GRB 131231A
GCN Circular 15711
Subject
GRB 131231A: AAO optical observations
Date
2014-01-09T16:06:01Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V.
Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the optical counterpart of the Fermi/LAT GRB 131231A
(Sonbas et al., GCN 15640; Xu et al. GCN 15641) with AS-32 (0.7m)
telescope of Abastumani Observatory on Jan. 3, 4, and 5. We obtained
several unfiltered images of 120 s exposure during each observational
set. On stacked images we clearly detect the afterglow. The photometry
based on the reference stars, R-mag, from Halpern (GCN 15646) is following:
Date T_start t-t0, exp, OT
(UT) mid, d s
2014-01-03 17:08:16 3.54893 33x120 20.26 �� 0.06
2014-01-04 16:53:04 4.53207 29x120 20.32 �� 0.08
2014-01-05 15:59:46 5.50061 34x120 20.74 �� 0.13
GCN Circular 15681
Subject
GRB 131231A : Lulin Optical Observations
Date
2014-01-05T01:36:03Z (12 years ago)
From
Yuji Urata at Nat. Central U. <urata@astro.ncu.edu.tw>
K.Y. Huang (NTNU), Y. Urata (NCU) on behalf of EAFON report:
We observed the optical afterglow of GRB131231A (Xu et al., GCN 15641)
using the Lulin One-meter Telescope (LOT) with g, r, i, and z
filters. The monitoring observation was made on the night of 1, 2 and
4, Jan, 2014. Based on nearby stars reported by Halpern (GCN15646) and
Perley (GCN15650), we made photometry of the GRB afterglow. The
temporal decay index alpha remains ~1 including the latest epoch. Some
of photometry is summarized below.
epoch(d) g-mag g-err
1.259 19.6 0.1
2.247 20.3 0.1
4.377 20.9 0.1
GCN Circular 15680
Subject
GRB 131231A: CARMA 3mm detection
Date
2014-01-05T01:15:53Z (12 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
We observed the position of GRB 131231A (Sonbas et al., GCN 15640; Jenke
and Xiong, GCN 15644) with the Combined Array for Research in Millimeter
Astronomy between 2013-01-01 23:54:54 UT and 2013-01-02 02:02:17 UT
(1.798-1.887 days post-GRB) at a mean frequency of ~93 GHz, under good
conditions.
We identify a weak source consistent with the optical localization (Xu
et al., GCN 15651; Singer et al., GCN 15643) in the reduced map. The
afterglow flux at this time is measured to be 0.85 +/- 0.25 mJy.
We thank observers B. A. Zauderer and M. Balokovic and the CARMA staff
for executing the observation.
GCN Circular 15676
Subject
GRB 131231A, Optical Observations
Date
2014-01-04T12:00:42Z (12 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S.B. Pandey, Brajesh Kumar and Archana Soam (ARIES Nainital India,
on behalf of larger Indian GRB collaboration)
The Fermi-LAT detected GRB 131231A (Sonbas et al., GCN 15640;
Xu et al., GCN 15641) was monitored with the 1.04m and 1.3m
telescopes at ARIES Nainital starting at 2014-01-01 13:15:13 (UT).
Several images in R_c and I_c pass-bands were obtained.
The optical afterglow was clearly detected in individual frames.
The preliminary photometry of the first R_c frame (exposure time
300 sec) yields afterglow magnitude to be 19.2+-0.1 mag.
The nearby USNO stars have been used for calibrate.
This massage may be cited.
GCN Circular 15673
Subject
GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
Date
2014-01-03T19:47:04Z (12 years ago)
From
Stephen Holland at STScI <sholland@stsci.edu>
S. T. Holland (STScI) and
V. Mangano (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began observations of the field of GRB 131231A 136.5 ks
after the Fermi/LAT trigger (Sonbas et al., 2013, GCNC 15640). The
preliminary UVOT position is
RA (J2000) 00:42:21.66 = 10.59025 (deg)
Dec (J2000) -01:39:10.6 = -1.65294 (deg)
with an estimated uncertainty of 0.43 arcsec (radius, 90% confidence,
statistical + systematic). We detect the optical afterglow at the
position reported by Xu et al. (2013, GCNC 15641). Preliminary UVOT
photometry is presented below.
