GRB 160131A
GCN Circular 18951
Subject
GRB 160131A: Swift detection of a burst with an optical counterpart
Date
2016-01-31T08:32:26Z (9 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
K. L. Page (U Leicester) and S. D. Barthelmy (GSFC) report on behalf
of the Swift Team:
At 08:20:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160131A (trigger=672236). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 78.182, -7.067 which is
RA(J2000) = 05h 12m 44s
Dec(J2000) = -07d 04' 02"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a large FRED-like peak
structure with a duration of about 100 sec. The peak count rate
was ~8100 counts/sec (15-350 keV), at ~16 sec after the trigger.
The XRT began observing the field at 08:21:41.6 UT, 69.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 78.1700, -7.0489 which is equivalent to:
RA(J2000) = +05h 12m 40.80s
Dec(J2000) = -07d 02' 56.0"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 77 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.
The initial flux in the 2.5 s image was 1.29e-08 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 78 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 05:12:40.34 = 78.16810
DEC(J2000) = -07:02:59.1 = -7.04975
with a 90%-confidence error radius of about 0.61 arc sec. This position is 7.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
13.88 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.11.
Burst Advocate for this burst is K. L. Page (klp5 AT leicester.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.)
GCN Circular 18953
Subject
GRB 160131A: LCOGT-FTN optical afterglow observations
Date
2016-01-31T10:50:40Z (9 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi, S. Dichiara (U. Ferrara), S. Kobayashi (LJMU), A. Gomboc
(U. Nova Gorica), C.G. Mundell (U. Bath), on behalf of a larger
collaboration report:
The 2-m LCOGT Faulkes Telescope North began observing Swift GRB160131A
(Page et al. GCN 18951) on Jan 31 at 09:37 UT (~77 minutes after the
burst trigger) with griZY filters. We clearly detect the optical
afterglow (Page et al. GCN 18951; Yurkov et al. GCN 18952), with a
magnitude of r=15.29 +- 0.01 at 81 minutes post GRB, as calibrated
against nearby USNOB-1 star RA(J2000)=05:12:41.5 DEC(2000)=-07:03:09.81
with R2=14.28. Observations are going on.
GCN Circular 18954
Subject
GRB160131A: Xinglong TNT optical observation
Date
2016-01-31T11:02:19Z (9 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, X. F. Wang, J. Y. Wei, Y. L. Qiu, J. S. Deng, X. M. Meng
D. Xu, J. Wang, X. H. Han and C. Wu on behalf of EAFON report:
We observed GRB 160131A (Page et al. GCN 18951) with
Xinglong 0.8-m TNT telescope at 10:22:09UT, about 2 hours after the burst.
The optical afterglow (Page et a.., GCN 18951, YurKov et al., GCN 18952)
was detected in our white, B, and R, I-band images.
The brightness of the optical afterglow is about 16.1 mag
at the mid time of 118 min afer the burst, calibrated by
the USNO B1.0 star (RA=05:12:39.8 DEC=-7:02:02 R2=15.51mag).
The message may be cited.
GCN Circular 18955
Subject
GRB 160131A: Xinglong 60cm WFT optical observation
Date
2016-01-31T12:19:37Z (9 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, X. M. Meng, Y. J. Xiao, J. Y. Wei, E. W. Liang, X. G. Wang,
Y. G. Yang, X. M. Lu, L. Huang, X. H. Han , H. B. Cai, Y. L. Qiu,
J. Wang, C. Wu, J. S. Deng, H. L. Li and D. Xu report:
We observed GRB 160131A (Page et al. GCN 18951) with
60cm WFT telescope at 10:29:14UT, about 127 min after the burst.
The optical afterglow (Page et a.., GCN 18951, YurKov et al., GCN 18952,
Guidorzi et al., GCN 18953, Xin et al., 18954) was detected
in our white and R-band images. The brightness of the optical afterglow
is about 15.85 mag at the mid time of 127.5 min afer the burst, calibrated by
the USNO B1.0 star (RA=05:12:39.8 DEC=-7:02:02 R2=15.51mag).
Observations are continuing
The message may be cited.
GCN Circular 18956
Subject
GRB 160131A: RATIR Optical Observations
Date
2016-01-31T13:36:58Z (9 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:
We observed the field of GRB 160131A (Page et al., GCN Circular 18951)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astron��mico Nacional on Sierra San Pedro M��rtir from 2016/01 31.35 to
2016/01 31.37 UTC (0.07 to 0.50 hours after the BAT trigger), obtaining
a total of 0.18 hours exposure in the r, i, and z bands.
