GRB 180113A
GCN Circular 22325
Subject
GRB 180113A: Swift detection of a burst
Date
2018-01-13T02:58:25Z (7 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
T. N. Ukwatta (LANL), J. R. Cummings (NASA/UMBC),
A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU) and M. H. Siegel (PSU) report on
behalf of the Neil Gehrels Swift Observatory Team:
At 02:47:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180113A (trigger=804999). Due to an observing constraint,
Swift could not slew to this burst.
The BAT on-board calculated location is
RA, Dec 19.215, +68.682 which is
RA(J2000) = 01h 16m 52s
Dec(J2000) = +68d 40' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 20 sec. The peak count rate
was ~9000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to an observing constraint, Swift will not be able to observe
this location until at least T0+36 hours. There will be no
XRT or UVOT data until this time.
Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com).
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 22328
Subject
GRB 180113A: Fermi GBM observation
Date
2018-01-13T17:45:19Z (7 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres (UAH) reports on behalf of the Fermi GBM Team:
"At 02:47:06.14 UT on 13 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180113A (trigger 537504431 / 180113116).
which was also detected by the Swift/BAT (Ukwatta et al., GCN 22325).
The GBM on-ground location is consistent with the Swift position.
The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 51 degrees.
The GBM light curve shows overlapping peaks
with a duration (T90) of about 11 s (50-300 keV).
The time-averaged spectrum from T0-1.4 s to T0+15.0 s is
best fit by a Band function with Epeak = 247 +/- 12 keV,
alpha = -0.59 +/- 0.04, and beta = -2.32 +/- 0.10.
The event fluence (10-1000 keV) in this time interval is
(1.007 +/- 0.012)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.45 s in the 10-1000 keV band
is 9.3 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 22330
Subject
GRB 180113A: KAIT Optical Observations
Date
2018-01-13T18:22:57Z (7 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 180113A (Ukwatta et al.,
GCN 22325) starting at 03:57:49 UT, 70 minutes after the burst,
and lasted for about 1.5 hours. Observations were performed with
a sequence in the clear (roughly R), V, and I filters, and the
exposure time was 60 s per image. The field is relative crowded,
after a preliminay analysis using the subtraction method, we do
not detect any optical afterglow candidate within the Swift-BAT
error circle (Ukwatta et al., GCN 22325). The typical limiting
magnitude of our single clear image is about 19.5 mag calibrated
to the APASS catalog.
GCN Circular 22332
Subject
GRB 180113A: Swift-BAT refined analysis
Date
2018-01-14T12:24:33Z (7 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180113A (trigger #804999)
(Ukwatta et al., GCN Circ. 22325). The BAT ground-calculated position is
RA, Dec = 19.211, 68.682 deg which is
RA(J2000) = 01h 16m 50.7s
Dec(J2000) = +68d 40' 55.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.
The mask-weighted light curve shows some weak emissions that starts at ~T-15 s,
followed by the main structure with several overlapping pulses from ~ T0 to ~T+15 s,
and a weak tail that lasts until ~T+70 s. T90 (15-350 keV) is 64 +- 16 sec
(estimated error including systematics).
The time-averaged spectrum from T-12.98 to T+67.02 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.08 +- 0.06. The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+10.52 sec in the 15-150 keV band
is 2.5 +- 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/804999/BA/
GCN Circular 22339
Subject
GRB 180113A: Swift ToO observations
Date
2018-01-15T11:28:20Z (7 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Swift/BAT GRB 180113A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00804999
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 22344
Subject
Konus-Wind observation of GRB 180113A
Date
2018-01-15T15:37:30Z (7 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 180113A (Swift/BAT detection: Ukwatta et al.,
GCN 22325, GCN 22332; Fermi-GBM detection: Veres, GCN 22328)
triggered Konus-Wind at T0=10027.005 s UT (02:47:07.005).
The KW light curve shows a single pulse with a total duration
of ~13 s. The emission is seen up to ~1 MeV.
As observed by Konus-Wind, the burst had a fluence of
(1.36 �� 0.10)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+0.448, of (3.1 �� 0.3)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.80(-0.12,+0.13),
and the peak energy Ep = 293(-29,+36) keV,
chi2 = 72/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-3.0.
The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.72(-0.12,+0.13),
and the peak energy Ep = 308(-30,+36) keV,
chi2 = 83/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-3.0.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180113_T10027/
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 22359
Subject
GRB 180113A CALET Gamma-Ray Burst Monitor detection
Date
2018-01-17T05:44:00Z (7 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
S. Torii (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The long-duration GRB 180113A (Ukwatta et al., GCN circ. 22325; Veres et al.,
GCN circ. 22328; Frederiks et al., GCN circ. 22344) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 02:47:03.27 on 13 January 2018. The burst
signal was seen by the all CGBM instruments.
The light curve of the SGM shows two overlapping pulses. The emission
starts at T+3 sec, peaks at T+4 sec and ends at T+16 sec. The T90 and
the T50 durations measured by the SGM data are 11.3 +- 1.3 sec and
7.0 +- 0.6 sec (40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1199846617
The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.
GCN Circular 22363
Subject
GRB 180113A: AstroSat CZTI detection
Date
2018-01-20T18:19:33Z (7 years ago)
From
Vidushi Sharma at IUCAA <vidushi@iucaa.in>
V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of Astrosat CZTI data showed the detection of bright GRB 180113A, which was also detected by Swift (Ukwatta T. N. et al., GCN 22325), Fermi-GBM (Veres P. et al., GCN 22328), Konus-Wind (Frederiks D. et al., GCN 22344) and CALET (Torii S. et al., GCN 22359).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 02:47:07.500 UT, ~1.5 s after the Swift-BAT trigger. The measured peak count rate is 345 cts/s above the background in combined data of four quadrants, with a total of 2536 cts. The local mean background count rate was 628 cts/s. Using cumulative rates, we measure a T90 of 14.3 s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.