293
293
Jun 13, 2011
06/11
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Singh, Upendra N.; Koch, Grady J.; Ismail, Syed; Kavaya, Michael; Yu, Jirong; Wood, Sidney A.; Emmitt, G. Davi
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A concept is explored for combining the Doppler and DIAL techniques into a single, multifunctional instrument. Wind, CO2 concentration, and aerosol density can all be measured. Technology to build this instrument is described, including the demonstration of a prototype lidar. Applications are described for use in the Earth science. The atmosphere of Mars can also be studied, and results from a recently-developed simulation model of performance in the Martian atmosphere are presented.
Topics: GAMMA RAY TELESCOPES, SATELLITE TRACKING, SCHEDULES, TDR SATELLITES, TELEMETRY, PREDICTIONS, MODAL...
217
217
May 31, 2011
05/11
by
Warner, Amanda Susa
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The High Plains is an economically important and climatologically sensitive region of the United States and Canada. The High Plains contain 100,000 sq km of Holocene sand dunes and sand sheets that are currently stabilized by natural vegetation. Droughts and the larger threat of global warming are climate phenomena that could cause depletion of natural vegetation and make this region susceptible to sand dune reactivation. This thesis is part of a larger study that is assessing the effect of...
Topics: X RAY TIMING EXPLORER, SPECTRA, GAMMA RAY TELESCOPES, EXTRAPOLATION, LIGHT CURVE, MIXTURES, PULSARS
213
213
May 23, 2011
05/11
by
Mustard, John F
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The main results have been published in the refereed literature, and thus this report serves mainly to summarize the main findings and indicate where the detailed papers may be found. Reflectance spectroscopy has been an important tool for determining the mineralogic makeup of the near surface materials on Mars. Analysis of the spectral properties of the surface have demonstrated that these attributes are heterogeneous from the coarse spatial but high spectral resolution spectra obtained with...
Topics: ACTIVE GALACTIC NUCLEI, BLAZARS, GAMMA RAYS, MARKARIAN GALAXIES, VARIABILITY, GAMMA RAY TELESCOPES,...
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296
Jun 12, 2011
06/11
by
Zhu, Dongming; Choi, Sung R.; Miller, Robert A
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Ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. Durability of the coating systems remains a critical issue with the ever-increasing temperature requirements. Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to coating performance. There is a need to characterize the...
Topics: SUPERNOVA REMNANTS, GAMMA RAYS, TITANIUM, RADIOACTIVE DECAY, SPECTRAL LINE WIDTH, STELLAR MODELS,...
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193
May 23, 2011
05/11
by
Hochstein, Lawrence I.; Stan-Lotter, Helg
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A sulfite-activated ATPase isolated from Sulfolobus solfataricus had a relative molecular mass of 370,000. It was composed of three subunits whose relative molecular masses were 63,000, 48,000, and 24,000. The enzyme was inhibited by the vacuolar ATPase inhibitors nitrate and N-ethylmaleimide; 4-chloro-7-nitrobenzo-furazan (NBD-Cl) was also inhibitory. N-Ethylmaleimide was predominately bound to the largest subunit while NBD-CL was bound to both subunits. ATPase activity was inhibited by low...
Topics: WAVELENGTHS, GAMMA RAY TELESCOPES, BLACK HOLES (ASTRONOMY), ACCRETION DISKS, BOLOMETERS, EMITTERS,...
AGILE and Fermi generated dramatic progress in high-energy (> approximately 200 MeV) gamma ray science but neither instrument optimized for observations below approximately 200 MeV.
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY ASTRONOMY, GAMMA RAY TELESCOPES, MISSION PLANNING,...
This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, SATELLITE OBSERVATION, GAMMA RAY...