We detect a bright uncatalogued source at 05:12:40.33 -07:03:00 (J2000,
��0.5 arcsec). In comparison with the USNO-B1 catalog, we obtain the
following mean magnitudes:
r = 13.35 �� 0.04
i = 13.01 �� 0.02
z = 12.67 �� 0.04
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The source fades roughly as t^-0.87 during our observations. This source
is presumably the optical counterpart reported by Page et al. (GCN
Circular 18951), Yurkov et al. (GCN Circular 18952), Guidorzi et al.
(GCN Circular 18953), and Xin et al. (GCN Circular 18954).
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 18957
Subject
GRB 160131A: LCOGT-SSO optical observations
Date
2016-01-31T14:28:09Z (9 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
D. Xu (NAOC/CAS), Y.-H. Han (NAOC/CAS, HUST), Y.-D. Hu (IAA-CSIC), Y.
Qing (Geneva Observatory), L.-P. Xin (NAOC/CAS) report on behalf of a
larger collaboration:
We observed the field of GRB 160131A (Page & Barthelmy, GCN 18951) using
the LCOGT-1m located at the Siding Spring Observatory. Observations
started at 11:50:49 UT and ended at 12:15:46 UT on 2016-01-31 (i.e.,
3.505 - 3.921 hr after the BAT trigger) and a series of 150s
U-/B-/V-/R-/I-band frames were obtained.
The afterglow of the burst (e.g., Page & Barthelmy, GCN 18951; Yurkov et
al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 1894,18955;
Watson et al., GCN 18956) is detected in our individual image in each
band. Preliminary analysis gives rise to the following magnitudes:
m(I) = 16.05 +/- 0.02
m(R) = 16.56 +/- 0.02
m(V) = 17.07 +/- 0.02
m(B) = 17.59 +/- 0.02
calibrated with four SDSS stars in the field.
GCN Circular 18958
Subject
GRB 160131A: Enhanced Swift-XRT position
Date
2016-01-31T16:23:54Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2574 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 160131A, 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 = 78.16795, -7.04988 which is equivalent
to:
RA (J2000): 05h 12m 40.31s
Dec (J2000): -07d 02' 59.6"
with an uncertainty of 2.2 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 18959
Subject
GRB 160131A: Swift-BAT refined analysis
Date
2016-01-31T19:00:27Z (9 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 160131A (trigger #672236)
(Page, et al., GCN Circ. 18951). The BAT ground-calculated position is
RA, Dec = 78.170, -7.037 deg, which is
RA(J2000) = 05h 12m 40.8s
Dec(J2000) = -07d 02' 13.0"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
The mask-weighted light curves shows a small precursor starting at ~T-2 sec
and the main peak is a FRED starting at ~T+10 sec, peaking at ~T+18 sec, and returning
to baseline at ~T+800 sec (although there is a possibility that it goes longer
but the observing window ended at T+950 sec).
T90 (15-350 keV) is 325 +- 72 sec (estimated error including systematics).
The time-averaged spectrum from T-1.49 to T+773.03 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.24 +- 0.05. The fluence in the 15-150 keV band is 2.04 +- 0.05 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+15.97 sec in the 15-150 keV band
is 6.4 +- 0.3 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/672236/BA/
GCN Circular 18960
Subject
GRB 160131A: iTelescope optical observations
Date
2016-01-31T19:52:46Z (9 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:
We have detected GRB 160131A optical afterglow at iTelescope observatory
(Siding Spring, Australia) using T9 0.32-m f/9 RCOS telescope and T17 and
T32 0.43-m f/6.8 astrographs. The observations were started at 2016-01-31
10:01:17 (UT). Several images using photometric R and V filters with 300 sec
and 120 sec exposure time were taken.
The afterglow was detected at the position RA 05:12:40.34 and DEC
-07:02:58.3.
The following magnitudes were obtained from the observations using
NOMAD1 0829-0078536 (R=15.390 and V=14.820) as a comparison star:
T32 observations
Tmid(s)+T0 Filter Exp. time Mag Mag. Err.
6197 V 300s 15.05 0.04
6796 V 300s 15.17 0.04
7395 V 300s 15.28 0.04
T17 observations
Tmid(s)+T0 Filter Exp. time Mag Mag. Err.
6651 R 4x300s 15.71 0.02
7946 R 4x300s 15.96 0.02
11649 R 4x300s 16.56 0.03
12952 R 4x300s 16.68 0.03
14244 R 4x300s 16.86 0.04
15709 R 4x300s 16.99 0.04
T9 observations
Tmid(s)+T0 Filter Exp. time Mag Mag. Err.
