THESEUS and Gamma-Ray Bursts . a valuable contribution to the understanding of prompt emission
Abstract
Recent advances in fitting prompt emission spectra in gamma-ray bursts (GRBs) are boosting our understanding of the still elusive origin of this radiation. These progresses have been possible thanks to a more detailed analysis of the low-energy part (< 100 keV) of the prompt spectrum, where the spectral shape is sometimes found to deviate from a simple power-law shape. This deviation is well described by a spectral break or, alternatively by the addition of a thermal component. Spectral data extending down to less than 1 keV are extremely relevant for these studies, but presently they are available only for a small subsample of Swift GRBs observed by XRT (the X-ray telescope, 0.3-10 keV) during the prompt emission. The space mission THESEUS will allow a systematic study of prompt spectra from 0.3 keV to several MeV. We show that observations performed by THESEUS will allow us to discriminate between different models presently considered for GRB prompt studies, solving the long-standing open issue about the nature of the prompt radiation, with relevant consequences on the location of the emitting region, magnetic field strength and presence of thermal components.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2018
- DOI:
- 10.48550/arXiv.1802.01683
- arXiv:
- arXiv:1802.01683
- Bibcode:
- 2018MmSAI..89..245N
- Keywords:
-
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- To be published in the Proceedings of the THESEUS Workshop 2017 (http://www.isdc.unige.ch/theseus/workshop2017.html), Journal of the Italian Astronomical Society (Mem.SAIt), Editors L. Amati, E. Bozzo, M. Della Valle, D. Gotz, P. O'Brien. Details on the THESEUS mission concept can be found in the white paper Amati et al. 2017 (arXiv:171004638) and Stratta et al. 2017 (arXiv:1712.08153)