GCN Circular 7000
Subject
Swift UVOT upper limits
Date
2007-10-25T19:00:39Z (19 years ago)
From
Paul Kuin at MSSL <npkuin@googlemail.com>
N.P.M. Kuin (MSSL/UCL) and C. Pagani (PSU) report on behalf of the
Swift UVOT team:
The Swift/UVOT observed the field of GRB 071025 (found with Swift
BAT, as reported in GCN 6986 of Pagani et al.) beginning 2007-10-25
04:11:11 UT, 137 seconds after the burst trigger time. After a 10 s
settling image in V, a 98 s finding chart exposure in the white filter
was taken, followed by observations in all filters.
No new source was found in any of the UVOT observations inside
the reported position of the Swift XRT error circle (Pagani et al,
GCN 6990, 6998) or the position of the detection of a transient
source in the red bands of which the most accurate was the PARITEL
observation in the J band (J. Bloom, GCN 6989), consistent with
the refined XRT position. We report upper limits at position
RA=23:40:17.078, DEC=+31:46:42.87 (J2000).
The 3-sigma upper limits for detecting a source at the reported position
in the co-added frames as determined are:
Filter Tstart Tstop Exp Magnitude
(s) (s) (s) (3-sigma UL)
White 155 16016 1377 22.82
v 137 17760 1319 21.22
b 3968 11968 1194 22.14
u 3760 23536 2085 22.13
uvw1 3552 22704 2164 22.05
uvm2 4784 21808 1082 21.43
uvw2 4368 16928 1279 21.89
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.074 mag in the
direction of the burst (Schlegel et al. 1998).