GCN Circular 6152
Subject
GRB 070224: Swift/UVOT Upper Limits
Date
2007-02-26T20:25:11Z (17 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
S. T. Holland (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),
M. M. Chester (PSU) and J. L. Racusin (PSU) report on the behalf of
the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 070224 starting 132 s
after the BAT trigger (Racusin et al. 2007, GCN Circ. 6137). We do
not find any source, in any of the UVOT observations, inside the
astrometrically corrected XRT error circle (Racusin et al., 2007 GCN
Circ. 6151).
The 3-sigma upper limits for detecting a source anywhere inside
the XRT error circle in the finding chart images, and the co-added
exposures are:
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------------
White Finding 156 254 96 20.4
V Finding 259 659 393 20.1
V 259 1367 806 20.5
B 737 747 10 18.6
U 713 733 19 18.7
UVW1 689 5512 132 20.0
UVM2 665 833 39 18.3
UVW2 766 785 19 18.2
White 154 962 206 20.9
V 35,712 126,303 1553 20.9
B 7159 128,636 1987 22.0
U 6954 93,932 1952 21.7
UVW1 6750 145,987 4321 22.2
UVM2 12,574 143,883 4621 22.4
UVW2 29,833 122,852 4358 22.6
-------------------------------------------------------------
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.06 mag towards
the direction of the burst (Schlegel et al. 1998).