Photospheric Emission in the Joint GBM and Konus Prompt Spectra of GRB 120323A [HEAP]

http://arxiv.org/abs/1703.07846


GRB 120323A is a very intense short Gamma Ray Burst (GRB) detected simultaneously during its prompt gamma-ray emission phase with the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope and the Konus experiment on board the Wind satellite. GBM and Konus operate in the keV–MeV regime, however, the GBM range is broader both toward the low and the high parts of the gamma-ray spectrum. Analysis of such bright events provide a unique opportunity to check the consistency of the data analysis as well as cross-calibrate the two instruments. We performed time-integrated and coarse time-resolved spectral analysis of GRB 120323A prompt emission. We conclude that the analyses of GBM and Konus data are only consistent when using a double-hump spectral shape for both data sets; in contrast, the single-hump of the empirical Band function, traditionally used to fit GRB prompt emission spectra, leads to significant discrepancies between GBM and Konus analysis results. Our two-hump model is a combination of a thermal-like and a non-thermal component. We interpret the first component as a natural manifestation of the jet photospheric emission.

Read this paper on arXiv…

S. Guiriec, N. Gehrels, J. McEnery, et. al.
Fri, 24 Mar 17
5/41

Comments: 7 pages of article (3 figures and 1 table) + 3 pages of Appendix (3 figures). Submitted to ApJ on 2017 March 22