GCN Circular 6573
Subject
GRB 070621: Swift/UVOT Upper Limits
Date
2007-06-22T17:22:32Z (17 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <sholland@milkyway.gsfc.nasa.gov>
S. T. Holland (CRESST/GSFC/USRA) and B. Sbarufatti (INAF-IASFPA)
report on the behalf of the Swift UVOT team:
The Swift/UVOT observed the field of GRB 070621 starting 120 s
after the BAT trigger (Sbarufatti, et al. 2007, GCN Circ. 6560). We
do not find any source, in any of the UVOT observations, inside the
refined XRT error circle (Sbarufatti, et al., 2007 GCN Circ. 6567), or
at the location of the NOT source (Malesani, et al. 2007, GCN
Circ. 6565).
The 3-sigma upper limits for detecting a source inside the
refined XRT error circle in the initial data products are:
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-----------------------------------------------------------------
V 226 1360 806 20.2
B 702 714 10 18.6
U 680 4799 88 19.7
UVW1 656 4744 236 20.3
UVM2 631 802 38 18.8
UVW2 733 752 19 18.1
White 120 954 204 21.3
-----------------------------------------------------------------
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.05 mag in the
direction of the burst (Schlegel et al. 1998).