GRB 160127A
GCN Circular 18938
Subject
GRB 160127A: Swift detection of a burst with an optical counterpart
Date
2016-01-27T09:05:29Z (9 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
A. Amaral-Rogers (U Leicester), A. P. Beardmore (U Leicester),
P.A. Evans (U Leicester), A. Y. Lien (GSFC/UMBC),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:
At 08:43:07 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 160127A (trigger=671828). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 225.956, +0.089 which is
RA(J2000) = 15h 03m 49s
Dec(J2000) = +00d 05' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multiple-peaked
structure with a duration of about 20 sec. The peak count rate
was ~800 counts/sec (15-350 keV), at ~3 sec after the trigger.
The XRT began observing the field at 08:44:25.9 UT, 78.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 225.98136, 0.07222 which is equivalent
to:
RA(J2000) = 15h 03m 55.53s
Dec(J2000) = +00d 04' 20.0"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 109 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. We cannot determine whether the source is
fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.71
x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 81 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
RA(J2000) = 15:03:55.70 = 225.98209
DEC(J2000) = +00:04:23.0 = 0.07305
with a 90%-confidence error radius of about 1.10 arc sec. This position is 3.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.13. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.06.
Burst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.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 18939
Subject
GRB 160127A: TAROT La Silla observatory optical light curve
Date
2016-01-27T12:14:43Z (9 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Bardho O. (UNS-CNRS-OCA),
Gendre B. (Etelman Observatory-UVI),
Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 160127A detected by SWIFT
(trigger 671828) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
The observations started 25.1s after the GRB trigger
(13.4s after the notice). The elevation of the field
increased from 42 degrees above horizon and weather
conditions were good.
We detected the candidate couterpart mentioned by
Amaral-Rogers et al. (GCNC 18938).
The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We detect the OT increasing its optical flux from
t0+25s to t0+45s (R~16.9) and fading until the end of
the trail at t0+85s.
Following images were acquired in tracking mode:
t1(s) t2(s) Rmag d_Rmag
99 129 17.9 0.6
141 171 17.4 0.1
182 212 17.1 0.7
223 253 17.1 0.0
306 396 17.1 0.2
407 497 17.4 0.4
610 700 17.6 0.1
711 801 17.6 0.2
914 1004 17.6 0.1
1015 1105 17.4 0.0
1742 1922 >18.4 0.6
Magnitudes were estimated with the stars:
NOMAD1 0900-0248256 ra=225.9885561 dec=+00.0840197 R=14.83
NOMAD2 0901-0246538 ra=225.9533572 dec=+00.1320336 R=14.83
Magnitudes are not corrected for galactic dust extinction.
After the first deacay observed in the trailed image from
t0+45s to t0+85s, we observed a bump (maximum flux at t0+220s
R~17.1) and we suspect a second bump (maximum flux at t0+1100s
R~17.3) followed by a steep decay. The OT become fainter
than 18.4 after t0+2000s.
GCN Circular 18940
Subject
GRB 160127A: Enhanced Swift-XRT position
Date
2016-01-27T12:39:17Z (9 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 1815 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 160127A, 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 = 225.98206, +0.07291 which is equivalent
to:
RA (J2000): 15h 03m 55.69s
Dec (J2000): +00d 04' 22.5"
with an uncertainty of 1.7 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 18941
Subject
GRB 160127A: RATIR Optical Observations
Date
2016-01-27T15:16:55Z (9 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Antonino Cucchiara (GSFC/STScI), 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), 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 160127A (Amaral-Rogers et al., GCN 18938)
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 27.39 to
2016/01 27.55 UTC (0.73 to 4.43 hours after the BAT trigger), obtaining
a total of 2.68 hours exposure in the r,i and z bands.
We detect the optical counterpart at
RA, Dec = 15:3:55.77, +00:04:22.4 (J2000, +/-0.5���).
In comparison with the SDSS DR9, we obtain the following magnitudes:
r 20.64 +/- 0.03
i 20.66 +/- 0.03
z 20.14 +/- 0.32
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
Further observations are planned.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 18943
Subject
GRB 160127A: Swift-XRT refined Analysis
Date
2016-01-27T18:07:07Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), A.
