RADIATION SPECTRAL SYNTHESIS OF RELATIVISTIC FILAMENTATION / Frederiksen Jacob Trier,Haugbolle Troels,Medvedev Mikhail V.,Nordlund Ake // ASTROPHYSICAL JOURNAL LETTERS. - 2010. - V. 722, l. 1. - P. L114-L119.

ISSN/EISSN:

2041-8205 / нет данных

Type:

Article

Abstract:

Radiation from many astrophysical sources, e. g., gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly compared with source lifetimes. Radiation emitted from these sources is typically associated with nonlinear plasma physics, complex field topologies, and non-thermal particle distributions. In such circumstances, a standard synchrotron paradigm may fail to produce accurate conclusions regarding the underlying physics. Simulating spectral emission and spectral evolution numerically in various relativistic shock scenarios is then the only viable method to determine the detailed physical origin of the emitted spectra. In this Letter, we present synthetic radiation spectra representing the early stage development of the filamentation (streaming) instability of an initially unmagnetized plasma, which is relevant for both collisionless shock formation and reconnection dynamics in relativistic astrophysical outflows as well as for laboratory astrophysics experiments. Results were obtained using a highly efficient in situ diagnostics method, based on detailed particle-in-cell modeling of collisionless plasmas. The synthetic spectra obtained here are compared with those predicted by a semi-analytical model for jitter radiation from the filamentation instability, the latter including self-consistent generated field topologies and particle distributions obtained from the simulations reported upon here. Spectra exhibit dependence on the presence-or the absence-of an inert plasma constituent, when comparing baryonic plasmas (i.e., containing protons) with pair plasmas. The results also illustrate that considerable care should be taken when using lower-dimensional models to obtain information about the astrophysical phenomena generating observed spectra.

Author keywords:

acceleration of particles; instabilities; magnetic fields; methods: numerical; plasmas; radiation mechanisms: non-thermal MAGNETIC-FIELD GENERATION; RAY BURST SHOCKS; COLLISIONLESS SHOCKS; PROMPT EMISSION; ACCELERATION

DOI:

10.1088/2041-8205/722/1/L114

Web of Science ID:

ISI:000282192300023

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	OCT 10
Publisher	IOP PUBLISHING LTD
Address	DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
Language	English
Keywords-Plus	MAGNETIC-FIELD GENERATION; RAY BURST SHOCKS; COLLISIONLESS SHOCKS; PROMPT EMISSION; ACCELERATION
Research-Areas	Astronomy \& Astrophysics
Web-of-Science-Categories	Astronomy \& Astrophysics
Author-Email	trier@nbi.dk
ResearcherID-Numbers	Frederiksen, Jacob Trier/P-6757-2015 Nordlund, Aake/M-4528-2014 Haugbolle, Troels/L-7984-2014
ORCID-Numbers	Frederiksen, Jacob Trier/0000-0002-3560-0044 Nordlund, Aake/0000-0002-2219-0541 Haugbolle, Troels/0000-0002-9422-8684
Funding-Acknowledgement	Danish Natural Science Research Council; NSF {[}AST-0708213]; NASA ATFP {[}NNX-08AL39G]; DOE {[}DE-FG02-07ER54940]; Ambrose Monell Foundation (IAS); Ib Henriksen Foundation (NBIA); European Commission through the SOLAIRE Network
Funding-Text	A.N., J.T.F., and T. H. acknowledge support from the Danish Natural Science Research Council. M.V.M.'s work has been supported by NSF grant AST-0708213, NASA ATFP grant NNX-08AL39G and DOE grant DE-FG02-07ER54940. M. V. M. also acknowledges support from The Ambrose Monell Foundation (IAS) and The Ib Henriksen Foundation (NBIA). Computer time was provided by the Danish Center for Scientific Computing (DCSC). This work was supported by the European Commission through the SOLAIRE Network (AN).
Number-of-Cited-References	19
Usage-Count-Since-2013	3
Journal-ISO	Astrophys. J. Lett.
Doc-Delivery-Number	654TC