350
350
Jun 2, 2011
06/11
by
Tartabini, Paul V.; Bose, David M.; McMinn, John D.; Martin, John G.; Strovers, Brian K
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An independent twelve degree-of-freedom simulation of the X-43A separation trajectory was created with the Program to Optimize Simulated trajectories (POST II). This simulation modeled the multi-body dynamics of the X-43A and its booster and included the effect of two pyrotechnically actuated pistons used to push the vehicles apart as well as aerodynamic interaction forces and moments between the two vehicles. The simulation was developed to validate trajectory studies conducted with a 14...
Topics: GAMMA RAY TELESCOPES, METHODOLOGY, COMPUTERIZED SIMULATION, ALGORITHMS, PHOTONS, PAIR PRODUCTION,...
This instrument, a proposed Fourier telescope for imaging in hard-x rays and gamma rays, would contain only one pair of grids made of an appropriate radiation-absorpting/ scattering material, in contradistinction to multiple pairs of such as grids in prior Fourier x- and gamma-ray telescopes. This instrument would also include a relatively coarse gridlike image detector appropriate to the radiant flux to be imaged. Notwithstanding the smaller number of grids and the relative coarseness of the...
Topics: NASA Technical Reports Server (NTRS), IMAGING TECHNIQUES, TELESCOPES, DIFFRACTION PATTERNS, GAMMA...
225
225
Jun 3, 2011
06/11
by
Merri, Mario; Shames, Peter, et al; Schmidt, Michael; Ercolani, Alessandro; Dankiewicz, Ivan; Cooper, Sam; Thompson, Roger; Symonds, Martin; Oyake, Amalaye; Vaughs, Ashton
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This CCSDS paper presents a reference architecture and service framework for spacecraft monitoring and control. It has been prepared by the Spacecraft Monitoring and Control working group of the CCSDS Mission Operations and Information Management Systems (MOIMS) area. In this context, Spacecraft Monitoring and Control (SM&C) refers to end-to-end services between on- board or remote applications and ground-based functions responsible for mission operations. The scope of SM&C includes: 1)...
Topics: DIFFUSION, ASTRONOMICAL MODELS, COSMIC RAYS, DIFFUSE RADIATION, GAMMA RAYS, X RAYS, POPULATIONS,...
During the period 15 March 1992 through 31 October 1997, 12 papers using ROSAT data, supported in part by this grant, were published in referred journals, and one paper was published in a conference proceedings. Their bibliographical references are listed in the Appendix, and the abstracts of these papers are given in the next 13 sections of this report. Finally, a summary of the work completed to date on the newest project, for which ROSAT data are still being received, is given in the section...
Topics: NASA Technical Reports Server (NTRS), ROSAT MISSION, GAMMA RAY OBSERVATORY, LATITUDE, GAMMA RAY...
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.
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, SPACEBORNE TELESCOPES, ASTRONOMICAL...
189
189
May 30, 2011
05/11
by
Wolpert, David H.; Sill, Joseph; Turner, Kaga
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Distributed search algorithms are crucial in dealing with large optimization problems, particularly when a centralized approach is not only impractical but infeasible. Many machine learning concepts have been applied to search algorithms in order to improve their effectiveness. In this article we present an algorithm that blends Reinforcement Learning (RL) and hill climbing directly, by using the RL signal to guide the exploration step of a hill climbing algorithm. We apply this algorithm to...
Topics: GAMMA RAY TELESCOPES, IMAGING TECHNIQUES, GAMMA RAY OBSERVATORY, SPACE MISSIONS, GAMMA RAY BURSTS,...
The discovery of a multitude of strongly gamma-ray emitting AGNs by EGRET and the detection of at least two AGNs at even higher energies by the Whipple Collaboration generated much interest in the study of those objects and extensive observations were conducted in the following years. The Michigan group concentrated its effort on continued observations of the two TeV gamma-ray sources, Markarian 421 and Markarian 501, to monitor variability in the high energy emission as well as to provide...
Topics: NASA Technical Reports Server (NTRS), ACTIVE GALACTIC NUCLEI, BLAZARS, GAMMA RAYS, MARKARIAN...
