A celestial source of X rays in the energy range 20 to 58 Kev.
Balloon flight experiment to search for celestial sources of X-rays in energy range 20 to 58 kev
COSMIC RADIATION↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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(abstract) Electromagnetic Compatability Program to Accommodate a Spacecraft Magnetic Search Coil Experiment
A search coil is a very sensitive instrument that measures low frequency magnetic field radiation. In order for the search coil to achieve its objectives, an electromagnetic clean environment must be provided. On a spacecraft, there are many potential sources of low frequency magnetic field emitter. Consequently, a very stringent program is needed to control the emission from these sources. This paper describes the details of such a program.
systems electric motors enclosures shielding↗
The Extreme Ultraviolet Explorer Mission
The Extreme Ultraviolet Explorer (EUVE) mission, currently scheduled from launch in September 1991, is described. The primary purpose of the mission is to survey the celestial sphere for astronomical sources of extreme ultraviolet (EUV) radiation with the use of three EUV telescope, each sensitive to a different segment of the EUV band. A fourth telescope is planned to perform a high-sensitivity search of a limited sample of the sky in the shortest wavelength bands. The all-sky survey is planned to be carried out in the first six months of the mission in four bands, or colors, 70-180 A, 170-250 A, 400-600 A, and 500-700 A. The second phase of the mission is devoted to spectroscopic observations of EUV sources. A high-efficiency grazing-incidence spectrometer using variable line-space gratings is planned to provide spectral data with about 1-A resolution. An end-to-end model of the mission, from a stellar source to the resulting scientific data, is presented. Hypothetical data from astronomical sources were processed through this model and are shown.
Bowyer, S.↗
X-ray observations of pulsars.
The X-ray pulsations from NP 0532, discovered by Fritz et al. (1969), have been studied. The detectors in the investigations had wide fields of view, and the entire Crab Nebula NP 0532 radiation was detected. The power density spectrum of X-radiation observed is presented together with the shapes of X-ray and optical pulses. Searches for X-ray pulsations from other X-ray sources have also been carried out. The summarized results are shown in a table.
Bradt, H. V.↗
The extreme ultraviolet explorer
The Extreme Ultraviolet Explorer (EUVE) mission, currently scheduled for launch in September 1991, is described. The primary purpose of the mission is to survey the celestial sphere for astronomical sources of Extreme Ultraviolet (EUV) radiation. The survey will be accomplished with the use of three EUV telescopes, each sensitive to a different segment of the EUV band. A fourth telescope will perform a high sensitivity search of a limited sample of the sky in the shortest wavelength bands. The all sky survey will be carried out in the first six months of the mission and will be made in four bands, or colors. The second phase of the mission, conducted entirely by guest observers selected by NASA, will be devoted to spectroscopic observations of EUV sources. The performance of the instrument components is described. An end to end model of the mission, from a stellar source to the resulting scientific data, was constructed. Hypothetical data from astronomical sources processed through this model are shown.
Bowyer, Stuart↗
A search for radiative neutrino decay from supernovae
This document presents the data analysis procedures proposed for use with the COMPTEL instrument aboard the Compton Gamma Ray Observatory (GRO) in the search for radiative neutrino decay from supernovae. The proposed analysis methodology is an extension of a standard procedure used by the COMPTEL team in searching for a variety of source types. We have applied the procedures to a set of simulated data to demonstrate the feasibility of the method to this project.
Miller, Richard S.↗
A VLA search for 2-cm continuum radiation from Comet Halley
The presently reported VLA search for icy-grain 2-cm continuum emission in the halo surrounding Comet Halley in mid-November, 1985, notes the 3-sigma upper limit for flux density at this wavelength to be consistent with the detections at 1.3 and 3.5 mm by Altenhoff et al. (1986) only in the case where the sources of the emission are inefficiently radiating particles. These particles are surmised to be either icy or small refractory grains; in either case, they would be sub-mm-sized and slightly dirty.