14761 V 5x120s 16.27 0.34
15454 V 5x120s 16.43 0.37
16190 V 5x120s 16.55 0.42
17083 V 5x120s 16.55 0.44
17767 V 5x120s 16.59 0.43
18452 V 5x120s 16.65 0.48
19179 V 5x120s 16.70 0.54
20295 V 5x120s 16.75 0.56
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
GCN Circular 18961
Subject
GRB 160131A: TNG optical observations
Date
2016-01-31T20:10:52Z (9 years ago)
From
Andrea Melandri at INAF-OAB <andrea.melandri@brera.inaf.it>
A. Melandri, P. D'Avanzo (INAF/OAB), V. D'Elia (INAF/OAR and ASI/ASDC), L. Di Fabrizio, G. Mainella (INAF/TNG) report on behalf of the CIBO collaboration:
We observed the field of GRB 160131A (Page et al., GCN 18951) with the 3.6m TNG telescope equipped with the DOLoRes camera in imaging mode. Observations started on 2016 Jan 31 at 19:52 UT and consisted of two images (120s each) obtained with the R filter.
The optical afterglow (Page et al., GCN 18951; Yurkov et al. GCN 18952; Guidorzi et al. GCN 18953; Xin et al., GCN 18954, GCN 18955; Watson et al. GCN 18956; Xu et al. GCN 18957) is clearly detected. From a preliminary analysis, we estimate a magnitude of R=18.1 +/- 0.1, calibrated against the USNO-B1 catalogue.
GCN Circular 18962
Subject
GRB 160131A: Khureltogot optical observations
Date
2016-01-31T20:22:21Z (9 years ago)
From
Alexei Pozanenko at IKI <alex@grb.rssi.ru>
E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of Swift GRB 160131A (Page et al., GCN Page) with ORI-40 telescope of Khureltogot observatory on Jan., 31 from(UT) 11:14 up to (UT) 16:34. We obtained several unfilteed images.
We clearly detect optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., GCN 18955; Watson et al., GCN 18956). Preliminary photometry of the afterglow in the first images is following
Date UT start t-T0 Filter Exp. OT Err
(mid, days) (s)
2016-01-31 11:14:41 0.12106 20 16.43 0.10
2016-01-31 11:27:26 0.13015 60 16.49 0.04
2016-01-31 11:28:30 0.13089 60 16.51 0.04
2016-01-31 11:29:35 0.13164 60 16.50 0.04
2016-01-31 11:30:39 0.13238 60 16.52 0.05
2016-01-31 11:31:43 0.13388 60 16.61 0.05
2016-01-31 11:33:52 0.13462 60 16.46 0.04
2016-01-31 11:34:57 0.13537 60 16.53 0.05
2016-01-31 11:36:01 0.13611 60 16.58 0.05
2016-01-31 11:37:06 0.13686 60 16.62 0.05
2016-01-31 11:38:10 0.13760 60 16.56 0.04
2016-01-31 11:39:14 0.13834 60 16.58 0.04
2016-01-31 11:40:18 0.13909 60 16.57 0.04
Photometry is based on nearby USNO B1.0 stars, R2 magnitude.
GCN Circular 18963
Subject
GRB 160131A: Swift-XRT refined Analysis
Date
2016-01-31T20:32:38Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows
(PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU) and K.L. Page report
on behalf of the Swift-XRT team:
We have analysed 10 ks of XRT data for GRB 160131A (Page et al. GCN
Circ. 18951), from 60 s to 23.6 ks after the BAT trigger. The data
comprise 523 s 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 Goad et al.
(GCN Circ. 18958).
The late-time light curve (from T0+3.8 ks) can be modelled with a
power-law decay with a decay index of alpha=1.09 (+/-0.05).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.44 (+/-0.03). The
best-fitting absorption column is 1.76 (+/-0.15) x 10^21 cm^-2, in
excess of the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.10 (+/-0.08) and a
best-fitting absorption column of 2.56 (+0.31, -0.29) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.4 x 10^-11 (5.2 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.56 (+0.31, -0.29) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: 7.9 sigma
Photon index: 2.10 (+/-0.08)
If the light curve continues to decay with a power-law decay index of
1.09, the count rate at T+24 hours will be 0.053 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x
10^-12 (2.8 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00672236.
This circular is an official product of the Swift-XRT team.
