GCN Circular 1169

GRB011130 (=XRF011130): Revised Localization of an X-ray Flash/X-ray Rich GRB

G. Ricker, D. Lamb, and S. Woosley on behalf of the HETE Science Team;

N. Butler, G. Crew, J. Doty, G. Monnelly, G. Prigozhin, R. 
Vanderspek, J. Villasenor, T. Cline, J.G. Jernigan, A. Levine, F. 
Martel, E. Morgan, J. Braga, R. Manchanda, and G. Pizzichini, on 
behalf of the HETE Operations and HETE Optical-SXC Teams;

C. Graziani, N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. 
Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, 
and T. Donaghy, on behalf of the HETE WXM Team;

J-L Atteia, M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf 
of the HETE FREGATE Team;

write:

The localization of H1764, an X-ray flash (XRF) reported as GRB011130 
in GCN Circular 1165
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 , has been greatly improved. The burst occurred 
at 22775.66 SOD (6:19:35 UT) on 30 November.

Selection by hand of optimal background and foreground time 
intervals, and the optimal energy interval has resulted in a 19.6 
sigma detection of GRB011130 in the WXM 2-10 keV energy band.  The 
improved statistical error radius in the WXM localization is 7.2 
arcmin (90% confidence). The spacecraft aspect has been improved to 
lie within a circle of 3.6 arcmin radius. The revised localization of 
H1864 is centered at:

R.A. = 03h05m36s.45, Dec. = 3o48'37"

A circle centered on this location having a radius 10 arcmin contains 
the burst location with > 90% confidence.

The revised location differs significantly (~4 degrees) from the 
originally reported one; the contributing factors to the large 
difference are explained in detail in the "Special Note on Burst 
1864" posted at:

http://space.mit.edu/HETE/Bursts/

A careful re-analysis of the full WXM data set indicates that the 
burst is considerably longer, and of higher fluence, than reported in 
GCN1135
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 . In the 2-10 keV band, the duration is ~30 s, with ~3100 
counts contained in the burst.

Further refinement of the spacecraft aspect, and thus the burst 
localization, continues.

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