ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Observation of gamma ray bursts and flares by the EGRET telescope on the Compton Gamma Ray Observatory (1992)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: The Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has observed energetic gamma ray bursts and flares. On May 3, 1991, EGRET detected a gamma ray burst both in the energy measuring NaI (Tl) scintillator and independently in the spark chamber imaging assembly. The NaI spectra were accumulated by a special BURST mode of EGRET. The spectra were measured over a range from 1 to 200 MeV, in three sequential spectra of 1,2, and 4 seconds. During the peak of the burst, six individual gamma rays were detected in the spark chamber, allowing a determination of the burst arrival direction. The intense flares of June were also detected. A solar flare on June 4 was observed to last for several minutes and for a brief time, less than a minute, had significant emission of gamma rays exceeding 150 MeV.
    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. 38-42.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Detection of high-energy gamma radiation from quasar 3C 279 by the EGRET telescope on the Compton Gamma Ray Observatory (1992)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Intense gamma radiation has been observed from the direction of the quasar 3C 279 throughout the energy range from 30 MeV to over 5 GeV by the Energetic Gamma Ray Experiment Telescope (EGRET) during the period June 15-28, 1991. Its spectrum is well represented by a photon differential power-law exponent of 2.0 +/- 0.1, with a photon intensity above 100 MeV of (2.8 +/- 0.4) x 10 exp -6/sq cm s. For E is greater than 100 MeV, the 2-sigma upper limits were 1.0 x 10 exp -6/sq cm s in 1973 from the SAS 2 observations and 0.3 x 10 exp -6/sq cm s for the combined 1976, 1978, and 1980 COS B observations. Hence, there has been a large increase in high-energy gamma-ray intensity relative to the earlier times, as there has been in the radio, infrared, optical, and X-ray ranges. This source is the most distant and by far the most luminous gamma-ray source yet detected.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X); 385; L1-L4
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Nuclear composition and energy spectra in the 1969 April 12 solar-particle event. (1972)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Measurement of the charge composition for several of the multicharged nuclei and the energy spectra for hydrogen, helium, and medium (6 less than or equal to Z less than or equal to 9) nuclei in the Apr. 12, 1969, solar-particle event. The energy/nucleon spectral shape of the medium nuclei was again the same as that of the helium nuclei, and the ratio of these two species was consistent with the present best average of 58 plus or minus 5. By combining the results obtained here with previous work, improved estimates of the Ne/O and Mg/O values of 0.16 plus or minus 0.03 and 0.056 plus or minus 0.014, respectively, were obtained. Silicon and sulfur abundances relative to O were determined to be 0.208 plus or minus 0.008 plus or minus 0.006, respectively, and 85% confidence upper limits for Ar and Ca relative to O of 0.017 and 0.010 were obtained. Previously, these last four nuclei had only been listed as a group.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; 171; Jan. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Variations of the relative abundances of He, /C, N, O/ and Fe-group nuclei in solar cosmic rays and their relationship to solar particle acceleration (1973)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Keywords: SPACE RADIATION
    Type: Solar Physics; 31; July 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Searches for gamma ray emission from radio pulsars (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Searches were made for pulsed high energy (E greater than 35 MeV) gamma radiation from 43 pulsars using the SAS-2 data base and radio parameters. No positive results were found, and the upper limits are consistent with the concept that gamma ray production efficiency increases with increasing apparent age. Two limits suggest that efficiency cannot be a simple function of apparent age beyond 1,000,000 years. Previously announced in STAR as N83-24463
    Keywords: SPACE RADIATION
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 127; 1, Oc
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Relative abundance of iron-group nuclei in solar cosmic rays. (1969)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: Iron group nuclei abundance relative to oxygen determined for solar cosmic ray event of 2 September 1966
    Keywords: SPACE RADIATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Observations of medium-energy gamma-ray emission from the galactic center region (1978)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: Measurements of the gamma-ray emission in the medium-energy range between 15 and 100 MeV, obtained during two balloon flights from Brazil, are presented. The importance of this energy region in determining whether neutral-pion decay or electron bremsstrahlung is the most likely dominant source mechanism is discussed, along with the implications of such observations. Specifically, the data from this experiment suggest that emission from the galactic plane is similar to the theoretical spectrum calculated by Fichtel et al. (1976), including both source mechanisms but with the bremsstrahlung component enhanced by a factor of about 2. A spectral distribution of gamma-rays produced in the residual atmosphere above the instrument is also presented and compared with other data. A rather smooth spectral variation from high to low energies is found for the atmospheric spectrum.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal; vol. 225
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Measurements of galactic plane gamma-ray emission in the energy range 10-80 MeV (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A spark chamber gamma ray telescope was developed and flown to observe diffuse gamma ray emission from the central region of the galaxy. The extension of observations down to 10 MeV provides important new data indicating that the galactic diffuse gamma ray spectrum continues as a power law down to about 10 MeV, an observation in good agreement with recent theoretical predictions. Data from other experiments in the range from 100 keV to 10 MeV show a significant departure from the extension of the power-law fit to the medium energy observations reported here, possibly indicating that a different mechanism may be responsible for the emissions below and above a few MeV. The intensity of the spectrum above 10 MeV implies a galactic electron spectrum which is also very intense down to about 10 MeV. Electrons in this energy range cannot be observed in the solar cavity because of solar modulation effects. The galactic gamma ray data are compared with recent theoretical predictions. Previously announced in STAR as N83-17444
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 270; July 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Charge composition of solar cosmic rays (1971)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The composition of energetic solar particles is reviewed for all solar events in which measurements on helium and heavier nuclei have been made simultaneously in the same detector during a given particle event. For nuclei of equal charge-to-mass ratio, the relative abundances have been the same within uncertainties in every measurement, and consistent with spectroscopic photospheric estimates. Iron has a slightly different charge-to-mass ratio but is still of considerable interest. An observation of the Fe/O in the January 24, 1971 solar event has provided a second determination of this value.
    Keywords: SPACE RADIATION
    Type: Goddard Space Flight Center Contrib. to the Twelfth Intern. Conf. on Cosmic Rays; p 53-58
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Detection of a long-duration solar gamma-ray flare on Jun. 11, 1991 with EGRET on Compton-GRO (1992)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: On 11 Jun. 1991, the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (Comption-GRO) observed high energy gamma radiation above 30 MeV from the Sun following an intense flare around 2:00 Universal Time (UT). After the decay of most of the x ray flare, which caused nearly complete deadtime losses in EGRET, high energy emission was registered during the interval from about 3:30 UT to at least 10:30 UT. Gamma rays were detected up to energies above 1 GeV. The solar origin of the emission is assured by the time profile of the gamma ray count rate and by time resolved sky maps, which show a clear maximum at the position of the sun. The gamma ray lightcurve of the flare can be described with two components: a fast decaying emission with an e-folding time constant of about 25 minutes and a slow decay with about 255 minutes. There are indications for a spectral evolution with time, such that the emission below 100 MeV fades away earlier than the 100 to 300 MeV radiation, roughly in the time scale of the fast component. The spectrum of the flare can be fitted with a composite of a proton generated pion neutral spectrum and an electron bremsstrahlung component. The latter can be identified with the fast decaying component of the lightcurve.
    Keywords: SPACE RADIATION
    Type: Max-Planck-Inst. fuer Physik und Astrophysik, EGRET Mission and Data Analysis; 5 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...