TY - GEN
T1 - Energy dissipation below gamma-ray bursts photosphere
T2 - 14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories
AU - Pe'Er, Asaf
N1 - Publisher Copyright: Copyright © 2018 by the Editors.All rights reserved.
PY - 2018
Y1 - 2018
N2 - It is now established that a thermal emission component plays a major role in shaping the prompt spectra of a non-negligible fraction of gamma-ray bursts (GRBs). By studying the properties of this component in a sample of 47 GRBs, we deduce that the Lorentz factor is 102 Γ 103, with mean value Γ 370. The acceleration radius r0 span a wide range, 106.5 r0 109.5 cm, with mean value r0 108 cm. This is higher than the gravitational radius of 10 M black hole by a factor of ≈ 30. We argue that this result provides an indirect evidence for jet propagation inside a massive star, and suggests the existence of recollimation shocks that take place at this radius. We further show that sub-photospheric dissipation of the jet kinetic energy provides a self-consistent, fully physically motivated model that can fit a wide range of GRB spectra. The leading radiative process is Comptonization of the thermal component, and synchrotron emission is sub-dominant. We create a DREAM (Dissipation with Radiative Emission as a Table Model) table model for XSPEC, and show how this model can describe different types of GRB spectra.
AB - It is now established that a thermal emission component plays a major role in shaping the prompt spectra of a non-negligible fraction of gamma-ray bursts (GRBs). By studying the properties of this component in a sample of 47 GRBs, we deduce that the Lorentz factor is 102 Γ 103, with mean value Γ 370. The acceleration radius r0 span a wide range, 106.5 r0 109.5 cm, with mean value r0 108 cm. This is higher than the gravitational radius of 10 M black hole by a factor of ≈ 30. We argue that this result provides an indirect evidence for jet propagation inside a massive star, and suggests the existence of recollimation shocks that take place at this radius. We further show that sub-photospheric dissipation of the jet kinetic energy provides a self-consistent, fully physically motivated model that can fit a wide range of GRB spectra. The leading radiative process is Comptonization of the thermal component, and synchrotron emission is sub-dominant. We create a DREAM (Dissipation with Radiative Emission as a Table Model) table model for XSPEC, and show how this model can describe different types of GRB spectra.
KW - Gamma-rays: bursts
KW - Hydrodynamics
KW - Radiation mechanism: non-thermal
KW - Radiation mechanism: thermal
UR - http://www.scopus.com/inward/record.url?scp=85059090022&partnerID=8YFLogxK
U2 - 10.1142/9789813226609_0369
DO - 10.1142/9789813226609_0369
M3 - منشور من مؤتمر
T3 - 14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Proceedings
SP - 2943
EP - 2949
BT - 14th Marcel Grossman Meeting On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories, Proceedings
A2 - Bianchi, Massimo
A2 - Jantzen, Robert T
A2 - Ruffini, Remo
PB - World Scientific Publishing Co. Pte Ltd
Y2 - 12 July 2015 through 18 July 2015
ER -