[vsnet-grb-info 4688] GRB 070520A: Swift UVOT Upper Limits
GCN Circulars
gcncirc at capella.gsfc.nasa.gov
Mon May 21 22:26:59 JST 2007
TITLE: GCN CIRCULAR
NUMBER: 6439
SUBJECT: GRB 070520A: Swift UVOT Upper Limits
DATE: 07/05/21 13:26:54 GMT
FROM: Stefan Immler at NASA/GSFC <immler at milkyway.gsfc.nasa.gov>
S. Immler (USRA/GSFC) and P. Romano (Univ. Bicocca & INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 070525A starting 152 s after
the BAT trigger (Romano et al., GCN 6423). We do not find any source
in any of the UVOT observations inside the XRT error circle. The 3-sigma
upper limits for detecting a source inside the XRT error circle in the
co-added frames are:
Filter T_start(s) T_stop(s) Exp(s) Mag (3-sigma UL)
White 168 4793 345 >20.2
V 152 11162 1288 >19.6
B 4389 6021 393 >20.0
U 4184 16822 1142 >20.3
UVW1 3979 16047 1279 >20.1
UWM2 3774 11805 1021 >20.4
UVW2 4799 10249 1082 >20.5
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V) = 0.02 mag towards
the direction of the burst (Schlegel et al. 1998).
More information about the vsnet-grb-info
mailing list