation in the ultraviolet spectrum.Requirements for the ultraviolet telescope optics quality are extremely high. Therefore, both to manufacture such a large space telescope as the T-170M and to transport it to the launch complex are rather difficult challenges in terms of technology.When manufacturing optical elements of the telescope T-170M, a combination of Al+MgF2 coatings has been preferred. At the same time, atmospheric oxygen penetrates through the pores in the magnesium fluoride, thereby forming a Al2O3 oxide layer on the sputtered aluminum, which significantly degrades the UV reflectivity of the mirror surface. It is also necessary to fulfill the requirements for surface cleanliness of optical system elements of the telescope during the finished product transportation and its storage and to provide for the autonomous operation of the system that maintains atmosphere control.To solve the set tasks:1    a dust-proof-and-moisture-proof sheath (DPAMPS was designed to prevent the optical system mirror surfaces of the telescope from coming in contact with atmosphere;2    to provide a controlled atmosphere inside the DPAMPS the need is justified to blow gaseous nitrogen of special purity (grade 1 in accordance with GOST 9293-74 with a dew point temperature of -50°С, at most, inside the telescope; calculations have proved that charging with the super-atmospheric pressure of 10 kPa provides the optimal conditions for maintaining the optical properties of the space telescope mirrors surface, and also minimizes the loads on the easily damaging elements of the telescope;3    to ensure the required cleanliness of the optical system elements surfaces of the telescope inside the DPAMPS, a class of purity Class 7 ISO, at worst, is established in accordance with GOST

  11. Transferrable monolithic multicomponent system for near-ultraviolet optoelectronics

    Science.gov (United States)

    Qin, Chuan; Gao, Xumin; Yuan, Jialei; Shi, Zheng; Jiang, Yuan; Liu, Yuhuai; Wang, Yongjin; Amano, Hiroshi

    2018-05-01

    A monolithic near-ultraviolet multicomponent system is implemented on a 0.8-mm-diameter suspended membrane by integrating a transmitter, waveguide, and receiver into a single chip. Two identical InGaN/Al0.10Ga0.90N multiple-quantum well (MQW) diodes are fabricated using the same process flow, which separately function as a transmitter and receiver. There is a spectral overlap between the emission and detection spectra of the MQW diodes. Therefore, the receiver can respond to changes in the emission of the transmitter. The multicomponent system is mechanically transferred from silicon, and the wire-bonded transmitter on glass experimentally demonstrates spatial light transmission at 200 Mbps using non-return-to-zero on–off keying modulation.

  12. Ultraviolet light curves of U Geminorum and VW Hydri

    International Nuclear Information System (INIS)

    Wu, C.-C.; Panek, R.J.; Holm, A.V.; Schiffer, F.H. III

    1982-01-01

    Ultraviolet light curves have been obtained for the quiescent dwarf novae U Gem and VW Hyi. The amplitude of the hump associated with the accretion hot spot is much smaller in the UV than in the visible. This implies that the bright spot temperature is roughly 12000 K if it is optically thick. A hotter spot would have to be optically thin in the near UV. The flux distribution of U Gem in quiescence cannot be fitted by model spectra of steady state, viscous accretion disks. The absolute luminosity, the flux distribution, and the far UV spectrum suggest that the primary star is visible in the far UV. The optical-UV flux distribution of VW Hyi could be matched roughly by the authors' model accretion disks, but the fitting is poorly constrained due to the uncertainty in its distance. (Auth.)

  13. Ultraviolet optical absorption of alkali cyanides and alkali halide cyanides

    International Nuclear Information System (INIS)

    Souza Camargo Junior, S.A. de.

    1982-09-01

    The ultraviolet absorption spectra of alkali cyanide and mixed alkali halide cyanide crystals were measured at temperatures ranging from 300K down to 4.2K. A set of small absorption peaks was observed at energies near 6 eV and assigned to parity forbidden X 1 Σ + →a' 3 Σ + transitions of the CN - molecular ions. It was observed that the peak position depends on the alkali atom while the absorption cross section strongly depends on the halogen and on the CN - concentration of the mixed crystals. These effects are explained in terms of an interaction between the triplet molecular excitons and charge transfer excitons. The experimental data were fit with a coupling energy of a few meV. The coupling mechanism is discussed and it is found to be due to the overlap between the wave functions of the two excitations. (Author) [pt

  14. Ultraviolet photoluminescence in Gd-doped silica and phosphosilicate fibers

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2017-04-01

    Full Text Available Optical fiber lasers operating in the near infrared and visible spectral regions have relied on the spectroscopic properties of rare earth ions such as Yb3+, Er3+, Tm3+, Nd3+, and Sm3+. Here, we investigate Gd3+ doping in phosphosilicate and pure silica fibers using solution doping and sol-gel techniques, respectively, for potential applications in the ultraviolet. Photoluminescence spectra for optical fiber bundles and fiber preforms were recorded and compared. Emissions at 312 nm (phosphosilicate and 314 nm (pure silica were observed when pumping to the Gd3+ 6DJ, 6IJ, and 6PJ = 5/2, 3/2 energy levels. Oxygen deficient center was observed in solution doping sample with a wide absorption band centered at around 248 nm not affecting pumping to 6IJ states.

