GRB 180718A
GCN Circular 22959
Subject
GRB 180718A short GRB detected by IPN and found in ground analysis of BAT data
Date
2018-07-18T23:38:33Z (7 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin and K. Hurley, on behalf of the IPN,
A. Y. Lien, D. Palmer, S. Barthelmy, J. Cummings,
and H. Krimm, on behalf of the Swift-BAT team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team, and
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:
The short-duration GRB 180718A was detected by
Fermi (GBM; trigger 553571869), INTEGRAL (SPI-ACS), and Swift (BAT),
at about 7065 s UT (01:57:45).
We have triangulated this GRB to a GBM-INTEGRAL annulus centered at
RA(2000)=260.736 deg (17h22m57s) Dec(2000)=+48.285 deg (+48d17'07"),
whose radius is 79.182 +/- 2.067 deg (3 sigma).
From the ground analysis using the available Swift/BAT event data
from T-1 to T+2 sec, we found a 6.3 sigma detection in an image with
intervals from T0-0.026 s to T0+0.165 s and energy range 15-150 keV,
where T0 = 2018-07-18 01:57:44.530 UTC.
The BAT ground-calculated position of this detection is
RA, Dec = 336.019, 2.790 deg which is
RA(J2000) = 22h 24m 04.6s
Dec(J2000) = +02d 47' 23.3"
with an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 25%.
The position is consistent with the annulus.
The BAT mask-weighted light curve shows
a single-pulse structure that starts at ~T0 and ends at ~T+0.1 s.
T90 (15-350 keV) is 0.08 +- 0.02 sec (estimated error including
systematics).
Due to the weakness of this burst, the BAT spectrum is
not well-constrained. However, the burst seems to be relatively soft
comparing to regular short GRBs.
The results of the batgrbproduct analysis are available at
https://gcn.gsfc.nasa.gov/notices_s/848489/BA/
A ToO observation with Swift/XRT has been requested.
GCN Circular 22960
Subject
GRB 180718A: Fermi GBM detection
Date
2018-07-19T03:53:43Z (7 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH), P. Veres (UAH), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 01:57:44.60 UT on 18 July 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180718A (trigger 553571869 / 180718082),
which was also detected by the INTEGRAL SPI-ACS and subsequently
localized by IPN. Ground analysis of the Swift/BAT data revealed
a detection consistent with the IPN annulus (GCN 22959).
The angle from the Fermi LAT boresight at the GBM trigger time is 61
degrees.
The GBM light curve consists of a single peak
with a duration (T90) of about 0.08 s (50-300 keV).
The time-averaged spectrum from T0-0.06 s to T0+0.02 s is
adequately fit by a Band function with Epeak = 187 +/- 61 keV,
alpha = -0.2 +/- 0.4, and beta = -2.3 +/- 0.5.
The event fluence (10-1000 keV) in this time interval is
(2.3 +/- 0.3)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.05 s in the 10-1000 keV band
is 9 +/- 1 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 22963
Subject
GRB 180718A: Swift ToO observations
Date
2018-07-19T08:58:17Z (7 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 ToO observation of the Swift/BAT GRB 180718A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020802
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. 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; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 22972
Subject
GRB 180718A: MASTER optical observation
Date
2018-07-20T13:00:27Z (7 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
D. Vlasenko, N.Tiurina, E. Gorbovskoy, V. Lipunov, V.Kornilov,
A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov,
P.Balanutsa, V.Vladimirov
Lomonosov Moscow State University,SAI
D. Buckley,
South African Astronomical Observatory (SAAO)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias (IAC)
A. Tlatov, V.Senik, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
R. Podesta, F. Podesta, C. Lopez, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)
H.Levato,
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
O. Gres, N.M.Budnev , Yu.Ishmuhametova
Irkutsk State University (ISU)
A. Gabovich, V. Yurkov, Yu. Sergienko
Blagoveschensk Educational State University (BSPU)
MASTER Global Robotic Net ( Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) inspected GRB180718A (Svinkin et al. GCN22959 ;
Fermi trigger 553571869 at 2018-07-18 01:57:44.60 UT , Hamburg et al.
