[vsnet-grb-info 12979] Swift XRT observations of GRB 130310A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14316
SUBJECT: Swift XRT observations of GRB 130310A
DATE:    13/03/15 22:03:36 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti at brera.inaf.it>

B. Sbarufatti (INAF-OAB/PSU), D. N. Burrows (PSU), P. E. Evans (U
Leicester) report on behalf of the Swift XRT team:

Swift performed a total of 7 pointings for this burst on March 11th: 4x1ks
covering the Fermi LAT error circle (Guiriec et al., GCN #1482) and 3x1.5
ks covering the IPN error box (Golenetskii et al., GCN #14284). We detect
a total of 5 sources:

#  RA          DEC          Err     counts  rate(counts/ks)
1  09 28 45.9  -17 18 49.5  7.4"    9	    11  (+11/-7)
2  09 29 27.0  -17 30 13.8  6.8"    12	    13  (+14/-8)
3  09 28 59.0  -17 00 40.8  5.4"    8	    9   (+10/-7)
4  09 27 58.9  -17 12 57.9  8.6"    10	    11  (+12/-7)
5  09 27 31.7  -17 08 55.3  11.0"   5	    4.7 (+6/-4)

The fluxes are computed at the 99% confidence level, following Kraft,
Burrows & Nousek (1991). The background level was computed both generally,
using the 'background' task of XIMAGE on each pointing, and locally, using
the 'sosta' task of XIMAGE, and selecting the highest value.
All sources are inside the LAT error circle, but only source #5 is inside
the IPN error box.

Swift performed another observation in the direction of source #5 on March
13th, with a 3.4 ks exposure. The 99% confidence level upper limit at the
position of source #5 is 4.6E-3 counts/s, which does not give strong
evidence for fading.

No further observations are planned.

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