Hoban, Susan↗
The space microwave interferometer and the search for cosmic background gravitational wave radiation
Present and planned investigations which use interplanetary spacecraft for gravitational wave searches are severely limited in their detection capability. This limitation has to do both with the Earth-based tracking procedures used and with the configuration of the experiments themselves. It is suggested that a much improved experiment can now be made using a multiarm interferometer designed with current operating elements. An important source of gravitational wave radiation, the cosmic background, may well be within reach of detection with these procedures. It is proposed to make a number of experimental steps that can now be carried out using TDRSS spacecraft and would conclude in the establishment of an operating multiarm microwave interferometer. This interferometer is projected to have a sensitivity to cosmic background gravitational wave radiation with an energy of less than 10(exp -4) cosmic closure density and to periodic waves generating spatial strain approaching 10(exp -19) in the range 0.1 to 0.001 Hz.
Anderson, Allen Joel↗
Analysis of small-scale microwave background radiation anisotropy in the presence of foreground contamination
Many of the current round of experiments searching for anisotropies in the microwave background radiation (MBR) are confronting the problem of how to disentangle the cosmic signal from contamination due to Galactic and intergalactic foreground sources. Here we show how commonly used likelihood function techniques can be generalized to account for foreground. Specifically we set some restrictions on the spectrum of foreground contamination but allow the amplitude to vary arbitrarily. The likelihood function thus generalized gives reasonable limits on the MBR anisotropy which, in some cases, are not much less restrictive than what one would get from more detailed modeling of the foreground. Furthermore, the likelihood function is exactly the same as one would obtain by simply projecting out foreground contamination and looking at the reduced data set. We apply this generalized analysis to the recent medium-angle data sets of ACME-HEMT (Gaier et al. 1992; Schuster et al. 1993) and MAX (Meinhold et al. 1993; Gunderson et al. 1993). The resulting analysis constrains the one free parameter in the standard cold dark matter theory to be Q(sub rms-ps) = 18(sub -5 sup +8) microKelvin. This best fit value, although in striking agreement with the normalization from Cosmic Background Explorer (COBE), is not a very good fit, with an overall chi-squared/degrees of freedom = 208/168. We also argue against three commonly used methods of dealing with foreground: (1) ignoring it completely; (2) subtracting off a best-fit foreground and treating the residuals as if uncontaminated; and (3) culling data which appears to be contaminated by foreground.
Dodelson, Scott↗
Search for Gravitational Waves From Scorpius X-1 in the Second Advanced LIGO Observing Run With an Improved Hidden Markov Model
We present results from a semi coherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO’s second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) ofh95%0¼3.47×10−25when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering.
B P Abbott↗
A search for high-energy photons from discrete sources of cosmic radio emission
Search for high energy photons from celestial radio sources
COSMIC RADIATION↗
Reported cosmic gamma-ray source in Cygnus.
High altitude balloon flights with gamma ray spark chamber for search of cosmic gamma ray source in Cygnus
BALLOON FLIGHT↗
The joint NASA/Goddard-University of Maryland research program in charged particle and high energy photon detector technology
The first measurements of Fe charge states in two coronal hole-association high speed streams, using the sensor on ISEE-3, are presented. Eight event intervals from the January to June 1983 timeframe were chosen for the study of magnetotail dynamics and its relationship to substorm activity and the possible formation of plasmoids. Techniques are being explored for measurement of secondary electrons which are characteristically emitted when ions hit a target material. Efforts are continuing to understand kilometer wavelength shock associated radio events. An all-sky survey of fast X-ray transients of duration of 5 to 10,000 s was completed. Research using high resolution gamma-ray spectroscopy of celestial sources in the 20 keV to 20 MeV range to search for and study narrow lines in low-energy gamma-ray spectrum continues. Research in high energy radiation from pulsars is being conducted.
Source record↗
On the optical search for the X-ray sources Cyg X-1 and Cyg X-2.
