GRB 170714A
GCN Circular 21340
Subject
GRB 170714A: Swift detection of a burst
Date
2017-07-14T12:52:55Z (8 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
A. D'Ai (INAF-IASFPA), D. N. Burrows (PSU), A. Cholden-Brown (PSU),
V. D'Elia (ASDC), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 12:25:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170714A (trigger=762535). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 34.321, +1.987 which is
RA(J2000) = 02h 17m 17s
Dec(J2000) = +01d 59' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). As is usual with an image trigger, the available
BAT light curve shows no significant structure.
The XRT began observing the field at 12:32:05.3 UT, 392.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 34.3498, 1.9901 which is equivalent to:
RA(J2000) = +02h 17m 23.95s
Dec(J2000) = +01d 59' 24.4"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 104 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the U filter starting
869 seconds after the BAT trigger. No credible 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 typical 3-sigma upper limit has been about 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03.
Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.it).
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.)
GCN Circular 21341
Subject
GRB 170714A: Enhanced Swift-XRT position
Date
2017-07-14T15:23:59Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 641 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 170714A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 34.34983, +1.99204 which is equivalent
to:
RA (J2000): 02h 17m 23.96s
Dec (J2000): +01d 59' 31.3"
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 21343
Subject
GRB 170714A: Swift-XRT refined Analysis
Date
2017-07-15T01:16:20Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. Cholden-Brown (PSU), S. J.
LaPorte (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), P.A.
Evans (U. Leicester), S.L. Gibson (U. Leicester) and A. D'Ai report on
behalf of the Swift-XRT team:
We have analysed 8.8 ks of XRT data for GRB 170714A (D'Ai et al. GCN
Circ. 21340), from 383 s to 22.6 ks after the BAT trigger. The data
comprise 1.3 ks in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 21341). The late-time light curve (from T0+5.0 ks) is
consistent with a constant source of mean count rate 1.4e+01 ct/sec. A
power-law fit gives an index of 1.7 (+1.8, -2.8).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.588 (+/-0.018). The
best-fitting absorption column is 9.3 (+/-0.6) x 10^20 cm^-2, in
excess of the Galactic value of 3.6 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.73 (+/-0.05) and a
best-fitting absorption column of 9.0 (+/-1.5) x 10^20 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.9 x 10^-11 (4.4 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 9.0 (+/-1.5) x 10^20 cm^-2
Galactic foreground: 3.6 x 10^20 cm^-2
Excess significance: 6.1 sigma
Photon index: 1.73 (+/-0.05)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00762535.
This circular is an official product of the Swift-XRT team.
GCN Circular 21345
Subject
GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
Date
2017-07-15T03:48:00Z (8 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann, A. de Ugarte Postigo, L. Izzo, and C. C. Thoene
(HETH/IAA-CSIC) report:
GRB 170714A (D'Ai et al. GCN #21340) exhibits very variable behavior in
its X-ray light curve beyond what is reported by D'Avanzo et al. (GCN
#21343). We especially point out a very rapid decay at ~ 18ks, from ~5
ct/s to 0.01 ct/s in about 1.3 ks. Even after this steep decay, which is a
typical sign of central-engine turn-off, the XRT light curve shows flaring
activity of a factor of ~5. All this activity is usually the sign of an
active central engine.
This highly variable behavior is reminiscent of two types of sources:
Ultra-long GRBs like GRBs 101225A, 111209A and 130925A (e.g., Thoene et
al., Nature, 480, 72; Gendre et al., ApJ, 766, 30; Levan et al., ApJ, 781,
13; Greiner et al., A&A, 568, A75; Kann et al., A&A, submitted,
arXiv:1706.00601) or relativistic tidal disruption events such as Sw J1644
(e.g., Levan et al., Science, 333, 199).
So far no optical source has been reported, and the X-ray afterglow shows
signs of additional absorption (D'Avanzo et al., GCN #21343), which may be
indicative of a reddened source in the center of its host and therefore a
RTDE. On the other hand, the source is significantly brighter than Sw
J1644, and no obvious host galaxy is seen in SDSS or PanSTARRS
pre-imaging. The hosts of GRBs 101225A and 111209A were also very faint,
and GRB 130925A showed very strong absorption.