GCN Circular 18964
Subject
GRB 160131A: Bassano Bresciano Observatory optical observations
Date
2016-01-31T20:48:03Z (9 years ago)
From
Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>
U.Quadri, L.Strabla and R.Girelli report:
We imaged the field of GRB 160131A (Page et al., GCN Circular 18951)
with the robotic telescope of (IAU station 565) Bassano Bresciano
Observatory, Italy (member of ISSP:Italian Supernovae Search Project)
The observations started 9.18 hour after the GRB trigger, at the end of
twilight, with our Newton telescope D=250 mm F/D=4.8
Initially weather conditions were good, but then the fog has
forbidden the observations.
We co-added 2 series of 10 exposures of 60 sec each:
Start T0 + 9.18 hour. End T0+ 9.87 hour
We clearly detect the optical counterpart (Page et al., GCN 18951;
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953;Xin et al.,
GCN 18954; Xin et al., GCN 18955; Watson et al., GCN 18956).
at the following coordinates:
05h 12m 40.37s -07d 02m 58.9s +/-2 arcsec
Photometry was performed using comparison stars with UCAC4 catalog.
in CV (clear + Jhonson V) and CR (Clear + Jhonson R) magnitudes,
and are not corrected for galactic dust extinction:
------------------------------------
JD Mag Filter SNR
------------------------------------
2457419.24025 17.360 CR 14.34
2457419.26062 17.241 CR 9.74
2457419.24025 17.671 CV 14.40
2457419.26062 17.498 CV 9.74
-------------------------------------
The images are available at:
http://www.osservatoriobassano.org/GRB.asp
The message may be cited.
GCN Circular 18965
Subject
GRB 160131A: TNG spectroscopic observations and redshift
Date
2016-01-31T22:10:53Z (9 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
D. Malesani (DARK/NBI), V. D'Elia (INAF/OAR and ASI/ASDC), P. D'Avanzo, A. Melandri (INAF-OAB), L. A. Antonelli (INAF/OAR and ASI/ASDC), L. Di Fabrizio, G. Mainella (INAF/TNG) report on behalf of the CIBO collaboration:
Following the observations reported in Melandri et al. (GCN 18961), we carried out further observations of the optical afterglow of GRB 160131A (Page et al., GCN 18951) with the 3.6m TNG telescope equipped with the DOLoRes camera in spectroscopic mode. A spectrum was acquired with the LR-B grism covering the range between 3500 and 8000 AA. The observation consisted of a single 1200 s exposure, starting on 2016 Jan 31 at 20:12 UT.
A preliminary analysis of the spectrum (based on archival calibration files) shows clearly the continuum with several absorption features due to Fe II, Mg II and Mg I at a common redshift of 0.97, which we propose as the redshift of the GRB.
We acknowledge support from the TNG visiting astronomer Ennio Poretti.
GCN Circular 18966
Subject
GRB 160131A: GTC spectroscopy of the afterglow
Date
2016-01-31T23:49:42Z (9 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
R. Sanchez-Ramirez (IAA-CSIC), Gabriel Gomez Velarde (GRANTECAN) and
Victor Herrera (GRANTECAN) report on behalf of a larger collaboration:
We observed the afterglow of GRB 160131A (Page et al. GCN 18951) with
the 10.4 m GTC equipped with OSIRIS. Observations consisted of 3x600s
spectra with grism R1000B (covering from 3700 to 7800 AA) and 3x600s
with grism R1000R (covering from 5100 to 10000 AA). The first spectrum
started at 21:52 UT (13.53 hr after the GRB onset) under very bad seeing
conditions (> 3").
In spite of the poor seeing we detect a strong continuum across the complete
range with multiple absorption features of FeII, NiII, MnII, MgII, MgI, and CaII
at a common redshift of 0.972, consistent with the value measured by
Malesani et al. from TNG (GCN 18965).
[GCN OPS NOTE(04feb16): Per author's request, GGV and VH were added
to the author list.]
GCN Circular 18967
Subject
GRB 160131A: GROND Detection of the Optical/NIR Afterglow
Date
2016-02-01T01:20:14Z (9 years ago)
From
Fabian Knust at MPE/GROND <fknust@mpe.mpg.de>
F. Knust, J. Bolmer, J. Greiner (all MPE Garching), and D. A. Kann, (TLS
Tautenburg) report on behalf of the GROND team:
We observed the field of GRB 160131A (Swift trigger 672236; Page et al.,
GCN #18951) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).
Observations started at 0:44 UT on 2016-02-01, 16 hrs after the GRB
trigger, and are continuing. They were performed at an average seeing of
1.3" and at an average airmass of 1.1.
