GCN Circular 5005
Subject
GRB 060425: IPN localization and KW spectrum of a short, hard burst
Date
2006-04-26T23:50:41Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of
the Swift-BAT team,
S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
and T. Cline on behalf of the Konus-Wind team,
A. von Kienlin, G. Lichti, A. Rau, D. Gotz, and S. Mereghetti,
on behalf of the INTEGRAL GRB team,
K. Hurley, D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger,
W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,
and K.Yamaoka, M.Ohno, Y.Fukazawa, T.Takahashi, M.Tashiro, Y. Terada,
T.Murakami, and K.Makishima on behalf of the Suzaku WAM team
report:
A short, hard GRB was observed at 2006-04-25 16:57:40 by Swift-BAT,
Konus-Wind, Suzaku-WAM, RHESSI, and INTEGRAL-SPI-ACS. The T90 was
0.13 +- 0.01 sec. This burst was Mars-occulted to Odyssey. The burst
had 2 main peaks of roughly similar intensity and hardness, the second
slightly shorter than the first.
The IPN triangulated error box is as follows:
----------------------
RA, deg Dec, deg (J2000)
----------------------
Center:
212.3007 -5.0667
Corners:
214.5693 -1.7277
210.9652 -7.0326
210.7765 -8.4092
213.8848 -3.1685
-----------------------
The area of the box is 2.53 sq. deg
Preliminary analysis of the Konus-Wind data yields a burst fluence of
2.57 (-1.85, +0.47) x 10^-6 erg/cm2. The peak flux measured from
T0(K-W)-0.036 s on a 16-ms time scale was
3.64 (-2.74, +1.06) x 10^-5 erg/cm2/sec. Both are quoted in the
20 keV - 10 MeV energy range. The K-W spectrum accumulated from
T0(K-W) to T0(K-W)+0.128 s is well fitted (in the 20 keV - 10 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) * exp(-(2-alpha)*E/Ep)
with alpha = 0.92 (-0.37, + 0.28) and Ep = 1403 (-594, 1273) keV
(chi^2 = 16.7/18 dof). T0(K-W) = 61063.000 s UT (16:57:43.000).
We note that the X-ray source 1RXS J140902.5-050430, and nearby galaxies
LEDA 1048719 and LEDA 1047950 are within this error box close to the
center.