Ioka 2010 火球模型产生超高洛仑兹因子

主要内容:
进而产生和观测一致的各种效应。
真的是经典的火球模型。

精彩摘抄:

文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1006.3073)

· References in the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

Title:		Very High Lorentz Factor Fireballs and Gamma-Ray Burst Spectra
Authors:		Ioka, Kunihito
Publication:		eprint arXiv:1006.3073
Publication Date:		06/2010
Origin:		ARXIV
Keywords:		Astrophysics - High Energy Astrophysical Phenomena
Comment:		43 pages, 6 figures, 1 table
Bibliographic Code:		2010arXiv1006.3073I

Abstract

Collisionless entrainment of the surrounding matter imports the relativistic baryon component in the Gamma-Ray Burst (GRB) fireball frame. We show that half the fireball energy can be transferred from radiation to the comoving hot motions of baryons under the photosphere. The yet baryon-poor fireball can re-expand to a very high Lorentz factor (VHLF) \Gamma ~ 10^3-10^6 by its own relativistic collisionless pressure beyond the photosphere (so-called collisionless bulk-acceleration), leading to the internal and external shocks. A simple synchrotron emission from the VHLF internal shocks produces (i) the extra power-law spectral component with variability observed in the Fermi GeV bursts, up to the TeV range for the future Cherenkov Telescope Array (CTA), (ii) the GeV onset delay with a weak luminosity dependence t_{delay} ~ L^{-1/5}, and (iii) the spectral break of GRB 090926 by the synchrotron cooling break or the maximum synchrotron cutoff limited by the dynamical time, not by the e+- creation cutoff. The relativistic baryon component could also heat the photospheric thermal photons into the main GRB Band spectrum via pp, p\gamma (Bethe-Heitler and photomeson) and Coulomb thermalization processes. This hot photosphere-internal-external shock model predicts the anti-correlation of ~TeV neutrinos and GeV gamma-rays, which may be detectable by IceCube. The spectral peak and luminosity (Yonetoku) relation is also reproduced if the progenitor stars are nearly identical. We also discuss the steep/shallow decay of early X-ray afterglows and short GRBs.

---

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)