GCN Circular 10540
Subject
SGR 1833-0832: Swift/UVOT Upper Limits
Date
2010-03-22T22:08:21Z (14 years ago)
From
Frank Marshall at GSFC <marshall@milkyway.gsfc.nasa.gov>
F.E. Marshall (NASA/GSFC) and J.M. Gelbord (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of SGR 1833-0832
71 s after the BAT trigger (Gelbord et al., GCN Circ. 10526).
No optical afterglow consistent with the XRT position
(Evans and Goad, GCN_Circ. 10529) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposures and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 71 220 147 >20.6
u_FC 283 533 246 >20.5
white 71 57748 1793 >22.3
v 612 69706 3549 >21.4
b 539 57397 3660 >21.3
u 283 75812 5479 >22.3
w1 4479 75666 6430 >21.8
m2 5710 74760 4446 >22.5
w2 5300 68903 3050 >22.3
The values quoted above are not corrected for the Galactic extinction
due to the very large reddening in the direction of the source
(Schlegel et al. 1998). The large X-ray column density to the source found
with the Swift/XRT (Gelbord and Vetere, GCN Circ. 10531) also
indicates very large optical extinction.