Observations of the Naked-Eye GRB 080319B: Implications of Nature's Brightest Explosion
Authors: J.S. Bloom (1,2), D. A. Perley (1), W. Li (1), N. R. Butler (1), A. A. Miller (1), D. Kocevski (1), D. A. Kann (3), R. J. Foley (1), H.-W. Chen (4), A. V. Filippenko (1), D. L. Starr (1,5), B. Macomber (1), J. X. Prochaska (6), R. Chornock (1), D. Poznanski (1), S. Klose (3) (1. UCB, 2. Sloan, 3. Tautenburg, 4. U of Chicago, 5. LCOGT, 6. UCO/Lick Observatory)
(Submitted on 24 Mar 2008)
Abstract: The first gamma-ray burst (GRB) confirmed to be bright enough to be seen with the naked eye, GRB 080319B, allowed for exquisite follow-up across the electromagnetic spectrum. We present our detailed optical and infrared observations of the afterglow, consisting of over 5000 images starting 122 s after the GRB trigger, in concert with our own analysis of the Swift UVOT, BAT, and XRT data.
The event is extreme not only in observed properties but intrinsically: it was the most luminous ever recorded at optical wavelengths and had an exceedingly high isotropic-equivalent energy release in gamma-rays. At early times, the afterglow evolution is broadly consistent with being reverse-shock dominated, then is subsumed by a forward shock at around 1000 s. Analysis of the forward shock suggests that the remarkable energetics of this burst may be owed largely to extreme collimation. The spectral energy distribution, spanning from ultraviolet through near-infrared, shows no evidence for a significant amount of dust extinction in the host frame.
We do find significant color evolution in the optical afterglow: starting at about 1000 s the index shifts blueward before apparently shifting back to the red at late times. Finally, we examine the detectability of such events with current and future facilities and find that such an event could be detected in gamma-rays by BAT out to z = 4.9 (8 sigma), while the nominal EXIST sensitivity would allow detection to z = 12.2. At K-band this source would have been easily detected with meter-class telescopes to z = 17.
Comments: Submitted to ApJ, 42 pages, 6 figures
Subjects: Astrophysics (astro-ph)
Cite as: arXiv:0803.3215v1 [astro-ph]
Submission history
From: Weidong Li [view email]
[v1] Mon, 24 Mar 2008 18:29:33 GMT (249kb)
http://arxiv.org/abs/0803.3215