We found a single point source within the 2.2" Swift-XRT error circle
reported by Goad et al. (GCN #18958), in agreement with the UVOT afterglow
(Page et al., GCN #18951) at
RA (J2000.0) = 05 h 12 m 40.32 s
Dec. (J2000.0) = -07d 02' 58.92
with an uncertainty of 0.5" in each coordinate.
Based on the first 4.40 min of total exposures in g'r'i'z' and 4.0 min in
JHK, we estimate preliminary magnitudes (all in AB system) of
g' = 18.7 +/- 0.05 mag,
r' = 18.4 +/- 0.05 mag,
i' = 18.3 +/- 0.05 mag,
z' = 18.2 +/- 0.05 mag,
J = 17.7 +/- 0.1 mag,
H = 17.6 +/- 0.1 mag, and
K = 17.1 +/- 0.1 mag.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.09 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).
GCN Circular 18968
Subject
GRB 160131A: MITSuME Ishigakijima Optical Observation
Date
2016-02-01T02:05:16Z (9 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:
We observed the field of GRB 160131A (Pagani and Barthelmy, GCNC 18951)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.
The observation started on 2016-01-31 14:06:17 UT (~5.8 h afterthe burst).
We detected the previously reported afterglow (Pagani and Barthelmy, GCNC 18951;
Yurkov et al., GCNC 18952; Guidorzi et al., GCNC 18953) in all the three bands.
Photometric results of the OT are listed below.
We used GSC2.3 catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
-----------------------------------------------------------------------
0.24373 14:11:29 540.0 17.92 0.09 17.19 0.05 16.88 0.06
-----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 18969
Subject
GRB 160131A: Xinglong/BFOSC spectroscopy
Date
2016-02-01T03:38:02Z (9 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
D. Xu, L.-P. Xin, J. Wang (NAOC/CAS) report on behalf of a larger
collaboration:
We observed the optical afterglow of GRB 160131A (e.g., Page et al., GCN
18951; Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al.,
GCN 18954) using the 2.16m telescope located at Xinglong, Heibei, China,
equipped with the BFOSC camera. A 2400s spectrum was acquired with the
G4+385LP grism covering the range of 3500 - 8500 AA, starting at
13:49:08 UT on 2016-01-31.
The spectrum shows a continuum across the whole range, superimposed with
absorption features of Mg II, Ca II H+K at a common redshift of 0.97,
being consistent with measurements by Malesani et al. (GCN 18965) and de
Ugarte Postigo et al. (GCN 18966).
We thank the excellent support of the Xinlong 2.16m staff, in particular
Meng Zhai and Junjun Jia.
GCN Circular 18970
Subject
GRB 160131A Swift/UVOT Detection
Date
2016-02-01T18:09:05Z (9 years ago)
From
Marissa McCaule at PSU <marissamc@swift.psu.edu>
L. M. McCauley (PSU), K. L. Page (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160131A
78 s after the BAT trigger (Page et al., GCN Circ. 18951).
A fading source consistent with the XRT position (Beardmore et al. GCN
Circ. 18159)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 05:12:40.33 = 78.16804 (deg.)
Dec (J2000) = -07:02:58.81 = -7.04967 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_fc 78 228 147 13.77+-1.10
white 5051 11361 1081 16.71+-0.02
v 4026 5662 393 15.72+-0.03
b 4846 10449 1138 16.81+-0.02
u 290 540 245 13.08+-0.03
u 4641 6277 393 15.64+-0.03
uvw1 4436 6072 393 16.18+-0.04
uvm2 4231 5867 393 16.64+-0.06
uvw2 3821 12083 1098 17.43+-0.05
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.11 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 18971
Subject
GRB 160131A: Mondy optical observations
Date
2016-02-01T19:53:38Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), E. Klunko (ISTP), A. Volnova (IKI), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the Swift GRB 160131A (Page et al., GCN 18951) with AZT-33IK
telescope of Sayan observatory (Mondy) starting on Feb.01 (UT)
13:01:56. We clearly detect optical afterglow (Page et al., GCN 18951;
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN
18954; Xin et al., GCN 18955; Watson et al., GCN 18956). Preliminary
photometry of the afterglow of the first image is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2016-02-01 13:01:56 1.19543 R 1*120 19.40 0.08
GCN Circular 18972
Subject
GRB 160131A: AbAO optical observations
Date
2016-02-01T20:28:41Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), R. Inasaridze (AbAO), V. Ayvazian (AbAO), A. Volnova
(IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger
GRB follow-up collaboration:
We observed the field of Swift GRB 160131A (Page et al., GCN 18951) with
AS-32 (0.7m) telescope of Abastumani Observatory starting on Jan. 31
(UT) 19:16:57. We obtained several unfiltered images of 120 s exposure.