If this event is an ULGRB, the flaring activity persists for nearly 40ks
until now, making it significantly longer than even GRB 111209A.
Despite the inclement visibility, observations of this source are strongly
encouraged.
GCN Circular 21346
Subject
GRB 170714A: z-band afterglow candidate for OSIRIS/GTC
Date
2017-07-15T06:37:17Z (8 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann
L. Izzo, C. C. Thoene (HETH/IAA-CSIC), N. Castro-Rodriguez
(GTC, IAC, ULL), A. Marante, J. A. Melian (GTC) report:
We observed the field of GRB 170714A (D'Ai et al. GCN 21340), an
ULGRB or RTDE candidate (Kann et al., GCN 21345) with OSIRIS at
the 10.4m GTC telescope in La Palma (Spain). Observations consisted
in several short exposures in i and z filters. The observations were not
easy, as the field was located 30 deg away from the 68% illuminated
Moon, implying a very high background.
In the combined z-band frame, with mean epoch at 05:10:24 UT (16.75 hr
after the burst) we detect a single object within the refined XRT error box
(Evans et al. GCN 21341) which is not present in PanSTARRS imaging,
with coordinates (J2000):
R.A.: 02:17:23.99
Dec.: +01:59:29.51
and a magnitude of z(AB)=22.3+/-0.2, which we identify as the possible
GRB afterglow, although we cannot make any statement about
variability at this time. In our preliminary analysis we do not detect the
object in any other band, implying a possible strong reddening.
Further follow up, especially in NIR bands is encouraged.
GCN Circular 21347
Subject
GRB 170714A, Swift-BAT refined analysis
Date
2017-07-15T15:32:14Z (8 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), A. D'Ai (INAF-IASFPA),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170714A (trigger #762535)
(D'Ai et al., GCN Circ. 21340). The BAT ground-calculated position is
RA, Dec = 34.322, 1.962 deg which is
RA(J2000) = 02h 17m 17.3s
Dec(J2000) = +01d 57' 43.3"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 61%.
The mask-weighted light curve shows continuous weak emission that starts
at ~ T-70 s and lasts beyond the end of the event data (T+963 s).
The time-averaged spectrum from T-72.9 to T+464.4 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.76 +- 0.17. The fluence in the 15-150 keV band is 2.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+262.88 sec in the 15-150 keV band
is 0.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/762535/BA/
GCN Circular 21350
Subject
GRB 170714A: TNG NIR observations
Date
2017-07-17T14:05:22Z (8 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, A. Melandri (INAF-OAB), V. D'Elia (INAF/OAR & ASI/ASDC), G. Mainella, W. Boschin (INAF-TNG) report on behalf of the CIBO collaboration:
We observed the field of GRB 170714A (D'Ai et al. GCN 21340) with the 3.6m Telescopio Nazionale Galileo (TNG) equipped with NICS. Observations were carried out in the near-infrared with the J filter under poor weather conditions (clouds and calima). Observations started on Jul 16 at 04:05:03 UT (~1.65 days after the burst) and consisted in a series of images for a total exposure time of 17 minutes.
No source is detected in the refined XRT error circle (Evans et al. GCN 21341). In particular we could not detect the candidate afterglow reported by de Ugarte Postigo et al. (GCN. 21346).
For the coadded image we estimate a preliminary 3sigma upper limit of J > 19.6 mag (AB, calibrated against the 2MASS catalogue).
GCN Circular 21351
Subject
GRB 170714A: Swift/UVOT Observations
Date
2017-07-17T19:28:04Z (8 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170714A
384 s after the BAT trigger (D'Ai et al., GCN Circ. 21340).
There is weak evidence for a fading source consistent with the
position of the z-band afterglow candidate reported by
de Ugarte Postigo et al. (GCN Circ. 21346).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
v 384 1695 175 >18.6
b 496 1644 155 20.0 +/- 0.33
b 5390 24672 1011 >20.3
u 471 1619 284 20.1 +/- 0.35
u 5185 30412 2351 20.4 +/- 0.18
u 81432 92912 1509 >20.7
w1 446 1594 136 >21.0
m2 6006 29000 2637 >20.9
w2 5596 34449 3032 >22.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
[GCN OPS NOTE(17jul17): Per author's request, please see GCN Circ 21353
for corrections to the above table.]
