Science.gov

Sample records for area telescope view

  1. The Large Area Telescope

    SciTech Connect

    Michelson, Peter F.; /KIPAC, Menlo Park /Stanford U., HEPL

    2007-11-13

    The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large Area Space Telescope (GLAST) mission, is an imaging, wide field-of-view, high-energy pair-conversion telescope, covering the energy range from {approx}20 MeV to more than 300 GeV. The LAT is being 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. The scientific objectives the LAT will address include resolving the high-energy gamma-ray sky and determining the nature of the unidentified gamma-ray sources and the origin of the apparently isotropic diffuse emission observed by EGRET; understanding the mechanisms of particle acceleration in celestial sources, including active galactic nuclei, pulsars, and supernovae remnants; studying the high-energy behavior of gamma-ray bursts and transients; using high-energy gamma-rays to probe the early universe to z {ge} 6; and probing the nature of dark matter. The components of the LAT include a precision silicon-strip detector tracker and a CsI(Tl) calorimeter, a segmented anticoincidence shield that covers the tracker array, and a programmable trigger and data acquisition system. 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 field-of-view and ensuring that nearly all pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. This paper includes a description of each of these LAT subsystems as well as a summary of the overall performance of the telescope.

  2. Jet emission in young radio sources: A Fermi large area telescope gamma-ray view

    SciTech Connect

    Migliori, G.; Siemiginowska, A.; Kelly, B. C.; Stawarz, Ł.; Celotti, A.; Begelman, M. C.

    2014-01-10

    We investigate the contribution of the beamed jet component to the high-energy emission in young and compact extragalactic radio sources, focusing for the first time on the γ-ray band. We derive predictions on the γ-ray luminosities associated with the relativistic jet assuming a leptonic radiative model. The high-energy emission is produced via Compton scattering by the relativistic electrons in a spherical region at the considered scales (≲10 kpc). Simulations show a wide range of γ-ray luminosities, with intensities up to ∼10{sup 46}-10{sup 48} erg s{sup –1} depending on the assumed jet parameters. We find a highly linear relation between the simulated X-ray and γ-ray luminosities that can be used to select candidates for γ-ray detection. We compare the simulated luminosity distributions in the radio, X-ray, and γ-ray regimes with observations for the largest sample of X-ray-detected young radio quasars. Our analysis of ∼4-yr Fermi Large Area Telescope (LAT) data does not yield any statistically significant detections. However, the majority of the model-predicted γ-ray fluxes for the sample are near or below the current Fermi-LAT flux threshold and compatible with the derived upper limits. Our study gives constraints on the minimum jet power (L {sub jet,} {sub kin}/L {sub disk} > 0.01) of a potential jet contribution to the X-ray emission in the most compact sources (≲ 1 kpc) and on the particle-to-magnetic field energy density ratio that are in broad agreement with equipartition assumptions.

  3. Jet Emission in Young Radio Sources: A Fermi Large Area Telescope Gamma-Ray View

    NASA Astrophysics Data System (ADS)

    Migliori, G.; Siemiginowska, A.; Kelly, B. C.; Stawarz, Ł.; Celotti, A.; Begelman, M. C.

    2014-01-01

    We investigate the contribution of the beamed jet component to the high-energy emission in young and compact extragalactic radio sources, focusing for the first time on the γ-ray band. We derive predictions on the γ-ray luminosities associated with the relativistic jet assuming a leptonic radiative model. The high-energy emission is produced via Compton scattering by the relativistic electrons in a spherical region at the considered scales (lsim10 kpc). Simulations show a wide range of γ-ray luminosities, with intensities up to ~1046-1048 erg s-1 depending on the assumed jet parameters. We find a highly linear relation between the simulated X-ray and γ-ray luminosities that can be used to select candidates for γ-ray detection. We compare the simulated luminosity distributions in the radio, X-ray, and γ-ray regimes with observations for the largest sample of X-ray-detected young radio quasars. Our analysis of ~4-yr Fermi Large Area Telescope (LAT) data does not yield any statistically significant detections. However, the majority of the model-predicted γ-ray fluxes for the sample are near or below the current Fermi-LAT flux threshold and compatible with the derived upper limits. Our study gives constraints on the minimum jet power (L jet, kin/L disk > 0.01) of a potential jet contribution to the X-ray emission in the most compact sources (lsim 1 kpc) and on the particle-to-magnetic field energy density ratio that are in broad agreement with equipartition assumptions.

  4. Wide field of view telescope

    DOEpatents

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  5. SkyView Virtual Telescope:

    NASA Astrophysics Data System (ADS)

    McGlynn, Thomas A.; McDonald, Laura M.; Scollick, Keith A.

    2015-11-01

    The SkyView Virtual telescope provides access to survey datasets ranging from radio through the gamma-ray regimes. Over 100 survey datasets are currently available. The SkyView library referenced here is used as the basis for the SkyView web site (at http://skvyiew.gsfc.nasa.gov) but is designed for individual use by researchers as well. SkyView's approach to access surveys is distinct from most other toolkits. Rather than providing links to the original data, SkyView attempts to immediately re-render the source data in the user-requested reference frame, projection, scaling, orientation, etc. The library includes a set of geometry transformation and mosaicking tools that may be integrated into other applications independent of SkyView.

  6. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  7. High-Resolution, Wide-Field-of-View Scanning Telescope

    NASA Technical Reports Server (NTRS)

    Sepulveda, Cesar; Wilson, Robert; Seshadri, Suresh

    2007-01-01

    A proposed telescope would afford high resolution over a narrow field of view (<0.10 ) while scanning over a total field of view nominally 16 wide without need to slew the entire massive telescope structure. The telescope design enables resolution of a 1-m-wide object in a 50- km-wide area of the surface of the Earth as part of a 200-km-wide area field of view monitored from an orbit at an altitude of 700 km. The conceptual design of this telescope could also be adapted to other applications both terrestrial and extraterrestrial in which there are requirements for telescopes that afford both wide- and narrow-field capabilities. In the proposed telescope, the scanning would be effected according to a principle similar to that of the Arecibo radio telescope, in which the primary mirror is stationary with respect to the ground and a receiver is moved across the focal surface of the primary mirror. The proposed telescope would comprise (1) a large spherical primary mirror that would afford high resolution over a narrow field of view and (2) a small displaceable optical relay segment that would be pivoted about the center of an aperture stop to effect the required scanning (see figure). Taken together, both comprise a scanning narrow-angle telescope that does not require slewing the telescope structure. In normal operation, the massive telescope structure would stare at a fixed location on the ground. The inner moveable relay optic would be pivoted to scan the narrower field of view over the wider one, making it possible to retain a fixed telescope orientation, while obtaining high-resolution images over multiple target areas during an interval of 3 to 4 minutes in the intended orbit. The pivoting relay segment of the narrow-angle telescope would include refractive and reflective optical elements, including two aspherical mirrors, to counteract the spherical aberration of the primary mirror. Overall, the combination of the primary mirror and the smaller relay optic

  8. GLAST Large Area Telescope Multiwavelength Opportunities

    NASA Technical Reports Server (NTRS)

    Thompson, David

    2008-01-01

    The Gamma-ray Large Area Space Telescope (GLAST) is scheduled for launch this year. Because the GLAST Large Area Telescope (LAT) has a huge field of view and the GLAST Observatory will be operated in scanning mode, it will survey the entire sky daily. The GLAST Mission and the LAT Collaboration invite cooperative efforts from theorists and observers at all wavelengths to help optimize the science. Possible topics include: (1) Blazars: These Active Galactic Nuclei are expected to be a major source class for LAT. Identifying new blazars, monitoring their variability, and joining programs to carry out planned or Target of Opportunity multiwavelength campaigns will all be important activities. The study of AGN gamma-ray jets can help link the accretion processes close to the black hole with the large-scale interaction of the AGN with its environment. (2) Unidentified Gamma-ray Sources: Modeling of possible gamma-ray sources is important to establish testable hypotheses. New gamma-ray sources need first to be identified with known objects by position, spectrum, or time variability, and then multiwavelength studies can be used to explore the astrophysical implications of high-energy radiation from these sources. The LAT team is committed to releasing a preliminary source list about six months after the start of science operations.

  9. GLAST Large Area Telescope Multiwavelength Planning

    NASA Technical Reports Server (NTRS)

    Reimer, O.; Michelson, P. F.; Cameron, R. A.; Digel, S. W.; Thompson, D. J.; Wood, K. S.

    2007-01-01

    Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-spectrum blazar monitoring; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification and characterization. Several of these activities are needed to be in place before launch.

  10. GLAST Large Area Telescope Multiwavelength Planning

    SciTech Connect

    Reimer, O.; Michelson, P.F.; Cameron, R.A.; Digel, S.W.; Thompson, D.J.; Wood, K.S.

    2007-01-03

    Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-band blazar monitoring; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification and characterization. Several of these activities are needed to be in place before launch.

  11. GLAST Large Area Telescope Multiwavelength Planning

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Cameron, R. A.; Digel, S. W.; Wood, K. S.

    2006-01-01

    Because gamma-ray astrophysics depends in many ways on multiwavelength studies, the GLAST Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority needs include: (1) radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-spectrum blazar flare measurements; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for unidentified gamma-ray sources. Work on the first three of these activities is needed before launch. The GLAST Large Area Telescope is an international effort, with U.S. funding provided by the Department of Energy and NASA.

  12. Gamma-Ray Large Area Space Telescope- GLAST Mission Overview

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander A.

    2007-01-01

    This viewgraph presentation reviews the Gamma-ray Large Area Space Telescope (GLAST), and the instrumentation that will be on the spacecraft: Large Area Telescope (LAT) and GLAST Burst Monitor (GBM). The presentation revierws in detail the LAT instrument.

  13. Fermi Large Area Telescope Second Source Catalog

    NASA Astrophysics Data System (ADS)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Bignami, G. F.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bottacini, E.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Campana, R.; Cañadas, B.; Cannon, A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Ceccanti, M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chipaux, R.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Corbet, R.; Cutini, S.; D'Ammando, F.; Davis, D. S.; de Angelis, A.; DeCesar, M. E.; DeKlotz, M.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Enoto, T.; Escande, L.; Fabiani, D.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Iafrate, G.; Itoh, R.; Jóhannesson, G.; Johnson, R. P.; Johnson, T. E.; Johnson, A. S.; Johnson, T. J.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Landriu, D.; Latronico, L.; Lemoine-Goumard, M.; Lionetto, A. M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Marelli, M.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Minuti, M.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Pinchera, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Romani, R. W.; Roth, M.; Rousseau, R.; Ryde, F.; Sadrozinski, H. F.-W.; Salvetti, D.; Sanchez, D. A.; Saz Parkinson, P. M.; Sbarra, C.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Shaw, M. S.; Shrader, C.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Tinebra, F.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vandenbroucke, J.; Van Etten, A.; Van Klaveren, B.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Werner, M.; Winer, B. L.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zimmer, S.

    2012-04-01

    We present the second catalog of high-energy γ-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely γ-ray-producing source classes. We dedicate this paper to the memory of our colleague Patrick Nolan, who died on 2011 November 6. His career spanned much of the history of high-energy astronomy from space and his work on the Large Area Telescope (LAT) began nearly 20 years ago when it was just a concept. Pat was a central member in the operation of the LAT collaboration and he is greatly missed.

  14. Viewing the Universe with Infrared Eyes: The Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.; Spitzer Science Center

    2016-01-01

    The Spitzer Space Telescope, launched on 2003 August 25, continues to produce new and exciting views of the Universe as seen in infrared light. Spitzer is the fourth and final space telescope in NASA's Great Observatory series. Originally it consisted of a liquid-helium-cooled 85-cm telescope and three imaging and spectroscopic instruments capable of observing infrared light (3-160 micron wavelength) from regions of space invisible to optical telescopes. In mid-2009 Spitzer's cryogen was exhausted, leaving the observatory with two operating imaging arrays at 3.6 and 4.5 micron wavelength. "Warm" Spitzer, as it is now called, continues to match the sensitivity achieved at these wavelengths during the cryogenic mission and remains very much in demand. The Spitzer Space Telescope has changed our view of the Universe. Spitzer's scientific results include the study of the formation and evolution of galaxies in the early Universe, star formation and evolution, exoplanets, the structure and evolution of planetary disks around nearby stars, the cosmic distance scale, clusters of galaxies, near-Earth asteroids, and comets. After a brief description of the Spitzer mission, achievements of Spitzer's extragalactic and galactic observational programs will be presented, including many of Spitzer's very spectacular images.

  15. Step-zoom dual-field-of-view infrared telescope

    NASA Astrophysics Data System (ADS)

    Nadeem Akram, Muhammad; Hammad Asghar, Muhammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8 -12- μm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one uses an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view.

  16. Step-zoom dual-field-of-view infrared telescope

    NASA Astrophysics Data System (ADS)

    Akram, Muhammad Nadeem; Asghar, Muhammad Hammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8-12-μm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one uses an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view.

  17. Step-zoom dual-field-of-view infrared telescope.

    PubMed

    Akram, Muhammad Nadeem; Asghar, Muhammad Hammad

    2003-05-01

    The design of a dual-field-of-view telescope for an 8-12-microm imaging waveband is described. Preliminary calculations are made to determine the first-order parameters of the narrow- and the wide-field modes. To achieve a switchable dual-field-of-view system, one use an optical configuration based on the axial motion of a single lens group along the optical axis. The same lens is also used for focusing at near objects and for athermalization by small axial movement. A total of six lenses with one conic surface are used in the design, making the telescope cost effective and lightweight. The final optical design is presented, along with the aberrations curves and modulation transfer function plots, showing excellent performance in both fields of view. PMID:12737462

  18. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

    SciTech Connect

    Nolan, P. L.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Abdo, A. A.; Ackermann, M.; Antolini, E.; Bonamente, E.; Atwood, W. B.; Belfiore, A.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Bastieri, D.; Bignami, G. F. E-mail: Gino.Tosti@pg.infn.it E-mail: tburnett@u.washington.edu; and others

    2012-04-01

    We present the second catalog of high-energy {gamma}-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely {gamma}-ray-producing source classes.

  19. Fermi Large Area Telescope Second Source Catalog

    NASA Technical Reports Server (NTRS)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M; Allafort, A.; Antolini, E; Bonnell, J.; Cannon, A.; Celik O.; Corbet, R.; Davis, D. S.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Harding, A. K.; Hays, E.; Johnson, T. E.; McConville, W.; McEnery, J. E; Perkins, J. S.; Racusin, J. L; Scargle, J. D.; Stephens, T. E.; Thompson, D. J.; Troja, E.

    2012-01-01

    We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24-month period. The Second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in 5 energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 11eV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely gamma-ray-producing source classes.

  20. Fermi Large Area Telescope Third Source Catalog

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Bonino, R.; Bottacini, E.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeKlotz, M.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Katsuta, J.; Kuss, M.; La Mura, G.; Landriu, D.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Romani, R. W.; Salvetti, D.; Sánchez-Conde, M.; Saz Parkinson, P. M.; Schulz, A.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, Y.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Torresi, E.; Tosti, G.; Troja, E.; Van Klaveren, B.; Vianello, G.; Winer, B. L.; Wood, K. S.; Wood, M.; Zimmer, S.; Fermi-LAT Collaboration

    2015-06-01

    We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in the 100 MeV-300 GeV range. Based on the first 4 yr of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the Second Fermi LAT catalog, the 3FGL catalog incorporates twice as much data, as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse γ-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources above 4σ significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 238 sources are considered as identified based on angular extent or correlated variability (periodic or otherwise) observed at other wavelengths. For 1010 sources we have not found plausible counterparts at other wavelengths. More than 1100 of the identified or associated sources are active galaxies of the blazar class; several other classes of non-blazar active galaxies are also represented in the 3FGL. Pulsars represent the largest Galactic source class. From source counts of Galactic sources we estimate that the contribution of unresolved sources to the Galactic diffuse emission is ˜3% at 1 GeV.