We detect optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN
18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al.,
GCN 18955; Watson et al., GCN 18956). Preliminary light curve can be
found in http://grb.rssi.ru/GRB160131A/GRB160131A_20160131_AbAO_lc.png
The photometry is base on nearby USNO-B1.0 stars:
USNO-B.1_id R2
0829-0078223 15.70
0829-0078147 14.56
0828-0074893 14.88
0828-0074768 14.81
GCN Circular 18973
Subject
GRB 160131A: Optical observations from T150 OSN
Date
2016-02-02T15:12:35Z (9 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
V. Casanova (IAA-CSIC) and F. Aceituno (IAA-CSIC) report:
We observed the afterglow of GRB 160131A (Page et al. GCN 18951)
from the 1.5m telescope (T150), at Sierra Nevada Observatory (Granada,
Spain) in two epochs on the first and second night after the GRB.
In the first epoch we performed observations in the V, R and I filters
and the object is well detected in all bands. During these observations
on January 31.807 (10.8 hr after the burst), the object has a magnitude of
R=17.90+/-0.02 (Vega), using as reference star the same
USNO-B1.0 object mentioned in the circular by Xin et al. (GCN 18954).
On the second night we performed photometry in 5 bands, U, B, V, R
and I, the object is again detected in all bands. In an image with mean
epoch February 1.835 (35.5 hr after the burst) we detect the object at
R=19.83+/-0.03.
GCN Circular 18974
Subject
Konus-Wind observation of GRB 160131A
Date
2016-02-02T15:36:05Z (9 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@mail.ioffe.ru>
A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, extremely hard-spectrum GRB 160131A
(Swift-BAT trigger #672236: Page & Barthelmy, GCN 18951;
Cummings et al., GCN 18959)
triggered Konus-Wind at T0=30044.577 s UT (08:20:44.577).
The burst light curve shows a single, FRED-like pulse
with a total duration (80-1400 keV) of ~200 s.
In the softest KW energy band the emission can be traced up to ~300 s.
The emission is seen up to ~15 MeV.
As observed by Konus-Wind, the burst
had a fluence of 3.26(-0.32,+0.31)x10^-4 erg/cm2,
and a 64-ms peak energy flux, measured from T0+2.704 s,
of 2.23(-0.46,+0.46)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+162.048 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.97(-0.15,+0.24),
the high energy photon index beta = -1.56(-0.10,+0.07),
the peak energy Ep = 586(-259,+518) keV,
chi2 = 98/97 dof.
The spectrum near the peak count rate
(measured from T0+0.256 to T0+14.592 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.94(-0.18,+0.13),
the high energy photon index beta = -1.56(-0.56,+0.06),
the peak energy Ep = 1152(-438,+3060) keV,
chi2 = 135/97 dof.
Assuming the redshift z=0.972 (Malesani et al., GCN 18965;
de Ugarte Postigo, Thoene & Sanchez-Ramirez, GCN 18966;
Xu, Xin & Wang, GCN 18969)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~8.3x10^53 erg,
the peak luminosity L_iso is ~1.1x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~1150 keV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160131_T30044/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 18976
Subject
GRB160131A: NOEMA detection of the millimetre afterglow
Date
2016-02-02T17:25:19Z (9 years ago)
From
Steve Schulze at U of Iceland <sts30@hi.is>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), S. Schulze (PUC, MAS), M. Bremer (IRAM), S. Mart��n (JAO), J. M. Winters (IRAM) report on behalf a larger collaboration:
We conduced millimetre observations of GRB160131A (Page et al., GCN 18951) with the NOrthern Extended Millimeter Array (NOEMA; Plateau de Bure, France) at 93 and 150 GHz. Observations started at 17:05 UT on February 1 (i.e. 1.36 days after the burst).
We clearly detect the afterglow at both frequencies. A preliminary analysis of the 93 GHz data reveals a flux density of 1.94 +/- 0.07 mJy. Further observations are scheduled.
We encourage follow-up observations at all frequencies.
