Berger 2008 短暴的宿主星系

主要内容:


精彩摘抄:


文章信息:

· arXiv e-print (arXiv:0805.0306)

· References in the Article

·

· Translate This Page

Title:		The Host Galaxies of Short-Duration Gamma-Ray Bursts: Luminosities, Metallicities, and Star Formation Rates
Authors:		Berger, E.
Publication:		eprint arXiv:0805.0306
Publication Date:		05/2008
Origin:		ARXIV
Keywords:		Astrophysics
Comment:		Submitted to ApJ
Bibliographic Code:		2008arXiv0805.0306B

Abstract

The association of some short-duration gamma-ray bursts (GRBs) with elliptical galaxies established that their progenitors, unlike those of long GRBs, belong to an old stellar population. However, the majority of short GRBs appear to occur in star forming galaxies, raising the possibility that some progenitors are related to recent star formation activity. Here we present optical spectroscopy of these hosts and measure their luminosities, star formation rates, and metallicities. We find luminosities of L_B~0.1-1.5 L*, star formation rates of SFR~0.2-6 M_sun/yr, and metallicities of 12+log(O/H)~8.5-8.9 (Z~0.6-1.6 Z_sun). A detailed comparison to the hosts of long GRBs reveals systematically higher luminosities, lower specific star formation rates (SFR/L_B) by about an order of magnitude, and higher metallicities by about 0.6 dex. The K-S probability that the short and long GRB hosts are drawn from the same underlying galaxy distribution is only 10^-3. On the other hand, short GRB hosts exhibit excellent agreement with the specific star formation rates and the luminosity-metallicity relation of field galaxies at z~0.1-1. We thus conclude that short GRB hosts are not dominated by young stellar populations like long GRBs hosts. Instead, short GRB hosts appear to be drawn uniformly from the underlying galaxy distribution, indicating that the progenitors have a wide age distribution of several Gyr.

---

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