GRB 061214
GCN Circular 5918
Subject
GRB 061214(?): Swift detection of a possible burst
Date
2006-12-14T12:39:01Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. B. Pandey (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
M. M. Chester (PSU), P. A. Evans (U Leicester),
O. Godet (U Leicester), C. Guidorzi (Univ Bicocca&INAF-OAB),
V. Mangano (INAF-IASFPA), F. E. Marshall (NASA/GSFC),
T. Mineo (INAF-IASFPA), S. R. Oates (UCL-MSSL), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC),
P. Romano (Univ. Bicocca & INAF-OAB), P. Schady (MSSL-UCL),
R. L. C. Starling (U Leicester) and E. Troja (INAF-IASFPA) report on
behalf of the Swift Team:
At 12:16:53 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 061214 (trigger=250908). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 7.777, -29.640 which is
RA(J2000) = 00h 31m 06s
Dec(J2000) = -29d 38' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). Given that this is a 4-msec trigger in the high
energy band makes this likely that this trigger is a cosmic ray shower.
The BAT light curve shows nothing significant, which is also consistant
with a cosmic ray shower. The peak count rate was ~1000 counts/sec
(15-350 keV), at ~0 sec after the trigger. Prior to receiving the full
data set in the next downlink, it seems equally likely at this point
that this is cosmic ray shower or a GRB.
The XRT began taking data at 12:18:15 UT, 82 seconds after the BAT
trigger. The XRT on-board centroid algorithm did not find a source in
the image and no prompt position is available. Analysis of promptly
downlinked photon counting data reveals no source in a 163 s exposure.
UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 87 seconds after the BAT trigger. No
afterglow candidate has been found in the initial data products. The
2.7'x2.7' sub-image covers 25% of the BAT error circle. The 3-sigma
upper limit is 19.9 mag. The 8'x8' region for the list of sources
generated on-board covers 100% of the BAT error circle. The list of
sources is typically complete to about 18 mag. No correction has been
made for the expected extinction corresponding to E(B-V) of 0.02.
GCN Circular 5919
Subject
GRB 061214(?): ROTSE-III Optical Limits
Date
2006-12-14T13:07:05Z (18 years ago)
From
Fang Yuan at ROTSE <yuanfang@umich.edu>
F. Yuan (U Mich), B. E. Schaefer (Louisiana State), T. Guver (U
Istanbul), D.A. Smith (Guilford) report on behalf of the ROTSE
collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to the possible burst GRB 061214 (Swift trigger 250908), producing
images beginning 7.0 s after the GCN notice time. An automated response
took the first image at 12:17:12.1 UT, 18.7 s after the burst, under
fair conditions. We took 10 5-sec, 10 20-sec and 20 60-sec exposures.
These unfiltered images are calibrated relative to USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma error circle, for both single images and coadding into sets of
10. Individual images have limiting magnitudes ranging from 14.9-16.8;
we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
12:17:12.1 12:19:32.0 139 17.1 18.7 Y
12:19:40.7 12:24:31.2 290 17.5 167.3 Y