The Early-time Optical Properties of Gamma-Ray Burst Afterglows

Details The Early-time Optical Properties of Gamma-Ray Burst Afterglows The Early-time Optical Properties of Gamma-Ray Burst Afterglows

2008-04-04

arxiv.org/abs/0804.0811v1

Astronomy and Astrophysics

Astrophysics

51 pages, 9 figures, 4 tables, submitted to ApJ

Scientific paper

10.1086/591243

We present a multiwavelength analysis of 63 Gamma-Ray Bursts observed with the world's three largest robotic optical telescopes, the Liverpool and Faulkes Telescopes (North and South). Optical emission was detected for 24 GRBs with brightnesses ranging from R = 10 to 22 mag in the first 10 minutes after the burst. By comparing optical and X-ray light curves from t = 100 to about 10^6 seconds, we introduce four main classes, defined by the presence or absence of temporal breaks at optical and/or X-ray wavelengths. While 15/24 GRBs can be modelled with the forward-shock model, explanation of the remaining nine is very challenging in the standard framework even with the introduction of energy injection or an ambient density gradient. Early X-ray afterglows, even segments of light curves described by a power-law, may be due to additional emission from the central engine. 39 GRBs in our sample were not detected and have deep upper limits (R < 22 mag) at early time. Of these, only ten were identified by other facilities, primarily at near infrared wavelengths, resulting in a dark burst fraction of about 50%. Additional emission in the early time X-ray afterglow due to late-time central engine activity may also explain some dark bursts by making the bursts brighter than expected in the X-ray band compared to the optical band.

Affiliated with

Also associated with

No associations

Rating

The Early-time Optical Properties of Gamma-Ray Burst Afterglows 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 Early-time Optical Properties of Gamma-Ray Burst Afterglows, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Early-time Optical Properties of Gamma-Ray Burst Afterglows will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-270024