  1. Dark Matter Searches with the Fermi Large Area Telescope

    SciTech Connect

    Meurer, Christine

    2008-12-24

    The Fermi Gamma-Ray Space Telescope, successfully launched on June 11th, 2008, is the next generation satellite experiment for high-energy gamma-ray astronomy. The main instrument, the Fermi Large Area Telescope (LAT), with a wide field of view (>2 sr), a large effective area (>8000 cm{sup 2} at 1 GeV), sub-arcminute source localization, a large energy range (20 MeV-300 GeV) and a good energy resolution (close to 8% at 1 GeV), has excellent potential to either discover or to constrain a Dark Matter signal. The Fermi LAT team pursues complementary searches for signatures of particle Dark Matter in different search regions such as the galactic center, galactic satellites and subhalos, the milky way halo, extragalactic regions as well as the search for spectral lines. In these proceedings we examine the potential of the LAT to detect gamma-rays coming from Weakly Interacting Massive Particle annihilations in these regions with special focus on the galactic center region.

  2. A large-area gamma-ray imaging telescope system

    NASA Technical Reports Server (NTRS)

    Koch, D. G.

    1983-01-01

    The concept definition of using the External Tank (ET) of the Space Shuttle as the basis for constructing a large area gamma ray imaging telescope in space is detailed. The telescope will be used to locate and study cosmic sources of gamma rays of energy greater than 100 MeV. Both the telescope properties and the means whereby an ET is used for this purpose are described. A parallel is drawn between those systems that would be common to both a Space Station and this ET application. In addition, those systems necessary for support of the telescope can form the basis for using the ET as part of the Space Station. The major conclusions of this concept definition are that the ET is ideal for making into a gamma ray telescope, and that this telescope will provide a substantial increase in collecting area.

  3. Telescope with a wide field of view internal optical scanner

    NASA Technical Reports Server (NTRS)

    Degnan, III, John James (Inventor); Zheng, Yunhui (Inventor)

    2012-01-01

    A telescope with internal scanner utilizing either a single optical wedge scanner or a dual optical wedge scanner and a controller arranged to control a synchronous rotation of the first and/or second optical wedges, the wedges constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers. The telescope with internal scanner further incorporates a first converging optical element that receives the redirected light and transmits the redirected light to the scanner, and a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

  4. Building ISOC Status Displays for the Large AreaTelescope aboard the Gamma Ray Large Area Space Telescope (GLAST) Observatory

    SciTech Connect

    Ketchum, Christina; /SLAC

    2006-09-01

    In September 2007 the Gamma Ray Large Area Space Telescope (GLAST) is scheduled to launch aboard a Delta II rocket in order to put two high-energy gamma-ray detectors, the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM) into low earth orbit. The Instrument Science Operations Center (ISOC) at SLAC is responsible for the LAT operations for the duration of the mission, and will therefore build an operations center including a monitoring station at SLAC to inform operations staff and visitors of the status of the LAT instrument and GLAST. This monitoring station is to include sky maps showing the location of GLAST in its orbit as well as the LAT's projected field of view on the sky containing known gamma-ray sources. The display also requires a world map showing the locations of GLAST and three Tracking and Data Relay Satellites (TDRS) relative to the ground, their trail lines, and ''footprint'' circles indicating the range of communications for each satellite. The final display will also include a space view showing the orbiting and pointing information of GLAST and the TDRS satellites. In order to build the displays the astronomy programs Xephem, DS9, SatTrack, and STK were employed to model the position of GLAST and pointing information of the LAT instrument, and the programming utilities Python and Cron were used in Unix to obtain updated information from database and load them into the programs at regular intervals. Through these methods the indicated displays were created and combined to produce a monitoring display for the LAT and GLAST.

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

    SciTech Connect

    Atwood, W.B.; Abdo, Aous A.; Ackermann, M.; Anderson, B. Axelsson, M.; Baldini, L.; Ballet, J.; Band, D.L.; Barbiellini, Guido; Bartelt, J.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bederede, D.; Bellardi, F.; Bellazzini, R.; Berenji, B.; Bignami, G.F.; Bisello, D.; Bissaldi, E.; Blandford, R.D.; /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) measure

  6. INTERIOR VIEW OF ENTRY AREA. VIEW THROUGH TO THE KITCHEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF ENTRY AREA. VIEW THROUGH TO THE KITCHEN IN THE BACKGROUND. NOTE THE PARTIAL VIEW OF THE ELEVEN-PANEL FRONT DOOR AND TONGUE-AND-GROOVE WOOD FLOORING. VIEW FACING NORTHEAST. - Hickam Field, Officers' Housing Type K, 304 Sixth Street, Honolulu, Honolulu County, HI

  7. 70. Smart view recreation area entrance road. View of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. Smart view recreation area entrance road. View of the snake or worm fences used to reinforce the roadway alignment. Looking north-northwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  8. 33. VIEW TO SOUTHEAST. AERIAL VIEW OF AREA DURING FLOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. VIEW TO SOUTHEAST. AERIAL VIEW OF AREA DURING FLOOD STAGE. GIANELLA BRIDGE AT UPPER RIGHT Photographer unknown, January 24, 1970 - Gianella Bridge, Spanning Sacramento River at State Highway 32, Hamilton City, Glenn County, CA

  9. VIEW OF OPEN GRASSY AREA BEHIND PLAYGROUND #1. VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF OPEN GRASSY AREA BEHIND PLAYGROUND #1. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  10. Design of hard x-ray focusing telescope with a large field-of-view

    NASA Astrophysics Data System (ADS)

    Chen, Shenghao; Mu, Baozhong; Ma, Shuang; Wang, Zhanshan

    2014-11-01

    X-ray Timing and Polarization (XTP) satellite with focusing optics and advanced detectors will study Black Hole, Neutron Star, Quark Star and the physics under extreme gravity, density and magnetism. XTP is about to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV. We present the design of XTP Telescope with a larger field of view in this paper. The initial structure design of nested conical Wolter-I telescope in X-rays is determined with the focal length f=4.5m, mirror length L=100mm, thickness t=0.3mm, inner and outer diameter Din-out=100-450mm. To optimize the structure parameters, a self-complied Matlab software is used to maximize the center geometrical collecting are. A constant deviation gap between every two mirrors is introduced, and we calculate geometrical area in on-axis and off-axis. Balancing the performance of the telescope, the final gap value is 0.06 mm. The geometrical collecting area of on-axis decreased by 5%, the average geometrical area of off-axis is increased about 1.7% and the field of view is improved from 22' to 24', meanwhile, number of mirrors and total weight of mirrors also are decreased by 5.8%, 5.3% respectively.

  11. Status of GLAST, the Gamma-ray Large-area Space Telescope

    SciTech Connect

    Rochester, L.; /SLAC

    2005-12-14

    GLAST is a satellite-based observatory consisting of the Large-Area Telescope (LAT), a modular 4 x 4-tower pair-conversion telescope with a field-of-view greater than 2 steradians, capable of measuring gamma-ray energies in the range 20 MeV to 300 GeV, and the GLAST Burst Monitor (GBM), a set of NaI and BGO detectors covering 8 steradians and sensitive to photons with energies between 10 keV and 25 MeV, allowing for correlative observations of transient events. The observatory is currently being constructed and is scheduled to be launched in August 2007.

  12. 3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH COMMUNITY KITCHEN IN BACKGROUND. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  13. 65. Smart view recreation area. View of one of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. Smart view recreation area. View of one of the parkway curves with a snake fence on the left and the stone drain on the right reinforcing the roadway alignment. Looking north-northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  14. 248. Smart view Recreation Area. View of one of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    248. Smart view Recreation Area. View of one of the parkway curves with a snake fence on the left and a stone drain on the right reinforcing the roadway alignment. Looking north-northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  15. 34. VIEW TO SOUTHWEST. AERIAL VIEW OF AREA DURING FLOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. VIEW TO SOUTHWEST. AERIAL VIEW OF AREA DURING FLOOD STAGE, LOOKING ALONG CENTERLINE OF GIANELLA BRIDGE, WITH HAMILTON CITY, GLENN COUNTY, IN THE BACKGROUND Photographer unknown, January 24, 1970 - Gianella Bridge, Spanning Sacramento River at State Highway 32, Hamilton City, Glenn County, CA

  16. Fermi Large Area Telescope Bright Gamma-ray Source List

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Band, D.L.; Barbiellini, Guido; Bastieri, Denis; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bignami, G.F.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; /more authors..

    2009-05-15

    Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

  17. A fast, wide field of view, catadioptric telescope for Whipple

    NASA Astrophysics Data System (ADS)

    McGuire, James P.

    2014-12-01

    We describe the optical design of a spaceborne f/1.3 catadioptric telescope with a 9 degree field and 77 cm aperture that is being proposed to study objects in the Kuiper belt, Sedna Region, and Oort cloud.

  18. Automated Science Processing for the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Chiang, James

    2012-03-01

    information on source properties during a flare (Exception to this are the locations on the sky of gamma-ray bursts which we will discuss in detail below.) Several features of the Fermi LAT data constrain the ability to detect transient signals. The main limitation is the detection rate of celestial photons. Even though the LAT is more sensitive than previous telescopes at these energies, the nominal photon detection rate is still significantly <10 counts per second (Hz). Spread over the whole sky in one 3 h interval, this is <2 photons per square degree. Another difficulty arises from the angular dependence of the photon sensitivity with respect to the "boresight" of the instrument. The LAT "effective area" (The effective area is proportional to the probability that a photon from a given direction on the sky will be detected by the instrument. It is the collecting area of an equivalent perfect detector) drops off roughly as cos(theta), where theta is the off-axis angle with respect to the instrument z-axis. The resulting field-of-view (FOV) is about 2.4 sr, or about 20% of the whole sky. At the few percent level, there is also a modulation of the effective area with azimuthal angle phi about the z-axis. These effects, combined with occultations by the Earth and the rocking motion of the satellite between the northern and southern celestial hemispheres on alternate orbits, means that the exposure to any point on the sky is modulated at the orbital timescale (∼95 min); and this modulation will be strongly imprinted on the count rate from a given location on the sky. In addition, the Fermi orbit precesses on a 53.4-day period and that will also modulate the signal from any given source. As discussed in Chapter 2a (also see Ref. [4]), the raw, unprocessed data stream transmitted to the ground by the LAT is dominated by charged particle backgrounds whose rates are O(102) higher than the photon rates. Charged particles are rejected via a complex particle reconstruction and

  19. GLAST large area telescope - daily survey of high energy sky

    NASA Astrophysics Data System (ADS)

    Kamae, Tuneyoshi

    2003-07-01

    GLAST Large Area Telescope was proposed to NASA in 1999 as a follow-up of EGRET on-board Compton Gamma-Ray Observatory by an international collaboration. The proposal has been approved as a part of the GLAST observatory mission in its capability to explore a wide range of astrophysics with 5-40 times higher sensitivity and extended energy coverage (20MeV to 300GeV) than EGRET. The instrument consists of 16 towers of e+e- pair tracker, 16 blocks of segmented electro-magnetic calorimeter, and a set of anti-coicidence plastic scintillator tiles covering the tracker towers. It will have 5-10 times larger on-axis effective area, 6 times wider field-of-view (FOV), and up to 5 times better angular resolution when compared with EGRET. The Large Area Telescope will cover about 40% of the sky above the Earth's horizon in its FOV at any given time and will scan nearly the entire Universe every orbit (~ 90min): about 20% of Gamma-Ray Bursts will be observed from the onset of the bursts to the initial after-glow phase; all longer-lasting transients and variabilities will be detected daily at the improved sensitivity. The instrument has been prototyped twice between 1995 and 2001, designed almost to the Flight Model by the international collaboration of the US (NASA and DoE), France, Italy, Japan, and Sweden. The first prototype consisted of one tower of e+e- pair trackers, one block of segmented calorimeters and a smaller set of anti-coicidence plastic scintillator tiles (Beam Test Engineering Model, BTEM), which was put into e+, p, and γ beams at SLAC in the winter of 1999-2000. It was subsequently modified for a balloon experiment (Balloon Flight Engineering Model, BFEM) and flown at Palestine, Texas in August 2001. Data collected in the test experiments have been analyzed and compared with predictions of computer simulation codes such as Geant4. These studies have confirmed validity of the basic design, brought up a few issues for further improvement, and gathered data on

  20. High Energy Astrophysics with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    This slide presentation reviews some of the findings of the Large Area Telescope (LAT) aboard the Fermi Observatory. It includes information about the LAT, and the Gamma-Ray Burst Monitor (GBM), detection of the quiet sun and the moon in gamma rays, Pulsars observed by the observatory, Globular Star Clusters, Active Galactic Nucleus, and Gamma-Ray Bursts, with specific information about GRB 080916C.

  1. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Baldini, L.; Uchiyama, Y.

    2011-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of Galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TcV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a Galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  2. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, David J.; Baldini, L.; Uchiyama, Y.

    2012-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TeV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  3. GLAST: Exploring Nature's Highest Energy Processes with the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Digel, Seth; Myers, J. D.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    The Gamma-ray Large Area Space Telescope (GLAST) is an international and multi-agency space mission that will study the cosmos in the energy range 10 keV-300 GeV. Several successful exploratory missions in gamma-ray astronomy led to the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Gamma Ray Observatory (CGRO). Launched in 1991, EGRET made the first complete survey of the sky in the 30 MeV-10 GeV range. EGRET showed the high-energy gamma-ray sky to be surprisingly dynamic and diverse, with sources ranging from the sun and moon to massive black holes at large redshifts. Most of the gamma-ray sources detected by EGRET remain unidentified. In light of the discoveries with EGRET, the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope vastly more capable than instruments flown previously, as well as a secondary instrument to augment the study of gamma-ray bursts. The main instrument, the Large Area Telescope (LAT), will have superior area, angular resolution, field of view, and deadtime that together will provide a factor of 30 or more advance in sensitivity, as well as provide capability for study of transient phenomena. The GLAST Burst Monitor (GBM) will have a field of view several times larger than the LAT and will provide spectral coverage of gamma-ray bursts that extends from the lower limit of the LAT down to 10 keV. The basic parameters of the GBM are compared to those of the Burst and Transient Source Experiment (BATSE) instrument on CGRO in Table 1-2. With the LAT and GBM, GLAST will be a flexible observatory for investigating the great range of astrophysical phenomena best studied in high-energy gamma rays. NASA plans to launch GLAST in late 2005.

  4. The GLAST Large Area Telescope Detector Performance Monitoring

    SciTech Connect

    Borgland, A.W.; Charles, E.; /SLAC

    2007-10-16

    The Large Area Telescope (LAT) is one of two instruments on board the Gamma-ray Large Area Telescope (GLAST), the next generation high energy gamma-ray space telescope. The LAT contains sixteen identical towers in a four-by-four grid. Each tower contains a silicon-strip tracker and a CsI calorimeter that together will give the incident direction and energy of the pair-converting photon in the energy range 20 MeV - 300 GeV. In addition, the instrument is covered by a finely segmented Anti-Coincidence Detector (ACD) to reject charged particle background. Altogether, the LAT contains more than 864k channels in the trackers, 1536 CsI crystals and 97 ACD plastic scintillator tiles and ribbons. Here we detail some of the strategies and methods for how we are planning to monitor the instrument performance on orbit. It builds on the extensive experience gained from Integration & Test and Commissioning of the instrument on ground.

