Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-11-09
Astrophys.J.661:458-467,2007
Astronomy and Astrophysics
Astrophysics
32 pages, 14 figures, submitted to ApJ
Scientific paper
10.1086/516732
The giant flare of December 27, 2004 from SGR 1806-20 represents one of the most extraordinary events captured in over three decades of monitoring the gamma-ray sky. One measure of the intensity of the main peak is its effect on X- and gamma-ray instruments. RHESSI, an instrument designed to study the brightest solar flares, was completely saturated for ~0.5 s following the start of the main peak. A fortuitous alignment of SGR 1806-20 near the Sun at the time of the giant flare, however, allowed RHESSI a unique view of the giant flare event, including the precursor, the main peak decay, and the pulsed tail. Since RHESSI was saturated during the main peak, we augment these observations with Wind and RHESSI particle detector data in order to reconstruct the main peak as well. Here we present detailed spectral analysis and evolution of the giant flare. We report the novel detection of a relatively soft fast peak just milliseconds before the main peak, whose timescale and sizescale indicate a magnetospheric origin. We present the novel detection of emission extending up to 17 MeV immediately following the main peak, perhaps revealing a highly-extended corona driven by the hyper-Eddington luminosities. The spectral evolution and pulse evolution during the tail are presented, demonstrating significant magnetospheric twist and evolution during this phase. Blackbody radii are derived for every stage of the flare, which show remarkable agreement despite the range of luminosities and temperatures covered. Finally, we place significant upper limits on afterglow emission in the hundreds of seconds following the giant flare.
Bellm Eric
Boggs Steven E.
Hajdas Wojtek
Hurley Kevein
Lin Robert P.
No associations
LandOfFree
The Giant Flare of December 27, 2004 from SGR 1806-20 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 Giant Flare of December 27, 2004 from SGR 1806-20, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Giant Flare of December 27, 2004 from SGR 1806-20 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-565105