On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission

Both induced Compton scattering and induced Raman scattering strongly limit the observability of the extremely bright (>10 21 K), prompt coherent radio emission recently predicted to emanate from gamma-ray bursts (GRBs). Induced Compton scattering is the main limiting factor when the region aroun...

Full description

Bibliographic Details
Main Author: Macquart, Jean-pierre
Format: Journal Article
Published: The American Astronomical Society 2007
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/4957
_version_ 1848744660318552064
author Macquart, Jean-pierre
author_facet Macquart, Jean-pierre
author_sort Macquart, Jean-pierre
building Curtin Institutional Repository
collection Online Access
description Both induced Compton scattering and induced Raman scattering strongly limit the observability of the extremely bright (>10 21 K), prompt coherent radio emission recently predicted to emanate from gamma-ray bursts (GRBs). Induced Compton scattering is the main limiting factor when the region around the progenitor is not dense but when one still considers the scattering effect of a tenuous circumburst ISM. For a medium of density 0.01n 0.01 cm-3 and a path length Lkpc and emission that is roughly isotropic in its rest frame, the brightness temperature is limited, where 100 100 is the Lorentz factor of the frame in which the emission occurs. Thus, for a burst at distance D the predicted emission is only visible if the jet is ultrarelativistic, with 3 , or if the intrinsic opening angle of the emission is G 10 (D/100 Mpc) extremely small. Thus, the presence or absence of such radio emission provides an excellent constraint on the Lorentz factor of the GRB outflow during the very early stages of its outburst. Induced Raman scattering imposes an even more stringent limit independent of the emission opening angle, but only effective if GRB emission must propagate through a dense progenitor wind within ~10 15 cm from the blast center.
first_indexed 2025-11-14T06:05:00Z
format Journal Article
id curtin-20.500.11937-4957
institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T06:05:00Z
publishDate 2007
publisher The American Astronomical Society
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-49572017-09-13T16:04:15Z On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission Macquart, Jean-pierre plasmas gamma rays waves radiation mechanisms scattering bursts nonthermal Both induced Compton scattering and induced Raman scattering strongly limit the observability of the extremely bright (>10 21 K), prompt coherent radio emission recently predicted to emanate from gamma-ray bursts (GRBs). Induced Compton scattering is the main limiting factor when the region around the progenitor is not dense but when one still considers the scattering effect of a tenuous circumburst ISM. For a medium of density 0.01n 0.01 cm-3 and a path length Lkpc and emission that is roughly isotropic in its rest frame, the brightness temperature is limited, where 100 100 is the Lorentz factor of the frame in which the emission occurs. Thus, for a burst at distance D the predicted emission is only visible if the jet is ultrarelativistic, with 3 , or if the intrinsic opening angle of the emission is G 10 (D/100 Mpc) extremely small. Thus, the presence or absence of such radio emission provides an excellent constraint on the Lorentz factor of the GRB outflow during the very early stages of its outburst. Induced Raman scattering imposes an even more stringent limit independent of the emission opening angle, but only effective if GRB emission must propagate through a dense progenitor wind within ~10 15 cm from the blast center. 2007 Journal Article http://hdl.handle.net/20.500.11937/4957 10.1086/513424 The American Astronomical Society unknown
spellingShingle plasmas
gamma rays
waves
radiation mechanisms
scattering
bursts
nonthermal
Macquart, Jean-pierre
On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title_full On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title_fullStr On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title_full_unstemmed On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title_short On the Detectability of Prompt Coherent Gamma-Ray Burst Radio Emission
title_sort on the detectability of prompt coherent gamma-ray burst radio emission
topic plasmas
gamma rays
waves
radiation mechanisms
scattering
bursts
nonthermal
url http://hdl.handle.net/20.500.11937/4957