GCN Circular 18977
Subject
GRB 160131A: VLA detection
Date
2016-02-02T21:22:19Z (9 years ago)
From
Tanmoy Laskar at UC Berkeley <tanmoylaskar@gmail.com>
T. Laskar (NRAO / UC Berkeley), K. D. Alexander, and E. Berger (Harvard)
report on behalf of a larger collaboration:
"We observed GRB 160131A (Page & Barthelmy; GCN 18951) at multiple
frequencies with the Karl G. Jansky Very Large Array (VLA) beginning on
2016 February 01.11 UT (0.76 days after the burst). At a mean frequency of
21.8 GHz, we detect a radio source with a preliminary flux density of ~
0.53 mJy at
RA = 15:12:40.351 +/- 0.001
Dec = -07:02:58.80 +/- 0.02
consistent with the enhanced Swift/XRT position (Goad et al.; GCN 18958)
and the optical position (Page & Barthelmy.; GCN 18951, Yurkov et al.; GCN
18952). Follow-up observations are planned. We thank the VLA staff for
rapidly scheduling these observations."
GCN Circular 18978
Subject
GRB 160131A: correction to VLA position
Date
2016-02-02T22:20:06Z (9 years ago)
From
Tanmoy Laskar at UC Berkeley <tanmoylaskar@gmail.com>
T. Laskar (NRAO / UC Berkeley) reports:
"Our original circular (Laskar et al.; GCN 18977) contained a typo in the
right ascension of the radio source. The correct position is
RA = 05:12:40.351 +/- 0.001
Dec = -07:02:58.80 +/- 0.02
Thanks to Frank Marshall for pointing out the error."
GCN Circular 18988
Subject
GRB 160131A: RATIR Optical Observations
Date
2016-02-04T16:54:53Z (9 years ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM),
Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC),
John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 160131A (Page, et al., GCN 18951) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2016/02 4.10 to 2016/02 4.36 UTC (89.96 to
96.25 hours after the BAT trigger), obtaining a total of 4.60 hours
exposure in the r, i, and z bands.
For a source within the Swift-XRT error circle (Osborne, et al., GCN
18958), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following detections and upper limit (3-sigma):
r = 21.64 +/- 0.05
i = 21.41 +/- 0.03
z > 20.48
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. We note that there is a faint,
possible source present in the DSS near this source which could be the GRB
host galaxy.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 18991
Subject
GRB 160131A: Mondy optcial observations
Date
2016-02-05T15:15:24Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Mazaeva (IKI), E. Klunko (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the Swift GRB 160131A (Page et al., GCN 18951) with AZT-33IK
telescope of Sayan observatory (Mondy) starting on Feb.04 (UT)
11:42:43. We detect optical afterglow (Page et al., GCN 18951; Yurkov et
al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin
et al., GCN 18955; Watson et al., GCN 18956) in a combined image.
Preliminary photometry is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2016-02-04 11:42:43 4.16058 R 29*120 21.70 0.23
USNO-B.1_id R2
0829-0078147 14.56
0829-0078222 18.96
0829-0078226 18.69
0829-0078129 17.62
GCN Circular 18992
Subject
GRB 160131A: TSHAO optical observations
Date
2016-02-05T18:49:47Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova
(IKI), A. Kusakin (Fesenkov Astrophysical Institute), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the Swift GRB 160131A (Page et al., GCN 18951) with
Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory
starting on Feb. 05 (UT) 14:22:45. We obtained several images in R
filter. We clearly detect optical afterglow (Page et al., GCN 18951;
Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN
18954; Xin et al., GCN 18955; Watson et al., GCN 18956) in a combined
image. Preliminary photometry is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2016-02-05 14:22:45 5.28802 R 21*300 22.40 0.20
Photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
0829-0078223 15.70
0829-0078147 14.56
0829-0078167 17.71
0829-0078222 18.96
0829-0078226 18.69
0829-0078129 17.62
GCN Circular 19004
Subject
GRB 160131A: TSHAO optical observations
Date
2016-02-08T22:04:39Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova
(IKI), A. Kusakin (Fesenkov Astrophysical Institute), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the Swift GRB 160131A (Page et al., GCN 18951) with
Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory.
We obtained several images in R filter on Feb. 06 and Feb. 07.The
optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 18952;
Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., GCN
18955; Watson et al., GCN 18956) is detected on Feb. 06 and not detected
on Feb. 07. Preliminary photometry is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2016-02-06 13:45:54 6.26762 R 21*300 22.40 0.3
2016-02-07 13:30:04 7.25330 R 21*300 >22.40 (3sigma)
Photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
0829-0078223 15.70
0829-0078147 14.56
0829-0078167 17.71
0829-0078222 18.96
0829-0078226 18.69
0829-0078129 17.62
GCN Circular 19009
Subject
Low frequency GMRT observations of GRB 160131A
Date
2016-02-10T10:15:28Z (9 years ago)
From
Poonam Chandra at TIFR <poonam@ncra.tifr.res.in>
Poonam Chandra (NCRA-TIFR) and A. J. Nayana (NCRA-TIFR) report on
behalf of a
larger collaboration:
We carried out the Giant Metrewave Radio Telescope (GMRT) observations of
GRB 160131A (GCN Circ. 18951) at 1280 and 610 MHz band on 2016 Feb 09.61
UT.
