GCN Circular 6597
Subject
Swift/UVOT Observations of GRB070704
Date
2007-07-05T10:16:46Z (17 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P. Schady (MSSL-UCL) and T. Sakamoto (NASA/ORAU) report on the behalf of the
Swift UVOT team:
The Swift/UVOT observed the field of GRB 070704 starting 142 s after the
BAT trigger (Sakamoto et al. 2007, GCN Circ. 6594). We do not find any
source, in any of the UVOT observations, inside the XRT error circle
(Sakamoto et al. 2007, GCN Circ. 6594).
The 3-sigma upper limits for detecting a source inside the refined XRT
error circle in the initial data products are:
Filter T_mid(s) Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------
V 654 597 19.16
B 749 10 17.56
U 729 20 17.64
UVW1 5603 439 18.91
UVM2 4431 239 19.36
UVW2 5697 220 19.27
White 574 209 19.65
-----------------------------------------------------------------
where T_mid is the weighted mid time of the coadded exposure. The values
quoted above are not corrected for the expected Galactic extinction
corresponding to a reddening of E_{B-V} = 1.81 mag in the direction of the
burst (Schlegel et al. 1998).