D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB),
D.N. Burrows (PSU) and A. Amaral-Rogers report on behalf of the
Swift-XRT team:
We have analysed 6.9 ks of XRT data for GRB 160127A (Amaral-Rogers et
al. GCN Circ. 18938), from 65 s to 19.1 ks after the BAT trigger. The
data comprise 121 s in Windowed Timing (WT) mode (the first 5 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. 18940).
The late-time light curve (from T0+6.0 ks) can be modelled with a
power-law decay with a decay index of alpha=1.6 (+/-0.3).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.65 (+0.23, -0.21). The
best-fitting absorption column is 1.7 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 5.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.85 (+/-0.15) and a
best-fitting absorption column of 9.7 (+4.4, -3.9) x 10^20 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.6 x 10^-11 (4.2 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 9.7 (+4.4, -3.9) x 10^20 cm^-2
Galactic foreground: 5.7 x 10^20 cm^-2
Excess significance: 1.7 sigma
Photon index: 1.85 (+/-0.15)
If the light curve continues to decay with a power-law decay index of
1.6, the count rate at T+24 hours will be 1.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.2 x
10^-14 (7.3 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00671828.
This circular is an official product of the Swift-XRT team.
GCN Circular 18944
Subject
GRB 160127A: Swift-BAT refined analysis
Date
2016-01-27T18:48:10Z (9 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
S. D. Barthelmy (GSFC), A. Amaral-Rogers (U Leicester),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), 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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 160127A (trigger #671828)
(Amaral-Rogers et al., GCN Circ. 18938). The BAT ground-calculated position is
RA, Dec = 225.966, 0.080 deg which is
RA(J2000) = 15h 03m 51.8s
Dec(J2000) = +00d 04' 46.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.
The mask-weighted light curve shows a double-peaked structure that starts
at ~ T-1 s and ends at ~ T+6 s. The two peaks occur at ~ T+1 and ~T+3 s,
respectively. T90 (15-350 keV) is 6.16 +- 0.94 sec (estimated error including
systematics).
The time-averaged spectrum from T-1.44 to T+5.70 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.99 +- 1.11,
and Epeak of 25.6 +- 0.0 keV (chi squared 44.15 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.5 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+3.34 sec in the 15-150 keV band is
1.4 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 2.43 +- 0.23 (chi squared 50.23 for 57 d.o.f.). 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/671828/BA/
GCN Circular 18945
Subject
GRB 160127A: Swift/UVOT Detection
Date
2016-01-27T20:48:49Z (9 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H. Siegel (PSU) and Amaral-Rogers (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160127A
82 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 18938).
A fading source consistent with the XRT position
(Evans et al. GCN Circ. 18940)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 15:03:55.76 = 225.98234 (deg.)
Dec (J2000) = +00:04:22.5 = 0.07291 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections 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) 82 232 147 17.59 +/- 0.04
white 574 2411 342 18.66 +/- 0.08
white 6837 7037 196 20.85 +/- 0.28
v 624 1942 156 18.46 +/- 0.19
b 550 1174 58 18.58 +/- 0.16
u (fc) 295 545 246 17.25 +/- 0.05
u 698 2362 174 18.31 +/- 0.13
u 6427 19117 1004 20.92 +/- 0.31
w1 674 1124 58 17.87 +/- 0.20
m2 824 1966 117 19.07 +/- 0.32
w2 600 1917 136 19.56 +/- 0.32
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 18946
Subject
GRB 160127A: LCOGT-Sutherland optical upper limit
Date
2016-01-28T05:58:41Z (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) report on behalf of a larger collaboration:
We observed the field of GRB 160127A (Amaral-Rogers et al., GCN 18938)
using the LCOGT-1m located at the Sutherland, South Africa. Observations
started at 01:14:53 UT on 2016-01-28 (i.e., 16.53 hr after the burst)
and a series of 120s Sloan r-band frames were obtained.
