GRB 160131A
GCN Circular 19206
Subject
GRB 160131A: 15 GHz upper limits from AMI-LA
Date
2016-03-17T19:13:30Z (10 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.
GCN Circular 19011
Subject
GRB160131A: detection of polarisation by Astrosat CZTI
Date
2016-02-12T13:23:06Z (10 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 19010
Subject
GRB 160131A: second epoch observations with the GMRT
Date
2016-02-11T10:00:38Z (10 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 19009
Subject
Low frequency GMRT observations of GRB 160131A
Date
2016-02-10T10:15:28Z (10 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 19004
Subject
GRB 160131A: TSHAO optical observations
Date
2016-02-08T22:04:39Z (10 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 18992
Subject
GRB 160131A: TSHAO optical observations
Date
2016-02-05T18:49:47Z (10 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