GCN Circular 21352
Subject
GRB170714A: VLA Observations of the Bastille Day Ultra-long Burst
Date
2017-07-17T19:51:14Z (8 years ago)
From
Assaf Horesh at Hebrew U, Jerusalem <assafh@mail.huji.ac.il>
A. Horesh (HUJI), S. B. Cenko (NASA/GSFC), A. Levan (U. Warwick), and N. Tanvir (U. Leicester) report:
We observed the ultra-long gamma-ray burst (T90 > 1000s; D���Ai et al. GCN 21340; Evans et al. GCN 21341; Kann et al. GCN 21345; Palmer et al. GCN 21347) with the Jansky Very Large Array (VLA).
Our observation was undertaken on 2017 July 16 in the C configuration.
We do not detect radio emission at the enhanced XRT position of the source, with a 3 sigma detection limit of 75 micro-Jy at a central frequency of 7.5 GHz.
Future VLA observations are planned under our program to search for late-time emission.
We thank the VLA staff for scheduling this target of opportunity.
GCN Circular 21353
Subject
Correction to GCN Circular 21351: GRB 170714A: Swift/UVOT Observations
Date
2017-07-17T21:37:38Z (8 years ago)
From
Frank Marshall at GSFC <femarsha@khamseen.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC)
reports on behalf of the Swift/UVOT team:
Some of the Swift UVOT exposures of GRB 170714A
previously reported by Marshall and D'Ai (GCN Circular 21351)
contain readout streaks due to nearby bright sources.
These streaks make the determination of magnitudes very difficult,
and this effect was not accounted for in the previous analysis.
The affected exposures have been removed from the corrected
table given below. As a result, the most significant detection
of a source with UVOT has been removed, and there is now
only weak evidence for a UVOT source at the position of
the z-band afterglow candidate reported by
de Ugarte Postigo et al. (GCN Circ. 21346).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
v 397 1695 175 >18.6
b 496 1644 155 20.0 +/- 0.33
b 92917 93309 382 >20.3
u 471 1619 284 20.1 +/- 0.35
u 81432 92912 1509 >20.7
w1 446 1594 136 >21.0
m2 76276 98985 2438 >21.3
w2 74458 86274 1771 >21.5
I apologize for any confusion caused by the earlier report.
GCN Circular 21356
Subject
GRB 170714A: NOEMA non-detection of the Bastille Day Burst
Date
2017-07-18T14:30:07Z (8 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D.A. Kann
(HETH/IAA-CSIC), S. Schulze (Weizmann Institute), L. Izzo,
C.C. Thoene (HETH/IAA-CSIC) and M. Krips (IRAM) report:
We observed the field of GRB 170714A (D'Ai et al. GCN 21340)
using the NOrthern Extended Millimeter Array (NOEMA, Plateau
de Bure, France) tuned at 92.5 GHz. Observations were
performed between 3:10 and 5:15 UT on 17 July 2017 (2.66 days
after the burst) and consisted of 1.33 hr on target with a bandwidth
of 3.6 GHz and using 8 antennas.
We do not detect any source consistent with the afterglow position
(de Ugarte Postigo et al. GCN 21346) down to a 3-sigma limit of
150 uJy. We do note the presence of an unrelated source 12���
Northwest of the afterglow position with a flux density of ~0.19 mJy,
which is coincident with an extended source in our GTC images.
This burst has been proposed to be either an ultra-long GRB or a
relativistic tidal-disruption event (Kann et al., GCN 21345). We
note that this deep non-detection, together with the non-detection
from the VLA (Horesh et al. GCN 21352) are consistent with a
scenario of an ULGRB like GRBs 101225A, 111209A and 130925A,
which have been faint at radio wavelengths (Frail, GCN 11550,
Zauderer et al., GCN 11770; Hancock et al., GCNs 12664, 12804;
Horesh et al. 2015, ApJ, 812, 86). Relativistic tidal-disruption events
such as Sw J1644 and SwJ2058 have been found to be much
brighter in radio wavelengths (e.g., Zauderer et al. 2011, Nature,
476, 425, Berger et al. 2012, ApJ, 748, 36, Zauderer et al., 2013,
ApJ, 767, 152; Cenko et al. 2012, ApJ, 753, 77).
