GRB 070124

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

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

V. Pal'shin, E. Mazets and S. Golenetskii, on behalf of the Konus-Wind
GRB 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, and

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

Mars Odyssey (GRS), Konus-Wind, and the Suzaku WAM observed this
burst at 31311 s.  It had a T90 of 0.8 s, a 20 keV - 3 MeV fluence
of ~5 x 10^-6 erg cm^-2, and a hard spectrum with an Epeak ~ 1 MeV.
Therefore we believe that this event falls into the short duration
class.  We have triangulated it to an 87 sq. arcmin. preliminary 
3 sigma error box whose coordinates are:

	  RA	  Dec
Center:  221.385 +54.568

Corners: 220.834 +54.187
         221.818 +54.825
         221.945 +54.947 
         220.956 +54.310

A Swift ToO observation of this error box has been scheduled.
Detailed spectral parameters are being derived and will be reported
later.

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

The short hard GRB 070124 localized by the IPN (Hurley et al.,
GCN 6022
Loading...
 
 ), triggered Konus-Wind at T0=31311.621 s UT (08:41:51.621).

As observed by Konus-Wind it had a duration of ~0.9 s,
a fluence of 5.20(-4.09, +0.71)x10^-6 erg/cm2,
and the 16-ms peak flux measured from T0+0.720 s
1.12(-0.94, +0.37)x10^-5  erg/cm2/s
(both in the 20 keV - 3 MeV energy range).
There is a hint of a weak tail seen up to several tens of seconds
after the trigger.

The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) is well fitted (in the 20 keV - 3 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)
with alpha = 0.93(-0.32, +0.24)
and Ep = 994 (-429, +1237) keV (chi2 = 59/68 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB070124_T31311/

L. Vetere, J. Racusin (PSU) report on behalf of the Swift-XRT team:

The Swift-XRT began observing the field containing the IPN burst GRB070124
(Hurley et al., GCN 6022
Loading...
 
 ) at 2007-01-25  15:36:39.8881 UT almost 31 hr after
the trigger. From the analysis of a 7.4 ks photon counting image, 6 sources
are found with the following positions and count rates:
       cts/s                  Ra          Dec
  1 1.78E-03+/-6.1E-04    14 44 50.7   +54 34 11.8
  2 1.95E-03+/-6.7E-04    14 46 15.2   +54 37 01.8
  3 1.34E-03+/-5.8E-04    14 46 18.2   +54 34 23.0
  4 1.34E-03+/-5.8E-04    14 44 53.9   +54 26 31.9
  5 1.39E-03+/-6.0E-04    14 46 18.6   +54 38 06.5
  6 1.66E-03+/-6.8E-04    14 46 07.7   +54 25 51.0

Only source number 4 is actually inside the IPN error box and it is 0.042
arcmin from a USNO-B1.0 Catalog's source. The other five can all be identified
with close galaxies. In particular source 5 is UGC9522 an edge-on Sab galaxy
with z=0.03866 that is 1.5 arcmin distant from the nearest edge of the IPN
error box.
At present we cannot tell whether these sources are fading or not. Further
observations are planned.

This circular is an official product of the Swift-XRT team.

K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Takahashi, 
T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), Y. Urata, M. Tashiro, 
K. Abe, K. Onda, Y. Sato, M. Suzuki (Saitama U.), T. Enoto, R. Miyawaki, 
K. Makishima (Univ. of Tokyo), M. Suzuki, T. Tamagawa, Y. Terada (RIKEN), 
K. Nakazawa, M. Kokubun, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), 
E. Sonoda, M. Yamauchi (Miyazaki U.), 
on behalf of the Suzaku WAM team report:

The IPN-localized short GRB 070124 (Hurley et al., GCN 6022
Loading...
 
 ) triggered 
the Suzaku Wide-band All-sky Monitor (WAM), which covers the energy range 
of 50 keV - 5 MeV, at 08:41:51.035 UT(=T0). 
The light curve shows two separate pulses with a total duration of 
about 0.8 seconds. The fluence in 100 - 2000 keV was 
3.1(-1.3, +0.4) x 10^-6 erg/cm2, while the 1-s peak flux measured from 
T0 was 3.4(-0.8, +0.3) photons/cm2/s in the same energy range.

The time-averaged spectrum from T0 sec to T0+2 sec is well fitted
by a cutoff power law model. 

  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak)
  alpha       -0.19 (-0.81 +0.64), and
  Epeak         686 (-117, +197) keV.

All the quoted errors are at statistical 90% confidence level, while
systematic errors are not included. 

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

L. Vetere, J. Racusin, C. Pagani, D.N. Burrows (PSU) report on behalf
of the Swift-XRT team:

The entire IPN error box for GRB 070124 (Hurley et al., GCN 6022
Loading...
 
 ) has
been observed by XRT in three different pointings (target id. 20046,
20048, 20049 for the central, upper and lower part, respectively) with
different exposure times:

 target id           Tstart                     Tend             expo
   20046     2007-01-25  15:36:39.9    2007-01-31  22:55:58.2   22.5ks
   20048     2007-01-31  00:26:23.5    2007-01-31  23:03:57.7    6.1ks
   20049     2007-01-31  00:34:25.5    2007-01-31  23:12:56.4    6.5ks

Only four sources are detected inside the IPN error box with the following
positions (uncertainty of 5 arcsec, radius, 90% containment, including
systematic uncertainty) and count rates:

    Ra(J2000)    Dec(J2000)       count/s         target id
   14 45 03.4   +54 27 56.4   (1.2 +/- 0.3)E-03     20046
   14 46 09.9   +54 38 58.2   (6.9 +/- 2.6)E-04     20046
   14 44 53.2   +54 26 30.5   (1.8 +/- 0.4)E-03     20046
   14 44 53.9   +54 26 37.2   (1.8 +/- 0.8)E-03     20048

None of these sources shows a fading behaviour, we thus conclude that
XRT did not detect the X-ray afterglow of GRB 070124.

This circular is an official product of the Swift-XRT team.