576
576
May 29, 2011
05/11
by
Cooper, K. G.; Wells, D
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Investment casting masters of a selected propulsion hardware component, a fuel pump housing, were rapid prototyped on the several processes in-house, along with the new Z-Corp process acquired through this project. Also, tensile samples were prototyped and cast using the same significant parameters. The models were then shelled in-house using a commercial grade zircon-based slurry and stucco technique. Next, the shelled models were fired and cast by our in-house foundry contractor (IITRI), with...
Topics: GALACTIC COSMIC RAYS, SUPERNOVAE, GAMMA RAY TELESCOPES, MOLECULAR CLOUDS, ACCELERATION (PHYSICS),...
No abstract available
Topics: NASA Technical Reports Server (NTRS), MAGNETARS, GAMMA RAY BURSTS, GAMMA RAY TELESCOPES, SPACEBORNE...
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May 26, 2011
05/11
by
Yang, Wei-Yu; Todling, Ricardo; Navon, I. Michae
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A detailed description of the development of the tangent linear model (TLM) and its adjoint model of the Relaxed Arakawa-Schubert moisture parameterization package used in the NASA GEOS-1 C-Grid GCM (Version 5.2) is presented. The notational conventions used in the TLM and its adjoint codes are described in detail.
Topics: GAMMA RAY OBSERVATORY, POINT SOURCES, CATALOGS (PUBLICATIONS), GAMMA RAYS, ASTROPHYSICS, GAMMA RAY...
This grant had as its main goal the reduction and analysis of the archival data for blazars collected (primarily) by the EGRET instrument, interpretation of these data in the context of current theoretical models, and development of new theoretical models for blazar jets.
Topics: NASA Technical Reports Server (NTRS), DATA PROCESSING, BLAZARS, MATHEMATICAL MODELS, DATA...
The Fermi/Gamma-ray Burst Monitor (GBM) was launched in June 2008. During the last five years the instrument has observed several hundreds of bursts from 8 confirmed magnetars and 19 events from unconfirmed sources. I will discuss the results of the GBM magnetar burst catalog, expand on the different properties of their diverse source population, and compare these results with the bursting activity of past sources. I will then conclude with thoughts of how these properties fit the magnetar...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, MAGNETARS, GAMMA RAY TELESCOPES,...
Our analysis of EGRET data for the radio pulsar PSR B1046-58, which lies it the Eta Carina region of the Galaxy, was highly successful, resulting in the discovery of strong evidence for gamma-ray pulsations from this source. This work was published in the Astrophysical Journal. Additional support for the association was published in a companion paper in which an analysis of the X-ray counterpart to PSR B1046-58 was done, and we showed that it was the only possible counterpart to the gamma ray...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAYS, GALAXIES, ASTROPHYSICS, DATA MANAGEMENT, PULSARS,...
The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of Al-26.
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, GAMMA RAY TELESCOPES, BLAZARS, GAMMA RAYS,...
Papers to be included in this symposium are: Detecting the Attenuation of Blazar Gamma-Ray Emission by Extragalactic Background Light with GLAST; Some Aspects of the Radio Emission of EGRET-Detected Blazars; GeV Outburst in Mrk 501; Spectral Modeling of the EGRET 3EG Gamma Ray Sources Near the Galactic Plane; X-ray and Gamma-ray Observations of the COS-B Field 2CG 075+00; Multiwavelength Studies of the Peculiar Gamma-Ray Source 3EG J1835+5918; EGRET/COMPTER Observations of an Unusual,...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY OBSERVATORY, GAMMA RAY TELESCOPES, PAPERS,...
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155
May 23, 2011
05/11
by
Schmitt, Didier A.; Sonnenfeld, Gerald; Husson, David; Tkaczuk, Jean; Andre, Eric; Schaffar, Lauranc
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Anti-human monoclonal antibodies were used to detect and quantify interleukins-1 and 2 and interleukin-2 receptor expression in peripheral blood mononuclear cells from a rhesus monkey. Interleukin-1 production could be induced by phorbol esters (PMA) and was potentiated by phytohemagglutinin (PHA). Interleukin-2 secretion could also be induced by the combination of PHA and PMA, but only weakly with PHA alone. Interleukin-2 receptor expression was present in a subpopulation of unstimulated...
