ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • SPACE RADIATION  (25)
  • ASTROPHYSICS  (17)
  • SPACECRAFT INSTRUMENTATION  (2)
  • 1
    Publication Date: 2011-08-16
    Keywords: SPACE RADIATION
    Type: Nature Physical Science; 246; Dec
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2011-08-16
    Description: Pulsar CP 1919 X ray emission upper limits from balloon flight data, comparing to NP 0532 over entire electromagnetic spectrum
    Keywords: SPACE RADIATION
    Type: ; ADEMIE DES SCIENCES
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2013-08-29
    Description: More than 270 gamma ray bursts have been observed to date with the BATSE (Burst and Transient Source Experiment) aboard the Compton Gamma Ray Observatory. Many have a duration of 10 seconds or more and complex structure with multiple peaks or spikes. Complex bursts in the energy range 30 keV to 1 MeV were systematically analyzed to determine the relations between intensity and spectral shape, or hardness. The burst hardness rises and falls in during spikes, but somewhat earlier than the intensity. A simple correlation between intensity and hardness is, therefore, not observed: the intensity lags instead. Results from one burst which shows evidence for longer lags in longer spikes are reported.
    Keywords: SPACE RADIATION
    Type: ESA, Environment Observation and Climate Modelling Through International Space Projects. Space Sciences with Particular Emphasis on High-Energy Astrophysics; p 161-162
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2011-08-18
    Description: HEAO 1 spectral observations of 12 active galaxies in the 12-165 keV and 2-50 keV ranges are reported. The spectra of these galaxies in the 2-165 keV range are well represented by a single power law model; within experimental uncertainties a narrow dispersion in power law index attributable to the individual galaxies is observed, while the 2-165 keV luminosities of these galaxies ranged from 3 x 10 to the 43rd to 3 x 10 to the 45th ergs/s. An apparent universality of the spectral form is found which can be interpreted as due to a common electron distribution with a temperature of tens of keV in the Compton scattering region or as a common nonthermal power-law distribution generating the observed flux through synchrotron-Compton processes. The data indicate that relativistic particles are likely to be responsible for the X-rays from cores of active galaxies through synchroton-Compton processes. In addition, it is noted that only weak number evolution, if any at all, is present in active galaxies.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 269; June 15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-06-28
    Description: BATSE's Spectral Detectors provide a series of high resolution spectra over the duration of a gamma-ray burst; fits to these spectra show the evolution of the continuum as the burst progresses. The burst continuum can usually be fit by the spectral form AE sup alpha exp(-E/kT) from around 25 keV to more than 3 MeV, with varying trends in the value and evolution of the spectral parameters. As a result of limited statistics for E greater than 1 - 2 MeV in the individual spectra, a high energy power law is not required. Only long duration strong bursts can be studied by fitting a series of spectra, and therefore our conclusions concern only this class of burst. The bursts we analyzed tend to be characterized by a hard-to-soft trend both for individual intensity spikes and for the burst as a whole: the hardness leads the count rate in spectra which resolve the temporal variations, while the hardness of successive spikes decreases. We also summarize the performance of the Spectral Detectors and the development of analysis tools to date.
    Keywords: SPACE RADIATION
    Type: In: Gamma-ray bursts; Proceedings of the Workshop, Univ. of Alabama, Huntsville, Oct. 16-18, 1991 (A93-40051 16-93); p. 169-179.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2019-06-28
    Description: Results are reported from an analysis of radioactivity induced in the NaI medium-energy detector of the hard X-ray and low-energy gamma-ray experiment during the HEAO-1 satellite mission (1977-1978). Consideration is given to the instrument characteristics, the origin and variability of background, and the separation of cosmic-ray activity from the internal activity due to South Atlantic Anomaly trapped protons. Energy spectra and tables listing the nuclide identifications are provided.
    Keywords: SPACE RADIATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-06-28
    Description: Contemporary gamma-ray spectroscopy instruments and their results are reviewed. Sensitivities of 10 to the -4th to 10 to the -3rd ph/sq cm-sec have been achieved for steady sources and 10 to the -2nd to 1 ph/sq cm-sec for transient sources. This has led to the detection of gamma-ray lines from more than 40 objects representing 6 classes of astrophysical phenomena. The lines carry model-independent information and are of fundamental importance to theoretical modeling and our understanding of the objects. The objectives and anticipated results of future instruments are discussed. Several instruments in development will have a factor of 10 sensitivity improvement to certain phenomena over contemporary instruments. A factor of 100 improvement in sensitivity will allow the full potential of gamma-ray spectroscopy to be realized. Instrument concepts which would achieve this with both present and advanced techniques are discussed.
    Keywords: SPACECRAFT INSTRUMENTATION
    Type: Advances in Space Research (ISSN 0273-1177); 3; 4 19; 1983
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-06-28
    Description: The 1.24-sec pulsations of Her X-1 in the energy range 13-75 keV have been analyzed in data obtained from the UCSD/MIT experiment on HEAO 1 during observations of the source on three dates in February 1978 and three in August 1978. Observational results are (1) the main pulse broadens somewhat with increasing energy; (2) the pulsation light curve undergoes pronounced changes at the leading edge of the main pulse from day to day; (3) spectral hardening within the main pulse is confirmed; (4) a 40-60 keV spectral feature in the spectrum is confirmed; (5) this feature is resolved, the pulse width broadening is greater than 20%, and its centroid varies with pulsation phase; and (6) the 13-75 keV spectrum does not noticeably vary from day to day, except for an overall intensity factor. Some implications of these results for the prevailing models of Her X-1 and the HZ Her-Her X-1 system are briefly discussed.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 240
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-06-28
    Description: Long-term measurements of the hard X-ray spectrum from 3 keV to 8 MeV of the black-hole candidate Cygnus X-1 in its low state are reported. Observations were made from October 26 to November 18, 1977 with the A2 (Cosmic X-ray) and A4 (Hard X-ray and Low-Energy Gamma-Ray) experiments on board HEAO 1 in the spacecraft's scanning mode. The measured spectrum below 200 keV is found to agree well with previous spectra which have been fit by a model of the Compton scattering of optical or UV photons in a very hot plasma of electron temperature 32.4 keV and optical depth 3.9 or 1.6 for spherical or disk geometry, respectively. At energies above 300 keV, however, flux excess is observed which may be accounted for by a distribution of electron temperatures from 15 to about 100 keV.
    Keywords: ASTROPHYSICS
    Type: Nature; 293; Sept. 24
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-06-28
    Description: X-ray spectra of GX 339-4 measured on three occasions in 1977 and 1978 are presented. These are the first reported measurements above 10 keV. The spectra can be described as the superposition of a soft component, which is dominant below about 20 keV, and a hard component at higher energy. Simultaneous measurements at lower energy show that the soft component vanished during the observation in early 1978. The behavior of these two components is similar to that of the spectrum of Cygnus X-1; this reinforces the previously noted resemblance in rapid X-ray variability.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 262
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...