Liang 2008 用余辉拟合推测高红移宿主星系的尘埃消光曲线

主要内容:


精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:0811.1867)

· References in the Article

·

· Translate This Page

Title:		Probing Cosmic Dust of the Early Universe through High-Redshift Gamma-Ray Bursts
Authors:		Liang, S. L.; Li, Aigen
Publication:		eprint arXiv:0811.1867
Publication Date:		11/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		14 pages, 3 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters
Bibliographic Code:		2008arXiv0811.1867L

Abstract

We explore the extinction properties of the dust in the distant universe through the afterglows of high-redshifted GRBs based on the "Drude" model which, unlike previous studies, does not require a prior assumption of template extinction laws. We select GRB070802 at z~2.45 (which shows clear evidence for the 2175\AA extinction bump) and GRB050904 at z~6.29, the 2nd most distant GRB observed to date. We fit their afterglow spectra to determine the extinction of their host galaxies. We find that (1) their extinction curves differ substantially from that of the Milky Way, the Small and Large Magellanic Clouds (which were widely adopted as template extinction laws in literature); (2) the 2175\AA extinction feature appears to be also present in GRB050904 at z~6.29; and (3) there does not appear to show strong evidence for a dependence of dust extinction on redshifts. The inferred extinction curves are closely reproduced in terms of a mixture of amorphous silicate and graphite, both of which are expected supernova condensates and have been identified in primitive meteorites as presolar grains originating from supernovae (which are considered as the main source of dust at high-z).

---

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