GRB 070520
GCN Circular 6423
Subject
GRB 070520: Swift detection of a burst
Date
2007-05-20T13:21:43Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
P. Romano (Univ. Bicocca & INAF-OAB), S. D. Barthelmy (GSFC),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC), C. Gronwall (PSU),
C. Guidorzi (Univ Bicocca&INAF-OAB), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), C. Pagani (PSU), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and
S. D. Vergani (DIAS-DCU) report on behalf of the Swift Team:
At 13:05:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070520 (trigger=279817). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 193.316, +74.993 which is
RA(J2000) = 12h 53m 16s
Dec(J2000) = +74d 59' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). This is an 88-sec image trigger, and as such
the TDRSS lightcurve does not show anything significant above background,
as is typical for image triggers.
The XRT began observing the field at 13:07:48 UT, 159 seconds after the
BAT trigger. XRT found a X-ray source
located at RA, Dec 193.3636, +74.9909 which is
RA(J2000) = 12h 53m 27.2s
Dec(J2000) = 74d 59' 27.2"
with an uncertainty of 5.4 arcseconds (radius, 90% containment).
This location is 45 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 1.1e-09 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 77 seconds with the White (160-650 nm)
filter starting 168 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The 3-sigma upper limit is 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT 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 6424
Subject
GRB 070520: Xinglong EST optical Upper Limit
Date
2007-05-20T15:06:24Z (18 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,
Y. Urata, and W.K. Zheng on behalf of EAFON report:
We have imaged the field of GRB 070520 (P. Romano et al., GCN 6423)
with the EST 1m telescope at Xinglong Observatory?
Observation started from 13:14:54 UT, 579s after the burst
with R band filter,
we derieved 3 sigam limit is ~20.6 in our 20*60s co-added images
withmean time ~20minutes.
This message may be cited.
GCN Circular 6484
Subject
GRB070520: optical observation
Date
2007-06-02T16:32:32Z (18 years ago)
From
Vasilij Rumjantsev at CrAO <rum@crao.crimea.ua>
V. Rumyantsev, D. Shakhovskoy (CrAO), V. Biryukov (CrAO, SAI MSU),
A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed error box of GRB070520 (Romano et al., GCN 6423) with AZT-11
(1.25m) and 1-m Zeiss (Simeiz) telescopes of CrAO in R-band on May 20 bet=
ween
(UT)19:50 and 22:00. No object is found in a refined XRT error box (Romano
et al., GCN 6427). Limiting magnitude of combined images is based on USNO
A2.0:
Mid time (UT), Exposure, R_Lim (3sigma), Telescope, Seeing
May 20.896 6x300 21.6 AZT-11 3.6"
May 20.835 53x60 22.4 1-m Zeiss 1.5"
The combined image of 1-m Zeiss telescope can be found in
http://grb.rssi.ru/GRB070520/GRB050720_z1000_Simeiz.gif
This message may be cited.
[GCN OPS NOTE(02jun07): The binary attachment was removed as well as the
diagnostics from MIMEDefang reacting to that binary.]