GCN Circular 21359
Subject
GRB 170714A: Bastille Day Burst redshift from OSIRIS/GTC
Date
2017-07-21T06:36:26Z (8 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D.A. Kann,
L. Izzo, C.C. Thoene (HETH/IAA-CSIC), G. Lombardi S. Geier
(GTC, IAC-ULL), A. Garcia, A. Perez (GTC) report:
Following the detection of the afterglow (de Ugarte Postigo et al. GCN
21346) of the ultra-long GRB 170714A (D'Ai et al. GCN 21340, Kann
et al. GCN 21345) we obtained further NIR and optical observations on
19 and 20 of July, with detections in r, i, z, and H-bands. An object is
still observed at the position earlier reported, indicating an important
host galaxy contribution.
On 21 July, at 4:53 UT (5.69 days after the burst) we obtained
spectroscopy of the afterglow/host galaxy with OSIRIS at the 10.4m
GTC telescope (La Palma, Spain). Observations consisted of 4x900 s
with grism R1000R, covering the range between 5100 and 10000 AA.
The combined spectrum shows a weak trace with several
superimposed emission lines, which we interpret as due to [OII], [OIII]
and H-beta, through which we derive a redshift for the host galaxy,
and hence for GRB 170714A, of 0.793.
GCN Circular 21360
Subject
GRB170714A: ATCA observation
Date
2017-07-22T22:50:47Z (8 years ago)
From
Luigi Piro at INAF <luigi.piro@iaps.inaf.it>
R. Ricci (INAF/IRA-Bologna), M. Wieringa (ATNF,CSIRO), L. Piro(INAF/IAPS),
E. Troja(NASA/GSFC), K. Bannister (ATNF,CSIRO) and B.
Gendre (Virgin Islands University) report:
We observed the ultra-long gamma-ray burst GRB170714A (D'Ai' et al. GCN
21340; Evans et al. GCN 21341; Kann et al. GCN 21345; Palmer et al. GCN
21347) with ATCA on 2017 July 20 at 17 and 21 GHz.
We detect a source ~7" northward of the position of the GRB optical
counterpart (de Ugarte Postigo et al. GCN 21346). Given the ATCA
configuration, this position is consistent at about 2.5 sigma with the GRB
optical counterpart. However, we cannot exclude contamination from the
source detected at higher frequency by NOEMA (de Ugarte Postigo et al.,
GCN 21356), thus we conservatively estimate an upper limit of ~ 50uJy at
19GHz to the radio emission from the GRB.
Future ATCA observations are planned under our program on ultralong GRBs
(PI:L. Piro).
We thank the ATCA staff for scheduling this target of opportunity.
GCN Circular 21379
Subject
GRB170714A: XMM observation of the afterglow
Date
2017-07-29T08:33:11Z (8 years ago)
From
Luigi Piro at INAF <luigi.piro@iaps.inaf.it>
B. Gendre (UVI, USA), L. Piro (IAPS/INAF, Italy), E. Troja (GSFC, USA), R.
Ricci (INAF/IRA-Bologna), M. Wieringa (ATNF,CSIRO), K. Bannister
(ATNF,CSIRO) report:
We observed the field of GRB 170714A (D'Ai et al., GCN 21340) with
XMM-Newton between 370,993 and 506,293 seconds post-trigger under our XMM
program on ultralong GRBs (PI: Piro).
The X-ray afterglow is clearly visible during the whole observation, at
the position:
RA: 2h17m24.02s
DEC: +1d59'28.51"
with an error of 1.3" (statistic + systematic, 90% confidence),
consistent with the position of the optical counterpart (de Ugarte Postigo
et al. GCN 21346) and of XRT (Evans et al. GCN 21341).
The observed mean X-ray flux(0.3-10 keV) is 3.7e-14 erg/s/cm2
We thank the ESA and XMM SOC staff for performing this TOO trigger.
