Radiation from sub-Larmor scale magnetic fields

Details Radiation from sub-Larmor scale magnetic fields Radiation from sub-Larmor scale magnetic fields

2010-02-27

arxiv.org/abs/1003.0063v3

ApJ, 737:55 (10pp) 2011

Astronomy and Astrophysics

Astrophysics

High Energy Astrophysical Phenomena

13 pages, 12 figures, matches published version

Scientific paper

Spontaneous rapid growth of strong magnetic fields is rather ubiquitous in high-energy density environments ranging from astrophysical sources (e.g., gamma-ray bursts and relativistic shocks), to reconnection, to laser-plasma interaction laboratory experiments, where they are produced by kinetic streaming instabilities of the Weibel type. Relativistic electrons propagating through these sub-Larmor-scale magnetic fields radiate in the jitter regime, in which the anisotropy of the magnetic fields and the particle distribution have a strong effect on the produced radiation. Here we develop the general theory of jitter radiation, which includes (i) anisotropic magnetic fields and electron velocity distributions, (ii) the effects of trapped electrons and (iii) extends the description to large deflection angles of radiating particles thus establishing a cross-over between the classical jitter and synchrotron regimes. Our results are in remarkable agreement with the radiation spectra obtained from particle-in-cell simulations of the classical Weibel instability. Particularly interesting is the onset of the field growth, when the transient hard synchrotron-violating spectra are common as a result of the dominant role of the trapped population. This effect can serve as a distinct observational signature of the violent field growth in astrophysical sources and lab experiments. It is also interesting that a system with small-scale fields tends to evolve toward the small-angle jitter regime, which can, under certain conditions, dominate the overall emission of a source.

Affiliated with

Also associated with

No associations

Rating

Radiation from sub-Larmor scale magnetic fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Radiation from sub-Larmor scale magnetic fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiation from sub-Larmor scale magnetic fields will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-629195