skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: LIMITS TO THE FRACTION OF HIGH-ENERGY PHOTON EMITTING GAMMA-RAY BURSTS

Abstract

After almost four years of operation, the two instruments on board the Fermi Gamma-ray Space Telescope have shown that the number of gamma-ray bursts (GRBs) with high-energy photon emission above 100 MeV cannot exceed roughly 9% of the total number of all such events, at least at the present detection limits. In a recent paper, we found that GRBs with photons detected in the Large Area Telescope have a surprisingly broad distribution with respect to the observed event photon number. Extrapolation of our empirical fit to numbers of photons below our previous detection limit suggests that the overall rate of such low flux events could be estimated by standard image co-adding techniques. In this case, we have taken advantage of the excellent angular resolution of the Swift mission to provide accurate reference points for 79 GRB events which have eluded any previous correlations with high-energy photons. We find a small but significant signal in the co-added field. Guided by the extrapolated power-law fit previously obtained for the number distribution of GRBs with higher fluxes, the data suggest that only a small fraction of GRBs are sources of high-energy photons.

Authors:
;  [1]
  1. Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109-1040 (United States)
Publication Date:
OSTI Identifier:
22167682
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 764; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; CORRELATIONS; COSMIC GAMMA BURSTS; COSMIC PHOTONS; EXTRAPOLATION; GAMMA ASTRONOMY; GAMMA DETECTION; GAMMA RADIATION; IMAGES; MEV RANGE; OPERATION; PHOTON EMISSION; RESOLUTION; SENSITIVITY; SIGNALS; STARS; TELESCOPE COUNTERS

Citation Formats

Akerlof, Carl W., and Zheng, WeiKang. LIMITS TO THE FRACTION OF HIGH-ENERGY PHOTON EMITTING GAMMA-RAY BURSTS. United States: N. p., 2013. Web. doi:10.1088/0004-637X/764/2/190.
Akerlof, Carl W., & Zheng, WeiKang. LIMITS TO THE FRACTION OF HIGH-ENERGY PHOTON EMITTING GAMMA-RAY BURSTS. United States. https://doi.org/10.1088/0004-637X/764/2/190
Akerlof, Carl W., and Zheng, WeiKang. 2013. "LIMITS TO THE FRACTION OF HIGH-ENERGY PHOTON EMITTING GAMMA-RAY BURSTS". United States. https://doi.org/10.1088/0004-637X/764/2/190.
@article{osti_22167682,
title = {LIMITS TO THE FRACTION OF HIGH-ENERGY PHOTON EMITTING GAMMA-RAY BURSTS},
author = {Akerlof, Carl W. and Zheng, WeiKang},
abstractNote = {After almost four years of operation, the two instruments on board the Fermi Gamma-ray Space Telescope have shown that the number of gamma-ray bursts (GRBs) with high-energy photon emission above 100 MeV cannot exceed roughly 9% of the total number of all such events, at least at the present detection limits. In a recent paper, we found that GRBs with photons detected in the Large Area Telescope have a surprisingly broad distribution with respect to the observed event photon number. Extrapolation of our empirical fit to numbers of photons below our previous detection limit suggests that the overall rate of such low flux events could be estimated by standard image co-adding techniques. In this case, we have taken advantage of the excellent angular resolution of the Swift mission to provide accurate reference points for 79 GRB events which have eluded any previous correlations with high-energy photons. We find a small but significant signal in the co-added field. Guided by the extrapolated power-law fit previously obtained for the number distribution of GRBs with higher fluxes, the data suggest that only a small fraction of GRBs are sources of high-energy photons.},
doi = {10.1088/0004-637X/764/2/190},
url = {https://www.osti.gov/biblio/22167682}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 764,
place = {United States},
year = {Wed Feb 20 00:00:00 EST 2013},
month = {Wed Feb 20 00:00:00 EST 2013}
}