Optical search of sky near X-ray positions of Cyg X-1 and Cyg X-2 for identification purposes
RADIATION SOURCE↗
Recent high energy gamma-ray results from SAS-2
Recent developments in gamma-ray astronomy due to the results from SAS-2 have focused on two areas. First, the emission from the plane of the Galaxy is the dominant feature in the gamma-ray sky. The galactic latitude and longitude distributions are consistent with the concept that the high-energy radiation originates from cosmic rays interacting with interstellar matter, and the measurements support a galactic origin for cosmic rays. Second, searches of the SAS-2 data for emission from localized sources have shown three strong discrete gamma-ray sources: the Crab nebula and PSR 0531 + 21, the Vela supernova remnant and PSR 0833-45, and a source near galactic coordinates 193 deg longitude, +3 deg latitude, which does not appear to be associated with other known celestial objects. Evidence has also been found for pulsed gamma-ray emission from two other radio pulsars, PSR 1818-04 and PSR 1747-46. A localized source near longitudes 76-80 deg may be associated with the X-ray source Cyg X-3.
Thompson, D. J.↗
Ice photochemistry as a source of amino acids and other organic molecules in meteorites, and implications for the origin of life and the search for life in the Solar System
The tons of extraterrestrial organic material that come to the Earth every day probably helped to made the Earth habitable, and possibly played a role in the origin of life. At the astrochemistry lab (http://www.astrochem.orq) we investigate the formation and distribution of organic molecules in space and consider the impact such molecules may have on the habitability of planets and the search for life in the Solar System. The organic compounds in meteorites include amino acids, aromatics of various sorts including purine and pyrimidine bases, and fatty acids that form bi-layer vesicles. The origin of many of these species remains mysterious, but in recent years we and others have performed experiments that suggest low temperature radiation chemistry could account for the presence and deuterium enrichment of many of these molecules. . I will present our laboratory experiments that show the viability of low temperature radiation chemistry as a source of organic molecules such as;amino acids (Nature, 2002, 416, 401-403), amphiphiles (Astrobiology, 2003, 2, 371, Proc. Nat. Acad. Sci. 2001, 98, 815), quinones (Science, 1999, 283, 1135) and other functionalized aromatic compounds (Meteoritics, 2001, 36, 351 ; Astrophysical Journal., 2003, 582, L25), some of which were invoked as potential biomarkers in the Alan Hills 84001 Martian meteorite. Understanding how components of proteins and DNA could form in sterile space environments is also of relevance to our search for life elsewhere in the Solar System, the great task now ahead of NASA. If we find evidence of Life elsewhere in the Solar System it will probably be in form of chemical biomarkers, quintessentially biological molecules that indicate the presence of micro-organisms. While most people think of molecules such as amino acids, and nucleo-bases as good candidate biomarkers, these molecules are produced non-biotically in space and are expected to be present on the surface of other planets even in the absence of Life. Understanding the range of non-biological organic molecules which could act as false biomarkers in space is a prerequisite for any reasonable search for Life on other worlds.
Bernstein, Max↗
A search for rapidly modulated emission in bright X-ray sources using the HEAO A-1 data base
A search was performed in the HEAO A-1 Data Base (located at the Naval Research Laboratory in Washington, D.C.) for evidence of rapidly-rotating neutron stars that could be sources of coherent gravitational radiation. A new data analysis algorithm, which was developed, is described. The algorithm was applied to data from observations of Cyg X-2, Cyg X-3, and 1820-30. Upper limits on pulse fraction were derived and reported.
Fairbank, William M.↗
Preliminary results from the first satellite of a high-resolution germanium gamma-ray spectrometer: Description of instrument, some activation lines encountered, and studies of the diffuse spectra
Gamma radiation from terrestrial and extraterrestrial sources were investigated with a high resolution Ge(Li) spectrometer-cryogen system flown onboard a low altitude, spin stabilized, polar orbiting satellite. A brief description is given of the instrument and preliminary results obtained from earth orbit are discussed. Attempts were made to use angular distributions and geomagnetic latitude spectral variations to determine diffuse background spectrum, detect gamma ray line emissions from solar flares, and search for positron annihilation radiation coming from the direction of the galactic center.
Nakano, G. H.↗