Are GRB jets baryonic/leptonic or magnetic? / Medvedev Mikhail V.,Pothapragada Sriharsha,Reynolds Sarah // . - 2011. - V. 1358, l. .

ISSN/EISSN:

0094-243X / нет данных

Type:

Proceedings Paper

Abstract:

Prompt GRB emission can carry information about local conditions in a jet and provide a link toward understanding of a GRB progenitor. Conventional interpretation of the prompt emission, regardless of the jet origin, is either synchrotron, perhaps with the (self)-comptonized component, or thermal. Whereas some GRBs are consistent with this interpretation, many are at odds with it. Particularly, the ubiquitous spectral variability and correlations still awaits its physical interpretation. In view of the recent discovery of the generation of small-scale magnetic fields during reconnection in pair plasmas and the claimed non-discovery of synchrotron-violating spectra in PIC simulations of relativistic shocks the reassessment of physical models of GRB jets and its radiation becomes imperative. Here we argue that the conventional assumption of the isotropy (in the co-moving frame) of the produced radiation pattern is too simplistic to explain the wealth of observational data. We show that the anisotropic spectra fit observations much better. The anisotropy of radiation can be due to the ambient (progenitor) magnetic field, it can also be induced by the shock dynamics and geometry, or reflect the anisotropy of the post-shock turbulence. Interestingly, different emission mechanisms (e. g., synchrotron, small-pitch-angle, jitter, thermal) can dominate in different environments (e. g., magnetic, baryonic or leptonic jets) and result in different spectro-temporal characteristics. We show how the corresponding spectral correlations can distinguish between the jet origin and composition or as least rule our certain models.

Author keywords:

gamma rays: bursts; radiation mechanisms: non-thermal; magnetic fields; shock waves; magnetic reconnection GAMMA-RAY BURSTS; RELATIVISTIC COLLISIONLESS SHOCKS; PROMPT EMISSION; JITTER RADIATION; PARTICLE-ACCELERATION; SPECTRAL EVOLUTION; FIELD GENERATION; BATSE; SIMULATIONS; CATALOG

DOI:

10.1063/1.3621742

Web of Science ID:

ISI:000302963100018

Соавторы в МНС:

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Другие поля

Поле	Значение
Editor	McEnery, JE and Racusin, JL and Gehrels, N
Booktitle	GAMMA RAY BURSTS 2010
Series	AIP Conference Proceedings
Note	Conference of the Gamma Ray Bursts, Annapolis, MD, NOV 01-04, 2010
Publisher	AMER INST PHYSICS
Address	2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA
Language	English
ISBN	978-0-7354-0916-3
Keywords-Plus	GAMMA-RAY BURSTS; RELATIVISTIC COLLISIONLESS SHOCKS; PROMPT EMISSION; JITTER RADIATION; PARTICLE-ACCELERATION; SPECTRAL EVOLUTION; FIELD GENERATION; BATSE; SIMULATIONS; CATALOG
Research-Areas	Astronomy \& Astrophysics
Web-of-Science-Categories	Astronomy \& Astrophysics
Number-of-Cited-References	27
Usage-Count-Last-180-days	1
Usage-Count-Since-2013	1
Doc-Delivery-Number	BZU09