[vsnet-grb-info 15314] GRB 140719A: Swift detection of a burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16606
SUBJECT: GRB 140719A: Swift detection of a burst
DATE:    14/07/19 06:14:30 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1 at star.le.ac.uk>

R. L. C. Starling (U Leicester), C. J. Mountford (U Leicester),
K. L. Page (U Leicester) and T. Sakamoto (AGU) report on behalf of the
Swift Team:

At 05:53:55.2 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140719A (trigger=605612).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 171.592, -50.135 which is 
   RA(J2000) = 11h 26m 22s
   Dec(J2000) = -50d 08' 03"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple 
structure with a duration of about 15 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 05:55:14.4 UT, 79.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 171.6008, -50.1350
which is equivalent to:
   RA(J2000)  = 11h 26m 24.20s
   Dec(J2000) = -50d 08' 06.1"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 20 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.63 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 1.1
(+1.09/-0.78) x 10^22 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 83 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. Data from the 2.7'x2.7' sub-image are
not available at this time. 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 0.14. 

Burst Advocate for this burst is R. L. C. Starling (rlcs1 AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)