  15. Spectroscopic modeling for tungsten EUV spectra

    International Nuclear Information System (INIS)

    Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Suzuki, Chihiro; Morita, Shigeru; Goto, Motoshi; Sasaki, Akira; Nakamura, Nobuyuki; Yamamoto, Norimasa; Koike, Fumihiro

    2014-01-01

    We have constructed an atomic model for tungsten extreme ultraviolet (EUV) spectra to reconstruct characteristic spectral feature of unresolved transition array (UTA) observed at 4-7 nm for tungsten ions. In the tungsten atomic modeling, we considered fine-structure levels with the quantum principal number n up to 6 as the atomic structure and calculated the electron-impact collision cross sections by relativistic distorted-wave method, using HULLAC atomic code. We measured tungsten EUV spectra in Large Helical Device (LHD) and Compact Electron Beam Ion Trap device (CoBIT) and compared them with the model calculation. The model successfully explain series of emission peaks at 1.5-3.5 nm as n=5-4 and 6-4 transitions of W"2"4"+ - W"3"2"+ measured in CoBIT and LHD and the charge state distributions were estimated for LHD plasma. The UTA feature observed at 4-7 nm was also successfully reconstructed with our model. The peak at ∼5 nm is produced mainly by many 4f-4d transition of W"2"2"+ - W"3"5"+ ions, and the second peak at ∼6 nm is produced by 4f-4d transition of W"2"5"+ - W"2"8"+ ions, and 4d-4p inner-shell transitions, 4p"54d"n"+"1 - 4p"64d"n, of W"2"9"+ - W"3"5"+ ions. These 4d-4p inner-shell transitions become strong since we included higher excited states such as 4p"54d"n4f state, which ADAS atomic data set does not include for spectroscopic modeling with fine structure levels. (author)

  16. Thin film optical coatings for the ultraviolet spectral region

    Science.gov (United States)

    Torchio, P.; Albrand, G.; Alvisi, M.; Amra, C.; Rauf, H.; Cousin, B.; Otrio, G.

    2017-11-01

    The applications and innovations related to the ultraviolet field are today in strong growth. To satisfy these developments which go from biomedical to the large equipment like the Storage Ring Free Electron Laser, it is crucial to control with an extreme precision the optical performances, in using the substrates and the thin film materials impossible to circumvent in this spectral range. In particular, the reduction of the losses by electromagnetic diffusion, Joule effect absorption, or the behavior under UV luminous flows of power, resistance to surrounding particulate flows... become top priority which concerns a broad European and international community. Our laboratory has the theoretical, experimental and technological tools to design and fabricate numerous multilayer coatings with desirable optical properties in the visible and infrared spectral ranges. We have extended our expertise to the ultraviolet. We present here some results on high reflectivity multidielectric mirrors towards 250 nm in wavelength, produced by Ion Plating Deposition. The latter technique allows us to obtain surface treatments with low absorption and high resistance. We give in this study the UV transparent materials and the manufacturing technology which have been the best suited to meet requirements. Single UV layers were deposited and characterized. HfO2/SiO2 mirrors with a reflectance higher than 99% at 300 nm were obtained. Optical and non-optical characterizations such as UV spectrophotometric measurements, X-Ray Diffraction spectra, Scanning Electron Microscope and Atomic Force Microscope images were performed

  17. Ultraviolet spectroscopy of planetary nebulae in the Magellanic Clouds

    International Nuclear Information System (INIS)

    Maran, S.P.; Aller, L.H.; Gull, T.R.; Stecher, T.P.

    1982-01-01

    Ultraviolet spectra of three high excitation planetary nebulae in the Magellanic Clouds (LMC P40, SMC N2, SMC N5) were obtained with the International Ultraviolet Explorer. The results are analyzed together with new visual wavelength spectrophotometry of LMC P40 and published data on SMC N2 and SMC N5 to investigate chemical composition and in particular to make the first reliable estimates of the carbon abundance in extragalactic planetary nebulae. Although carbon is at most only slightly less abundant in the LMC and SMC planetary nebulae than in galactic planetaries, it is almost 40 times more abundant in the SMC planetaries than in the SMC interstellar medium, and is about 6 times more abundant in the LMC planetary than in the LMC interstellar medium. According to our limited sample, the net result of carbon synthesis and convective dredgeup in the progenitors of planetary nebulae, as reflected in the nebular carbon abundance, is roughly the same in the Galaxy, the LMC, and the SMC

  18. Spectral signature of ultraviolet solar irradiance in Zacatecas

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo V, J. L; Mireles G, F; Rios M, C; Quirino T, L. L; Davila R, J. I [Universidad Autonoma de Zacatecas, Zacatecas, Zacatecas (Mexico)

    2006-10-15

    This study presents an analysis of the global ultraviolet spectral irradiance (290-400 nm) registered in Zacatecas, a city near the Tropic of Cancer, located at 2500 m above sea level, latitude of 22 degrees N and longitude of 102 degrees W. The spectra have been measured using a Bentham radiometer with a 0.5 nm step in wavelength. The measurements show relatively high levels of ultraviolet irradiance (UV), which may be characteristic of areas close to the Tropic of Cancer. Faced with an increase of the incidence of skin cancer among the population of Zacatecas, these measurements highlight that a damage prevention plan is required. [Spanish] En este trabajo se presenta un analisis de la radiacion espectral global ultravioleta (290-400 nm) registrada en Zacatecas, una ciudad vecina al tropico de cancer, situada a 2500 m sobre el nivel del mar, latitud de 22 grados N y longitud de 102 grados O. Los espectros correspondientes han sido medidos mediante un espectroradiometro Bentham con un paso de 0.5 nm de longitud de onda. Las mediciones muestran niveles de radiacion ultravioleta (UV) relativamente elevados, que pueden ser caracteristicos de las zonas vecinas al tropico de cancer. Frente al aumento de incidencia de cancer en la piel en la poblacion del estado de Zacatecas, estas mediciones ponen en relieve la necesidad de formular un plan preventivo de danos.

  19. Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters

    NARCIS (Netherlands)

    Cenarro, A. J.; Peletier, R. F.; Sanchez-Blazquez, P.; Selam, S. O.; Toloba, E.; Cardiel, N.; Falcon-Barroso, J.; Gorgas, J.; Jimenez-Vicente, J.; Vazdekis, A.

