[vsnet-grb-info 4303] GRB 070201: clarification on localization and Konus-Wind spectra

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6094
SUBJECT: GRB 070201: clarification on localization and Konus-Wind spectra
DATE:    07/02/10 17:21:40 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 report:

The ecliptic latitudes band of GRB 070201
was given incorrectly in GCN 6088. The correct band is +30 +90 deg.
The coordinates of the portion of the Wind-INTEGRAL annulus
reported in GCN 6088 and the map posted at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB070124_T31311/
are correct
(more accurate coordinates of the intersection the
ecliptic latitude lower limit (+30) with the center of
the annulus are RA, Dec = 13.471,   +38.601 deg).

We apologize for the confusion and thank Derek Fox,
Eran Ofek, and Daniel Perley for pointing out the error.

As was noted by Perley and Bloom (GCN 5947)
the burst location area includes the M31 galaxy's outer
spiral arms.

The position of NGC 5985 galaxy suggested by Ofek (GCN 6092)
is definitely out of the burst location area.
The confusion was caused by the error in the reported ecliptic
latitude band.

Preliminary analysis shows that the burst had a
fluence of 1.57(-0.21, +0.06)x10^-5 erg/cm2,
and the 2-ms peak flux measured from T0+0.016 s
9.4(-2.9,+1.7)x10^-4  erg/cm2/s
(both in the 20 keV - 1 MeV energy range).

Assuming this burst originated from a source in M31 (D ~770 kpc),
the isotrpoic energy release would be ~1x10^45 erg,
which is between the energy release in initial pulse
of the 5th March 1979 giant flare from SGR 0526-66 (~2x10^44 erg)
and the 27th December 2004 giant flare from SGR 1806-20 (~2x10^46 erg).

The time-integrated spectrum of the burst
(from T0 to T0+0.256 s) is well fitted (in the 20 keV - 1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 0.98(-0.11, +0.10)
and Ep = 293 (-31, +38) keV (chi2 = 39/40 dof).

The spectrum of the burst maximum
(from T0 to T0+0.064 s) is well fitted (in the 20 keV - 1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 0.52(-0.15, +0.14)
and Ep = 357 (-38, +44) keV (chi2 = 39/40 dof).

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

Due to large uncertainties in the burst position
and large dead times caused by very high count rates
these values should be considered only as preliminary.