------------------------------------------------------
Filter TSTART TSTOP Exposure Mag Err
------------------------------------------------------
u 246,875 248,554 1652 19.57 0.10
white 136,762 138,942 1650 19.37 0.05
white 228,985 231,172 1639 20.07 0.07
------------------------------------------------------
The quoted magnitudes and upper limits have not been corrected for the
Galactic extinction along the line of sight to this burst of E_{B-V} =
0.02 mag (Schlafly et al. 2011, ApJS, 737, 103). The photometry is in
the UVOT photometric system (Breeveld et al. 2011, AIP
Conf. Proc. 1358, 373).
The white observations yield a power-law decay index of alpha ~ 1.25
between 1.6 and 2.7 days. This is consistent with that found by
Perley et al. (2014, GCNC 15650) between 1.0 and 1.9 days. The
power-law decay index in the X-ray band at this time is alpha ~ 1.6
(Mangano et al. 2014, 15648), suggesting that there may be a cooling
break between the optical and X-ray regimes.
GCN Circular 15672
Subject
GRB 131231A: Fermi GBM correction to GCN 15644
Date
2014-01-03T19:03:04Z (12 years ago)
From
Peter Jenke at MSFC <peter.a.jenke@nasa.gov>
P. Jenke (UAH) reports on behalf of the Fermi GBM team:
"The quoted fluence (10-1000 keV) in GCN 15644 (P. Jenke et al)
was in fact the time integrated average energy flux for this burst. The actual
fluence (10-1000 kev) for this event is (1.400 +/- 0.001)E-4 ergs/cm^2."
GCN Circular 15670
Subject
Konus-Wind observation of GRB 131231A
Date
2014-01-03T17:15:47Z (12 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long-duration GRB 131231A
(Fermi-LAT detection: Sonbas, et al., GCN 15640;
Fermi-GBM observation: Jenke & Xiong, GCN 15644)
triggered Konus-Wind at T0=17132.361 s UT (04:45:32.361).
The light curve shows a broad mult-peaked pulse from ~T0-13 s to ~T0+35 s.
The emission is seen up to ~15 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131231_T17132/
Note: periodic 'dips' in the count rate are due
to the GRB source occultation by the s/c structure.
As observed by Konus-Wind, the burst
had a fluence of (1.55 � 0.05)x10-4 erg/cm2,
and a 64-ms peak flux, measured from T0+7.488 s,
of (2.14 � 0.13)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+34.303 s)
is best fit in the 35 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.28 � 0.04,
the high energy photon index beta = -2.47 � 0.05,
the peak energy Ep = 163 � 6 keV,
chi2 = 93.8/95 dof.
The spectrum near the maximum count rate
(measured from T0+5.888 s to T0+8.448 s)
is best fit in the 35 keV - 10 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.76 � 0.09,
and the peak energy Ep = 226 � 14 keV,
chi2 = 94.3/82 dof.
Assuming the redshift z=0.644 (Xu, et al., GCN 15645;
Cucchiara, GCN 15652),
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 (1.7 � 0.1)x10^53 erg,
the peak luminosity L_iso is (3.9 � 0.2)x10^52 erg/s,
and the rest-frame peak energy Ep,i = (270 � 10) keV
All the quoted results are preliminary.
GCN Circular 15652
Subject
GRB 131231A: Gemini-South Redshift
Date
2014-01-02T21:09:59Z (12 years ago)
From
Antonino Cucchiara at NASA/GSFC <antonino.cucchiara@nasa.gov>
A. Cucchiara (ORAU/NASA-GSFC) reports on behalf
of a larger collaboration:
"On January 1.09 UT (~21.5 hours after the trigger) we observed
the afterglow of GRB 131231A (Sombas et al. GCN 15640, Xu et
al. GCN 15641, Malesani et al. 15642, Singer et al. GCN 15643)
with the Gemini South telescope equipped with the GMOS
camera.
A series of spectroscopic observations in Nod & Shuffle more, was
carried out using the R400 grating covering the 6000-10000 A
wavelength range at an average airmass of 2.1.
The resulting spectra show absorption features from CaH+K,
as well as emission lines from forbidden [OII]3727 and
[OIII]4959,5007 transitions at the common redshift of z=0.6439,
consistent with the one reported by Xu et al. (GCN 15645).
We thank the Gemini staff for performing these observations,
in particular E. Marin and E. Wenderoth."