Topics: SCANNING, BALLOON-BORNE INSTRUMENTS, COMPUTERIZED SIMULATION, NONLINEARITY, POINTING CONTROL...
A research and development program of the Infra-Red Test has been conducted by the French Space Agency (CNES). A choice, after characterization, among several possibilities has been made on the type of methods and facilities for the I.R. test. An application to the Thermal Vacuum Test of the SIGMA Telescope is described.
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, INFRARED RADIATION, PERFORMANCE TESTS,...
The Swift Gamma-ray Burst Explorer is a NASA Mid-sized Explorer (MIDEX) with the primary mission of determining the origins of Gamma-Ray Bursts (GRBs). It will be the first mission to autonomously respond to newly-discovered GRBs and provide immediate follow-up with narrow field instruments capable of multi-wavelength (UV, Optical, X-ray) observations. The characteristics of GRBs that are the key mission design drivers, are their non-repeating and brief duration bursts of multi-wavelength...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY ASTRONOMY, GAMMA RAY TELESCOPES, GAMMA RAY BURSTS,...
Since the launch of AGILE and FERMI, the scientific progress in high-energy (Eg greater than approximately 200 MeV) gamma-ray science has been, and will continue to be dramatic. Both of these telescopes cover a broad energy range from approximately 20 MeV to greater than 10 GeV. However, neither instrument is optimized for observations below approximately 200 MeV where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. Hence, while...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY ASTRONOMY, GAMMA RAY TELESCOPES, ENERGY...
The present report concerns the following projects 'High energy emission from hot accretion disks from active galactic nuclei'; 'OSSE spectral timing and monitoring observations of Cygnus X- 1'; 'OSSE observations of blazars'; and 'Search for correlated time variations of bright EGRET blazars'. The most favored model for the central engine inAGNs is the supermassive black hole hypothesis (Rees 1978). The observed luminosities range from approx. 10 logical and 44-45 erg /s for objects such as Mk...
Topics: NASA Technical Reports Server (NTRS), WAVELENGTHS, GAMMA RAY TELESCOPES, BLACK HOLES (ASTRONOMY),...
Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; pulsars and their wind nebulae; gamma-ray pulsars and MSPs; GeV PWN search; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; supernova remnants, resolved GeV sources, galactic transients, LAT...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, GAMMA RAYS, SPACEBORNE TELESCOPES,...
1,793
1.8K
Jun 12, 2011
06/11
by
Lazcano, Antonio; Bada, Jeffrey L
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The field of prebiotic chemistry effectively began with a publication in Science 50 years ago by Stanley L. Miller on the spark discharge synthesis of amino acids and other compounds using a mixture of reduced gases that were thought to represent the components of the atmosphere on the primitive Earth. On the anniversary of this landmark publication, we provide here an accounting of the events leading to the publication of the paper. We also discuss the historical aspects that lead up to the...
Topics: GAMMA RAY ASTRONOMY, HOLES (ELECTRON DEFICIENCIES), GAMMA RAY TELESCOPES, GAMMA RAYS, RADIATION...
No abstract available
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, GAMMA RAY ASTRONOMY, GAMMA RAYS,...
The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity from 20 MeV to >300 GeV. The observatory scans the entire sky every three hours and allows a general search for flaring activity on daily timescales. This search is conducted automatically as part of the ground processing and allows a fast response to transient events, typically less than a day. Most flares are spatially associated with...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, GAMMA RAYS, SPACEBORNE TELESCOPES,...