    2007-01-01

    We present a homogeneous set of stellar atmospheric parameters (T-eff, log g, [Fe/H]) for MILES, a new spectral stellar library covering the range lambda lambda 3525-7500 angstrom at 2.3 angstrom (FWHM) spectral resolution. The library consists of 985 stars spanning a large range in atmospheric

  20. Design energy spectra for Turkey

    OpenAIRE

    López Almansa, Francisco; Yazgan, Ahmet Utku; Benavent Climent, Amadeo

    2012-01-01

    This work proposes design energy spectra in terms of velocity, derived through linear dynamic analyses on Turkish registers and intended for regions with design peak acceleration 0.3 g or higher. In the long and mid period ranges the analyses are linear, taking profit of the rather insensitivity of the spectra to the structural parameters other than the fundamental period; in the short period range, the spectra are more sensitive to the structural parameters and nonlinear analyses would be re...

  1. Spectra of chemical trees

    International Nuclear Information System (INIS)

    Balasubramanian, K.

    1982-01-01

    A method is developed for obtaining the spectra of trees of NMR and chemical interests. The characteristic polynomials of branched trees can be obtained in terms of the characteristic polynomials of unbranched trees and branches by pruning the tree at the joints. The unbranched trees can also be broken down further until a tree containing just two vertices is obtained. The effectively reduces the order of the secular determinant of the tree used at the beginning to determinants of orders atmost equal to the number of vertices in the branch containing the largest number of vertices. An illustrative example of a NMR graph is given for which the 22 x 22 secular determinant is reduced to determinants of orders atmost 4 x 4 in just the second step of the algorithm. The tree pruning algorithm can be applied even to trees with no symmetry elements and such a factoring can be achieved. Methods developed here can be elegantly used to find if two trees are cospectral and to construct cospectral trees

  2. Sequencing BPS spectra

    Energy Technology Data Exchange (ETDEWEB)

    Gukov, Sergei [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Max-Planck-Institut für Mathematik,Vivatsgasse 7, D-53111 Bonn (Germany); Nawata, Satoshi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Centre for Quantum Geometry of Moduli Spaces, University of Aarhus,Nordre Ringgade 1, DK-8000 (Denmark); Saberi, Ingmar [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Stošić, Marko [CAMGSD, Departamento de Matemática, Instituto Superior Técnico,Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Mathematical Institute SANU,Knez Mihajlova 36, 11000 Belgrade (Serbia); Sułkowski, Piotr [Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena, CA 91125 (United States); Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland)

    2016-03-02

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincaré polynomials in numerous examples. Among these structural properties is a novel “sliding” property, which can be explained by using (refined) modular S-matrix. This leads to the identification of modular transformations in Chern-Simons theory and 3d N=2 theory via the 3d/3d correspondence. Lastly, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.

  3. Sequencing BPS spectra

    International Nuclear Information System (INIS)

    Gukov, Sergei; Nawata, Satoshi; Saberi, Ingmar; Stošić, Marko; Sułkowski, Piotr

    2016-01-01

    This paper provides both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explain from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincaré polynomials in numerous examples. Among these structural properties is a novel “sliding” property, which can be explained by using (refined) modular S-matrix. This leads to the identification of modular transformations in Chern-Simons theory and 3d N=2 theory via the 3d/3d correspondence. Lastly, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.

  4. ASERA: A spectrum eye recognition assistant for quasar spectra

    Science.gov (United States)

    Yuan, Hailong; Zhang, Haotong; Zhang, Yanxia; Lei, Yajuan; Dong, Yiqiao; Zhao, Yongheng

    2013-11-01

    Spectral type recognition is an important and fundamental step of large sky survey projects in the data reduction for further scientific research, like parameter measurement and statistic work. It tends out to be a huge job to manually inspect the low quality spectra produced from the massive spectroscopic survey, where the automatic pipeline may not provide confident type classification results. In order to improve the efficiency and effectiveness of spectral classification, we develop a semi-automated toolkit named ASERA, ASpectrum Eye Recognition Assistant. The main purpose of ASERA is to help the user in quasar spectral recognition and redshift measurement. Furthermore it can also be used to recognize various types of spectra of stars, galaxies and AGNs (Active Galactic Nucleus). It is an interactive software allowing the user to visualize observed spectra, superimpose template spectra from the Sloan Digital Sky Survey (SDSS), and interactively access related spectral line information. It is an efficient and user-friendly toolkit for the accurate classification of spectra observed by LAMOST (the Large Sky Area Multi-object Fiber Spectroscopic Telescope). The toolkit is available in two modes: a Java standalone application and a Java applet. ASERA has a few functions, such as wavelength and flux scale setting, zoom in and out, redshift estimation, spectral line identification, which helps user to improve the spectral classification accuracy especially for low quality spectra and reduce the labor of eyeball check. The function and performance of this tool is displayed through the recognition of several quasar spectra and a late type stellar spectrum from the LAMOST Pilot survey. Its future expansion capabilities are discussed.