GCN Circular 15650
Subject
GRB 131231A: P60 observations
Date
2014-01-02T05:09:18Z (12 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
We imaged the location of GRB 131231A with the Palomar 60-inch (P60)
robotic telescope on UT 2014-01-01 between 03:28:31 and 04:22:05, and
again on 2014-01-02 between 01:56:28 and 02:37:12. Observations were
taken in the g, r, i, and z filters during each epoch.
The afterglow (Xu et al., GCN 15641) is well-detected in individual
exposures in all bands. Both nights were photometric and we calibrated
the field using an observation of the nearby standard field SA92.
Some photometry of the GRB afterglow in the gri bands (all on the
SDSS/AB system) is:
r = 18.84 +/- 0.02 (t = 0.965 d)
i = 18.72 +/- 0.02 (t = 0.970 d)
g = 19.14 +/- 0.02 (t = 0.982 d)
r = 19.77 +/- 0.03 (t = 1.886 d)
i = 19.64 +/- 0.04 (t = 1.893 d)
g = 20.06 +/- 0.03 (t = 1.907 d)
The power-law temporal decay index in all bands is approximately alpha=1.3.
We also give gri magnitudes of the five nearby calibration stars
presented by Halpern (GCN 15646) for reference:
star RA dec R g r i
A 00:42:30.4 -01:36:13 16.07 16.86 16.28 16.11
B 00:42:11.7 -01:37:29 17.95 19.50 18.24 17.66
C 00:42:15.9 -01:39:08 17.92 19.16 18.20 17.85
D 00:42:20.0 -01:41:53 17.22 17.62 17.48 17.58
E 00:42:28.8 -01:40:16 17.96 18.76 18.18 18.02
GCN Circular 15648
Subject
GRB 131231A: Swift-XRT observations
Date
2014-01-01T17:39:26Z (12 years ago)
From
Vanessa Mangano at PSU <vxm22@psu.edu>
V. Mangano (PSU), K. Page (U. Leicester), D. Malesani (DARK/NBI)
report on behalf of the Swift-XRT team:
We have analysed 4.0 ks of XRT data for the Fermi/LAT-detected burst:
GRB 131231A, from 52.1 ks to 62.5 ks after the Fermi/LAT trigger. The
data are entirely in Photon Counting (PC) mode.
An X-ray source is detected at a position consistent with the optical afterglow
(Xu et al., GCN 15641) at a mean count rate of 0.4 ct/s.
The refined XRT position is RA, Dec = 10.5904, -1.6519 which is equivalent to:
RA (J2000): 00 42 21.70
Dec(J2000): -01 39 06.7
with an uncertainty of 3.5 arcsec (radius, 90% confidence). This
position is 695 arcsec from the Fermi/LAT position and 4 arcsec
from the optical afterglow.
The light curve can be modelled with a power-law decay with an
index of alpha=1.6 (+/-0.7).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.86 (+0.13, -0.13). The
best-fitting absorption column at the redshift of 0.642 (Xu et al., GCN 15645)
is 1.4 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of
2.6 x 10^20 cm^-2 (Kalberla et al. 2005).
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced
from this spectrum is 3.0 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1.
Further ToO observations have already been scheduled for today.
This circular is an official product of the Swift-XRT team.
GCN Circular 15647
Subject
GRB 131231A : xinglong TNT optical observation
Date
2014-01-01T13:10:54Z (12 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, J. Y. Wei, X. F. Wang, Y. L. Qiu, J. S. Deng, J. Wang,
X. H. Han and C. Wu on behalf of EAFON report:
We began to observe GRB 131231A (Sonbas et al., GCN 15640;
Xu et al., GCN 15641,15645; Malesani et al., GCN 15642; Singer et al. GCN 15643;
Halpern GCN 15646) with Xinglong 0.8-m TNT telescope at 10:29:40 (UT) ,
Jan. 1th, at 2014, about 29.73 hours after the burst.
12*300 sec B,V,R-band images were obtained.
The optical afterglow (Xu et al., GCN 15641) was clearly detected
with a magnitude of 18.97+/-0.1 mag in R band, calibrated by USNO B1.0 R2mag
at the mean time of 29.73 hours after the burst.
Compared with the report by Halpern GCN 15646, the brightness of this afterglow
decayed for 0.36 mag during the epoch between 22.55 hours and 29.73 hours after the burst.
This message may be cited.
GCN Circular 15646
Subject
GRB 131231A: MDM afterglow observation
Date
2014-01-01T08:13:16Z (12 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern (Columbia U.) reports:
I observed the afterglow of GRB 131231A (Sonbas et al., GCN 15640;
Xu et al., GCN 15641) using the 1.3m McGraw-Hill telescope of the
MDM Observatory on 2014 January 1, from 01:40 to 03:18 UT.