Simultaneous observations by the large number of gamma-ray burst detectors operating in the GLAST era will provide the spectra, lightcurves and locations necessary for studying burst physics and testing the putative relations between intrinsic burst properties. The detectors' energy band and the accumulation timescale of their trigger system affect their sensitivity to hard vs. soft and long vs. short bursts. Coordination of the Swift and GLAST observing plans consistent with Swift's other...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, RED SHIFT, ACTUATORS, LIGHT CURVE,...
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,...
Topics: NASA Technical Reports Server (NTRS), EXTERNAL TANKS, GAMMA RAY TELESCOPES, SPACE PLATFORMS, SPACE...
Simple formulae are often used to estimate the sensitivity of coded mask X-ray or gamma-ray telescopes, but t,hese are strictly only applicable if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask or if any of a number of other simplifying conditions are not fulfilled. We derive more general...
Topics: NASA Technical Reports Server (NTRS), X RAY TELESCOPES, SENSITIVITY, SPATIAL RESOLUTION, GAMMA RAY...
Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; gamma-ray pulsars and MSPs; GeV PWN - where to look; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; GeV PWNe spectra; GeV nebula limits; Nebula search of LAT pulsars; supernova remnants; SNR: GeV...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, GAMMA RAYS, SPACEBORNE TELESCOPES,...
The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope Observatory (Fermi) is detecting about two TGFs per week. This rate has increased by a factor of approx.eight since launch when flight software was uploaded to the spacecraft in November 2009 in order to increase the sensitivity of GBM to TGFs. Weaker, un-triggered TGFs are now also being observed about once per day over selected low-latitude regions Americas. The high efficiency and time resolution (2 s) of GBM allows...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, GAMMA RAY BURSTS, SPACEBORNE...
This has been an exiciting year for high energy gamma-ray astronomy, both from space and from ground-based observatories. It has been a particularly active period for the Whipple Observatory gamma-ray group. In phase 1 of the Compton Gamma Ray Observatory (GRO), there has not been too much opportunity for overlapping observations with the Energetic Gamma Ray Experiment Telescope (EGRET) and the other GRO telescopes; however, significant progress was made in the development of data analysis...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY ASTRONOMY, GAMMA RAY OBSERVATORY, GAMMA RAY...
We present new theoretical estimates of the relative contribution of unresolved blazars and star forming galaxies to the extragalactic gamma-ray background and discuss constraints on the contributions from other possible components. We find that the Fermi data do not rule out a scenario in which the extragalactic gamma-ray background is dominated by emission from unresolved blazars. The spectrum of unresolved FSRQs, when accounting for the energy dependent effects of source confusion, could be...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAYS, BLAZARS, BACKGROUND RADIATION, GAMMA RAY...
Supernovae are incredibly energetic events which drive the dynamic state of the interstellar medium and accelerate cosmic rays up to energies of a few PeV. I present multi-wavelength observations constraining the shocks, chemistry, dust grain processing, and magnetic fields in a large sample of supernova remnants interacting with dense clouds. These are among the most luminous Galactic sources detected by the Fermi Gamma-Ray Space Telescope. Surprisingly, spectral breaks are seen between GeV...
Topics: NASA Technical Reports Server (NTRS), SUPERNOVA REMNANTS, COSMIC RAYS, INTERSTELLAR MATTER, DUST,...
This viewgraph presentation describes the fermi gamma-ray burst monitor and reviews it's on-orbit performance. The topics include: 1) Instrument description; 2) Background rates and spectra; 3) On-board trigger; 4) Localizations; 5) spectra and 6) Future improvements.
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, GAMMA RAY TELESCOPES, SPACECRAFT...
Intense millisecond flashes of MeV photons are being observed with space-borne detectors. These terrestrial gamma-ray flashes (TGFs) were discovered with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory (CGRO) in the early 1990s. They are now being observed with several other instruments, including the Gamma-ray Burst Monitor (GBM) detectors on the Fermi Gamma-ray Space Telescope. Although Fermi-GBM was designed and optimized for the observation of...