  5. The ATHENA telescope and optics status

    Science.gov (United States)

    Bavdaz, Marcos; Wille, Eric; Ayre, Mark; Ferreira, Ivo; Shortt, Brian; Fransen, Sebastiaan; Collon, Maximilien; Vacanti, Giuseppe; Barriere, Nicolas; Landgraf, Boris; Haneveld, Jeroen; van Baren, Coen; Zuknik, Karl-Heintz; Della Monica Ferreira, Desiree; Massahi, Sonny; Christensen, Finn; Krumrey, Michael; Burwitz, Vadim; Pareschi, Giovanni; Spiga, Daniele; Valsecchi, Giuseppe; Vernani, Dervis; Oliver, Paul; Seidel, André

    2017-08-01

    The work on the definition and technological preparation of the ATHENA (Advanced Telescope for High ENergy Astrophysics) mission continues to progress. In parallel to the study of the accommodation of the telescope, many aspects of the X-ray optics are being evolved further. The optics technology chosen for ATHENA is the Silicon Pore Optics (SPO), which hinges on technology spin-in from the semiconductor industry, and uses a modular approach to produce large effective area lightweight telescope optics with a good angular resolution. Both system studies and the technology developments are guided by ESA and implemented in industry, with participation of institutional partners. In this paper an overview of the current status of the telescope optics accommodation and technology development activities is provided.

  6. EDUCATIONAL ASTRONOMICAL OBSERVATIONS ON REMOTE ACCESS TELESCOPES

    Directory of Open Access Journals (Sweden)

    Ivan P. Kriachko

    2016-01-01

    Full Text Available The purpose of this article is to show the way of overcoming one of the major problems of astronomy teaching methods in upper secondary school – organization of educational astronomical observations. Nowadays it became possible to perform such observations on remote access telescopes. By using up-to-date informational and communicational technologies, having an opportunity to work with robotic telescopes allows us to organize a unique cognitive and research oriented activities for students while conducting their specialized astronomical studies. Below here is given a brief description of the most significant robotic telescopes and the way of the usage of open remote access telescopic network which was created by professors and scientists of Harvard-Smithsonian Center for Astrophysics, USA.

  7. Possible GRB Observation with the MAGIC Telescope

    Science.gov (United States)

    Bastieri, D.; Bigongiari, C.; Mariotti, M.; Peruzzo, L.; Saggion, A.

    2001-08-01

    The MAGIC Telescope, with its reflecting parabolic dish of 17 m of diameter and its careful design of a robust, lightweight, alto-azimuthal mount, is an ideal detector for GRB phenomena. The telescope is an air Cherenkov telescope that, even in the first phase, equipped with standard PMTs, can reach an energy threshold below 30 GeV. The threshold is going to drop well below 10 GeV in the envisaged second phase, when chamber PMTs will be substituted by high quantum efficiency APDs. The telescope can promptly respond to GRB alerts coming, for instance, from GCN, and can reposition itself in less than 30 seconds, 20 seconds being the time to turn half a round for the azimuth bearing. In this report, the effective area of the detector as a function of energy and zenith angle is taken into account, in order to evaluate the expected yearly occurrence and the response to different kinds of GRBs.

  8. Direct illumination LED calibration for telescope photometry

    International Nuclear Information System (INIS)

    Barrelet, E.; Juramy, C.

    2008-01-01

    A calibration method for telescope photometry, based on the direct illumination of a telescope with a calibrated light source regrouping multiple LEDs, is proposed. Its purpose is to calibrate the instrument response. The main emphasis of the proposed method is the traceability of the calibration process and a continuous monitoring of the instrument in order to maintain a 0.2% accuracy over a period of years. Its specificity is to map finely the response of the telescope and its camera as a function of all light ray parameters. This feature is essential to implement a computer model of the instrument representing the variation of the overall light collection efficiency of each pixel for various filter configurations. We report on hardware developments done for SNDICE, the first application of this direct illumination calibration system which will be installed in Canada France Hawaii telescope (CFHT) for its leading supernova experiment (SNLS)

  9. Proposed National Large Solar Telescope Jagdev Singh

    Indian Academy of Sciences (India)

    proposed to design, fabricate and install a 2-meter class solar telescope at a suitable site in India to ... which can facilitate simultaneous measurements of the solar atmospheric parameters and of the vector ... Intensity variation of. 1% or less.

  10. A 16-m Telescope for the Advanced Technology Large Aperture Telescope (ATLAST) Mission

    Science.gov (United States)

    Lillie, Charles F.; Dailey, D. R.; Polidan, R. S.

    2010-01-01

    Future space observatories will require increasingly large telescopes to study the earliest stars and galaxies, as well as faint nearby objects. Technologies now under development will enable telescopes much larger than the 6.5-meter diameter James Webb Space Telescope (JWST) to be developed at comparable costs. Current segmented mirror and deployable optics technology enables the 6.5 meter JWST telescope to be folded for launch in the 5-meter diameter Ariane 5 payload fairing, and deployed autonomously after reaching orbit. Late in the next decade, when the Ares V Cargo Launch Vehicle payload fairing becomes operational, even larger telescope can be placed in orbit. In this paper we present our concept for a 16-meter JWST derivative, chord-fold telescope which could be stowed in the 10-m diameter Ares V fairing, plus a description of the new technologies that enable ATLAST to be developed at an affordable price.

  11. Compositional stratigraphy of crustal material from near-infrared spectra

    International Nuclear Information System (INIS)

    Pieters, C.M.

    1987-01-01

    An Earth-based telescopic program to acquire near-infrared spectra of freshly exposed lunar material now contains data for 17 large impact craters with central peaks. Noritic, gabbroic, anorthositic and troctolitic rock types can be distinguished for areas within these large craters from characteristic absorptions in individual spectra of their walls and central peaks. Norites dominate the upper lunar crust while the deeper crustal zones also contain significant amounts of gabbros and anorthosites. Data for material associated with large craters indicate that not only is the lunar crust highly heterogeneous across the nearside, but that the compositional stratigraphy of the lunar crust is nonuniform. Crustal complexity should be expected for other planetary bodies, which should be studied using high spatial and spectral resolution data in and around large impact craters

  12. Compositional stratigraphy of crustal material from near-infrared spectra

    Science.gov (United States)

    Pieters, Carle M.