GCN Circular 21396
Subject
GRB 170714A: Chandra observations
Date
2017-07-31T12:35:17Z (8 years ago)
From
Eleonora Troja at GSFC <eleonora.troja@nasa.gov>
E. Troja (NASA/UMCP), L. Piro (INAF/IASF), B. Gendre (UVI)
report on behalf of a larger collaboration:
We observed the field of the ultralong GRB 170714A (D'Ai et al.,
GCN 21340) with the Chandra X-ray Observatory beginning on 2017
Jul 28.67 UT (14 days post-burst) for a total exposure of 14.9 ks.
We clearly detect the GRB counterpart with coordinates:
RA(J2000) = 02:17:23.97
Dec(J2000) = +01:59:29.72
with a 68% uncertainty of 0.5 arcsec. This position is consistent with
the XRT position (http://www.swift.ac.uk/xrt_positions/00762535/), and
the optical source reported by de Ugarte Postigo et al. (GCN 21346).
By adopting the spectral parameters of the Swift/XRT analysis (D'Avanzo
et al., GCN 21343), we estimate an average X-ray flux of
~1.1E-14 erg/cm2/s during our observation. This is consistent with a
late-time power-law decay of slope ~-1.
We thank Andrea Prestwich, Belinda Wilkes and the CXC staff for
rapidly scheduling this observation.
GCN Circular 21424
Subject
GRB 170714A: ATCA detection of the radio counterpart
Date
2017-08-08T13:13:31Z (8 years ago)
From
Luigi Piro at INAF <luigi.piro@iaps.inaf.it>
L. Piro(INAF/IAPS), R. Ricci (INAF/IRA-Bologna), M. Wieringa (ATNF,CSIRO),
E. Troja(NASA/GSFC), K. Bannister (ATNF,CSIRO) and B. Gendre (UVI, USA)
report:
We carried out a second observation of our monitoring campaign of the
field of the ultralong GRB 170714A (D'Ai' et al. GCN 21340; Evans et al.
GCN 21341; Kann et al. GCN 21345; Palmer et al. GCN 21347) with ATCA on
2017 Aug 4 for 9 hours at 17 and 21 GHz.
We detect a source at:
RA: 02h17m23.96s
Dec: +01:59'32.9"
with a 90% error of ~2.5" in DEC and ~0.1" in RA, consistent with the
position of the GRB X-ray counterpart by Chandra (Troja et al. GCN 21396)
and the optical source reported by de Ugarte Postigo et al. (GCN 21346).
We associate this source to the radio afterglow of the burst. The flux
measured at 19 GHz is 71 +/- 19 uJy.
In comparison to the first ATCA observation (Ricci et al. GCN 21360), the
present configuration improves significantly the resolution and allows us
to distinguish the radio afterglow from the unrelated source associated to
the NOEMA observation (de Ugarte Postigo et al., GCN 21356).
We thank the ATCA staff for scheduling this target of opportunity observation.
GCN Circular 21464
Subject
GRB 170714A: 15 GHz upper limits from AMI
Date
2017-08-11T17:56:56Z (8 years ago)
From
Kunal Mooley at Oxford U <kunal.mooley@physics.ox.ac.uk>
K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender
(Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D.
Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods,
P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)
The AMI Large Array robotically triggered on the Swift alert for GRB
170714A (D'Ai et al., GCN 21340) as part of the 4pisky program, and
subsequent follow up observations were obtained up to 10 days
post-burst. Our observations at 15 GHz on 2017 Jul 15.11, Jul 18.27, Jul
20.23 and Jul 22.25 (UT) do not reveal any radio source at the XRT
location (Evans et al., GCN 21341), with 3sigma upper limits of 279 uJy,
172 uJy, 288 uJy and 210 uJy respectively. These upper limits are
consistent with the results from previously-reported radio observations
(Horesh et al., GCN 21352; Ricci et al., GCN 21360; Piro et al., GCN
21424).
We thank the AMI staff for scheduling these observations. The AMI-GRB
database is a log of all GRB follow up observations with the AMI, and is
available at http://4pisky.org/ami-grb/.