  5. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF GRB 110625A

    SciTech Connect

    Tam, P. H. T.; Kong, A. K. H.; Fan Yizhong

    2012-08-01

    Gamma-ray bursts (GRBs) that emit photons at GeV energies form a small but significant population of GRBs. However, the number of GRBs whose GeV-emitting period is simultaneously observed in X-rays remains small. We report {gamma}-ray observations of GRB 110625A using Fermi's Large Area Telescope in the energy range 100 MeV-20 GeV. Gamma-ray emission at these energies was clearly detected using data taken between 180 s and 580 s after the burst, an epoch after the prompt emission phase. The GeV light curve differs from a simple power-law decay, and probably consists of two emission periods. Simultaneous Swift X-Ray Telescope observations did not show flaring behaviors as in the case of GRB 100728A. We discuss the possibility that the GeV emission is the synchrotron self-Compton radiation of underlying ultraviolet flares.

  6. The calorimeter of the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Grove, J. Eric; Johnson, W. Neil

    2010-07-01

    The Large Area Telescope (LAT), the primary instrument on the Fermi Gamma-ray Space Telescope, has been making revolutionary observations of the high-energy (20 MeV - 300 GeV) gamma-ray sky since its launch in June 2008. The LAT calorimeter is a modular array of 1536 CsI(Tl) crystals supported within 16 carbon fiber structures and read out at each crystal end with silicon PIN photodiodes to provide both energy and position information. The hodoscopic crystal stack allows imaging of electromagnetic showers and cosmic rays for improved energy measurement and background rejection. Signals from the array of photodiodes are processed by custom ASICs and commercial ADCs. We describe the calorimeter design and the primary factors that led those design choices.

  7. Optical design of interferometric telescopes with wide fields of view.

    PubMed

    Sabatke, Erin E; Burge, James H; Hinz, Philip

    2006-11-01

    The performance of wide-field multiple-aperture imaging systems is dominated by easily understood, low-order errors. Each aperture produces an individual image, each pair of apertures produces a set of fringes under a diffraction envelope, and the system bandwidth produces a coherence envelope. For wide-field imaging, each of these elements must be coincident in the image plane as the field angle changes. We explore the causes of image degradation, derive first-order rules for preserving image quality across field, and give an example design that enforces some of the rules to achieve a relatively wide-field interferometric imaging telescope. PMID:17068543

  8. Hubble Space Telescope - New view of an ancient universe

    NASA Technical Reports Server (NTRS)

    Leckrone, David S.; Longair, Malcolm S.; Stockman, Peter; Olivier, Jean R.

    1989-01-01

    Scheduled for a March 1990 Shuttle launch, the Hubble Space Telescope (HST) will give astronomers a tool of unprecedented accuracy to observe the universe: an optically superb instrument free of the atmospheric turbulence, distortion, and brightness that plague all earthbound telescopes. The observatory will carry into orbit two cameras, a pair of spectrographs, a photometer, and fine guidance sensors optimized for astrometry. The diffraction limit for the 2.4-m aperture of the HST corresponds to 90 percent of the radiation from a point source falling within a circle of 0.1 arcsec angular radius at a wavelength of 633 nm. The 15-year mission will make observations in the ultraviolet as well as the optical spectral region, thus, widening the wavelength window to a range extending from the Lyman alpha wavelengnth of 122 nm to just about 2 microns. The observational program that awaits the HST will include the study of planetary atmospheres, in particular the search for aerosols; the study of globular star clusters within the Galaxy; and the determination of the present rate of expansion of the universe. The HST will achieve resolutions of 0.1 arcsec consistently, regardless of observation duration. The HST engineering challenge is also discussed.

  9. SWIFT BURST ALERT TELESCOPE, FERMI LARGE AREA TELESCOPE, AND THE BLAZAR SEQUENCE

    SciTech Connect

    Sambruna, R. M.; Mushotzky, R. F.; Maraschi, L.

    2010-02-10

    Using public Fermi Large Area Telescope (LAT) and Swift Burst Alert Telescope observations, we constructed the first sample of blazars selected at both hard X-rays and gamma rays. Studying its spectral properties, we find a luminosity dependence of the spectral slopes at both energies. Specifically, luminous blazars, generally classified as flat spectrum radio quasars, have hard continua in the medium-hard X-ray range but soft continua in the LAT gamma-ray range (photon indices GAMMA{sub X} {approx}< 2 and GAMMA{sub G} {approx}> 2), while lower luminosity blazars, classified as BL Lacs, have opposite behavior, i.e., soft X-ray and hard gamma-ray continua (GAMMA{sub X} {approx}> 2.4 and GAMMA{sub G} < 2). The trends are confirmed by detailed Monte Carlo simulations explicitly taking into account the observational biases of both instruments. Our results support the so-called blazar sequence which was originally based on radio samples of blazars and radio luminosities. We also argue that the X-ray-to-gamma-ray continua of blazars may provide independent insights into the physical conditions around the jet, complementing/superseding the ambiguities of the traditional classification based on optical properties.

  10. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2007-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class; pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

  11. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2007-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered p ulsars. As the only presently known galactic GeV source class, pulsar s will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsar s, including millisecond pulsars, giving much better statistics for e lucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric partic le acceleration and radiation mechanisms, by comparing data with theo retical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all un identified EGRET sources, to possibly uncover more radio-quiet Geming a-like pulsars.

  12. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2006-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST) will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class, pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

  13. 12. VIEW WEST, AREA SOUTH OF RECESS AREA, SHOWING CUT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW WEST, AREA SOUTH OF RECESS AREA, SHOWING CUT STONE AND RUBBLESTONE CONSTRUCTION - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  14. Wide field of view three-mirror telescopes having a common optical axis

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1988-01-01

    Two coincident-optical-axis, three-mirror telescopes have been designed that feature relatively low focal ratios (f/2.3 and f/3), unobscured optical aperture, large circular fields of view (6 and 8 deg), good resolution, flat field, reimaging with accessible field stop, Lyot or glare stop, effective stray light suppression, and ease of spectral filter integration. The design for the f/3 telescope with 8 deg field of view has been fabricated and validated using single-point diamond-turned optics.

  15. NASA Goddard Space Flight Center, on Behalf of the Fermi Large Area Telescope Collaboration

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2010-01-01

    Because high-energy gamma rays can be produced by processes that also produce neutrinos, the gamma-ray survey of the sky by the Fermi (Gamma-ray Space Telescope offers a view of potential targets for neutrino observations. Gamma-ray bursts. Active Galactic Nuclei, and supernova remnants are all sites where hadronic, neutrino-producing interactions are plausible. Pulsars, pulsar wind nebulae, and binary sources are all phenomena that reveal leptonic particle acceleration through their gamma-ray emission. While important to gamma-ray astrophysics, such sources are of less interest to neutrino studies. This talk will present a broad overview of the constantly changing sky seen with the Large Area Telescope (LAT)on the Fermi spacecraft.

  16. Hubble Space Telescope View of Comet C/2013 A1

    NASA Astrophysics Data System (ADS)

    Li, Jian-Yang; Samarasinha, Nalin H.; Kelley, Michael S.; Farnham, Tony L.; Bodewits, Dennis; A'Hearn, Michael F.; Lisse, Carey M.; Delamere, W. A.; Mutchler, Max J.

    2014-11-01

    Comet C/2013 A1 (Siding Spring) is a dynamically new comet whose physical and chemical status should be the least evolved since the formation of cometesimals during the planetary system formation processes. Its close encounter with Mars on October 19, 2014 at a distance of 138,000 km allows for imaging its nucleus and inner coma by MRO/HiRISE at 140 m/pix resolution. Such an encounter offers us the opportunity to do cometary flyby science for a dynamically new comet for the first time ever. We observed C/Siding Spring using Hubble Space Telescope (HST) from October 2013 to March 2014 when the comet was at 4.58, 3.77, and 3.28 AU from the Sun, and will observe it again during its close encounter with Mars at 1.40 AU heliocentric distance. One of the objectives of these observations is to study the long-term evolution of the dust coma of C/Siding Spring, including its dust features and color, in order to provide context for better understanding the evolution of the activity of a dynamically new comet from the “flyby” observations during its Mars encounter. Our early observations show that C/Siding Spring’s coma contains two dust features, and the spatial distribution and temporal evolution of the color of its coma are consistent with the existence of icy grains. New observations to be performed during the encounter will reveal the evolution of the dust features and color from previously observed, as well as any newly developed features. We will report our results from the HST observations, including the preliminary results from the encounter observations.

  17. Fermi Large Area Telescope Operations: Progress Over 4 Years

    SciTech Connect

    Cameron, Robert A.; /SLAC

    2012-06-28

    The Fermi Gamma-ray Space Telescope was launched into orbit in June 2008, and is conducting a multi-year gamma-ray all-sky survey, using the main instrument on Fermi, the Large Area Telescope (LAT). Fermi began its science mission in August 2008, and has now been operating for almost 4 years. The SLAC National Accelerator Laboratory hosts the LAT Instrument Science Operations Center (ISOC), which supports the operation of the LAT in conjunction with the Mission Operations Center (MOC) and the Fermi Science Support Center (FSSC), both at NASA's Goddard Space Flight Center. The LAT has a continuous output data rate of about 1.5 Mbits per second, and data from the LAT are stored on Fermi and transmitted to the ground through TDRS and the MOC to the ISOC about 10 times per day. Several hundred computers at SLAC are used to process LAT data to perform event reconstruction, and gamma-ray photon data are subsequently delivered to the FSSC for public release with a few hours of being detected by the LAT. We summarize the current status of the LAT, and the evolution of the data processing and monitoring performed by the ISOC during the first 4 years of the Fermi mission, together with future plans for further changes to detected event data processing and instrument operations and monitoring.

  18. A look through the telescope. A different view of the sun

    NASA Astrophysics Data System (ADS)

    Sgaramella, Antonella

    2016-04-01

    The project presented is based on the direct observation of the sun using telescopes. Three instruments were used: a refracting telescope with h-alpha filter to observe solar prominences, a refracting telescope with a solar multimedia view eyepiece and an astronomical binoculars to observe the Sun in white light. Some pictures were made using a camera connected to the telescopes. Granulation and prominences were visible. A few sun spots were observed. The results of the observation and pictures have been collected in a poster built up by the students of Liceo scientifico "Carlo .Cafiero"in Barletta (Italy). This work has been developed thanks to the collaboration of the Astronomical Observatory of Acquaviva (Bari) Italy.

  19. Spitzer Space Telescope's View of Galaxy Messier 101

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Click on the image for larger version

    The galaxy Messier 101 is a swirling spiral of stars, gas, and dust. Messier 101 is nearly twice as wide as our Milky Way galaxy. Spitzer's view, taken in infrared light, reveals the galaxy's delicate dust lanes as yellow-green filaments. Such dense dust clouds are where new stars can form. In this image, dust warmed by the light of hot, young stars glows red. The rest of the galaxy's hundreds of billions of stars are less prominent and form a blue haze. Astronomers can use infrared light to examine the dust clouds where stars are born.

  20. Large-area cryocooling for far-infrared telescopes

    NASA Astrophysics Data System (ADS)

    Hoang, Triem T.; O'Connell, Tamara A.; Ku, Jentung; Butler, C. D.; Swanson, Theodore D.

    2003-10-01

    Requirements for cryocooling of large-area heat sources begin to appear in studies of future space missions. Examples are the cooling of (i) the entire structure/mirror of large Far Infrared space telescopes to 4-40K and (ii) cryogenic thermal bus to maintain High Temperature Superconductor electronics to below 75K. The cryocooling system must provide robust/reliable operation and not cause significant vibration to the optical components. But perhaps the most challenging aspect of the system design is the removal of waste heat over a very large area. A cryogenic Loop Heat Pipe (C-LHP)/ cryocooler cooling system was developed with the ultimate goal of meeting the aforementioned requirements. In the proposed cooling concept, the C-LHP collected waste heat from a large-area heat source and then transported it to the cryocooler coldfinger for rejection. A proof-of-concept C-LHP test loop was constructed and performance tested in a vacuum chamber to demonstrate the feasibility of the proposed C-LHP to distribute the cryocooler cooling power over a large area. The test loop was designed to operate with any cryogenic working fluid such as Oxygen/Nitrogen (60-120K), Neon (28-40K), Hydrogen (18-30K), and Helium (2.5-4.5K). Preliminary test results indicated that the test loop had a cooling capacity of 4.2W in the 30-40K temperature range with Neon as the working fluid.

  1. GLAST, the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Ritz, Steven

    2007-01-01

    The Gamma-ray Large Area Space Telescope, GLAST, is a mission to measure the cosmic gamma-ray flux in the energy range 20 MeV to greater than 300 GeV, with supporting measurements for gamma-ray bursts from 10 keV to 25 MeV. With its upcoming launch in 2008, GLAST will open a new and important window on a wide variety of phenomena, including black holes and active galactic nuclei; the optical-UV extragalactic background light, gamma-ray bursts; the origin of cosmic rays and supernova remnants; and searches for hypothetical new phenomena such as supersymmetric dark matter annihilations and Lorentz invariance violation. In addition to the science opportunities, this talk includes a description of the instruments, the collaboration between particle physicists and astrophysicists, the opportunities for guest observers, and the mission status.

  2. PROSPECTS FOR GRB SCIENCE WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Band, D. L.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Battelino, M.; Bissaldi, E.; Bogaert, G.; Chiang, J.; Do Couto e Silva, E.; Cohen-Tanugi, J.; Cutini, S.; De Palma, F.; Dingus, B. L.; Fishman, G.

    2009-08-20

    The Large Area Telescope (LAT) instrument on the Fermi mission will reveal the rich spectral and temporal gamma-ray burst (GRB) phenomena in the >100 MeV band. The synergy with Fermi's Gamma-ray Burst Monitor detectors will link these observations to those in the well explored 10-1000 keV range; the addition of the >100 MeV band observations will resolve theoretical uncertainties about burst emission in both the prompt and afterglow phases. Trigger algorithms will be applied to the LAT data both onboard the spacecraft and on the ground. The sensitivity of these triggers will differ because of the available computing resources onboard and on the ground. Here we present the LAT's burst detection methodologies and the instrument's GRB capabilities.

  3. Study of the LAT PSF of the Gamma Ray Large Area Telescope

    SciTech Connect

    Cecchi, C.; Germani, S.; Pepe, M.; Bonamente, E.; Ciprini, S.; Lubrano, P.; Tosti, G.

    2007-07-12

    GLAST is the next generation telescope for the study of the Gamma Ray Universe. The GLAST mission is composed of two instruments: the LAT (Large Area Telescope) exploring the energy range between 20 MeV and 300 GeV and the GBM (Gamma ray Burst Monitor) studying the region from 10 KeV up to 30 MeV.GLAST represents an important step beyond EGRET providing a large improvement in instrument performance: large Field of View (FOV), large energy range extending to unexplored region of energies larger than 10 GeV, large effective area, a factor of 30 improvement in sensitivity, a much smaller dead time and a very good Point Spread Function (PSF).Since GLAST will operate in a continuous scanning mode, for most of the time during the mission, photons from a source will be detected at different angles in the LAT field of view requiring a good PSF in order to disentangle between sources.We will present results on PSF studies performed with various sets of data. The selection criteria and algorithm have been initially developed on DC1 and DC2 data (simulation of one and 55 days respectively of data collected by the LAT), applied to the data collected with the 16 LAT towers during the I and T integration phase with cosmic ray muons and finally applied to the testbeam data collected in August 2006 at the CERN beam line.