    1987-01-01

    An Earth-based telescopic program to acquire near-infrared spectra of freshly exposed lunar material now contains data for 17 large impact craters with central peaks. Noritic, gabbroic, anorthositic and troctolitic rock types can be distinguished for areas within these large craters from characteristic absorptions in individual spectra of their walls and central peaks. Norites dominate the upper lunar crust while the deeper crustal zones also contain significant amounts of gabbros and anorthosites. Data for material associated with large craters indicate that not only is the lunar crust highly heterogeneous across the nearside, but that the compositional stratigraphy of the lunar crust is nonuniform. Crustal complexity should be expected for other planetary bodies, which should be studied using high spatial and spectral resolution data in and around large impact craters.

  13. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET

    International Nuclear Information System (INIS)

    Brown, Peter J.; Roming, Peter W. A.; Ciardullo, Robin; Gronwall, Caryl; Hoversten, Erik A.; Pritchard, Tyler; Milne, Peter; Bufano, Filomena; Mazzali, Paolo; Elias-Rosa, Nancy; Filippenko, Alexei V.; Li Weidong; Foley, Ryan J.; Hicken, Malcolm; Kirshner, Robert P.; Gehrels, Neil; Holland, Stephen T.; Immler, Stefan; Phillips, Mark M.; Still, Martin

    2010-01-01

    We examine the absolute magnitudes and light-curve shapes of 14 nearby (redshift z = 0.004-0.027) Type Ia supernovae (SNe Ia) observed in the ultraviolet (UV) with the Swift Ultraviolet/Optical Telescope. Colors and absolute magnitudes are calculated using both a standard Milky Way extinction law and one for the Large Magellanic Cloud that has been modified by circumstellar scattering. We find very different behavior in the near-UV filters (uvw1 rc covering ∼2600-3300 A after removing optical light, and u ∼ 3000-4000 A) compared to a mid-UV filter (uvm2 ∼2000-2400 A). The uvw1 rc - b colors show a scatter of ∼0.3 mag while uvm2-b scatters by nearly 0.9 mag. Similarly, while the scatter in colors between neighboring filters is small in the optical and somewhat larger in the near-UV, the large scatter in the uvm2 - uvw1 colors implies significantly larger spectral variability below 2600 A. We find that in the near-UV the absolute magnitudes at peak brightness of normal SNe Ia in our sample are correlated with the optical decay rate with a scatter of 0.4 mag, comparable to that found for the optical in our sample. However, in the mid-UV the scatter is larger, ∼1 mag, possibly indicating differences in metallicity. We find no strong correlation between either the UV light-curve shapes or the UV colors and the UV absolute magnitudes. With larger samples, the UV luminosity might be useful as an additional constraint to help determine distance, extinction, and metallicity in order to improve the utility of SNe Ia as standardized candles.

  14. The ARC (Astrophysical Research Consortium) telescope project.

    Science.gov (United States)

    Anderson, K. S.

    A consortium of universities intends to construct a 3.5 meter optical-infrared telescope at a site in south-central New Mexico. The use of innovative mirror technology, a fast primary, and an alt-azimuth mounting results in a compact and lightweight instrument. This telescope will be uniquely well-suited for addressing certain observational programs by virtue of its capability for fully remote operation and rapid instrument changes.

  15. The ATHENA telescope and optics status

    DEFF Research Database (Denmark)

    Bavdaz, Marcos; Wille, Eric; Ayre, Mark

    2017-01-01

    chosen for ATHENA is the Silicon Pore Optics (SPO), which hinges on technology spin-in from the semiconductor industry, and uses a modular approach to produce large effective area lightweight telescope optics with a good angular resolution. Both system studies and the technology developments are guided...... by ESA and implemented in industry, with participation of institutional partners. In this paper an overview of the current status of the telescope optics accommodation and technology development activities is provided....

  16. CLIC Telescope optimization with ALLPIX simulation

    CERN Document Server

    Qi, Wu

    2015-01-01

    A simulation study of CLIC-EUDET telescope resolution with MIMOSA 26 as reference sensors under DESY (5.6 GeV electron beam) and CERN-SPS (120-180 GeV pion^{-} beam) conditions. During the study, a virtual DUT sensor with cylindrical sensing area was defined and used with ALLPIX software. By changing the configuration of telescope, some results for DESY's setup were found agreeing with the theoretical calculation.

  17. LYCORIS - A Large Area Strip Telescope

    CERN Document Server

    Krämer, U; Stanitzki, M; Wu, M

    2018-01-01

    The LYCORIS Large Area Silicon Strip Telescope for the DESY II Test Beam Facility is presented. The DESY II Test Beam Facility provides elec- tron and positron beams for beam tests of up to 6 GeV. A new telescope with a large 10 × 20 cm2 coverage area based on a 25 μm pitch strip sensor is to be installed within the PCMAG 1 T solenoid. The current state of the system is presented.

  18. HYDROGEN PERMITTED LINES IN THE FIRST NEAR-IR SPECTRA OF Th 28 MICROJET: ACCRETION OR EJECTION TRACERS?

    International Nuclear Information System (INIS)

