TITLE:   GCN CIRCULAR
NUMBER:  4552
SUBJECT: GRB 060121 (=H4010): Results of preliminary spectral analysis
DATE:    06/01/22 00:54:29 GMT
FROM:    Don Lamb at U.Chicago  <lamb@oddjob.uchicago.edu>

GRB 060121 (=H4010): Results of preliminary spectral analysis

M. Boer, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley, on
behalf of the HETE Science Team;
 
M. Arimoto, T. Donaghy, E. Fenimore, M. Galassi, C. Graziani,
N. Ishikawa, A. Kobayashi, J. Kotoku, M. Maetou, M. Matsuoka,
Y. Nakagawa, T. Sakamoto, R. Sato, T. Shimokawabe, Y. Shirasaki,
S. Sugita, M. Suzuki, T. Tamagawa, K. Tanaka, and A. Yoshida, on behalf
of the HETE WXM Team;
 
N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek,
J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga,
R. Manchanda, G. Pizzichini, and S. Gunasekera, on behalf of the HETE
Operations and HETE Optical-SXC Teams;
 
J-F Olive, J-P Dezalay, and K. Hurley, on behalf of the HETE FREGATE
Team;
 
report:

A preliminary analysis of the WXM and FREGATE spectral data for GRB
060121 (=H4010) shows that the data is adequately fit by a power-law
times exponential model with best-fit parameters 

alpha = -0.46 +/- 0.07
E_peak = 120 +/- 7 keV.

Thus the spectrum of the burst is very hard, as expected for a 
short/hard GRB.

The preliminary spectral analysis gives fluences for the burst of 0.66
x 10-6 erg cm-2 in the 2-30 keV energy band, 4.3 x 10-6 erg cm-2 in the
30-400 keV energy band, and 4.9 x 10-6 erg cm-2 in the 2-400 keV energy
band.  The burst is thus quite bright, given that its T90 duration is
about 2 seconds.

Further information about this burst will be available at the following 
URL:

http://space.mit.edu/HETE/Bursts/GRB060121