  4. The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Celik, Q.; Cobet, R.; Davis, D. S.; Ferrara, E. C.; Gehrels, N.; Guiriec, S.; McConville, W.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Thompson, D. J.

    2012-01-01

    The Fermi 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, high-energy -ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  5. A First Year View of the Galaxy with the Fermi Gamma-ray Space Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    After one year of survey observations and more than 70 billion triggers, Fermi is revealing an unprecedented view of the high energy gamma-ray sky. The observatory carries two instruments, the Gamma-ray Burst Monitor (GBM, 8 keV - 40 MeV) and the Large Area Telescope (LAT, 20 MeV - X300 GeV), which in combination cover over 7 orders of magnitude in energy. The LAT provides substantially more sensitivity than previous instruments in this waveband and has opened up the energy window from 10-100 GeV. This is particularly relevant for the study of gamma-ray sources in the Galaxy. The first year data have revealed new classes of Galactic emitters as well as providing spectacular detail on some old friends. I'll review the fascinating range of Galactic emission now seen - from pulsars their nebulae to X-ray binaries and supernova remnants - with particular emphasis on the impact of the Fermi pulsars.

  6. Pulsar Simulations for the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Razzano, M.; Harding, A. K.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Burnett, T.; Chiang, J.; Digel, S. W.; Dubois, R.; Kuss, M. W.; Latronico, L.; McEnery, J. E.; Omodei, N.; Pesce-Rollins, M.; Sgro, C.; Spandre, G.; Thompson, D. J.

    2009-01-01

    Pulsars are among the prime targets for the Large Area Telescope (LAT) aboard the recently launched Fermi observatory. The LAT will study the gamma-ray Universe between 20 MeV and 300 GeV with unprecedented detail. Increasing numbers of gamma-ray pulsars are being firmly identified, yet their emission mechanisms are far from being understood. To better investigate and exploit the tAT capabilities for pulsar science. a set of new detailed pulsar simulation tools have been developed within the LAT collaboration. The structure of the pulsar simulator package (PulsarSpeccrum) is presented here. Starting from photon distributions in energy and phase obtained from theoretical calculations or phenomenological considerations, gamma-rays are generated and their arrival times at the spacecraft are determined by taking Into account effects such as barycentric effects and timing noise. Pulsars in binary systems also can be simulated given orbital parameters. We present how simulations can be used for generating a realistic set of gamma rays as observed by the LAT, focusing on some case studies that show the performance of the LAT for pulsar observations.

  7. FERMI LARGE AREA TELESCOPE DETECTION OF SUPERNOVA REMNANT RCW 86

    SciTech Connect

    Yuan, Qiang; Huang, Xiaoyuan; Liu, Siming; Zhang, Bing

    2014-04-20

    Using 5.4 yr Fermi Large Area Telescope data, we report the detection of GeV γ-ray emission from the shell-type supernova remnant RCW 86 (G315.4-2.3) with a significance of ∼5.1σ. The data slightly favors an extended emission of this supernova remnant. The spectral index of RCW 86 is found to be very hard, Γ ∼ 1.4, in the 0.4-300 GeV range. A one-zone leptonic model can well fit the multi-wavelength data from radio to very high energy γ-rays. The very hard GeV γ-ray spectrum and the inferred low gas density seem to disfavor a hadronic origin for the γ-rays. The γ-ray behavior of RCW 86 is very similar to several other TeV shell-type supernova remnants, e.g., RX J1713.7-3946, RX J0852.0-4622, SN 1006, and HESS J1731-347.

  8. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE VELA PULSAR

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Bartelt, J.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Atwood, W. B.; Bagagli, R.; Baldini, L.; Bellardi, F.; Bellazzini, R.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bisello, D.; Baughman, B. M. E-mail: massimiliano.razzano@pi.infn.it

    2009-05-10

    The Vela pulsar is the brightest persistent source in the GeV sky and thus is the traditional first target for new {gamma}-ray observatories. We report here on initial Fermi Large Area Telescope observations during verification phase pointed exposure and early sky survey scanning. We have used the Vela signal to verify Fermi timing and angular resolution. The high-quality pulse profile, with some 32,400 pulsed photons at E {>=} 0.03 GeV, shows new features, including pulse structure as fine as 0.3 ms and a distinct third peak, which shifts in phase with energy. We examine the high-energy behavior of the pulsed emission; initial spectra suggest a phase-averaged power-law index of {gamma} = 1.51{sup +0.05} {sub -0.04} with an exponential cutoff at E{sub c} = 2.9 {+-} 0.1 GeV. Spectral fits with generalized cutoffs of the form e{sup -(E/E{sub c}){sup b}} require b {<=} 1, which is inconsistent with magnetic pair attenuation, and thus favor outer-magnetosphere emission models. Finally, we report on upper limits to any unpulsed component, as might be associated with a surrounding pulsar wind nebula.

  9. The new event analysis of the Fermi large area telescope

    NASA Astrophysics Data System (ADS)

    Sgrò, Carmelo

    2014-07-01

    Since its launch on June 11, 2008 the Fermi Large Area Telescope (LAT) has been exploring the gamma-ray sky at energies from 20 MeV to over 300 GeV. Five years of nearly flawless operation allowed a constant improvement of the detector knowledge and, as a consequence, continuous update of the event selection and the corresponding instrument response parametrization. The final product of this effort is a radical revision of the entire event-level analysis, from the event reconstruction algorithms in each subsystem to the background rejection strategy. The potential improvements include a larger acceptance coupled with a significant reduction in background contamination, better angular and energy resolution and an extension of the energy reach below 100 MeV and in the TeV range. In this paper I will describe the new reconstruction and the event-level analysis, show the expected instrument performance and discuss future prospects for astro-particle physics with the LAT.

  10. Infrared View of Comet Fragment G from W. M. Keck Telescope

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This view of Jupiter shows the plume from the impact of fragment G of Comet Shoemaker-Levy 9. The image was made at infrared wavelenths (2.2 microns) using the 10-meter W. M. Keck Telescope in Hawaii. Credit: Dr. Imke de Pater, Dr. James Graham, Michael Brown, and Michael Liu, University of California, and Dr. Marina Fomenkova, University of California at San Diego, W. M. Keck Observatory.

  11. The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)

    NASA Astrophysics Data System (ADS)

    Cui, Xiang-Qun; Zhao, Yong-Heng; Chu, Yao-Quan; Li, Guo-Ping; Li, Qi; Zhang, Li-Ping; Su, Hong-Jun; Yao, Zheng-Qiu; Wang, Ya-Nan; Xing, Xiao-Zheng; Li, Xin-Nan; Zhu, Yong-Tian; Wang, Gang; Gu, Bo-Zhong; Luo, A.-Li; Xu, Xin-Qi; Zhang, Zhen-Chao; Liu, Gen-Rong; Zhang, Hao-Tong; Yang, De-Hua; Cao, Shu-Yun; Chen, Hai-Yuan; Chen, Jian-Jun; Chen, Kun-Xin; Chen, Ying; Chu, Jia-Ru; Feng, Lei; Gong, Xue-Fei; Hou, Yong-Hui; Hu, Hong-Zhuan; Hu, Ning-Sheng; Hu, Zhong-Wen; Jia, Lei; Jiang, Fang-Hua; Jiang, Xiang; Jiang, Zi-Bo; Jin, Ge; Li, Ai-Hua; Li, Yan; Li, Ye-Ping; Liu, Guan-Qun; Liu, Zhi-Gang; Lu, Wen-Zhi; Mao, Yin-Dun; Men, Li; Qi, Yong-Jun; Qi, Zhao-Xiang; Shi, Huo-Ming; Tang, Zheng-Hong; Tao, Qing-Sheng; Wang, Da-Qi; Wang, Dan; Wang, Guo-Min; Wang, Hai; Wang, Jia-Ning; Wang, Jian; Wang, Jian-Ling; Wang, Jian-Ping; Wang, Lei; Wang, Shu-Qing; Wang, You; Wang, Yue-Fei; Xu, Ling-Zhe; Xu, Yan; Yang, Shi-Hai; Yu, Yong; Yuan, Hui; Yuan, Xiang-Yan; Zhai, Chao; Zhang, Jing; Zhang, Yan-Xia; Zhang, Yong; Zhao, Ming; Zhou, Fang; Zhou, Guo-Hua; Zhu, Jie; Zou, Si-Cheng

    2012-09-01

    The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST's special design allows both a large aperture (effective aperture of 3.6 m-4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror's surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67 m × 6.05 m) and active Schmidt mirror (5.74m × 4.40m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multi-waveband properties in celestial objects.

  12. Software development for the Hobby-Eberly Telescope's Segment Alignment Maintenance System using LabVIEW

    NASA Astrophysics Data System (ADS)

    Hall, Drew; Ly, William; Howard, Richard T.; Weir, John T.; Rakoczy, John M.

    2002-12-01

    The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMS), utilized inductive sensors to measure the relative motions of the mirror segments. Software was developed in LabVIEW to tie the sensors, operator interface, and mirror-control motors together. Developing the software in LabVIEW allowed the system to be flexible, understandable, and able to be modified by the end users. Since LabVIEW is built using block diagrams, the software naturally followed the designed control system's block and flow diagrams, and individual software blocks could be easily verified. LabVIEW's many built-in display routines allowed easy visualization of diagnostic and health-monitoring data during testing. Also, since LabVIEW is a multi-platform software package, different programmers could develop the code remotely on various types of machines. LabVIEW's ease of use facilitated rapid prototyping and field-testing. There were some unanticipated difficulties in the software development, but the use of LabVIEW as the software "language" for the development of SAMS contributed to the overall success of the project.

  13. 18. Control Area, Frequency Changer and Generator Building, interior view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Control Area, Frequency Changer and Generator Building, interior view of remaining control panels VIEW WEST - NIKE Missile Battery PR-79, Control Area, Tucker Hollow Road south of State Route 101, Foster, Providence County, RI

  14. The Capabilities of the GLAST Large Area Telescope for Blazar Variability Studies

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2006-01-01

    One of the more notable features of the Large Area Telescope (LAT) on GLAST is its extremely large field of view, which covers more than 20% of the sky at any instant. In survey mode the LAT will be rocked about the orbital plane to provide coverage of the entire gamma-ray sky above 20 MeV every three hours. This will be the default observing mode for the first year of operations and is likely to be the dominant observing mode throughout the rest of the mission. Thus the LAT will provide long, evenly sampled, gamma-ray lightcurves for a large number of sources. In this talk we describe the nature and quality of the data that will be provided by the LAT and use simulated lightcurves to illustrate some of the scientific questions that can be addressed with LAT observations.

  15. An optical design of the telescope in the Wide Field of View Cherenkov/Fluorescence Telescope Array

    NASA Astrophysics Data System (ADS)

    Liu, Jiali; Yang, Rui; Xiao, Gang; Cao, Zhen; Ma, Lingling; Zha, Min; Zhang, Bingkai; Zhang, Shoushan; Zhang, Yong

    2015-07-01

    Spherical design and Davies-cotton design, which can supply a wide Field of View (FOV) and have a single optical element structure, are the two candidate optics for Wide FOV Cherenkov/Fluorescence Telescope Array (WFCTA). To obtain a good imaging quality, we have done a detailed study to acquire optimal configurations for these two optics. In this paper, first, a proper curvature radius for the reflector, an optimized location for the camera, as well as a tolerance for the distortion of images for two designs have been presented. Furthermore, using such optimal configurations, the features of Cherenkov images initiated by proton and iron showers both with two optics have been investigated. Based on these results, it can be concluded that spherical design has the prior optical properties, such as a wider FOV of 16°, a higher and more homogeneous resolution for all incident directions within the 16° FOV and a lower light loss in the spots, as well as more signals collected in an Cherenkov image, relatively shorter arrival time difference for lights in a shower and brighter PMTs in the central part of a shower track. Thus it will be chosen as WFCTA optics. Finally, the optical properties of the two designs with 10° FOV have also been investigated. It should be mentioned that with such a smaller FOV, Davies-cotton optics is an effective design for it has a great imaging quality comparing with the setup of 16° FOV.

  16. A step-zoom dual field-of-view IR telescope

    NASA Astrophysics Data System (ADS)

    Akram, Muhammad N.; Asghar, Muhammad H.

    2002-12-01

    In this paper, the design of a dual field-of-view telescope for 8 - 12 μm imaging waveband is described. Preliminary calculations are done to determine the first-order parameters of the narrow and wide-field modes. To achieve a switchable dual field-of-view system, an optical configuration based on the axial motion of a single lens group along the optical axis is used. The same lens is also used for focusing at near objects and for athermalization by very small axial movement. A total of 6 lenses with one conic surface are used in the design making it cost effective and lightweight. The final optical design is presented along with the aberrations curves and the MTF plots showing excellent performance in both field-of-views.

  17. 2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  19. Overhead View of Area Surrounding Pathfinder

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Overhead view of the area surrounding the Pathfinder lander illustrating the Sojourner traverse. Red rectangles are rover positions at the end of sols 1-30. Locations of soil mechanics experiments, wheel abrasion experiments, and APXS measurements are shown. The A numbers refer to APXS measurements as discussed in the paper by Rieder et al. (p. 1770, Science Magazine, see image note). Coordinates are given in the LL frame.

    The photorealistic, interactive, three-dimensional virtual reality (VR) terrain models were created from IMP images using a software package developed for Pathfinder by C. Stoker et al. as a participating science project. By matching features in the left and right camera, an automated machine vision algorithm produced dense range maps of the nearfield, which were projected into a three-dimensional model as a connected polygonal mesh. Distance and angle measurements can be made on features viewed in the model using a mouse-driven three-dimensional cursor and a point-and-click interface. The VR model also incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. As the rover moved, graphical models of the rover were added for each position that could be uniquely determined using stereo images of the rover taken by the IMP. Images taken by the rover were projected into the model as two-dimensional 'billboards' to show the proper perspective of these images.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  20. Gamma-ray and Radio Properties of Six Pulsars Detected by the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Weltevrede, P.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; Dermer, C. D.; Desvignes, G.; de Angelis, A.; de Luca, A.; de Palma, F.; Digel, S. W.; Dormody, M.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Freire, P. C. C.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giavitto, G.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hays, E.; Hobbs, G.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Keith, M.; Kerr, M.; Knödlseder, J.; Kocian, M. L.; Kramer, M.; Kuss, M.; Lande, J.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Makeev, A.; Manchester, R. N.; Mazziotta, M. N.; McEnery, J. E.; McGlynn, S.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Ransom, S. M.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Van Etten, A.; Vasileiou, V.; Venter, C.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Wang, N.; Watters, K.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.

    2010-01-01

    We report the detection of pulsed γ-rays for PSRs J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850, and J1718-3825 using the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (formerly known as GLAST). Although these six pulsars are diverse in terms of their spin parameters, they share an important feature: their γ-ray light curves are (at least given the current count statistics) single peaked. For two pulsars, there are hints for a double-peaked structure in the light curves. The shapes of the observed light curves of this group of pulsars are discussed in the light of models for which the emission originates from high up in the magnetosphere. The observed phases of the γ-ray light curves are, in general, consistent with those predicted by high-altitude models, although we speculate that the γ-ray emission of PSR J0659+1414, possibly featuring the softest spectrum of all Fermi pulsars coupled with a very low efficiency, arises from relatively low down in the magnetosphere. High-quality radio polarization data are available showing that all but one have a high degree of linear polarization. This allows us to place some constraints on the viewing geometry and aids the comparison of the γ-ray light curves with high-energy beam models.

