GCN Circular 3371
Subject
GRB 050505: Further Swift UVOT observations.
Event
Date
2005-05-06T14:17:46Z (20 years ago)
From
Simon Rosen at MSSL-UCL <srr@mssl.ucl.ac.uk>
S. Rosen (MSSL), C. Hurkett (Leicester), S. Holland (GSFC), P. Roming
(PSU), A. Blustin (MSSL), N. Gehrels (GSFC), K. Mason (MSSL), J. Nousek
(PSU), on behalf of the Swift UVOT team
Further to the initial Swift UVOT results (Rosen et. al. 3367) we report
the results of co-added, deeper exposures of GRB 050505 with the Swift
Ultra-Violet/Optical Telescope (UVOT) on May 06, 2005.
We detect no source at the Keck determined location (Cenko et al, GCN
3366) in any of the UVOT filters with the following 5 sigma and 3 sigma
limits (in 6" radius apertures)
Filter Lim_Mag Lim_mag Total duration (s) T_range (s)
5sigma 3sigma
V 19.82 20.35 2527 2807 - 28543
B 20.50 21.04 1999 3236 - 26917
U 20.26 20.84 2890 3132 - 22757
UVW1 20.81 21.36 1999 3029 - 22040
UVM2 21.13 21.68 2422 2924 - 21132
UVW2 21.27 21.83 1997 3342 - 27826
T_range is since the BAT trigger time (Hullinger et al. 3364).
The magnitudes are based on preliminary zero-points, measured in
orbit, and will require refinement with further calibration.
We note that for the estimated redshift of 4.1 - 4.3 (GCN 3368), the Lyman
limit lies between the UVOT B and V filters - the lack of a UVOT
detection in V may be significant, depending on the brightness of the
source detected by Keck and the true redshift.
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