GRB 140723A
GCN Circular 16631
Subject
GRB 140723A: Swift-XRT and UVOT observations
Date
2014-07-25T13:23:29Z (11 years ago)
From
Valerio D'Elia at ASDC <delia@asdc.asi.it>
V. D'Elia (ASDC), L. Izzo (URoma/ICRA), A. Breeveld (UCL-MSSL), P.
Evans (U. Leicester) report on behalf of the Swift team:
Swift began observing the field of GRB 140723A on 2014-07-23 at 15:20
UT, 49 ks after the LAT trigger (Bissaldi et al., GCN Circ. 16623). A
tiled observation of four contiguous fields centered on the LAT >
coordinates has been secured. The total integration time is 3 ks, >
i.e., about 750 s per field. Our mosaic covers more than 90% of the
LAT error circle (Bissaldi et al., GCN Circ. 16623), but less than 10%
of the observed area lies within the IPN error localization, published
after our observation began (Hurley et al., GCN Circ. 16625).
In the XRT exposure, we do not find any new source, down to a three
sigma upper limit of 1.4E-02 cts/s. In the UVOT u-band data we do not
find any new source down to a three sigma upper limit of about 20.2 mag.
This circular is an official product of the Swift team.
GCN Circular 16630
Subject
GRB 140723A: LCO-Sutherland optical candidate retraction
Date
2014-07-24T13:53:49Z (11 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi, S. Dichiara (U. Ferrara), C.G. Mundell (LJMU)
on behalf of a large collaboration report:
From the analysis of the finally reduced frames we retract the
uncatalogued source reported in our previous message
(GCN Circ. 16627) as the possible optical afterglow candidate
to GRB 140723A. The source turned out to be not real.
We apologise for the confusion.
GCN Circular 16629
Subject
GRB 140723A: MASTER optical observation
Date
2014-07-24T13:49:03Z (11 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, D.Denisenko, V. Lipunov, M.Pruzhinskaya, V.Kornilov,
D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov,
A.Kuznetsov, V.V.Chazov, A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinsky, I.Zalozhnih, A. Popov
Ural Federal University, Yekaterinburg, Kourovka
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Tunka was pointed to the GRB 140723A (Fermi trigger 427772193)
48377 s (~13.4 h) after trigger time at 2014-07-23 15:02:47 UT directly
after sunset. Observations were made at high zenith distance (z ~ 76d)
with the error box setting to the horizon. Therefore we have only two
(180s exposure) successful images.
On our images we have not found optical transient within Fermi-LAT
error-box (Bissaldi et al. GCN 16623, Burns et. al GCN 16626) and IPN
(Hurley et al. GCN 16625, Golenetskii et. al GCN 16628) brighter than
18.3 mag. Thus we can not confirm the LCO-Sutherland OT (Guidorzi et al.
GCN 16627) despite ~2 hours earlier time of observations and our upper
limit being 1 magnitude deeper than the estimated object magnitude.
The 6x6 acrminutes MASTER-Tunka image around probable OT position (Guidorzi et
al. GCN 16627) is available here:
http://master.sai.msu.ru/static/GRB/GRB140723_LAT.png
Our white (clear) band is well described by a parity 0.8R+0.2B (USNO B1).
The message may be cited.
GCN Circular 16628
Subject
Konus-Wind observation of GRB 140723A
Date
2014-07-24T11:27:45Z (11 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, hard-spectrum GRB 140723A
(Fermi-LAT detection: Bissaldi et al., GCN 16623;
IPN triangulation: Hurley et al., GCN 16625;
Fermi-BBM detection: Burns, GCN 16626)
triggered Konus-Wind at T0=5790.357 s UT (01:36:30.357).
The light curve shows a single FRED-like pulse
with a total duration of ~45 s.
The emission is seen up to 10 MeV.
As observed by Konus-Wind, the burst had a fluence
of 2.3(-0.5,+0.8)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0-0.064 s, of 5.8(-1.6,+1.9)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.10(-0.20,+0.26),
and the peak energy Ep = 1142(-452,+1005) keV,
chi2 = 71/98 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep with an upper limit on beta of -1.9
The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.03(-0.21,+0.26),
and the peak energy Ep = 931(-287,+528) keV,
chi2 = 97/98 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140723_T05790/
All the quoted errors are at the 90% sigma confidence level.
All the quoted values are preliminary.