  1. These views of Neptune, as seen through the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These views of Neptune, as seen through the Hubble Space Telescope, are helping planetary scientists gain some insight into the weird and wild weather that is a hallmark of the eighth planet from the sun. On Neptune, winds blow at 900 miles per hour and huge storms -- some the size of Earth itself -- come and go with regularity. How, precisely, Neptune's weather is driven is a mystery since the sun, which drives the Earth's weather, is 900 times dimmer there than on Earth. The bottom images show Neptune's Hubble portrait circa 1996. The top images were taken this year and help illustrate the dynamic weather features that dominate the planet.

  2. View of eastern coast of Sicily area

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A vertical view of the eastern coast of Sicily area is seen in this Skylab 3 Earth Resources Experiments Package S190-B (five-inch earth terrain camera) infrared photograph taken from the Skylab space station in Earth orbit. Mount Etna, the highest volcano in Europe (10,958 feet), is still active as evidenced by the thin plume of smoke emaneting from its crest. On the flanks of Etna recent lava flows appear black in contrast to the older flows and volcanic debris that are red. Numerous small, circular cinder cones on the flanks represent sites of previous eruptions. Catania, on the Mediterranean coast south of Etna, is the largest of several cities and villages which appear as light-gray patches on the lower slopes of the volcano. Plano de Catania, south of the city of Catania, is outlined by polygonal light and dark agricultural tracts. Several lakes, the largest of which is Lake Pozzillo, show up as dark blue in the photograph. The unusual colors in the picture are due to the use of

  3. Tiling strategies for optical follow-up of gravitational-wave triggers by telescopes with a wide field of view

    NASA Astrophysics Data System (ADS)

    Ghosh, Shaon; Bloemen, Steven; Nelemans, Gijs; Groot, Paul J.; Price, Larry R.

    2016-08-01

    Aims: Binary neutron stars are among the most promising candidates for joint gravitational-wave and electromagnetic astronomy. The goal of this work is to investigate various observing strategies that telescopes with wide field of view might incorporate while searching for electromagnetic counterparts of gravitational-wave triggers. Methods: We examined various strategies of scanning the gravitational-wave sky localizations on the mock 2015-16 gravitational-wave events. First, we studied the performance of the sky coverage using a naive tiling system that completely covers a given confidence interval contour using a fixed grid. Then we propose the ranked-tiling strategy where we sample the localization in discrete two-dimensional intervals that are equivalent to the telescope's field of view and rank them based on their sample localizations. We then introduce an optimization of the grid by iterative sliding of the tiles. Next, we conducted tests for all the methods on a large sample of sky localizations that are expected in the first two years of operation of the Laser interferometer Gravitational-wave Observatory (LIGO) and Virgo detectors. We investigated the performance of the ranked-tiling strategy for telescope arrays and compared their performance against monolithic telescopes with a giant field of view. Finally, we studied the ability of optical counterpart detection by various types of telescopes. Results: Our analysis reveals that the ranked-tiling strategy improves the localization coverage over the contour-covering method. The improvement is more significant for telescopes with larger fields of view. We also find that while optimizing the position of the tiles significantly improves the coverage compared to contour-covering tiles. For ranked-tiles the same procedure leads to negligible improvement in the coverage of the sky localizations. We observed that distributing the field of view of the telescopes into arrays of multiple telescopes significantly

  4. 20. Interior view of rehabilitation area in rehabilitation and testing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of rehabilitation area in rehabilitation and testing facilities; near center of occupied portion; view to northeast. - Ellsworth Air Force Base, Mess & Administration Building, 2279 Risner Drive, Blackhawk, Meade County, SD

  5. 4. VIEW OF AREA EXCAVATED FOR ACCESS TO MERCURY RETORT. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF AREA EXCAVATED FOR ACCESS TO MERCURY RETORT. VIEW SOUTH FROM RETORT. (OCTOBER, 1995) - McCormick Group Mine, Mercury Retort, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  6. 18. A southeastward aerial view of entire complex. Area east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. A southeastward aerial view of entire complex. Area east of Cherles Street (behind water tower in view) is not part of this project. - American Chain & Cable Company, East Princess Street (400 Block), York, York County, PA

  7. 13. Interior view of food storage area looking towards hallway; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Interior view of food storage area looking towards hallway; southeast corner of building on lower floor; view to north. - Ellsworth Air Force Base, Mess & Administration Building, 1561 Ellsworth Street, Blackhawk, Meade County, SD

  8. 67. Smart view recreation area comfort station, reflecting Appalachian Architecture, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. Smart view recreation area comfort station, reflecting Appalachian Architecture, was completed by the summer of 1940 by era crews. View to the south-southeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  9. Interior view of east side shop area with lathes and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of east side shop area with lathes and hydraulic presses, view facing northeast - U.S. Naval Base, Pearl Harbor, One-Story Storehouse, Avenue A near Eighth Street intersection, Pearl City, Honolulu County, HI

  10. VIEW OF THE AREA BETWEEN THE BEACH (LEFT) AND BEACH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE AREA BETWEEN THE BEACH (LEFT) AND BEACH ROAD. NOTE THE RESIDENCES ON OPPOSITE SIDE OF BEACH ROAD. VIEW FACING NORTH. - Hickam Field, Fort Kamehameha Historic Housing, Along Worchester Avenue & Hope Street, Honolulu, Honolulu County, HI

  11. 5. VIEW OF TRAIL WHERE IT PASSES THROUGH SAGE AREA, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF TRAIL WHERE IT PASSES THROUGH SAGE AREA, OWL CREEK IN CENTER OF PHOTOGRAPH. VIEW LOOKING EAST - Hole-in-the-Rock Trail, Running From Bluff Vicinity to Escalante, Garfield County, Bluff, San Juan County, UT

  12. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffrey J.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Schattenburg, Mark L.; Schwartz, Daniel A.; Trolier-McKinstry, Susan E.; Ulmer, Melville P.; Vaynman, Semyon; Vikhlinin, Alexey; Wang, Xiaoli; Weisskopf, Martin C.; Wilke, Rudeger H. T.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (>1 sq m) and finer angular resolution(<1).Combined with the special requirements of nested grazing incidence optics, the mass and envelope constraints of spaceborne telescopes render such advances technologically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (>100 sq m) of lightweight (1 kg/sq m areal density) high quality mirrors-possibly entailing active (in-space adjustable) alignment and figure correction. This paper discusses relevant programmatic and technological issues and summarizes progress toward large area sub-arcsecond x-ray telescopes. Key words: X-ray telescopes, x-ray optics, active optics, electroactive devices, silicon mirrors, differential deposition, ion implantation.

  13. 99. ARAIII. Overall view of drilling area in reactor pit. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    99. ARA-III. Overall view of drilling area in reactor pit. Bridge over pit in use for operations. Shows water in pool, reactor, hoist, operators, and general view of interior of reactor pit area. August 12, 1963. Ineel photo no. 63-4454. Photographer: Benson. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  14. INTERIOR SECOND FLOOR EAST ENGINEERING DESIGN AREA DETAIL VIEW, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR SECOND FLOOR EAST ENGINEERING DESIGN AREA DETAIL VIEW, FACING NORTH. - NASA Industrial Plant, Systems Integration & Checkout Facility, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  15. 13. VIEW INTO BLOCK AREA SHOWING KEY MECHANISM, NOTE FLOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW INTO BLOCK AREA SHOWING KEY MECHANISM, NOTE FLOOR SEPARATION AT THRESHOLD AND KEY-WINDING MECHANISM - Montgomery County Jail, Washington & Spring Streets, Crawfordsville, Montgomery County, IN

  16. Interior view of second floor sleeping area; camera facing south. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of second floor sleeping area; camera facing south. - Mare Island Naval Shipyard, Marine Barracks, Cedar Avenue, west side between Twelfth & Fourteenth Streets, Vallejo, Solano County, CA

  17. COMPARATIVE VIEW OF A STAR BEFORE AND AFTER THE INSTALLATION OF THE CORRECTIVE OPTICS SPACE TELESCOP

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This pair of images of a single star, taken with the European Space Agency's Faint Object Camera (FOC), demonstrate that NASA's Hubble Space Telescope has been restored fully to its planned optical performance. The COSTAR mirrors remove the effect of spherical aberration in the HST's primary mirror. The FOC will now be able to observe extremely faint celestial objects with a clarity and sensitivity unmatched by ground-based telescopes. [left] An FOC image a star taken prior to the sts-61 space shuttle HST servicing mission that installed COSTAR. The broad halo (one arc second diameter) around the star is caused by scattered unfocussed starlight. Because of aberration, only a small fraction of the light is concentrated in the star's pinpoint image (.1 arc second diameter). [right] Following the installation, deployment, and alignment of COSTAR, the FOC met its pre-launch specifications. Most of the starlight is concentrated into a .1 arc second circle, and the blurry 'skirt' of light is completely gone. By comparison, large ground based telescopes can concentrate 1/10th of starlight into an area smaller than one arc second, even under optimum observing condition. This clearly shows that the effects of spherical aberration have been successfully removed from the FOC. PHOTO RELEASE NO: STScI-PR94-08

  18. Fermi: The Gamma-Ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  19. Fermi: The Gamma-Ray Large Area Telescope Mission Status

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  20. Fermi: The Gamma-Ray Large Area Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10 seconds of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  1. Fermi: The Gamma-Ray Large Area Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2015-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  2. 5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  3. 6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  4. 72. OVERALL VIEW OF WEAPONS STORAGE AREA IGLOO FIELDS. TAKEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. OVERALL VIEW OF WEAPONS STORAGE AREA IGLOO FIELDS. TAKEN FROM ROOF OF BUILDING 232 (MINE SHOP) LOOKING NORTH. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  5. 76. VIEW OF SECOND WEAPONS STORAGE AREA ALONG SERVICE ROAD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. VIEW OF SECOND WEAPONS STORAGE AREA ALONG SERVICE ROAD SHOWING BUILDINGS 338-333 LOOKING NORTHWEST. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  6. 17. Control Area, Frequency Changer and Generator Building VIEW NORTHWEST, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Control Area, Frequency Changer and Generator Building VIEW NORTHWEST, SOUTH AND EAST ELEVATION - NIKE Missile Battery PR-79, Control Area, Tucker Hollow Road south of State Route 101, Foster, Providence County, RI

  7. 1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL REGISTRY BOOTH. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  8. 2. VIEW EAST, East Control Area, west radar tower in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW EAST, East Control Area, west radar tower in foreground, east radar lower in background - Newport NIKE Missile Battery D-57/58, Integrated Fire Control Area, Newport Road, Carleton, Monroe County, MI

  9. 1. DISTANT VIEW OF FRONT FROM SOUTHWEST SHOWING AREA OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. DISTANT VIEW OF FRONT FROM SOUTHWEST SHOWING AREA OF COUNCIL CHAMBERS, SHOP WITH PORTION OF WATER TREATMENT PLANT AND TRACK FILL AREA IN RIGHT HAND CORNER - Hardin City Water Works, 101 East Fourth Street, Hardin, Big Horn County, MT

  10. Interior view of the enclosed area, note the twolightover singlepanel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of the enclosed area, note the two-light-over single-panel door to the main warehouse area, view facing northeast - U.S. Marine Corps Base Hawaii, Kaneohe Bay, Warehouse 250, Aviation Storehouse, C Street between Fifth & Sixth Streets, Kaneohe, Honolulu County, HI

  11. 30. Launch Area, Generator Building, interior view showing diesel fuel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Launch Area, Generator Building, interior view showing diesel fuel tank, fuel pump (foreground) and fuel lines leading to power-generating units (removed) VIEW NORTHWEST - NIKE Missile Battery PR-79, Launch Area, East Windsor Road south of State Route 101, Foster, Providence County, RI

  12. 16. Control Area, Interconnecting Corridor, interior view showing highcapacity venting ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Control Area, Interconnecting Corridor, interior view showing high-capacity venting system and black-out shades on south wall VIEW WEST - NIKE Missile Battery PR-79, Control Area, Tucker Hollow Road south of State Route 101, Foster, Providence County, RI

  13. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  14. The future of ELTs (extremely large telescopes): a very personal view

    NASA Astrophysics Data System (ADS)

    Mountain, C. Matt

    2004-07-01

    "The Future of ELTs" is an intriguing as well as daunting title. But this is not about telescopes. After all, what could top visions of telescopes ranging from a "mere" 20 meters, to 100 meters, to plastic 30-meter telescopes in space, to new telescopes for the Moon and even a "hyper-telescope" designed to fill the volcanic crater on La Palma? Instead, this is about an equally interesting subject: Advanced Telescope Builders of the Early 21st Century, which reflects on the gathering of unique individuals that Arne Ardeberg and the University of Lund have so graciously brought together at this workshop.

  15. 7. "AERIAL VIEW OF THE TEST AREA, DIRECTORATE OF MISSILE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. "AERIAL VIEW OF THE TEST AREA, DIRECTORATE OF MISSILE CAPTIVE TEST, EDWARDS AFB. 8 AUG 57." In upper left corner, photo no. "8462 57" cropped out: "A-AFFTC 8 AUG 57, RETL TEST AREA" This photo is a high oblique view, showing the wing of the photo plane and Test Area 1-115. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Leuhman Ridge near Highways 58 & 395, Boron, Kern County, CA

  16. An Analysis Methodology for the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Morris, Robin D.; Cohen-Tanugi, Johann

    2004-01-01

    The Large Area Telescope (LAT) instrument on the Gamma Ray Large Area Space Telescope (GLAST) has been designed to detect high-energy gamma rays and determine their direction of incidence and energy. We propose a reconstruction algorithm based on recent advances in statistical methodology. This method, alternative to the standard event analysis inherited from high energy collider physics experiments, incorporates more accurately the physical processes occurring in the detector, and makes full use of the statistical information available. It could thus provide a better estimate of the direction and energy of the primary photon.

