GRB 060429

K. Hurley and T. Cline, on behalf of the Ulysses, Mars Odyssey,
and Konus GRB teams,

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, and D. Frederiks
on behalf of the Konus-Wind team,

I. Mitrofanov, A. Kozyrev, M. Litvak, A. Sanin, V. Tret'yakov and
A. Parshukov, on behalf of the HEND-Odyssey GRB team,

W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on
behalf of the GRS-Odyssey GRB team,

A. von Kienlin, G. Lichti, A. Rau, D. Gotz, and S. Mereghetti,
on behalf of the INTEGRAL GRB team,  report:

A ~0.25 s long, hard spectrum GRB, 060429, occurred around 44391 s
UT.  It was observed by Konus-Wind, Mars Odyssey, and
INTEGRAL-SPI-ACS.  Ulysses was off.

The burst has been triangulated to RA, Dec = 115.488, -24.959 deg (J2000).
The corners of the 3 sigma error box are:
-----------------------
RA, deg   Dec, deg
-----------------------
115.679 -25.067
115.891 -24.675
115.083 -25.240
115.297 -24.852
--------------------

This error box may be improved.

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, and D. Frederiks
  on behalf of the Konus-Wind team,

  K.Yamaoka, M.Ohno, Y.Fukazawa, T.Takahashi, M.Tashiro, Y. Terada,
  T.Murakami, and K.Makishima on behalf of the Suzaku-WAM team,

  K. Hurley and T. Cline, on behalf of the Ulysses, Mars Odyssey,
  and Konus GRB teams,

  I. Mitrofanov, A. Kozyrev, M. Litvak, A. Sanin, V. Tret'yakov and
  A. Parshukov, on behalf of the HEND-Odyssey GRB team,

  W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on
  behalf of the GRS-Odyssey GRB team,

  D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger,
  W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,

  A. von Kienlin, G. Lichti, A. Rau, D. Gotz, and S. Mereghetti,
  on behalf of the INTEGRAL GRB team,  report:

  The short hard GRB 060429 (Hurley et al., GCN 5039
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 ) was also
  detected by Suzaku-WAM and RHESSI, resulting in a smaller error box.


  The refined 3 sigma error box is:
  -----------------------
  RA, deg   Dec, deg (J2000)
  -----------------------
  Center:
    115.5126  -24.9525

  Corners:
    115.2478 -25.1930
    115.4979 -25.1205
    115.7763 -24.7102
    115.5271 -24.7844
  --------------------

  The error box area is 267 sq. arcmin.

  This error box may be improved.

  As observed by Konus-Wind this burst had fluence
  6.29(-2.69,+0.64)x10^-6 erg/cm2,
  and the 16-ms peak flux measured from T0+0.012 s
  1.07(-0.47,+0.16)x10^-4  erg/cm2/s
  (both in the 20 keV - 5 MeV energy range).

  The spectrum integrated over the most intense part
  of the burst (from T0 to T0+0.064 s) is well
  fitted (in the 20 keV - 5 MeV range)
  by a power law with exponential cutoff model:
  dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
  with alpha = 0.638 (-0.162, +0.141)
  and Ep = 1558 (-320, +416) keV (chi2 = 18.5/26 dof).
  The Konus-Wind trigger time T0=44389.712 s UT (12:19:49.712).

  All the quoted errors are at the 90% confidence level.

M. Ohno, T. Takahashi, Y. Fukazawa (Hiroshima U.), 
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), 
Y. Terada, T. Tamagawa (RIKEN), S. Hong (Nihon U.), 
K. Abe, Y. Endo, K. Onda, M. Tashiro (Saitama U.), 
G. Sato, K. Nakazawa, T. Takahashi (ISAS/JAXA), 
R. Miyawaki, M. Kokubun, K. Makishima (Univ. of Tokyo) 
and the HXD-II team report: 

The short hard burst, GRB 060429 (Hurley et al., GCN 5039
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 ,  
Golenetskii et al., GCN 5067
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 ), triggered the Suzaku 
Wide-band All-sky Monitor (WAM) which is sensitive to an 
energy band of 50 keV - 5 MeV at 12:19:51 (UT). 
The observed light curve shows a single-peak structure
with a duration (T90) of 0.11 seconds. 
The fluence in 100 - 1000 keV was 1.97 +- 0.17 X10^-6 erg/cm2. 
The 1-sec peak flux was 3.2 +- 0.3 photons/cm2/sec 
in the same energy range.

Preliminary result shows that the time-averaged spectrum 
is well fitted by a single power law with a photon index 
of 1.07 +- 0.13.

All the quoted errors are at statistical 90% confidence level.
The WAM in-flight calibration is still under way, and systematic 
errors, such as the flux calibration uncertainties of about 20%, 
are not included in the errors.

The WAM light curve of this event is available at 
http://www.astro.isas.ac.jp/suzaku/research/HXD-WAM/WAM-GRB/grb/grb_table.html

Further detailed analysis and the refinement are in progress.