    Coffey, Deirdre; Podio, Linda; Bacciotti, Francesca; Nisini, Brunella

    2010-01-01

    We report the first near-infrared detection of the bipolar microjet from T Tauri star ThA 15-28 (hereafter Th 28). Spectra were obtained with Very Large Telescope (VLT)/ISAAC for the slit both perpendicular and parallel to the flow to examine jet kinematics and gas physics within the first arcsecond from the star. The jet was successfully detected in both molecular and atomic lines. The H 2 component was found to be entirely blueshifted around the base of the bipolar jet. It shows that only the blue lobe is emitting in H 2 while light is scattered in the direction of the red lobe, highlighting an asymmetric extinction and/or excitation between the two lobes. Consistent with this view, the red lobe is brighter in all atomic lines. Interestingly, the jet was detected not only in [Fe II], but also in Brγ and Paβ lines. Though considered tracers mainly of accretion, we find that these high excitation hydrogen permitted lines trace the jet as far as 150 AU from the star. This is confirmed in a number of ways: the presence of the [Fe II] 2.13 μm line which is of similarly high excitation; H I velocities which match the jet [Fe II] velocities in both the blue and red lobe; and high electron density close to the source of >6 x 10 4 cm -3 derived from the [Fe II] 1.64, 1.60 μm ratio. These near-infrared data complement Hubble Space Telescope Imaging Spectrograph (HST/STIS) optical and near-ultraviolet data for the same target which were used in a jet rotation study, although no rotation signature could be identified here due to insufficient angular resolution. The unpublished HST/STIS Hα emission is included here alongside the other H I lines. Identifying Brγ and Paβ as tracers of ejection is significant because of the importance of finding strong near-infrared probes close to the star, where forbidden lines are quenched, which will help understand accretion ejection when observed with high spatial resolution instruments such as VLTI/AMBER.

  19. Stratospheric ozone, ultraviolet radiation and climate change

    International Nuclear Information System (INIS)

    Boucher, O.

    2008-01-01

    It is well known that an overexposure to ultraviolet radiation is associated with a number of health risks such as an increased risk of cataracts and skin cancers. At a time when climate change is often blamed for all our environmental problems, what is the latest news about the stratospheric ozone layer and other factors controlling ultraviolet radiation at the surface of the Earth? Will the expected changes in the chemical composition of the atmosphere and changes in our climate increase or decrease the risk for skin cancer? This article investigates the role of the various factors influencing ultraviolet radiation and presents the latest knowledge on the subject. (author)

  20. Ultraviolet safety assessments of insect light traps

    OpenAIRE

    Sliney, David H.; Gilbert, David W.; Lyon, Terry

    2016-01-01

    ABSTRACT Near-ultraviolet (UV-A: 315?400?nm), ?black-light,? electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV ?Black-light? ILTs were measured at...

  1. Stimulation of hair cells with ultraviolet light

    Science.gov (United States)

    Azimzadeh, Julien B.; Fabella, Brian A.; Hudspeth, A. J.

    2018-05-01

    Hair bundles are specialized organelles that transduce mechanical inputs into electrical outputs. To activate hair cells, physiologists have resorted to mechanical methods of hair-bundle stimulation. Here we describe a new method of hair-bundle stimulation, irradiation with ultraviolet light. A hair bundle illuminated by ultraviolet light rapidly moves towards its tall edge, a motion typically associated with excitatory stimulation. The motion disappears upon tip-link rupture and is associated with the opening of mechanotransduction channels. Hair bundles can be induced to move sinusoidally with oscillatory modulation of the stimulation power. We discuss the implications of ultraviolet stimulation as a novel hair-bundle stimulus.

  2. Hartman Testing of X-Ray Telescopes

    Science.gov (United States)

    Saha, Timo T.; Biskasch, Michael; Zhang, William W.

    2013-01-01

    Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

  3. SCIENTIFIC EFFICIENCY OF GROUND-BASED TELESCOPES

    International Nuclear Information System (INIS)

    Abt, Helmut A.

    2012-01-01

    I scanned the six major astronomical journals of 2008 for all 1589 papers that are based on new data obtained from ground-based optical/IR telescopes worldwide. Then I collected data on numbers of papers, citations to them in 3+ years, the most-cited papers, and annual operating costs. These data are assigned to four groups by telescope aperture. For instance, while the papers from telescopes with an aperture >7 m average 1.29 more citations than those with an aperture of 2 to 7 m) telescopes. I wonder why the large telescopes do so relatively poorly and suggest possible reasons. I also found that papers based on archival data, such as the Sloan Digital Sky Survey, produce 10.6% as many papers and 20.6% as many citations as those based on new data. Also, the 577.2 papers based on radio data produced 36.3% as many papers and 33.6% as many citations as the 1589 papers based on optical/IR telescopes.

  4. The DAG project, a 4m class telescope: the telescope main structure performances

    Science.gov (United States)

    Marchiori, G.; Busatta, A.; Ghedin, L.; Marcuzzi, E.; Manfrin, C.; Battistel, C.; Pirnay, O.; Flebus, Carlo; Yeşilyaprak, C.; Keskin, O.; Yerli, S.

    2016-07-01

    Dogu Anatolu Gözlemevi (DAG-Eastern Anatolia Observatory) Project is a 4m class optical, near-infrared Telescope and suitable enclosure which will be located at an altitude of 3.170m in Erzurum, Turkey. The DAG telescope is a project fully funded by Turkish Ministry of Development and the Atatürk University of Astrophysics Research Telescope - ATASAM. The Project is being developed by the Belgian company AMOS (project leader), which is also the optics supplier and EIE GROUP, the Telescope Main Structure supplier and responsible for the final site integration. The design of the Telescope Main Structure fits in the EIE TBO Program which aims at developing a Dome/Telescope systemic optimization process for both performances and competitive costs based on previous project commitments like NTT, VLT, VST and ASTRI. The optical Configuration of the DAG Telescope is a Ritchey-Chretien with two Nasmyth foci and a 4m primary thin mirror controlled in shape and position by an Active Optic System. The main characteristics of the Telescope Main Structure are an Altitude-Azimuth light and rigid structure system with Direct Drive Systems for both axis, AZ Hydrostatic Bearing System and Altitude standard bearing system; both axes are equipped with Tape Encoder System. An innovative Control System characterizes the telescope performance.