  17. West wall, display area (room 101), view 3 of 4: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West wall, display area (room 101), view 3 of 4: north part, showing senior battle staff viewing bridge), projection booths, control consoles, and pneumatic tube message port - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  18. West wall, display area (room 101), view 2 of 4: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West wall, display area (room 101), view 2 of 4: south part, showing commander's quarters and viewing bridge on second floor, controller's room, console, and projection booth on main floor - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  19. 4. GENERAL VIEW OF TIPPLE AREA WITH RUINS OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. GENERAL VIEW OF TIPPLE AREA WITH RUINS OF THE TIPPLE ON THE LEFT AND THE BOILER HOUSING ON THE RIGHT (VIEW TO THE NORTH). - Foster Gulch Mine, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  20. 77. Rocky Knob Recreation area. View of the valley from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    77. Rocky Knob Recreation area. View of the valley from Belcher's Curve. Notice that the scenic easement allows A the boundary of the parkway to disappear creating a park that appears bigger than it is. View to west-southwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  1. 8. Interior view of former food service and storage area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Interior view of former food service and storage area looking towards hall way; showing closed and open doorways to walk-in storage; near southwest corner of building on main floor; view to southwest. - Ellsworth Air Force Base, Mess & Administration Building, 1561 Ellsworth Street, Blackhawk, Meade County, SD

  2. Contextual view of Warner's Ranch. Trees of spring area block ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Contextual view of Warner's Ranch. Trees of spring area block view of Ranch house and barn; visible building is newer barn. Note approximate location of Overland Trail crossing left to right and San Diego cutoff running up hill on right. Camera facing west-southwest. - Warner Ranch, Ranch House, San Felipe Road (State Highway S2), Warner Springs, San Diego County, CA

  3. INTERIOR VIEW OF THE BEDROOM 1 DRESSING AREA. SHOWING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE BEDROOM 1 DRESSING AREA. SHOWING THE WINDOW WITH TRANSOM LIFT, AND SLIDING CLOSET DOORS. NOTE THE SMALL CLOSET DOORS NEAR THE CEILING. VIEW FACING NORTH. - Hickam Field, Officers' Housing Type J, 701 Beard Street, Honolulu, Honolulu County, HI

  4. General view in the Horizontal Processing Area of the Space ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view in the Horizontal Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view is looking at SSME 2052 and 2051 mounted on their SSME Engine Handlers. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  5. General view in the Horizontal Processing Area of the Space ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view in the Horizontal Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view is looking at SSME number 2048 mounted on an SSME engine Handler. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. West wall, display area (room 101), view 4 of 4: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West wall, display area (room 101), view 4 of 4: northwest corner, with D.M. logistics office below (room 137), and D.O./D.D.O. offices above. Lower stairs lead to entry shown in view 13 - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  7. West wall, display area (room 101), view 1 of 4: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West wall, display area (room 101), view 1 of 4: southwest corner, showing stairs to commander's quarters and viewing bridge, windows to controller's room (room 102), south end of control consoles, and holes in pedestal floor for computer equipment cables (tape drive I/O?) - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  8. VIEW OF ENTRY TO HOUSING AREA, SHOWING MARINE GUARD POSTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ENTRY TO HOUSING AREA, SHOWING MARINE GUARD POSTED ON ACACIA ROAD. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  9. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  10. VIEW OF BACKYARD AREA BEHIND FACILITIES 529 (BIRCH CIRCLE) AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF BACKYARD AREA BEHIND FACILITIES 529 (BIRCH CIRCLE) AND 606 (CEDAR DRIVE). VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  11. VIEW OF OPEN GRASSY AREA NEAR PLAYGROUND #1, BEHIND FACILITIES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF OPEN GRASSY AREA NEAR PLAYGROUND #1, BEHIND FACILITIES 804 AND 806, SHOWING NEIGHBORHOOD’S NORTHERN BOUNDARY FENCE. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  12. 140. VIEW OF CHECKOUT AREA (117), LSB (BLDG. 770), FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    140. VIEW OF CHECKOUT AREA (117), LSB (BLDG. 770), FROM AGENA TRANSFER AREA SHELTER (117A). NITROGEN TEST PANEL ON EAST WALL OF AGENA TRANSFER AREA SHELTER (117A). - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  13. INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF IRON TREATMENT (DESULPHURIZATION) AREA. MOLTEN IRON PROCEEDS FROM CUPOLA TO IRON TREATMENT AREAS BEFORE BEING TRANSFERRED TO PIPE CASTING MACHINES. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  14. View from west to east of exclusion area sentry building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from west to east of exclusion area sentry building. A portion of the warhead handling building can be seen on the left. Launch area is in the background - Stanley R. Mickelsen Safeguard Complex, Exclusion Area Sentry Station, On Patrol Road at entrance to Missile Field, Nekoma, Cavalier County, ND

  15. Opposed port alignment system (OPAS): a commercial astronomical telescope modified for viewing the interior of the NIF target chamber

    NASA Astrophysics Data System (ADS)

    Manuel, Anastacia M.; McCarville, Tom J.; Seppala, Lynn G.; Klingmann, Jeff L.; Kalantar, Daniel H.

    2012-10-01

    The National Ignition Facility (NIF) requires high resolution live images of regions inside the target chamber in order to align diagnostic instruments to fusion targets and to monitor target stability. To view the interior of the target chamber, we modified a commercial 11-inch Schmidt-Cassegrain telescope to develop the Opposed Port Alignment System (OPAS). There are two OPAS systems installed on the target chamber ports directly opposite the diagnostics. This paper describes the optical design, highlighting the two key modifications of the telescope. The first key modification was to reposition the Schmidt corrector plate and to uniquely mount the secondary mirror to a precision translation stage to adjust focus from 5.5 m to infinity. The stage is carefully aligned to ensure that the telescope's optical axis lies on a straight line during focus adjustments. The second key modification was a custom three element lens that flattens the field, corrects residual aberrations of the Schmidt-Cassegrain and, with a commercial 1:1 relay lens, projects the final image plane onto a large format 50 mega-pixel camera. The OPAS modifications greatly extend the Schmidt-Cassegrain telescope's field of view, producing nearly diffraction-limited images over a flat field covering +/-0.4 degrees. Also discussed in the paper are the alignment procedure and the hardware layout of the telescope.

  16. 8. View north from hallway, through administration area to front ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View north from hallway, through administration area to front entrance. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  17. VIEW OF NORTHERN QUARRY AREA, OVERGROWN WITH VEGETATION, FACING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NORTHERN QUARRY AREA, OVERGROWN WITH VEGETATION, FACING WEST - Granite Hill Plantation, Quarry No. 2, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  18. View of quarry work area, facing east, with broken lintel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of quarry work area, facing east, with broken lintel in foreground - Granite Hill Plantation, Quarry No. 4, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  19. VIEW OF SMALL QUARRY FACE AND WORK AREA IN MIDDLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF SMALL QUARRY FACE AND WORK AREA IN MIDDLE OF QUARRY, FACING NORTH - Granite Hill Plantation, Quarry No. 2, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  20. 20. VIEW OF THE RECORDS STORAGE AREA LOCATED ON THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF THE RECORDS STORAGE AREA LOCATED ON THE FIRST FLOOR MEZZANINE. (1/83) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

  1. 1. General view of building front looking west from area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. General view of building front looking west from area near abandoned fog signal building. - Block Island Southeast Light, Spring Street & Mohegan Trail at Mohegan Bluffs, New Shoreham, Washington County, RI

  2. 208. AERIAL VIEW OF POTOMAC AND AREA TO BE FILLED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    208. AERIAL VIEW OF POTOMAC AND AREA TO BE FILLED WITH DREDGING OPERATION IN LOWER RIGHT CORNER, 1930. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  3. 18. DETAIL VIEW OF DAMAGED AREA OF WEST APPROACH SPAN, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL VIEW OF DAMAGED AREA OF WEST APPROACH SPAN, SHOWING GRANITE OUTCROP BEING REMOVED, LOOKING EAST-SOUTHEAST - Middle Fork Stanislaus River Bridge, Spans Middle Fork Stanislaus River at State Highway 108, Dardanelle, Tuolumne County, CA

  4. 17. DETAIL VIEW SHOWING METAL DECK PLATES COVERING DAMAGED AREA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. DETAIL VIEW SHOWING METAL DECK PLATES COVERING DAMAGED AREA OF WEST APPROACH SPAN - Middle Fork Stanislaus River Bridge, Spans Middle Fork Stanislaus River at State Highway 108, Dardanelle, Tuolumne County, CA

  5. 8. View inside Building 802, "Control Area", facing southeast. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View inside Building 802, "Control Area", facing southeast. - Naval Air Station Fallon, 100-man Fallout Shelter, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  6. 113. Doughton Park Recreation Area. Distant view of road cut, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    113. Doughton Park Recreation Area. Distant view of road cut, roadway, and stone railing at ice cliffs. Looking northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  7. 27. View in the Shagbark Hickory area looking north to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. View in the Shagbark Hickory area looking north to the visitor's center (duplicate of HALS no. LA-1-2 (CT)) - Briarwood: The Caroline Dormon Nature Preserve, 216 Caroline Dormon Road, Saline, Bienville Parish, LA

  8. INTERIOR VIEW, WATERSIDE MALL Southwest Washington, Urban Renewal Area, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, WATERSIDE MALL - Southwest Washington, Urban Renewal Area, Bounded by Independence Avenue, Washington Avenue, South Capitol Street, Canal Street, P Street, Maine Avenue & Washington Channel, Fourteenth Street, D Street, & Twelfth Street, Washington, District of Columbia, DC

  9. Block 1. Photograph portrays general view of designated seating area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Block 1. Photograph portrays general view of designated seating area at mid point of Block 1 and illustrates poor maintenance of vegetation within the park - Skyline Park, 1500-1800 Arapaho Street, Denver, Denver County, CO

  10. 5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO WEST FRONT ENTRANCE VISABLE TO THE RIGHT - Isaac N. Hagan House, Kentuck Knob, U.S. Route 40 vicinity (Stewart Township), Chalkhill, Fayette County, PA

  11. Interior view of lift mechanism area of eastern lift span, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of lift mechanism area of eastern lift span, showing trunion gears at left and right, and counterweight above. - Arlington Memorial Bridge, Spanning Potomac River between Lincoln Memorial & Arlington National Cemetery, Washington, District of Columbia, DC

  12. Interior view of lift mechanism area of eastern lift span ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of lift mechanism area of eastern lift span looking south, showing trunion gears at left and right, and counterweight above. - Arlington Memorial Bridge, Spanning Potomac River between Lincoln Memorial & Arlington National Cemetery, Washington, District of Columbia, DC

  13. 9. INTERIOR VIEW OF EYE PRESS AREA; TO LEFT IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. INTERIOR VIEW OF EYE PRESS AREA; TO LEFT IS A TWO-BAY SLOTTED TYPE FURNACE, TO CENTER IS EYE PRESS, TO RIGHT IS CURCULAR SAW - Warwood Tool Company, Foot of Nineteenth Street, Wheeling, Ohio County, WV

  14. 34. VIEW OF GATE INTO LAUNCH AREA, LOOKING SOUTHWEST; 'CATFISH' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. VIEW OF GATE INTO LAUNCH AREA, LOOKING SOUTHWEST; 'CATFISH' DOORS OPEN Marilyn Ziemer, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  15. 45. VIEW OF 'CATFISH' LAUNCH AREA, LOOKING NORTHWEST Everett Weinreb, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. VIEW OF 'CATFISH' LAUNCH AREA, LOOKING NORTHWEST Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  16. 12. VIEW OF NATURAL BRIDGE OVERLOOK PARKING AREA, FACING NORTHEAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW OF NATURAL BRIDGE OVERLOOK PARKING AREA, FACING NORTHEAST. NOTE DETERIORATION OF WALL AND USE OF AESTHETICALLY INTRUSIVE FENCING. - Bryce Canyon National Park Rim Road, State Highway 63 to Rainbow Point, Tropic, Garfield County, UT

  17. View of northwest elevation of Building No. 42. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of northwest elevation of Building No. 42. Parking Area No. 28 at front right. Looking southeast - Easter Hill Village, Building No. 42, Northwest corner of Foothill Avenue & South Twenty-eighth Street, Richmond, Contra Costa County, CA

  18. Interior view of dining area showing china dresser, and bifold ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of dining area showing china dresser, and bi-fold door to hall, facing southeast. - Albrook Air Force Station, Company Officer's Quarters, East side of Canfield Avenue, Balboa, Former Panama Canal Zone, CZ

  19. Overall view of administration area with building 11110 in background, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view of administration area with building 11110 in background, looking east from facility gate. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Pilot Plant Road, China Lake, Kern County, CA

  20. Interior view of living and dining areas showing china dresser ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of living and dining areas showing china dresser and structural system, facing northeast. - Albrook Air Force Station, Field Officer's Quarters, West side of Dargue Avenue Circle, Balboa, Former Panama Canal Zone, CZ

  1. INTERIOR VIEW, PREPARING LARGE MOLD IN BOX FLOOR AREA. WORKERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, PREPARING LARGE MOLD IN BOX FLOOR AREA. WORKERS JUST FILLED THE FLASK WITH SAND FROM A HIGH VELOCITY MECHANICAL SAND THRUSTER. - Stockham Pipe & Fittings Company, Ductile Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  2. 5. VIEW OF NORTH PARK AVENUE TRAILHEAD PARKING AREA FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF NORTH PARK AVENUE TRAILHEAD PARKING AREA FACING SOUTHEAST. - Arches National Park Main Entrance Road, Beginning at U.S. Highway 191, approximately 6 miles north of Moab, Moab, Grand County, UT

  3. 2. VIEW OF VISITOR CENTER AND PARKING AREA AT MAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF VISITOR CENTER AND PARKING AREA AT MAIN ENTRANCE, FACING EAST - Arches National Park Main Entrance Road, Beginning at U.S. Highway 191, approximately 6 miles north of Moab, Moab, Grand County, UT

  4. 5. VIEW OF SITE, AREA B; LOG BUILDING AND BUNKHOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF SITE, AREA B; LOG BUILDING AND BUNKHOUSE (Features 9 and 10) AT FAR LEFT AND HOUSE (Feature 13) AT CENTER (n.d.) - Gold Dust Mine, Mill & Camp Complex, Wards Gulch, Salmon, Lemhi County, ID

  5. View of west elevation of Building No. 46. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of west elevation of Building No. 46. Parking Area No. 21 in foreground. Looking east - Easter Hill Village, Building No. 46, West side of South Twenty-eighth Street, north of Hinkley Avenue, Richmond, Contra Costa County, CA

  6. 1. VIEW OF DETENTION WARD AREA, LOOKING NORTHWEST FROM Y ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF DETENTION WARD AREA, LOOKING NORTHWEST FROM Y STREET - Fort McCoy, Building No. T-1065, Northeast of Intersection of South Ninth Avenue & South "Y" Street, Block 10, Sparta, Monroe County, WI

  7. 14. VIEW OF AREA TO BE INUNDATED FOR EASTSIDE RESERVOIR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW OF AREA TO BE INUNDATED FOR EASTSIDE RESERVOIR, LOOKING SOUTHEAST FROM OBSERVATORY HILL AT NORTH END OF WEST DAM. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  8. 111. Doughton Park Recreation Area. View of parkway with the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    111. Doughton Park Recreation Area. View of parkway with the road crossing alligator back. Facing southeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  9. 114. Doughton Park Recreation Area. View of Laurel Spring Valley ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    114. Doughton Park Recreation Area. View of Laurel Spring Valley in distance, alligator back, and overlook in foreground. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  10. 115. Doughton Park Recreation Area. View of roadway alignment around ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    115. Doughton Park Recreation Area. View of roadway alignment around alligator back and parking overlook in foreground. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  11. 109. Doughton Park Recreation Area. View of alligator back and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    109. Doughton Park Recreation Area. View of alligator back and the parkway seen from bluff mountain. Looking west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  12. VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FACING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FACING SOUTHWEST FROM NORTHEAST CORNER - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  13. VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FROM FORMER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FROM FORMER PROJECTIONIST ROOM, FACING WEST - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  14. VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FACING NORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF INTERIOR OF BUILDING 23, GYMNASIUM AREA, FACING NORTHEAST FROM SOUTHWEST CORNER - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  15. 1. VIEW LOOKING NORTH IN SHOP AREA. BUILDING 15 ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW LOOKING NORTH IN SHOP AREA. BUILDING 15 ON RIGHT, BUILDING 22 ON LEFT, AND BUILDING 1 IN DISTANCE. - Chollas Heights Naval Radio Transmitting Facility, 6410 Zero Road, San Diego, San Diego County, CA

  16. 7. INTERIOR VIEW, PATTERN MAKING WORK BENCH AREA WEST WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. INTERIOR VIEW, PATTERN MAKING WORK BENCH AREA WEST WALL LOOKING WEST LATHE ON LEFT DELTA BAND SAW LEFT, DELTA 6' JOINTS AND DELTA TABLE SAW ON RIGHT. - Knight Foundry, 13 Eureka Street, Sutter Creek, Amador County, CA