GCN Circular 16627
Subject
GRB 140723A: LCO-Sutherland optical candidate
Date
2014-07-23T22:44:56Z (11 years ago)
From
Simone Dichiara at Ferrara U/Italy <dichiara@fe.infn.it>
C. Guidorzi, S. Dichiara (U. Ferrara), C.G. Mundell (LJMU)
on behalf of a large collaboration report:
We observed Fermi GRB 140723A (Bissaldi et al. GCN Circ 16623;
Burns et al. GCN Circ. 16626) with one of the Las Cumbres
Observatory 1-m telescopes in Sutherland (South Africa) on
July 23 at 16:51:02 UT, i.e. ~15.2 hours after the GBM trigger,
with the r' and i' filters.
From initial quick-look images, we identify an possible
uncatalogued object within the LAT error circle at the
following position:
RA(J2000) = 14:02:30.25
Dec(J2000)= -03:40:21.0
with an uncertainty of 2" and R~17 mag, calibrated against
nearby USNOB1 stars.
GCN Circular 16626
Subject
GRB 140723A: Fermi GBM detection
Date
2014-07-23T18:47:59Z (11 years ago)
From
Eric Burns at U of Alabama <EricKayserBurns@gmail.com>
E. Burns (UAH) reports on behalf of the Fermi GBM Team:
"At 01:36:30.73 UT on 23 July 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140723A (trigger 427772193 / 140723067).
It was also detected by Fermi LAT (Bissaldi et al. 2014, GCN 16623).
The GBM on-ground location is consistent with the LAT position.
The GBM light curve consists of a single pulse with a duration (T90)
of about 56 s (50-300 keV). The time-averaged spectrum from T0+0.002 s
to T0+56.801 s is well fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.1 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 968 +/- 231 keV.
The event fluence (10-1000 keV) in this time interval is
(1.46 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.000 s in the 10-1000 keV band
is 4.8 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 16625
Subject
IPN Triangulation of GRB 140723A
Date
2014-07-23T18:20:26Z (11 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and
T. Cline on behalf of the Konus-Wind team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C.
Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and
V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein,
on behalf of the Fermi GBM team, report:
The long-duration GRB 140723A (Bissaldi et al., GCN Circ. 16623) has
been observed by Konus-Wind, Fermi(GBM trigger 427772193), MESSENGER
(GRNS), and INTEGRAL (SPI-ACS), so far, at about 5791 s UT (01:36:31).
We have triangulated it to a GBM-MESSENGER annulus centered at
RA(2000)=284.016 deg (18h 56m 04s) Dec(2000)=-22.344 deg (-22d 20' 38"),
whose radius is 72.790 + / - 0.166 deg (3 sigma).
The LAT error circle (that is RA, Dec, RErr = 210.63, -3.73, 0.35),
whose area is 0.4 sq. deg, is mainly outside the annulus. The distance
between the annulus center line and the center of the LAT position is
0.43 deg.
This localization may be improved.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB140723_T05790/IPN/
GCN Circular 16624
Subject
GRB 140723A Tiled Swift observations
Date
2014-07-23T15:21:07Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 140723A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00027
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; and 2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular 16623
Subject
GRB 140723A: Fermi-LAT detection
Date
2014-07-23T14:19:02Z (11 years ago)
From
Elisabetta Bissaldi at U.Innsbruk/IAPP <Elisabetta.Bissaldi@uibk.ac.at>
E. Bissaldi (University & INFN Trieste), R. Desiante (Udine
University & INFN Trieste), M. Axelsson (Stockholm University),
D. Kocevski (NASA/GSFC) and F. Piron (LUPM)
report on behalf of the Fermi-LAT team:
At UT 01:36:30.73 on July 23rd, 2014, Fermi-LAT detected
high-energy emission from GRB 140723A, which was also
detected by Fermi-GBM (trigger427772193 / 140723067).
The best LAT on-ground location is found to be
(RA, Dec) = 210.63, -3.73 (deg, J2000)
with an approximate error radius of 0.35 deg (90% containment,
statistical error only). This was 55 deg from the LAT
boresight at the time of the trigger.
An image with the 68% and 90% containment regions
have been posted at:
http://slac.stanford.edu/~bissaldi/GRB140723A_LAT_tsmap.png
The data from the Fermi-LAT show a significant increase
in the event rate that is spatially and temporally
correlated with the GBM emission with high significance.
More than 170 photons above 100 MeV and 3 photons
above 1 GeV are observed within 1200 s, before the spacecraft
entered the SAA. The source entered the FoV again around 5800 s
after the trigger. The highest-energy photon is a
1.8 GeV event, which is observed 163 s after the GBM trigger.
A Swift ToO has been requested for this burst.
The Fermi-LAT point of contact for this burst
is Elisabetta Bissaldi (Elisabetta.Bissaldi@ts.infn.it).
The Fermi-LAT is a pair conversion telescope designed to
cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.