Topics: NASA Technical Reports Server (NTRS), PHOTONS, SPACEBORNE TELESCOPES, THUNDERSTORMS, GAMMA RAY...
After more than 2 years of science operations, the Fermi Gamma-ray Space Telescope continues to survey the high-energy sky on a daily basis. In addition to the more than 1400 sources found in the first Fermi Large Area Telescope Catalog (I FGL), new results continue to emerge. Some of these are: (1) Large-scale diffuse emission suggests possible activity from the Galactic Center region in the past; (2) a gamma-ray nova was found, indicating particle acceleration in this binary system; and (3)...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, CRAB NEBULA, PARTICLE ACCELERATION,...
Gamma-ray telescopes flown on satellites have poor angular resolution with typical point source error circles of a few square degrees. It is shown that a major improvement in angular resolution for the detection of gamma-rays in the GeV region can be obtained with a single crystal as converter. The electron produced by a gamma ray incident at a small angle to a major crystal axis or plane is captured into channeling and radiates gamma rays. The channeling radiation and the electron-positron...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY ASTRONOMY, GAMMA RAY TELESCOPES, ANGULAR...
The Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has observed PSR B1706-44 a number of times between 1991 and 1995. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics that distinguish this pulsar from others: the light curve is complex, with evidence of three pulses; there is no detectable unpulsed emission; and the energy spectrum changes slope at 1 GeV. No two of the...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAYS, ENERGY SPECTRA, GAMMA RAY OBSERVATORY, PULSARS,...
The purpose of this INTEGRAL AO 1 proposal was to observe the gamma-ray lines at 1157 keV, as well as 68 keV and 78 keV of the (44)Ti decay chain from the youngest known galactic supernova remnant Cas A. The radioactive decay of (44)Ti in Cas A was first detected by COMPTEL in the 1157 keV line and later confirmed in the lower energy lines using BeppoSAX data. Despite the second confirming measurement, the flux value still has a considerable error, due to a low signal over background ratio and...
Topics: NASA Technical Reports Server (NTRS), SUPERNOVA REMNANTS, GAMMA RAYS, TITANIUM, RADIOACTIVE DECAY,...
This viewgraph presentation reviews the prospects of extending the understanding of gamma ray pulsars, and answering the open questions left from the limited observations that are available from current observatories. There are 2 new gamma ray observatories that are either on orbit or will be shortly launched: (1) Astro-rivelatore Gamma a Immagini LEggero (AGILE), and Gamma-ray Large Area Space Telescope (GLAST). On board GLAST there will be two instruments Large Area Telescope (LAT), and GLAST...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, PULSARS, GAMMA RAY SOURCES (ASTRONOMY),...
No abstract available
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY BURSTS, GAMMA RAYS, GAMMA RAY TELESCOPES, SPECTRAL...
Measurements of detection efficiency, angular resolution, and energy resolution properties of a gamma ray telescope used to study celestial gamma rays from balloon flight altitudes are described. Nearly monochromatic photons produced at the National Bureau of Standards tagged photon facility were used for the calibration. Details of the photon beam configuration and properties and results of the measurements made at photon energies of 15.1 and 31.1 MeV are presented. Finally, the data are...
Topics: NASA Technical Reports Server (NTRS), CALIBRATING, GAMMA RAY TELESCOPES, MONOCHROMATIC RADIATION,...
The work under the Grant has involved continued participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The EGRET team continues to submit IAU Astronomical telegrams and present many papers at scientific meetings. The EGRET Team was also successful on many proposals for the Cycle 4 portion of the mission,...
Topics: NASA Technical Reports Server (NTRS), DATA PROCESSING, DOCUMENTS, GAMMA RAY OBSERVATORY, GAMMA RAY...
The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970's and enable a new era of discovery and understanding of the Universe. Direct...
Topics: NASA Technical Reports Server (NTRS), MISSION PLANNING, LISA (OBSERVATORY), LASER INTERFEROMETRY,...
