The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ?

Details The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ? The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ?

2001-03-20

arxiv.org/abs/astro-ph/0103306v2

Astrophys.J. 558 (2001) 442-447

Astronomy and Astrophysics

Astrophysics

19 pages, 3 fig.s, minor revisions, accepted for publication in ApJ

Scientific paper

10.1086/322467

We present X-ray observations of the afterglow of GRB000926 performed around and after the break observed in the optical light curve two days after the burst. The steep X-ray light curve observed around the break confirms the presence of this feature in X-rays. However, the spectral and temporal properties are not consistent with a standard jet scenario based on synchrotron emission, requiring a more complicated model. We find that X-ray and optical data are compatible with a moderately collimated fireball (with opening angle $\theta\approx25 \deg$) expanding in a dense medium ($n\approx 4\times 10^4$ cm$^{-3}$). This produces two breaks in the light curve. The first, at $t\approx$ 2 days, is due to jet behavior. The second, around 5 days, is attributed to the transition of the fireball to a non-relativistic expansion. This transition predicts a{\it flattening} of the light curve, that explains the late X-ray measurement in excess above the extrapolation of the simple jet scenario, and is also consistent with optical data.

Affiliated with

Also associated with

No associations

Rating

The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The X-ray afterglow of GRB000926 observed by BeppoSAX and Chandra: a mildly collimated fireball in a dense medium ? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-2134