The previously reported afterglow (Amaral-Rogers et al., GCN 18938;
Klotz et al., GCN 18939; Cucchiara et al., GCN 18941) is not detected in
our stacked image, down to a limiting magnitude of m(r) ~20.5,
calibrated with the SDSS field.
GCN Circular 18947
Subject
GRB 160127A: VLA Detection
Date
2016-01-29T02:54:28Z (9 years ago)
From
Kate Alexander at Harvard <kalexander@cfa.harvard.edu>
K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger
(Harvard) report on behalf of a larger collaboration:
We observed GRB 160127A (Amaral-Rogers et al., GCN 18938) at multiple
frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2016
January 28.46 UT (1.09 days after the burst). At a mean frequency of 21.8
GHz, we detect a radio source with a preliminary flux density of ~70 uJy at
RA = 15:03:55.773 +/- 0.013
Dec = +00:04:22.07 +/- 0.17
consistent with the enhanced Swift/XRT position (Evans et al., GCN 18940)
and the optical position (Cucchiara et al., GCN 18941; Siegel &
Amaral-Rogers, GCN 18945). Follow-up observations are planned.
We thank the VLA staff for rapidly executing these observations.
GCN Circular 18948
Subject
GRB 160127A: MITSuME Akeno optical upper limits
Date
2016-01-29T08:23:14Z (9 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
Y.Saito, T.Fujiwara, T. Yoshii, Y. Tano, Y. Tachibana,
Y.Ono, S.Harita, Y.Muraki, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 160127A (A. Amaral-Rogers et al., GCN Circular #18938) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2016-01-27 17:04:39 UT (~8.4 h after the burst).
We did not find previously reported afterglow (A. Amaral-Rogers et al., GCN Circular #18938;
A. Klotz et al., GCN Circular #18939; A. Cucchiara et al., GCN Circular #18941) in all three bands.
We obtained following limits for the magnitudes.
T0+[hour] MID-UT T-EXP[sec] g' Rc Ic
-----------------------------------------------------------------------------
10.19 18:54:38 11700 > 20.7 > 20.4 > 19.2
-----------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
GCN Circular 18949
Subject
GRB 160127A: Khureltogot optical observations
Date
2016-01-29T11:37:43Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), S. Schmalz (AIP), A. Volnova (IKI), N. Tungalag
(Research Center of Astronomy and Geophysics MAS), I. Molotov (KIAM),
A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of Swift GRB 160127A (Amaral-Rogers et al., GCN
18938) with ORI-40 telescope of Khureltogot observatory starting on
Jan., 27 (UT) 19:32:48. We marginally detect optical afterglow
(Amaral-Rogers et al., GCN 18938; Klotz et al., GCN 18939; Cucchiara et
al., GCN 18941). Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err UL(3sigma)
(mid, days) (s)
2016-01-27 19:32:48 0.48499 none 90*60 21.0 0.35 21.0
2016-01-27 21:10:18 0.55333 none 89*60 n/d n/d 21.2
Photometry is based on nearby SDSS stars, R magnitude deduced from
Lupton's transformations.
SDSS_DR9_id R(Lupton)
J150358.16+000929.4 16.36
J150406.02+000738.4 16.03
J150341.40+000835.8 15.17
J150334.55+000806.9 16.20
J150334.11+000513.3 17.32
GCN Circular 18950
Subject
GRB 160127A: RATIR Optical Observations
Date
2016-01-29T16:56:34Z (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 160127A (Amaral-Rogers et al., GCN Circular
18938) 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 29.43 to
2016/01 29.55 UTC (49.72 to 52.43 hours after the BAT trigger),
obtaining a total of 1.48 hours exposure in the r, i, and z bands.
We no longer detect the optical counterpart reported by Amaral-Rogers et
al. (GCN Circular 18938), Klotz et al. (GCN Circular 18939), Cucchiara
et al. (GCN Circular 18941), and Siegel et al. (GCN Circular 18945). In
comparison with the SDSS DR9 catalog, we obtain the following 3-sigma
upper limits:
r > 23.15
i > 23.09
z > 20.00
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.