GCN Circular 11019
Subject
GRB 100727A: Swift/UVOT Upper Limits
Date
2010-07-28T16:14:12Z (14 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <Stephen.T.Holland@nasa.gov>
S. T. Holland (CRESST/GSFC/USRA) and
D. C. Morris (GWU/GSFC)
report on the behalf of the Swift UVOT team:
The Swift/UVOT observed the field of GRB 100727A starting 47 s
after the BAT trigger (Morris, et al., 2010, GCN Circ. 10998).
Settled observations started at 65 s. We do not find any new source,
relative to the DSS, USNO-B1.0, or 2MASS at the position of the XRT
afterglow (Osborne, et al. 2010, GCN Circ. 11000). Preliminary
3-sigma upper limits for detecting a source in the finding charts, and
in the co-added images, using a 2.5 arcsecond radius circular
aperture, are
Filter T_start T_stop Exp(s) Mag
------------------------------------------------
white (fc) 65 215 147 >20.8
856 1006 147 >21.2
u (fc) 278 527 246 >20.5
v 609 18,409 1414 >20.9
b 533 24,918 1215 >21.7
u 278 24,189 2335 >21.7
uvw1 658 29,885 2289 >21.9
uvm2 633 28,542 2390 >21.8
uvw2 584 17,496 1415 >21.8
white 65 7075 805 >22.1
------------------------------------------------
The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.05 mag (Schlegel, et al., 1998, ApJS, 500,
525). All photometry is on the UVOT photometry system described in
Poole et al. (2008, MNRAS, 383, 627).