GRB 160327A
GCN Circular 19453
Subject
GRB 160327A: 15 GHz upper limits from AMI
Date
2016-05-24T15:04:33Z (10 years ago)
From
Kunal Mooley at Oxford U <kunal.mooley@physics.ox.ac.uk>
K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson
(Curtin), C. Rumsey, D. Titterington, S. 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
160327A (Racusin et al., GCN 19235) 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 2016 Mar 27.75, Mar 28.94, Mar
30.94, Apr 04.79, and Apr 06.83 (UT) do not reveal any radio source at
the XRT location (Goad et al., GCN 19237), with 3sigma upper limits of
84 uJy, 69 uJy, 96 uJy, 102 uJy, and 93 uJy respectively.
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/.
GCN Circular 19250
Subject
GRB 160327A: Continued RATIR Optical and NIR Observations
Date
2016-04-01T19:20:19Z (10 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 160327A (Racusin, et al., GCN 19235) for a
third epoch 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 2016/04 1.22 to
2016/04 1.41 UTC (115.97 to 120.62 hours after the BAT trigger), obtaining
a total of 3.18 hours exposure in the r and i bands and 1.34 hours exposure
in the Z, Y, J, and H bands.
We are able to detect two of the three sources identified by the GTC (de
Ugarte Postigo, et al., GCN 19245). The afterglow (GTC source #1 and
Golkhou, et al., GCN 19236) is detected in our night 2 observations on 28
March (Golkhou, et al., GCN 19243) but not on 1 April. The GTC source #2
is detected on 28 March and 1 April and is the dominant source in terms of
brightness. We do not detect GTC source #3 on either night.
In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following
detections and upper limits (3-sigma):
Afterglow (GTC Source #1):
28 March 1 April
r > 24.37 r > 24.41
i = 24.20 +/- 0.31 i > 24.38
Z = 22.98 +/- 0.28 Z > 23.15
Y > 22.85 Y > 22.91
J > 22.67 J > 22.61
H > 22.21 H > 22.23
GTC Source #2:
28 March 1 April
r = 23.84 +/- 0.22 r > 24.42
i = 23.33 +/- 0.14 i = 23.57 +/- 0.17
Z = 22.57 +/- 0.20 Z = 22.71 +/- 0.25
Y = 22.83 +/- 0.35 Y > 22.73
J = 22.43 +/- 0.29 J > 22.60
H = 21.75 +/- 0.24 H > 22.24
GTC Source #3:
28 March 1 April
r > 24.37 r > 24.41
i > 24.34 i > 24.39
Z > 23.19 Z > 23.11
Y > 22.86 Y > 22.76
J > 22.66 J > 22.6
H > 22.21 H > 22.25
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
In addition to our first night observations (Golkhou, et al., GCN 19236),
which show the afterglow peaking and then fading, our observations on 28
March and 1 April confirm the fading of the afterglow. The above
photometric analysis, based on PSF fitting, may still suffer from modest
contamination between sources. More detailed analyses are under way.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 19247
Subject
GRB 160327A: Early RAPTOR Limits
Date
2016-03-29T22:58:53Z (10 years ago)
From
James Wren at LANL <jwren@lanl.gov>
J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:
The RAPTOR network of robotic optical telescops made observations of Swift
trigger 680655 (Racusin, et al., GCN 19235). Our Raptor-S telescope began
imaging at 09:16:27.58 UT, 19.9 s after the Swift trigger time. We do not
detect the optical counterpart reported by RATIR (Golkhou, et al., GCN 19236).
We derive the following 3-sigma limits for our unfiltered observations based
on comparison to the USNO-B1.0 catalog R-band.
t-mid(s) exp(s) mag_limit
-------------------------------
32.5 5 17.4
67.8 40 18.6
131.8 10 18.0
180.4 100 19.2
249.9 200 19.6
GCN Circular 19246
Subject
GRB 160327A: JCMT SCUBA-2 sub-mm observation
Date
2016-03-29T19:28:48Z (10 years ago)
From
Ian Smith at Rice U <ian@spacsun.rice.edu>
I.A. Smith (Rice U.), N.R. Tanvir (U. of Leicester), and Y. Urata (NCU)
report:
We observed the location of GRB 160327A (Racusin et al., GCN Circ. 19235)
using the SCUBA-2 sub-millimeter continuum camera on the James Clerk
Maxwell Telescope. The observation started at 10:24 UT on 2016-03-27,
corresponding to 68 minutes after the burst trigger. Exposures totaling
1.0 hours were made in good weather conditions. No source was detected,
with the RMS background noise being 2.0 mJy/beam at 850 microns and
26.0 mJy/beam at 450 microns.
We thank Callie Matulonis and Iain Coulson for the prompt support of
these observations that were taken under project M16AP005.
GCN Circular 19245
Subject
GRB 160327A: Imaging and spectroscopy from GTC
Date
2016-03-29T18:18:21Z (10 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), N.R. Tanvir (U. Leicester),
Z. Cano (U. Iceland), L. Izzo (U. Roma1), J.P.U. Fynbo (DARK/NBI),
R. Sanchez-Ramirez (IAA-CSIC), C.C. Thoene (IAA-CSIC), P. Pesev
(GRANTECAN, IAC, ULL) report:
We observed the field of GRB 160327A (Racusin, et al., GCN 19235) with
OSIRIS mounted on the 10.4 m GTC telescope, located at Roque de los
Muchachos Observatory (La Palma, Spain) starting at 00:26 UT on 28th
March 2016 (15.17 hr after the burst).
In the acquisition image, we identify the afterglow proposed by Golkhou
et al. (GCN 19236) and later also observed by Zheng & Filippenko (GCN
19242). At the time of our observation, the object was at a magnitude
of i(AB) = 23.89 +/-0.12 (as compared to nearby SDSS stars), with
coordinates of (J2000.0, +/-0.5"):
R.A.: 09:46:48.56
Dec.: +54:00:46.3
We also note the presence of two other sources within 2.5��� of the GRB
afterglow: The first one is located at 09:46:48.35, +54:00:47.8 and has a
magnitude of i(AB) = 23.76+/-0.11, and the second one is at 09:46:48.55,
+54:00:44.2 with a magnitude of i(AB) = 24.24+/-0.15. We suspect that
these sources may be contributing to the magnitudes given by Golkhou
et al. (GCN 19243), especially in the bluer bands.
Spectroscopy of the GRB afterglow and the first of the two other objects
was obtained by exposing 3x1200 s with grism R1000R, which covers
between 5100 and 10100 Angstrom. We detect a trace of the GRB
afterglow above 7300 AA, below which the emission drops abruptly. The
other object shows a continuum over the complete spectral range,
suggesting that this object is unrelated to the GRB. The afterglow
spectrum is indicative of a Lyman-alpha drop at a redshift between 4.90
and 5.01, with a most probable value at z = 4.99, although even lower
redshifts could not be discarded for unusually large Hydrogen column
densities. Due to the low S/N of the spectrum we are not able to confirm
any other absorption lines at this time.
GCN Circular 19243
Subject
GRB 160327A: Continued RATIR Optical and NIR Observations
Date
2016-03-28T20:27:50Z (10 years ago)
From
V. Zach Golkhou at ASU/RATIR <golkhou@gmail.com>
V. Zach Golkhou (ASU), 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), and Vicki Toy (UMD) report:
We observed the field of GRB 160327A (Racusin, et al., GCN 19235