Shao 2007 dust echo for GRB afterglow

主要内容:
They can fit the X-ray afterglow now. That is to say, the X-ray afterglow comes from dust echo of Wind bubble.

精彩摘抄:

sketch
fitting

文章信息:

arXiv:0711.3800 [ps, pdf, other]

Title: Echo Emission From Dust Scattering and X-Ray Afterglows of Gamma-Ray Bursts

Authors: L. Shao (1 and 2), Z. G. Dai (1), N. Mirabal (3) ((1)Nanjing University, China, (2)University of Colorado, USA, (3)Columbia University, USA)

Comments: 25 pages, 3 figures, 2 tables. Accepted for publication in ApJ

Subjects: Astrophysics (astro-ph)

We investigate the effect of X-ray echo emission in gamma-ray bursts (GRBs). We find that the echo emission can provide an alternative way of understanding X-ray shallow decays and jet breaks. In particular, a shallow decay followed by a "normal" decay and a further rapid decay of X-ray afterglows can be together explained as being due to the echo from prompt X-ray emission scattered by dust grains in a massive wind bubble around a GRB progenitor. We also introduce an extra temporal break in the X-ray echo emission. By fitting the afterglow light curves, we can measure the locations of the massive wind bubbles, which will bring us closer to finding the mass loss rate, wind velocity, and the age of the progenitors prior to the GRB explosions.