  17. 2. DETAIL VIEW OF JOURNAL LATHE, AXLE FINISHING AREA. Grinding ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. DETAIL VIEW OF JOURNAL LATHE, AXLE FINISHING AREA. Grinding bearing diameters on locomotive axle. Norton grinder, 1942 (dated). Melvin Grassmeyer, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  18. 3. DETAIL VIEW OF JOURNAL LATHE, AXLE FINISHING AREA. Grinding ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DETAIL VIEW OF JOURNAL LATHE, AXLE FINISHING AREA. Grinding bearing diameters on locomotive axle. Norton grinder, 1942 (dated). Melvin Grassmeyer, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  19. 8. VIEW OF HELIPAD IN LAUNCH AREA, LOOKING WEST. BASKETBALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF HELIPAD IN LAUNCH AREA, LOOKING WEST. BASKETBALL COURT ON RIGHT, RETAINING WALL VISIBLE Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  20. 16. VIEW OF ROAD AND LEVELED AREA IN FRONT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW OF ROAD AND LEVELED AREA IN FRONT OF HATCH ADIT (FEATURE B-28) WHICH IS ON THE RIGHT SIDE OF PHOTOGRAPH. (OCTOBER, 1995) - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  1. 68. Smart view recreation area comfort station with postandrail fence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Smart view recreation area comfort station with post-and-rail fence reflecting Appalachian culture. Facing west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  2. 37. INTERIOR VIEW, PAINTING AREA SHOWING PAINT VAT AND CONVEYOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. INTERIOR VIEW, PAINTING AREA SHOWING PAINT VAT AND CONVEYOR LINE WITH THE TOOLS HANGING FROM HOOKS TO DRY; NOTE PINCH POINT CROW BARS (CENTER) - Warwood Tool Company, Foot of Nineteenth Street, Wheeling, Ohio County, WV

  3. DETAIL VIEW OF ELECTRONICS TEST AREA, FLIGHT KITS FACILITY, ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF ELECTRONICS TEST AREA, FLIGHT KITS FACILITY, ROOM NO. 1N12, FACING WEST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  4. 3. VIEW OF PROPOSED AREA FOR SECOND FLOOR ADDITION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF PROPOSED AREA FOR SECOND FLOOR ADDITION OF BUILDING 499 FROM MAIN STREET AND CENTER DRIVE, FACING SOUTHEAST. - U.S. Naval Base, Pearl Harbor, Fleet Accounting & Dispersing Center, 178 Main Street, Pearl City, Honolulu County, HI

  5. 5. GLACIER POINT ROAD VIEW AT SENTINEL DOME PARKING AREA. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GLACIER POINT ROAD VIEW AT SENTINEL DOME PARKING AREA. LOOKING E. GIS: N-37 42 43.8 / W-119 35 12.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  6. View south of sail loft mid loft area. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View south of sail loft - mid- loft area. Note inflatable boats undergoing pressure testing. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  7. Route No. 1 through Badlands Topographical Area, view to eastnortheast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Route No. 1 through Badlands Topographical Area, view to east-northeast - Route No. 1-Overton-Lake Mead Road, Between Overton Beach & Park Boundary, 6 miles south of Overton, Overton, Clark County, NV

  8. Water in the Moon's polar areas: Results of LEND neutron telescope mapping

    NASA Astrophysics Data System (ADS)

    Mitrofanov, I. G.; Sanin, A. B.; Litvak, M. L.

    2016-02-01

    The results of LEND neutron telescope mapping of the lunar surface are presented. The estimations obtained show that the water content in the regolith in the polar areas of the Moon reaches 0.4 % by weight and not directly determined by the illuminated surface.

  9. Optical/infrared views of the distant universe with ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Gallagher, J. S.; Tolstoy, E.

    1997-05-01

    Ground-based optical/IR observatories offer access to the rest frame ultraviolet and visible spectral regions of objects with high redshifts. Current observations of high redshift objects with natural seeing of 0.5-1 arcsec include optical/IR photometry and a variety of spectroscopic measurements. These take advantage of the large apertures and efficient instruments of ground-based observatories to obtain high spectral resolution and to reach low surface brightnesses, which is required to overcome cosmological effects. The success of natural guide star adaptive optics systems suggests that observations could become routine with image diameters <=0.25 arcsec (and often approaching 0.1 arcsec) over modest fields of view in the IJHK bands. The combination of adaptive optics on 8-10-m class telescopes, versatile arrays of powerful instruments (including multi-slit or integral field unit spectrographs), and airglow suppression schemes will support deeper and more intensive infrared investigations of faint galaxies, and will allow us to take advantage of increased brightness in strong emission lines. This work should lead to a better understanding of selection effects at high redshift, as well as the identification and measurement of internal properties for typical galaxies at early epochs.

  10. CONTEXTUAL AERIAL VIEW OF "EXCLUSION" MTR AREA WITH IDAHO CHEMICAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXTUAL AERIAL VIEW OF "EXCLUSION" MTR AREA WITH IDAHO CHEMICAL PROCESSING PLANT IN BACKGROUND AT CENTER TOP OF VIEW. CAMERA FACING EAST. EXCLUSION GATE HOUSE AT LEFT OF VIEW. BEYOND MTR BUILDING AND ITS WING, THE PROCESS WATER BUILDING AND WORKING RESERVOIR ARE LEFT-MOST. FAN HOUSE AND STACK ARE TO ITS RIGHT. PLUG STORAGE BUILDING IS RIGHT-MOST STRUCTURE. NOTE FAN LOFT ABOVE MTR BUILDING'S ONE-STORY WING. THIS WAS LATER CONVERTED FOR OFFICES. INL NEGATIVE NO. 3610. Unknown Photographer, 10/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. The Fermi Large Area Telescope: Highlights from the first year on orbit

    SciTech Connect

    Raino, S.

    2010-03-26

    Since its launch from Cape Canaveral on June 11, 2008, the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope has been performing a survey of the high-energy astrophysical phenomena, including pulsars, black holes and active galactic nuclei; gamma-ray bursts; the origin of cosmic rays and supernova remnants and searches for new phenomena such as supersymmetric dark-matter annihilation. In this contribution I report on the performance of the LAT and on the highlight results achieved in its first year of observations.

  12. 8. AERIAL VIEW OF THE EAST TEST AREA DURING A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. AERIAL VIEW OF THE EAST TEST AREA DURING A SATURN I STATIC TEST. THIS PHOTO WAS TAKEN IN 1960 JUST PRIOR TO THE CHANGE OVER OF LAND, FACILITIES AND MISSION FROM ARMY/MICOM (MISSILE COMMAND) TO NASA/MSFC (MARSHALL SPACE FLIGHT CENTER). MSFC PHOTO LAB. - Marshall Space Flight Center, East Test Area, Dodd Road, Huntsville, Madison County, AL

  13. 10. View inside Building 802, the "Sitting Area" looking from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View inside Building 802, the "Sitting Area" looking from the "Control Area" towards the doors to the "Sleeping Quarters", facing south. - Naval Air Station Fallon, 100-man Fallout Shelter, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  14. 11. View inside Building 802, the "Sitting Area" looking from ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View inside Building 802, the "Sitting Area" looking from the "Sleeping Quarters" toward the doors to the "Control Area", facing north. - Naval Air Station Fallon, 100-man Fallout Shelter, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  15. View from southeast to northwest of exclusion area sentry station ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from southeast to northwest of exclusion area sentry station (far right) and missile field. Covers for fourteen sprint silos can be seen - Stanley R. Mickelsen Safeguard Complex, Exclusion Area Sentry Station, At Service Road entrance to Missile Field, Nekoma, Cavalier County, ND

  16. 75. VIEW OF SECOND WEAPONS STORAGE AREA IGLOO FIELD FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    75. VIEW OF SECOND WEAPONS STORAGE AREA IGLOO FIELD FROM ROOF OF BUILDING 328 LOOKING NORTHWEST SHOWING BUILDING 327-318. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  17. INTERIOR VIEW, LOOKING NORTH, CUPOLA AREA WITH MOLTEN METAL BEING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, LOOKING NORTH, CUPOLA AREA WITH MOLTEN METAL BEING POURED OUT OF THE CUPOLA INTO THE POURING LADLE. FROM THE POURING LADLE, THE IRON IS LATER POURED INTO A TRANSFER LADLE FOR TRANSPORT TO THE CASTING MACHINES. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

  18. 28. View of data test area for DR data take ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. View of data test area for DR data take off set operators panel and cabinet at second floor of transmitter building no. 102 in MIP area. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  19. 10. AERIAL VIEW OF THE EAST TEST AREA. DODD ROAD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. AERIAL VIEW OF THE EAST TEST AREA. DODD ROAD RUNS TOP TO BOTTOM, JUST LEFT OF CENTER. THE STATIC TEST TOWER IS TOWARD THE BOTTOM RIGHT, THE REDSTONE INTERIM TEST STAND IS TOWARD THE TOP LEFT. 1961, MSFC PHOTO LAB. - Marshall Space Flight Center, East Test Area, Dodd Road, Huntsville, Madison County, AL

  20. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; Lillie, Charles F.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Weisskopf, Martin C.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (approx. = 3 square meters) and fine angular resolution (approx. = 1 inch). Combined with the special requirements of nested grazing-incidence optics, the mass and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 square meters) of lightweight (approx. = 1 kilogram/square meter areal density) high-quality mirrors at an acceptable cost (approx. = 1 million dollars/square meter of mirror surface area). This paper reviews relevant technological and programmatic issues, as well as possible approaches for addressing these issues-including active (in-space adjustable) alignment and figure correction.

  1. The Anti-Coincidence Detector for the GLAST Large Area Telescope

    SciTech Connect

    Moiseev, A.A.; Hartman, R.C.; Ormes, J.F.; Thompson, D.J.; Amato, M.J.; Johnson, T.E.; Segal, K.N.; Sheppard, D.A.

    2007-03-23

    This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LAT's first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and 4 sides of the LAT tracking detector, requiring a total active area of {approx}8.3 square meters. The ACD detector utilizes plastic scintillator tiles with wave-length shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997.

  2. A view in the mirror - Or through the looking glass. [history of development of optical telescopes

    NASA Technical Reports Server (NTRS)

    Meinel, A. B.; Meinel, M. P.

    1986-01-01

    The development of optical telescopes from the age of astrology to those of today and the future is discussed. The rationales for changes in the design of telescopes during this time are explored. The cost drivers, and how to reduce them, are also discussed.

  3. General view in the Vertical Processing Area of the Space ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view in the Vertical Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view shows a SSME Rotating Sling in the foreground right and SSME 2056 in the foreground and SSMEs 2050, 2062 and 2054 in succession towards the background. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  4. Performance of the Anti-Coincidence Detector on the GLAST Large Area Telescope

    SciTech Connect

    Thompson, D.J.; Charles, E.; Hartman, R.C.; Moiseev, A.A.; Ormes, J.F.; /NASA, Goddard /Denver U.

    2007-10-22

    The Anti-Coincidence Detector (ACD), the outermost detector layer in the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT), is designed to detect and veto incident cosmic ray charged particles, which outnumber cosmic gamma rays by 3-4 orders of magnitude. The challenge in ACD design is that it must have high (0.9997) detection efficiency for singly-charged relativistic particles, but must also have a low probability for self-veto of high-energy gammas by backsplash radiation from interactions in the LAT calorimeter. Simulations and tests demonstrate that the ACD meets its design requirements. The performance of the ACD has remained stable through stand-alone environmental testing, shipment across the U.S., installation onto the LAT, shipment back across the U.S., LAT environmental testing, and shipment to Arizona. As part of the fully-assembled GLAST observatory, the ACD is being readied for final testing before launch.

  5. View of Baton Rouge, Louisiana area seen from Skylab

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A view of the Baton Rouge, Louisiana area is seen in this Skylab 3 Earth Resources Package S190-B (five-inch earth terrain camera) photograph taken from the Skylab space station in Earth orbit. The large body of water in the upper right hand corner is Lake Pontchartrain. The Mississippi river flows through the center of the photo. Major thoroughfares and residential areas are clearly visible.

  6. 16. DETAIL VIEW OF DAMAGED AREA OF WEST APPROACH SPAN, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. DETAIL VIEW OF DAMAGED AREA OF WEST APPROACH SPAN, SHOWING REMAINING GRANITE OUTCROP BEING BROKEN UP BY HYDRAULIC HAMMER MOUNTED ON A BACKHOE, LOOKING EAST-NORTHEAST - Middle Fork Stanislaus River Bridge, Spans Middle Fork Stanislaus River at State Highway 108, Dardanelle, Tuolumne County, CA

  7. 76. View of copper screen shielded and grounded test area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. View of copper screen shielded and grounded test area in transmitter building no. 102, room 115. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  8. View of Parking Area No. 11 on Hinkley Avenue. Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Parking Area No. 11 on Hinkley Avenue. Building No. 14 at left. Looking southeast - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  9. View of Parking Area No. 32 from Foothill Avenue. Buildings ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Parking Area No. 32 from Foothill Avenue. Buildings No. 23, 24, 34, 25, and 35, from left to right. Looking south - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  10. View of Hinkley Avenue. Parking Area No. 7 on right, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Hinkley Avenue. Parking Area No. 7 on right, Building No. 8 on right and Building No. 9 on left. Looking east - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  11. View of Parking Area No. 9. Building No. 11 on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Parking Area No. 9. Building No. 11 on left and Building No. 9 on right. Looking south - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  12. 9. VIEW LOOKING SOUTHEAST AT THE 771 AREA COMPLEX. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW LOOKING SOUTHEAST AT THE 771 - AREA COMPLEX. THE 711 COMPLEX, ORIGINALLY KNOWN AS PLANT C, HOUSED ALL THE PLUTONIUM PROCESSES UNTIL 1956 WHEN BUILDING 776/777 BECAME OPERATIONAL. - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

  13. 113. VIEW OF MACHINE SHOP FROM WEST. AREA IN FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    113. VIEW OF MACHINE SHOP FROM WEST. AREA IN FOREGROUND WAS ONCE ENCLOSED AS PART OF THE SHOP. THE TRAM LINE AND SNOWSHED RAN TO THE RIGHT (SOUTH) TO EAGLE MINE PORTAL. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  14. 10. VIEW EAST, RECESS AREA WITH BOTTOM HORIZONTAL BEAM FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW EAST, RECESS AREA WITH BOTTOM HORIZONTAL BEAM FOR EAST GATE - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  15. 11. VIEW WEST, RECESS AREA WITH PORTION OF MITER SILL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW WEST, RECESS AREA WITH PORTION OF MITER SILL (Numbers painted on stones for reconstruction purposes) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  16. 10. View of Western Rail and Surrounding Area to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View of Western Rail and Surrounding Area to the West (Lakeside Road was named Roxbury Avenue on the original plat. It was renamed Lakeside Road when a portion of the plat was replatted on August 1, 1925) - North Bridge, Spanning Quarton Lake branch of River Rouge, Birmingham, Oakland County, MI

  17. 10. View of Western Rail and Surrounding Area to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View of Western Rail and Surrounding Area to the West (Lakeside Road was named Roxbury Avenue on the original plat. It was renamed Lakeside Road when a portion of the plat was replatted on August 1, 1925) - South Bridge, Spanning Quarton Lake branch of River Rouge, Birmingham, Oakland County, MI