  5. Tunable absorption resonances in the ultraviolet for InP nanowire arrays.

    Science.gov (United States)

    Aghaeipour, Mahtab; Anttu, Nicklas; Nylund, Gustav; Samuelson, Lars; Lehmann, Sebastian; Pistol, Mats-Erik

    2014-11-17

    The ability to tune the photon absorptance spectrum is an attracting way of tailoring the response of devices like photodetectors and solar cells. Here, we measure the reflectance spectra of InP substrates patterned with arrays of vertically standing InP nanowires. Using the reflectance spectra, we calculate and analyze the corresponding absorptance spectra of the nanowires. We show that we can tune absorption resonances for the nanowire arrays into the ultraviolet by decreasing the diameter of the nanowires. When we compare our measurements with electromagnetic modeling, we generally find good agreement. Interestingly, the remaining differences between modeled and measured spectra are attributed to a crystal-phase dependence in the refractive index of InP. Specifically, we find indication of significant differences in the refractive index between the modeled zinc-blende InP nanowires and the measured wurtzite InP nanowires in the ultraviolet. We believe that such crystal-phase dependent differences in the refractive index affect the possibility to excite optical resonances in the large wavelength range of 345 InP nanowire-based solar cells and photodetectors.

  6. The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

    International Nuclear Information System (INIS)

    McCarthy, K. J.; Zurro, B.; Baciero, A.

    2002-01-01

    A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs

  7. The Normal-incidence Vacuum-ultraviolet Spectrometer for the TJ-II and First Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, K.J.; Zurro, B.; Baciero, A.

    2002-07-01

    A normal-incidence spectrometer, operating in the extreme-ultraviolet and ultraviolet wavelength regions, has been commissioned for the TJ-II stellarator. The instrument has been custom built by McPherson, Chelmsford, MA, and has several unique features and accessories that are described here. The instrument and CCD detector has been tested and calibrated, and its performance evaluated, using spectral lines from glow discharges and a RF excited flow lamp. Finally, the first spectra collected with the instrument of TJ-II plasmas are presented and a preliminary estimation of an oxygen ion temperature is made. (Author) 23 refs.

  8. THE INFRARED TELESCOPE FACILITY (IRTF) SPECTRAL LIBRARY: COOL STARS

    International Nuclear Information System (INIS)

    Rayner, John T.; Cushing, Michael C.; Vacca, William D.

    2009-01-01

    We present a 0.8-5 μm spectral library of 210 cool stars observed at a resolving power of R ≡ λ/Δλ ∼ 2000 with the medium-resolution infrared spectrograph, SpeX, at the 3.0 m NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The stars have well-established MK spectral classifications and are mostly restricted to near-solar metallicities. The sample not only contains the F, G, K, and M spectral types with luminosity classes between I and V, but also includes some AGB, carbon, and S stars. In contrast to some other spectral libraries, the continuum shape of the spectra is measured and preserved in the data reduction process. The spectra are absolutely flux calibrated using the Two Micron All Sky Survey photometry. Potential uses of the library include studying the physics of cool stars, classifying and studying embedded young clusters and optically obscured regions of the Galaxy, evolutionary population synthesis to study unresolved stellar populations in optically obscured regions of galaxies and synthetic photometry. The library is available in digital form from the IRTF Web site.

  9. The Infrared Telescope Facility (IRTF) Spectral Library: Cool Stars

    Science.gov (United States)

    Rayner, John T.; Cushing, Michael C.; Vacca, William D.

    2009-12-01

    We present a 0.8-5 μm spectral library of 210 cool stars observed at a resolving power of R ≡ λ/Δλ ~ 2000 with the medium-resolution infrared spectrograph, SpeX, at the 3.0 m NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The stars have well-established MK spectral classifications and are mostly restricted to near-solar metallicities. The sample not only contains the F, G, K, and M spectral types with luminosity classes between I and V, but also includes some AGB, carbon, and S stars. In contrast to some other spectral libraries, the continuum shape of the spectra is measured and preserved in the data reduction process. The spectra are absolutely flux calibrated using the Two Micron All Sky Survey photometry. Potential uses of the library include studying the physics of cool stars, classifying and studying embedded young clusters and optically obscured regions of the Galaxy, evolutionary population synthesis to study unresolved stellar populations in optically obscured regions of galaxies and synthetic photometry. The library is available in digital form from the IRTF Web site.

  10. Photodetector of ultra-violet radiation

    International Nuclear Information System (INIS)

    Dorogan, V.; Vieru, T.; Coseac, V.; Chirita, F.

    1999-01-01

    The invention relates to photodetectors on the semiconductors base, in particular, to photodetectors of ultra-violet radiation and can be used in the optoelectronics systems for determining the intensity and dose of ultraviolet radiation emitted by the Sun and other sources. In the structure of the photodetector of ultraviolet radiation with a superficial potential barrier formed of semiconductors A 3 B 5 with the prohibited power width Eg 1 , solid solutions thereof with the prohibited power width Eg 2 and SnO 2 or ITO, in the semiconductors A 3 B 5 at a surface distance less than the absorption length of the visible radiation it is formed an isotype heterojunction between the semiconductors A 3 B 5 and solid solutions thereof with the prohibited power width Eg 2 > Eg 1 . The technical result consists in manufacturing of a photodetector sensitive solely to the ultraviolet radiation

  11. Outdoor ultraviolet exposure of children and adolescents

    International Nuclear Information System (INIS)

    Diffey, B.L.; Gibson, C.J.

