Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of
Magnetic Field in Voids and Thermal History of the IGM
F. Miniati, and A. Elyiv. (2012)cite arxiv:1208.1761Comment: 7 pages, 6 figures, comments very welcome.
Abstract
The stability properties of a low density ultra relativistic pair beam
produced in the intergalactic medium by multi-TeV gamma-ray photons from
blazars are analyzed. The problem is relevant for probes of magnetic field in
cosmic voids through gamma-ray observations. In addition, dissipation of such
beams could affect considerably the thermal history of the intergalactic medium
and structure formation. We use a Monte Carlo method to quantify the shower
properties, in particular the bulk Lorentz factor and the angular spread of the
beam, as a function of distance from the blazar. We find that the fastest
growing modes, like any perturbation mode with even a very modest component
perpendicular to the beam direction, requires a kinetic treatment. Combined
with the effect of non-linear Landau damping, which suppresses the growth of
plasma oscillations, the beam relaxation timescale is found typically longer
than a Hubble time. Finally, density inhomogeneities associated with cosmic
structure induce severe loss of resonance between the beam particles and plasma
oscillations, strongly inhibiting their growth. We conclude that relativistic
pair beams produced by blazars in the intergalactic medium are stable on
timescales much longer compared to the electromagnetic cascade's. There appears
to be no effect of pair-beams on the intergalactic medium.
Description
[1208.1761] Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of Magnetic Field in Voids and Thermal History of the IGM
%0 Generic
%1 miniati2012relaxation
%A Miniati, Francesco
%A Elyiv, Andrii
%D 2012
%K beam blazar instability pair
%T Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of
Magnetic Field in Voids and Thermal History of the IGM
%U http://arxiv.org/abs/1208.1761
%X The stability properties of a low density ultra relativistic pair beam
produced in the intergalactic medium by multi-TeV gamma-ray photons from
blazars are analyzed. The problem is relevant for probes of magnetic field in
cosmic voids through gamma-ray observations. In addition, dissipation of such
beams could affect considerably the thermal history of the intergalactic medium
and structure formation. We use a Monte Carlo method to quantify the shower
properties, in particular the bulk Lorentz factor and the angular spread of the
beam, as a function of distance from the blazar. We find that the fastest
growing modes, like any perturbation mode with even a very modest component
perpendicular to the beam direction, requires a kinetic treatment. Combined
with the effect of non-linear Landau damping, which suppresses the growth of
plasma oscillations, the beam relaxation timescale is found typically longer
than a Hubble time. Finally, density inhomogeneities associated with cosmic
structure induce severe loss of resonance between the beam particles and plasma
oscillations, strongly inhibiting their growth. We conclude that relativistic
pair beams produced by blazars in the intergalactic medium are stable on
timescales much longer compared to the electromagnetic cascade's. There appears
to be no effect of pair-beams on the intergalactic medium.
@misc{miniati2012relaxation,
abstract = {The stability properties of a low density ultra relativistic pair beam
produced in the intergalactic medium by multi-TeV gamma-ray photons from
blazars are analyzed. The problem is relevant for probes of magnetic field in
cosmic voids through gamma-ray observations. In addition, dissipation of such
beams could affect considerably the thermal history of the intergalactic medium
and structure formation. We use a Monte Carlo method to quantify the shower
properties, in particular the bulk Lorentz factor and the angular spread of the
beam, as a function of distance from the blazar. We find that the fastest
growing modes, like any perturbation mode with even a very modest component
perpendicular to the beam direction, requires a kinetic treatment. Combined
with the effect of non-linear Landau damping, which suppresses the growth of
plasma oscillations, the beam relaxation timescale is found typically longer
than a Hubble time. Finally, density inhomogeneities associated with cosmic
structure induce severe loss of resonance between the beam particles and plasma
oscillations, strongly inhibiting their growth. We conclude that relativistic
pair beams produced by blazars in the intergalactic medium are stable on
timescales much longer compared to the electromagnetic cascade's. There appears
to be no effect of pair-beams on the intergalactic medium.},
added-at = {2012-08-10T07:46:31.000+0200},
author = {Miniati, Francesco and Elyiv, Andrii},
biburl = {https://www.bibsonomy.org/bibtex/21168be35746981dd1b4c97846697204b/miki},
description = {[1208.1761] Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of Magnetic Field in Voids and Thermal History of the IGM},
interhash = {eb18c2d9de61931002dbb9082c94b4f1},
intrahash = {1168be35746981dd1b4c97846697204b},
keywords = {beam blazar instability pair},
note = {cite arxiv:1208.1761Comment: 7 pages, 6 figures, comments very welcome},
timestamp = {2012-08-10T07:46:31.000+0200},
title = {Relaxation of Blazar Induced Pair Beams in Cosmic Voids: Measurement of
Magnetic Field in Voids and Thermal History of the IGM},
url = {http://arxiv.org/abs/1208.1761},
year = 2012
}