Kocevski 2008 晚期X射线耀发时标的演化

主要内容:


精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· Electronic Refereed Journal Article (HTML)

· Full Refereed Journal Article (PDF/Postscript)

· arXiv e-print (arXiv:astro-ph/0702452)

· References in the article

· Citations to the Article (9) (Citation History)

· Refereed Citations to the Article

· SIMBAD Objects (19)

· Also-Read Articles (Reads History)

·

· Translate This Page

Title:		Pulse Width Evolution of Late-Time X-Ray Flares in Gamma-Ray Bursts
Authors:		Kocevski, Daniel; Butler, Nathaniel; Bloom, Joshua S.
Affiliation:		AA(Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720.), AB(Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720.; Space Sciences Laboratory, University of California, Berkeley, CA, 94720-7450.), AC(Astronomy Department, University of California, 601 Campbell Hall, Berkeley, CA 94720.; Sloan Research Fellow.)
Publication:		The Astrophysical Journal, Volume 667, Issue 2, pp. 1024-1032. (ApJ Homepage)
Publication Date:		10/2007
Origin:		UCP
ApJ Keywords:		Gamma Rays: Bursts, X-Rays: General
Abstract Copyright:		(c) 2007: The American Astronomical Society
DOI:		10.1086/520041
Bibliographic Code:		2007ApJ...667.1024K

Abstract

We study the duration and variability of late-time X-ray flares following gamma-ray bursts (GRBs) observed by the narrow-field X-ray telescope (XRT) aboard the Swift spacecraft. These flares are thought to be indicative of late-time activity by the central engine that powers the GRB and produced by means similar to those which produce the prompt emission. We use a nonparametric procedure to study the overall temporal properties of the flares and a structure function analysis to look for an evolution of the fundamental variability timescale between the prompt and late-time emission. We find a strong correlation in 28 individual X-ray flares in 18 separate GRBs between the flare duration and their time of peak flux since the GRB trigger. We also find a qualitative trend of decreasing variability as a function of time since trigger, with a characteristic minimum variability timescale Δt/t=0.1 for most flares. The correlation between pulse width and time is consistent with the effects of internal shocks at ever-increasing collision radii, but could also arise from delayed activity by the central source. Contemporaneous detections of high-energy emission by GLAST could test between these two scenarios, as any late-time X-ray emission would undergo inverse Compton scattering as it passes through the external shock. The profile of this high-energy component should depend on the distance between the emitting region and the external shock.

---

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