    1996-01-01

    The weekday and weekend outdoor ultraviolet exposure of young people from primary and secondary schools in three geographically distinct regions of England was determined over a 3-month period in summer. Ultraviolet exposure was measured using personal film badges worn by each young person and time spent outdoors, in hourly intervals, assessed using exposure records. In each area a class of 9-10 year-old children from a primary school and a class of 14-15-year-old adolescents from a secondary school took part, giving a total of 180 subjects. We found that primary school children received higher outdoor ultraviolet exposure than young people in secondary schools, and geographical differences in exposure could not be accounted for solely by differences in ambient ultraviolet. There was little difference between the exposure of males and females. Children and adolescents did not behave as homogeneous groups with regard to exposure. (Author)

  12. Ultraviolet light - nature's own disinfection process

    Energy Technology Data Exchange (ETDEWEB)

    Munkeberg, T [Thorolf Gregersen a/s, Oslo (Norway)

    1978-05-18

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m/sup 3/ /hr, though there is no reason why this should not be increased.

  13. Ultraviolet light - nature's own disinfection process

    International Nuclear Information System (INIS)

    Munkeberg, T.

    1978-01-01

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m 3 /hr, though there is no reason why this should not be increased. (JIW)

  14. Inactivation of mitochondrial ATPase by ultraviolet light

    International Nuclear Information System (INIS)

    Chavez, E.; Cuellar, A.

    1984-01-01

    The present work describes experiments that show that far-ultraviolet irradiation induce the inhibition of ATPase activity in both membrane-bound and soluble F1. It was also found that ultraviolet light promotes the release of tightly bound adenine nucleotides from F1-ATPase. Experiments carried out with submitochondrial particles indicate that succinate partially protects against these effects of ultraviolet light. Titration of sulfhydryl groups in both irradiated submitochondrial particles and soluble F1-ATPase indicates that a conformational change induced by photochemical modifications of amino acid residues appears involved in the inactivation of the enzyme. Finally, experiments are described which show that the tyrosine residue located in the active site of F1-ATPase is modified by ultraviolet irradiation

  15. Stability and Transient Effects in Ultraviolet Filaments

    National Research Council Canada - National Science Library

    Niday, Thomas

    2004-01-01

    .... Much of the work in this field has been done with infrared pulses; however, it has been proposed that ultraviolet pulses have the advantage that longer pulse lengths can be used, thereby delivering more energy...

  16. PMMA Wettability Caused by Ultraviolet Radiation

    OpenAIRE

    Dehtjars, J; Lancere, L; Poļaka, N; Soudnikovich, A; Tjuļkins, F; Valters, V

    2010-01-01

    The article is targeted to explore ultraviolet radiation (UV) influence on PMMAf or eye prostheses. UV beingt he Sun lightc omponenta nd could effect PMMA surface that in turn contributesi nteractionw ith tear. PMMA wettabilityw as poweredb y UV.

  17. Ultraviolet treatment on high performance filaments

    International Nuclear Information System (INIS)

    Gu Huang

    2005-01-01

    Quartz, Kevlar, carbon, and glass filaments were irradiated by ultraviolet ray with various periods. Tensile strength of the treated fibres was tested and analyzed, and the outward appearance of the treated filaments was shown

  18. Open principle for large high-resolution solar telescopes

    NARCIS (Netherlands)

    Hammerschlag, R.H.; Bettonvil, F.C.M.; Jägers, A.P.L.; Sliepen, G.

    2009-01-01

    Vacuum solar telescopes solve the problem of image deterioration inside the telescope due to refractive index fluctuations of the air heated by the solar light. However, such telescopes have a practical diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the pioneering demonstrator

  19. Vacuum-Ultraviolet Photovoltaic Detector.

    Science.gov (United States)

    Zheng, Wei; Lin, Richeng; Ran, Junxue; Zhang, Zhaojun; Ji, Xu; Huang, Feng

    2018-01-23

    Over the past two decades, solar- and astrophysicists and material scientists have been researching and developing new-generation semiconductor-based vacuum ultraviolet (VUV) detectors with low power consumption and small size for replacing traditional heavy and high-energy-consuming microchannel-detection systems, to study the formation and evolution of stars. However, the most desirable semiconductor-based VUV photovoltaic detector capable of achieving zero power consumption has not yet been achieved. With high-crystallinity multistep epitaxial grown AlN as a VUV-absorbing layer for photogenerated carriers and p-type graphene (with unexpected VUV transmittance >96%) as a transparent electrode to collect excited holes, we constructed a heterojunction device with photovoltaic detection for VUV light. The device exhibits an encouraging VUV photoresponse, high external quantum efficiency (EQE) and extremely fast tempera response (80 ns, 10 4 -10 6 times faster than that of the currently reported VUV photoconductive devices). This work has provided an idea for developing zero power consumption and integrated VUV photovoltaic detectors with ultrafast and high-sensitivity VUV detection capability, which not only allows future spacecraft to operate with longer service time and lower launching cost but also ensures an ultrafast evolution of interstellar objects.

  20. Human exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Bernhardt, J.H.; Matthes, R.

    1987-01-01

    Ultraviolet radiation is that part of the electromagnetic spectrum located between the softest ionizing radiation and visible radiation. The lower limit of 100 nm is equivalent to photon energies of 12.4 eV, which corresponds approximately to the limit for the production of ionization in biologically important materials. A historical subdividing of the UV-region takes some of the biological effects into account. In this arrangement the range 400-315 nm, the so-called black light region, is called UV-A. In this wavelength region, fluorescence can be induced in many substances. UV-B covers the range 315-280 nm (the skin erythemal region). Most of the biologically active and potentially harmful UV from the sun reaching the surface of the earth is part of this spectral region. UV-C includes the radiation of wavelengths less than 280 nm (the germicidal region). It should be noted that this classification is somewhat arbitrary, and today it is more usual to evaluate the biological effectiveness of the whole UV-range from 200 to 400 nm