Heterogeneity in Short Gamma-ray Bursts

Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

30 pages, 11 figures, 3 tables; accepted to The Astrophysical Journal

Scientific paper

We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample comprises 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales - durations, pulse structure widths, and peak intervals - for EE bursts are factors of ~ 2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts - the anti-correlation of pulse intensity and width - continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/XRT. The median flux of the initial XRT detections for EE bursts (~ 6 x 10^-10 erg cm^-2 s^-1) is ~> 20 x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts (~ 60,000 s) is ~ 30 x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into more dense environments than non-EE bursts, or that the sometimes-dominant EE component efficiently powers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Heterogeneity in Short Gamma-ray Bursts 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 Heterogeneity in Short Gamma-ray Bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heterogeneity in Short Gamma-ray Bursts will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-266149

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.