The data is badly affected by RFI and hence we could not obtain the
expected rms.
The 3-sigma upper limit on the GRB flux in the Swift error cicle (GCN
Circ. 18970)
are 570 and 382 uJy in 1280 and 610 MHz bands, respectively.
The GMRT data for GRB 160131A is public for anyone to use.
Further observations are planned. We thank GMRT staff for making these
observations possible.
GCN Circular 19010
Subject
GRB 160131A: second epoch observations with the GMRT
Date
2016-02-11T10:00:38Z (9 years ago)
From
Poonam Chandra at TIFR <poonam@ncra.tifr.res.in>
Poonam Chandra (NCRA-TIFR) and A. J. Nayana (NCRA-TIFR) report on
behalf of a
larger collaboration:
We reobserved GRB 160131A (GCN Circ. 18951) with the Giant Metrewave Radio
Telescope (GMRT) at 1420 MHz band on 2016 Feb 10.78 UT. While we do not
detect
the GRB radio afterglow, we place very constraining 3-sigma upper limit
on the
GRB flux in the Swift error cicle (GCN Circ. 18970) to be 105 uJy.
The GMRT data for GRB 160131A is public for anyone to use.
Further observations are planned. We thank GMRT staff for making these
observations possible.
--
_________________________________________
Poonam Chandra
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Pune University Campus, Ganeshkhind
Pune 411007, Maharashtra, INDIA
Phone: +91 20 2571 9290
Fax: +91 20 2569 7257
Email: poonam@ncra.tifr.res.in
Web: www.ncra.tifr.res.in:8081/~poonam/
_________________________________________
GCN Circular 19011
Subject
GRB160131A: detection of polarisation by Astrosat CZTI
Date
2016-02-12T13:23:06Z (9 years ago)
From
Dipankar Bhattacharya at IUCAA <dipankar@iucaa.in>
S. V. Vadawale (PRL), T. Chattopadhyay (PRL), N. P. S. Mithun (PRL),
A. R. Rao (TIFR), D. Bhattacharya (IUCAA), Varun Bhalerao (IUCAA)
report on behalf of the Astrosat CZTI collaboration:
Astrosat CZT Imager detected GRB 160131A (Page and Barthelmy, GCN 18951)
at an incident angle of 63 degrees from the telescope pointing axis.
The T90 was measured to be 106 s and 97 s in 30 - 100 keV and 100 - 300
keV respectively. CZTI being sensitive to polarimetry [Chattopadhyay et
al, 2014, EXPA, Vadawale et al 2015, A&A], we have analysed the double
events due to Compton scattering and detect a clear azimuthal modulation
of 0.30 +/- 0.12 %, with a detection significance of 2.5 sigma. Based on a
preliminary mass modelling, we estimate that the source polarisation
fraction lies between ~ 50 - 60 % in 100-300 keV band. A detailed mass
modeling to refine this measurement and its estimated uncertainty is in
progress. In an earlier event, GRB 151006A (Bhalerao et al. GCN 18422)
CZT Imager data showed a marginal evidence for polarisation signal. From
the higher detection confidence for this brighter GRB160131A, we estimate
that CZT Imager can provide time resolved spectro-polarimetry for GRBs
with fluence larger than 10^-4 erg per cm^2.
This message may be cited.
GCN Circular 19206
Subject
GRB 160131A: 15 GHz upper limits from AMI-LA
Date
2016-03-17T19:13:30Z (9 years ago)
From
Kunal Mooley at Oxford U <kunal.mooley@physics.ox.ac.uk>
K. P. Mooley, R. P. Fender, T. D. Staley (Oxford), G. Ghirlanda, F.
Nappo (INAF, Merate), C. Rumsey, D. Titterington, S. Carey, J. Hickish,
Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A.
Scaife (Manchester)
We observed the XRT position of GRB 160131A discovered by Swift (Page et
al., GCN 18951; Goad et al., GCN 18958) at 15 GHz with the Arcminute
Microkelvin Imager (AMI-LA) on 2016 Feb 24.79 UT and Mar 06.79 UT,
corresponding to 24.5 days and 34.5 days post-burst respectively. We do
not detect any radio source at the XRT location, with 3sigma upper
limits of 150 uJy and 210 uJy respectively.
We thank the AMI scheduling team for carrying out these observations.