Toma 2008 模拟统计伽玛暴本身的偏振

主要内容:
现在, 暴本身的辐射机制还很不清楚!

文章是想用不同模型模拟一下偏振, 和将要launched仪器如POET (Polarimeters for Energetic Transients)比较, 从而确定哪个模型比较可靠.

不过我觉得这个工作是应该在确定了几个模型都能解释现有观测之后, 为了进一步确定究竟哪个模型是对的, 然后引入偏振, 鉴别之. 但现在是模型都还不能解释现有观测.

精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:0812.2483)

· References in the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

Title:		Statistical Properties of Gamma-Ray Burst Polarization
Authors:		Toma, Kenji; Sakamoto, Takanori; Zhang, Bing; Hill, Joanne E.; McConnell, Mark L.; Bloser, Peter F.; Yamazaki, Ryo; Ioka, Kunihito; Nakamura, Takashi
Publication:		eprint arXiv:0812.2483
Publication Date:		12/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		12 pages, 12 figures, 1 table, submitted to ApJ
Bibliographic Code:		2008arXiv0812.2483T

Abstract

The emission mechanism and the origin and structure of magnetic fields in gamma-ray burst (GRB) jets are among the most important open questions concerning the nature of the central engine of GRBs. In spite of extensive observational efforts, these questions remain to be answered and are difficult or even impossible to infer with the spectral and lightcurve information currently collected. Polarization measurements will lead to unambiguous answers to several of these questions. Recent developments in X-ray and gamma-ray polarimetry techniques have demonstrated a significant increase in sensitivity enabling several new mission concepts, e.g. POET (Polarimeters for Energetic Transients), providing wide field of view and broadband polarimetry measurements. If launched, missions of this kind would finally provide definitive measurements of GRB polarizations. We perform Monte Carlo simulations to derive the distribution of GRB polarizations in three emission models; the synchrotron model with a globally ordered magnetic field (SO model), the synchrotron model with a locally random magnetic field (SR model), and the Compton drag model (CD model). The results show that POET, or other polarimeters with similar capabilities, can constrain the GRB emission models by using the statistical properties of GRB polarizations. In particular, the ratio of the number of GRBs for which the polarization degrees can be measured to the number of GRBs that are detected (N_m/N_d) and the distributions of the polarization degrees (Pi) can be used as the criteria. If N_m/N_d > 30% and Pi is clustered between 0.2 and 0.7, the SO model will be favored. If instead N_m/N_d <> 0.8 are observed, then the CD model will be favored.

---

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