GCN22960; Swift BAT position RA,Dec2000= 22h 24m 04.6s +02d 47' 23.3"
(Svinkin et al GCN22959; Evans et al. GCN22963)
MASTER-Kislovodsk robotic telescope (MASTER-Net:
http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) located in Russia (Pulkovo Solar Station) was pointed to
the GRB180718A (D. Svinkin et al., GCN Circ #22959) 60867 sec after
trigger time at 2018-07-18 18:52:12 UT . On our first (180s exposure) set
we do not found optical transients within Swift error-box (ra=336.019
dec=2.790 r=0.05) brighter then 18.5.
The observations made on zenit distance = 13.51 degrees, galaxy latitude b
= -43.86 degree.
The moon (39 % bright part) is 15 degrees above the horizon. The distance
between moon and object is 142
The sun altitude is -17.5 degree.
The errorbox observed 2 nights till 2018-07-19 22:23:00
MASTER-Tavrida robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Russia (SAI Crimea astronomical station) was pointed to the GRB180718A (D.
Svinkin et al., GCN Circ #22959) 63704 sec after trigger time at
2018-07-18 19:39:29 UT . On our first (180s exposure) set we do not
found optical transients within Swift error-box (ra=336.019 dec=2.790
r=0.05) brighter then 18.6.
The observations made on zenit distance = 15.68 degrees, galaxy latitude b
= -43.86 degree.
The moon (39 % bright part) is 13 degrees above the horizon. The distance
between moon and object is 142
The sun altitude is -18 degree.
The errorbox observed 2 nights till 2018-07-19 21:25:48
MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Spain (IAC Teide Observatory) was pointed to the GRB180718A (D. Svinkin et
al., GCN Circ #22959) 161995 sec after trigger time at 2018-07-19 22:57:40
UT . On our first (180s exposure) set we do not found optical
transients within Swift error-box (ra=336.019 dec=2.790 r=0.05) brighter
then 17.5.
The observations made on zenit distance = 18.52 degrees, galaxy latitude b
= -43.86 degree.
The moon (39 % bright part) is 25 degrees above the horizon. The distance
between moon and object is 128
The sun altitude is -11.80 degree.
The errorbox observed till 2018-07-19 23:53:58
The visibility GRB error box (coord: 336.019 2.790 error_box: 0.05)
at trigger time at different MASTER sites:
obj: 43.32 sun: -3.21 - Tavrida (Crimea, Russia)
obj: 53.60 sun: -39.34 - IAC, Teide, (Tenerife, Spain)
obj: 53.56 sun: -45.24 - SAAO (Sutherland, SA)
obj: 40.32 sun: 1.49 - Kislovodsk (Russia)
obj: 23.50 sun: 16.36 - Ural(Kourovka, Russia)
obj: 0.76 sun: 41.53 - Tunka (near Baykal Lake, Russia)
obj: -14.45 sun: 55.06 - Amur(Blagoveschensk)
obj: 6.93 sun: -51.86 - OAFA (Argentina)
The message may be cited.
GCN Circular 23030
Subject
GRB 180718A: Swift-XRT observations
Date
2018-07-24T13:37:13Z (7 years ago)
From
Boris Sbarufatti at PSU <bxs60@psu.edu>
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore
(U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J. LaPorte
(PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT
team:
Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 180718A (Svinkin et al. GCN Circ. 22959),
collecting 1.5 ks of Photon Counting (PC) mode data between T0+113.7 ks
and T0+115.2 ks.
No X-ray sources have been detected consistent with being within 296
arcsec of the Swift/BAT position. The 3-sigma upper limit in the field
ranges from ~0.005 to ~0.013 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 2.1e-13 to 5.1e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020802.
This circular is an official product of the Swift-XRT team.
GCN Circular 23216
Subject
GRB 180718A: 15 GHz upper limits from the AMI Short GRB Program
Date
2018-09-10T06:44:13Z (7 years ago)
From
Kunal Mooley at NRAO,Caltech <kmooley@caltech.edu>
J. Bright (Oxford), K. P. Mooley (NRAO, Caltech; Jansky Fellow), R. P.
Fender (Oxford)
We observed the field of short GRB 180718A (Svinkin et al., GCN 22959)
with the AMI Large Array at 15 GHz. Our observation on 2018 Jul 22.03
(UT) (3.95 d post-burst) does not reveal any potential afterglow
candidate consistent with the BAT location (Svinkin et al., GCN 22959),
and our 3sigma upper limit to the flux density is 180 uJy.
We thank the MRAO staff for scheduling these observations. Results from
the AMI Short GRB program are posted on the AMI-GRB database available
at http://4pisky.org/ami-grb/.