High-energy spectral breaks in gamma-ray bursts

Authors

Bradley E. Schaefer, NASA Goddard Space Flight Center
Bonnard J. Teegarden, NASA Goddard Space Flight Center
Thomas L. Cline, NASA Goddard Space Flight Center
Gerald J. Fishman, NASA Marshall Space Flight Center
Charles A. Meegan, NASA Marshall Space Flight Center
Robert B. Wilson, NASA Marshall Space Flight Center
William S. Paciesas, NASA Marshall Space Flight Center
Geoffrey N. Pendleton, NASA Marshall Space Flight Center
James L. Matteson, University of California, San Diego
David L. Band, University of California, San Diego
John P. Lestrade, Mississippi State University

Document Type

Article

Publication Date

7-10-1992

Abstract

We present model fits for 18 gamma-ray burst spectra from 100 keV to 27 MeV made with the BATSE spectroscopy detectors on the Compton Gamma Ray Observatory. Most of the bursts are well fitted as power laws with spectral indices between -1.36 and -2.29; however, five bursts show definite departures from a simple power-law fit at high energies. Three of these bursts are well fitted with broken power-law spectra and break energies of from 400 to 690 keV, such as might arise from photon-photon interactions. If so, then the source compactness and hence distance will be sharply constrained. Two of the bursts have spectra with sharply confined slope changes and are well fitted with broken power-law spectra with break energies of 1.2 and 1.6 MeV at peak, such as might arise from photon-magnetic field interactions. If so, then these spectral breaks provide strong evidence for the existence of high magnetic fields in the burst emission region.

Publication Source (Journal or Book title)

Astrophysical Journal

Recommended Citation

Schaefer, B., Teegarden, B., Cline, T., Fishman, G., Meegan, C., Wilson, R., Paciesas, W., Pendleton, G., Matteson, J., Band, D., & Lestrade, J. (1992). High-energy spectral breaks in gamma-ray bursts. Astrophysical Journal, 393 (2 PART II) https://doi.org/10.1086/186449