GRB 090902B: afterglow observations and implications

Details GRB 090902B: afterglow observations and implications GRB 090902B: afterglow observations and implications

2010-03-22

arxiv.org/abs/1003.4250v1

ApJ, 714, 799, 2010

Astronomy and Astrophysics

Astrophysics

High Energy Astrophysical Phenomena

6 pages, 2 figures, Accepted for publication in ApJ

Scientific paper

10.1088/0004-637X/714/1/799

The optical-infrared afterglow of the LAT-detected long duration burst, GRB 090902B, has been observed by several instruments. The earliest detection by ROTSE-IIIa occurred 80 minutes after detection by the GBM instrument onboard the Fermi Gamma-Ray Space Telescope, revealing a bright afterglow and a decay slope suggestive of a reverse shock origin. Subsequent optical-IR observations followed the light curve for 6.5 days. The temporal and spectral behavior at optical-infrared frequencies is consistent with synchrotron fireball model predictions; the cooling break lies between optical and XRT frequencies ~ 1.9 days after the burst. The inferred electron energy index is $p = 1.8 \pm 0.2$, which would however imply an X-ray decay slope flatter than observed. The XRT and LAT data have similar spectral indices and the observed steeper value of the LAT temporal index is marginally consistent with the predicted temporal decay in the radiative regime of the forward shock model. Absence of a jet break during the first 6 days implies a collimation-corrected $\gamma$-ray energy $E_{\gamma} > 2.2\times10^{52}\rm$ ergs, one of the highest ever seen in a long-duration GRBs. More events combining GeV photon emission with multi-wavelength observations will be required to constrain the nature of the central engine powering these energetic explosions and to explore the correlations between energetic quanta and afterglow emission.

Affiliated with

Also associated with

No associations

Rating

GRB 090902B: afterglow observations and implications 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 GRB 090902B: afterglow observations and implications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GRB 090902B: afterglow observations and implications will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-207091