[vsnet-grb-info 4862] GRB 070626: IPN localization and Konus spectrum of a bright long

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6592
SUBJECT: GRB 070626: IPN localization and Konus spectrum of a bright long
DATE:    07/07/03 16:07:58 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
and T. Cline on behalf of the Konus-Wind team,

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

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

A very long, bright GRB triggered Konus-Wind at 2007-06-26
T0=14850.883 s UT (04:07:30.883). It was also observed by Suzaku-WAM, 
RHESSI and the MESSENGER neutron spectrometer, which also serves as a 
GRB detector.

The burst started at T-T0 ~-120 s and ended at T-T0 ~210 sec.
The Earth-crossing time of the onset was 14733 s UT (04:05:33).
The burst light curve shows several multipeaked pulses.

We have triangulated it to a 3 sigma error box whose coordinates are:

-----------------------------------------------
    RA(2000)                    Dec(2000)
-----------------------------------------------
Center:
  141.355 (09h 25m 25s)   -39.865 (-39d 51' 54")
Corners:
  139.529 (09h 18m 07s)   -39.872 (-39d 52' 20")
  142.903 (09h 31m 37s)   -40.020 (-40d 01' 11")
  143.210 (09h 32m 50s)   -39.805 (-39d 48' 17")
  139.838 (09h 19m 21s)   -39.673 (-39d 40' 24")
-------------------------------------------------

The error box area is 2047 square arcminutes.
The box may be improved.

Preliminary analysis of the Konus-Wind data yields
a burst fluence of ~4x10^-4 erg/cm2 (in the 20 keV - 4 MeV range),
the spectrum of the main part of the burst (from T0 to T0+190 s)
can be fitted (in the 20 keV - 4 MeV range)
by GRBM (Band) model for which:
the low-energy photon index is alpha = -1.5,
the high energy photon index beta = -2.3,
the peak energy Ep = 240 keV.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB070626_T14850/

Detailed spectral parameters will be reported later.