  18. 1. VIEW OF THE SMITH NO. 3 SITE AREA TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF THE SMITH NO. 3 SITE AREA TO THE NORTHWEST. THE MINE OFFICE BUILDING IS IN THE FOREGROUND AND THE TIPPLE AND PROCESSING PLANT ARE IN THE BACKGROUND. - Smith Mine, Bear Creek 1.5 miles West of Town of Bear Creek, Red Lodge, Carbon County, MT

  19. 5. VIEW OF BERYLLIUM PROCESSING AREA, ROLLING MILL. BERYLLIUM FORMING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF BERYLLIUM PROCESSING AREA, ROLLING MILL. BERYLLIUM FORMING BEGAN IN SIDE A OF THE BUILDING IN 1962. (11/5/73) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  20. View of south elevation of Building No. 45. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of south elevation of Building No. 45. Parking Area No. 22 in foreground, Building No. 40, No. 42, and No. 43 at left rear, note boulders as a landscape design element. Looking north - Easter Hill Village, Building No. 45, East side of South Twenty-eighth Street, south of Foothill Avenue, Richmond, Contra Costa County, CA

  1. View of open space and recreational area at rear of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of open space and recreational area at rear of Building No. 39. Note boulders as landscape design element. Buildings No. 23, 25, 25, 27, and 39 from left to right. Looking west - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  2. 76. Rocky Knob Recreation area, Belcher's Curve. View of a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. Rocky Knob Recreation area, Belcher's Curve. View of a parkway scenic easement. These have helped preserve the rural character of the landscape through which the parkway passes. Facing east-southeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  3. 15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. PROCESSES IN THIS MODULE OCCURRED UNDER HIGH PRESSURES AND TEMPERATURES. (5/70) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  4. 92. VIEW OF PRECIPITATION AREA FROM SOUTHWEST. VACUUM CLARIFIER TANK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. VIEW OF PRECIPITATION AREA FROM SOUTHWEST. VACUUM CLARIFIER TANK No. 1 AT LOWER LEFT, UNDER LAUNDER FEED TO GOLD TANK No. 2, AND VACUUM CLARIFIER TANK No. 2, AT MIDRIGHT. VACUUM RECEIVER TANK ON UPPER LEFT. PIPE TO TOP CENTER OF TANK TAKES OUTFLOW FROM CLARIFIER LEAVES. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  5. VIEW LOOKING WEST, HARDIETYNES IN MIDDLE GROUND, BIRMINGHAM AREA 'MAX' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW LOOKING WEST, HARDIE-TYNES IN MIDDLE GROUND, BIRMINGHAM AREA 'MAX' BUS FACILITY IN FOREGROUND. 10TH AVENUE TO THE LEFT, US 280 IN BACKGROUND. - Hardie-Tynes Manufacturing Company, 800 Twenty-eighth Street, North, Birmingham, Jefferson County, AL

  6. View of west elevation of Building No. 36. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of west elevation of Building No. 36. Parking Area No. 35 at left, South Twenty-sixth Street in foreground, Building No. 35 and right rear. Looking southeast - Easter Hill Village, Building No. 36, Northeast corner of Foothill Avenue & South Twenty-sixth Street, Richmond, Contra Costa County, CA

  7. View of east elevation of Building No. 45. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of east elevation of Building No. 45. Parking Area No. 23 in foreground, South 28th Street at middle. Looking east - Easter Hill Village, Building No. 45, East side of South Twenty-eighth Street, south of Foothill Avenue, Richmond, Contra Costa County, CA

  8. View of Parking Area No. 20 seen from balcony of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Parking Area No. 20 seen from balcony of Building No. 19. Buildings No. 20, 21, and 46, from left to right. Looking east - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  9. 8. SANDSORTING BUILDING, VIEW OF LOADING AREA WITH METAL SPOUTS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. SAND-SORTING BUILDING, VIEW OF LOADING AREA WITH METAL SPOUTS AND WOODEN CONTROL LEVERS (THE TRACK OF THE RAILROAD SIDING RAN ALONG THE SIDE OF THE BUILDING) - Mill "C" Complex, Sand-Sorting Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  10. 16. VIEW TO NORTHEAST OF SECONDFLOOR ASSEMBLY AREA FROM NEAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW TO NORTHEAST OF SECOND-FLOOR ASSEMBLY AREA FROM NEAR SOUTHWEST WEST. NOTE DIFFERENCE IN ROOF STRUCTURE BETWEEN SAWTOOTH SKYLIGHTS OVER MOST OF THE SECOND FLOOR (RIGHT) AND THE PORTION OF THE ROOF RUNNING ALONG THE WEST EDGE OF THE BUILDING (LEFT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  11. View of south elevation of Building No. 46. Parking Area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of south elevation of Building No. 46. Parking Area No. 14 in foreground, Building No. 45 at right rear. Looking north - Easter Hill Village, Building No. 46, West side of South Twenty-eighth Street, north of Hinkley Avenue, Richmond, Contra Costa County, CA

  12. 49. INTERIOR VIEW OF HARDENER AREA SHOWING GAUGE THAT MEASURES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. INTERIOR VIEW OF HARDENER AREA SHOWING GAUGE THAT MEASURES HARDNESS, THE NAIL MUST BREAK IN THE CENTER RANGE OF THE CURVED BAR TO HAVE THE CORRECT HARDNESS (THE NAIL WILL BREAK TOO EASILY IF TOO HARD AND WILL BEND TOO MUCH IF TOO SOFT) - LaBelle Iron Works, Thirtieth & Wood Streets, Wheeling, Ohio County, WV

  13. 16. Detail view of the scale area at the north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Detail view of the scale area at the north end of the 1937 main section, looking east-northeast; the original office is at th left, and the scale at the right - Ewing Livestock Market, South side of First Avenue North, 500 feet west of Route 724, Ewing, Lee County, VA

  14. VIEW, LOOKING WEST TOWARD GRINDING AREA, OF MAINTENCE SHOP. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW, LOOKING WEST TOWARD GRINDING AREA, OF MAINTENCE SHOP. NOTE TRACK IN FLOOR FOR CARTS WITH HEAVY ITEMS, OVERHEAD JIB CRANE AT UPPER RIGHT, PARTIALLY OBSCURED "SG" LOGO ON CABINET, AND SIGNS ABOVE DOORWAY TO MILL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  15. 1. VIEW NORTHEAST OF WHEELHOUSE AREA, TAILRACE (CENTER), AND DAM; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW NORTHEAST OF WHEELHOUSE AREA, TAILRACE (CENTER), AND DAM; MILL NO. 5 (HAER No. CT-44-B) AND BRIDGE AT RIGHT - Willimantic Linen Company, Mill No. 1, Immediately West of South Main Street, North Bank of Willimantic River, Windham, Windham County, CT

  16. 12. OVERHEAD VIEW OF THE EVISCERATION AREA; LOOKING NORTH FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. OVERHEAD VIEW OF THE EVISCERATION AREA; LOOKING NORTH FROM THE VISITORS' GALLERY; NOTE THE RAISED CONCRETE PLATFORMS FOR WORKERS; VISCERA TABLE HAS BEEN REMOVED - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  17. 1. VIEW OF EMPIRE MINE AREA WITH TAILINGS, ORE CHUTE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF EMPIRE MINE AREA WITH TAILINGS, ORE CHUTE, AND COLLAPSED BUILDINGS VISIBLE, AND BARE SWITCHBACK HILLSIDE FROM WHICH #4, #5 AND #6 WERE MADE. CAMERA IS POINTED NORTHWEST. - Florida Mountain Mining Sites, Empire State Mine, West side of Florida Mountain, Silver City, Owyhee County, ID

  18. View north from inside historic Mount Zion Cemetery entrance area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View north from inside historic Mount Zion Cemetery entrance area across a pile of removed gravestones along the subtle ridgeline to the Doughty-Beck monument. - Mount Zion Cemetery/ Female Union Band Cemetery, Bounded by 27th Street right-of-way N.W. (formerly Lyons Mill Road), Q Street N.W., & Mill Road N.W., Washington, District of Columbia, DC

  19. View south from inside historic Mount Zion Cemetery entrance area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View south from inside historic Mount Zion Cemetery entrance area across a pile of removed gravestones to Mill Street houses. - Mount Zion Cemetery/ Female Union Band Cemetery, Bounded by 27th Street right-of-way N.W. (formerly Lyons Mill Road), Q Street N.W., & Mill Road N.W., Washington, District of Columbia, DC

  20. 66. BIG MEADOWS. VIEW OF PARKING AREA AT THE GATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. BIG MEADOWS. VIEW OF PARKING AREA AT THE GATED ENTRANCE TO RAPIDAN FIRE ROAD, THE ACCESS ROAD TO CAMP HOOVER. LOOKING SOUTH, MILE 51.3. - Skyline Drive, From Front Royal, VA to Rockfish Gap, VA , Luray, Page County, VA

  1. View northwest of building 19 area used for pattern shop ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northwest of building 19 area used for pattern shop storage (foreground), building 17 section of structure on left. This structure consists of two formerly separate buildings. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Machine Shops, League Island, Philadelphia, Philadelphia County, PA

  2. View of open space and recreational area at rear of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of open space and recreational area at rear of Building No. 39. Note boulders as landscape design element. Buildings No. 41 and 23 from left to right. Looking east - Easter Hill Village, Bordered by South Twenty-sixth Street, South Twenty-eighth Street, Hinkley Avenue, Foothill Avenue & Corto Square, Richmond, Contra Costa County, CA

  3. VIEW OF INTERIOR OF BUILDING 708, ALTAR AREA (CHANCEL). THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF INTERIOR OF BUILDING 708, ALTAR AREA (CHANCEL). THE ROUND STAINED GLASS WINDOW ABOVE THE CROSS DEPICTS A CROWNED LAMB UPON AN ALTAR IN FRONT OF A CROSS. - U.S. Naval Base, Pearl Harbor, Chapel, Corner of Oakley & Nimitz Street, Pearl City, Honolulu County, HI

  4. The Gamma-ray Large Area Space Telescope and Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    McEnery, Julie; Ritz, Steve

    2006-01-01

    The Gamma-ray Large Area Telescope (GLAST) is a satellite-based observatory to study the high energy gamma-ray sky. The main instrument on GLAST, the Large Area Telescope (LAT) is a pair-conversion telescope that will survey the sky from 20 MeV to greater than 300 GeV. With the GLAST launch in 2007, the LAT will open a new and important window on a wide variety of high energy phenomena, including supermassive black holes and active galactic nuclei, gamma-ray bursts, supernova remnants and cosmic ray acceleration and dark matter. A second instrument, the GLAST Burst Monitor (GBM), greatly enhances GLAST s capability to study GRB by providing important spectral and timing information in the 10 keV to 30 MeV range. We describe how the instruments, spacecraft and ground system work together to provide observations of gamma-ray bursts from 8 keV - 300 GeV and to provide rapid notification of bursts to the wider gamma-ray burst community.

  5. Gamma Ray Large Area Space Telescope (GLAST) Balloon Flight Engineering Model: Overview

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Godfrey, G.; Williams, S. M.; Grove, J. E.; Mizuno, T.; Sadrozinski, H. F.-W.; Kamae, T.; Ampe, J.; Briber, Stuart; Dann, James; White, Nicholas E. (Technical Monitor)

    2001-01-01

    The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (greater than 20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophysical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scintillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment.

  6. Wide-Field-of-View Millimeter-Wave Telescope Design with Ultra-Low Cross-Polarization

    SciTech Connect

    Bernacki, Bruce E.; Kelly, James F.; Sheen, David M.; Hatchell, Brian K.; Valdez, Patrick LJ; Tedeschi, Jonathan R.; Hall, Thomas E.; McMakin, Douglas L.

    2012-05-01

    As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since most millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degrees of freedom that offer larger fields of view than possible with single-reflector designs. Dragone’s graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone’s geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone’s design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low polarization crosstalk and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.

  7. A population of gamma-ray millisecond pulsars seen with the Fermi Large Area Telescope.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Bignami, G F; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Camilo, F; Caraveo, P A; Carlson, P; Casandjian, J M; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cognard, I; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbet, R; Cutini, S; Dermer, C D; Desvignes, G; de Angelis, A; de Luca, A; de Palma, F; Digel, S W; Dormody, M; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Frailis, M; Freire, P C C; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hobbs, G; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Johnston, S; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kramer, M; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Manchester, R N; Marelli, M; Mazziotta, M N; McConville, W; McEnery, J E; McLaughlin, M A; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Ransom, S M; Ray, P S; Razzano, M; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stappers, B W; Starck, J L; Striani, E; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J B; Thayer, J G; Theureau, G; Thompson, D J; Thorsett, S E; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Van Etten, A; Vasileiou, V; Venter, C; Vilchez, N; Vitale, V; Waite, A P; Wallace, E; Wang, P; Watters, K; Webb, N; Weltevrede, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

    2009-08-14

    Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars (MSPs) outside of globular clusters, using rotation parameters from radio telescopes. Strong gamma-ray pulsations were detected for eight MSPs. The gamma-ray pulse profiles and spectral properties resemble those of young gamma-ray pulsars. The basic emission mechanism seems to be the same for MSPs and young pulsars, with the emission originating in regions far from the neutron star surface. PMID:19574349

  8. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS

    SciTech Connect

    Castro, Daniel; Slane, Patrick

    2010-07-01

    We report the detection of {gamma}-ray emission coincident with four supernova remnants (SNRs) using data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. G349.7+0.2, CTB 37A, 3C 391, and G8.7-0.1 are SNRs known to be interacting with molecular clouds, as evidenced by observations of hydroxyl (OH) maser emission at 1720 MHz in their directions. SNR shocks are expected to be sites of cosmic-ray acceleration, and clouds of dense material can provide effective targets for production of {gamma}-rays from {pi}{sup 0} decay. The observations reveal unresolved sources in the direction of G349.7+0.2, CTB 37A, and 3C 391, and a possibly extended source coincident with G8.7-0.1, all with significance levels greater than 10{sigma}.

  9. The On-Orbit Calibrations for the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Ampe, J.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Bagagli, R.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bartelt, J.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bederede, D.; Bellardi, F.; Bellazzini, R.; Belli, F.; Berenji, B.; Bisello, D.; /more authors..

    2011-11-17

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope began its on-orbit operations on June 23, 2008. Calibrations, defined in a generic sense, correspond to synchronization of trigger signals, optimization of delays for latching data, determination of detector thresholds, gains and responses, evaluation of the perimeter of the South Atlantic Anomaly (SAA), measurements of live time, of absolute time, and internal and spacecraft boresight alignments. Here we describe on-orbit calibration results obtained using known astrophysical sources, galactic cosmic rays, and charge injection into the front-end electronics of each detector. Instrument response functions will be described in a separate publication. This paper demonstrates the stability of calibrations and describes minor changes observed since launch. These results have been used to calibrate the LAT datasets to be publicly released in August 2009.

  10. Studying the High Energy Gamma Ray Sky with Gamma Ray Large Area Space Telescope (GLAST)

    NASA Technical Reports Server (NTRS)

    Kamae, T.; Ohsugi, T.; Thompson, D. J.; Watanabe, K.

    1998-01-01

    Building on the success of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the Gamma Ray Large Area Space Telescope (GLAST) will make a major step in the study of such subjects as blazars, gamma Ray bursts, the search for dark matter, supernova remnants, pulsars, diffuse radiation, and unidentified high energy sources. The instrument will be built on new and mature detector technologies such as silicon strip detectors, low-power low-noise LSI, and a multilevel data acquisition system. GLAST is in the research and development phase, and one full tower (of 25 total) is now being built in collaborating institutes. The prototype tower will be tested thoroughly at Stanford Linear Accelerator Center (SLAC) in the fall of 1999.