Nineteen 5-minute exposures were obtained in the R-band.
Conditions were photometric, and the Landolt standard-star field
around PG0231+051 was used for calibration. The afterglow magnitudes
measured for the first and last exposures of the sequence are:
--------------------------------
Jan 1 UT t-t0(hr) R +/-
--------------------------------
01:40 20.92 18.48 0.02
03:18 22.55 18.61 0.02
--------------------------------
The following stars in field were calibrated, and can be used for
comparison:
-----------------------------------------
Star R.A.(2000) Decl.(2000) R
-----------------------------------------
A 00 42 30.4 -01 36 13 16.07
B 00 42 11.7 -01 37 29 17.95
C 00 42 15.9 -01 39 08 17.92
D 00 42 20.0 -01 41 53 17.22
E 00 42 28.8 -01 40 16 17.96
-----------------------------------------
GCN Circular 15645
Subject
GRB 131231A: VLT/X-shooter redshift
Date
2014-01-01T02:36:10Z (12 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
D. Xu (DARK/NBI), D. Malesani (DARK/NBI), N. R. Tanvir (Univ.
Leicester), V. D'Elia (ASI/ASDC), A. de Ugarte Postigo (IAA/CSIC and
DARK/NBI), T. Kruehler (ESO), J. P. U. Fynbo (DARK/NBI) report on behalf
of a larger collaboration:
We observed the optical counterpart of the Fermi/LAT GRB 131231A (Sonbas
et al., GCN 15640; Jenke & Xiong, GCN 15644; Xu et al., GCN 15641) with
the ESO VLT equipped with the X-shooter spectrograph. The mean time of
our observation is 2014 Jan 1.04 UT, that is 20.2 hr after the GRB. The
spectrum covers the wavelength range 3200 to 18,000 AA.
The trace of the afterglow is well visible in all arms. We detect
several absorption features which we interpret as due to Fe II, Mg II,
Ca H and K, all at a common redshift z = 0.642 (wavelength solution
based on archival calibration lamps). Emission lines corresponding to
the [O III] doublet are also detected at the same redshift.
We acknowledge excellent support from the observing staff in Paranal, in
particular Steffen Mieske.
GCN Circular 15644
Subject
GRB 131231A: Fermi GBM detection
Date
2014-01-01T00:42:48Z (12 years ago)
From
Peter Jenke at MSFC <peter.a.jenke@nasa.gov>
P. Jenke (UAH) and S. Xiong (UAH) reports on behalf of the Fermi GBM Team:
"At 04:45:16.083 UT on December 31 2013, the Fermi Gamma-Ray
Burst Monitor triggered and located
GRB 131231A (trigger 410157919/131231198).
This GRB was detected in a ground analysis by
the Fermi LAT (Sonbas et al. GCN 15640).
It was also detected in optical follow-up observations
of the GBM position by DARK/NBI (Xu et al. GCN 15641)
and iPTF (Singer et al. GCN 15643), and confirmed by NOT
observations of the Fermi LAT position (Malesani et al. GCN 15642).
The on-ground calculated location from GBM is consistent
with the positions reported from these follow-up observations.
The trigger resulted in an Autonomous Repoint Request (ARR)
that was accepted and the LAT slewed to the GBM in-flight
location. The initial angle from the LAT boresight is 38 deg
from Fermi/GBM position.
The GBM light curve consists of a single large peak preceded
by a smaller peak which resulted in the trigger. The
duration (T90) of the burst was about 31 s (50-300 keV).
The time-averaged spectrum from T0+.003 s to T0+56 s is
best fit with a Band function with Epeak = 146 +/- 3 keV,
alpha = -1.10 +/- 0.01 and beta = -2.14 +/- 0.01.
The event fluence (10-1000 keV) in this time interval is
(2.51 +/- 0.01)E-06 erg/cm^2. The 1.0-sec peak photon flux
measured starting from T0+22 s in the 10-1000 keV band
is 67.3 +/- 0.8 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 15643
Subject
GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
Date
2013-12-31T23:07:42Z (12 years ago)
From
Leo Singer at CIT/PTF <lsinger@caltech.edu>
L. P. Singer (Caltech), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal
(Carnegie Observatories) report on behalf of the intermediate Palomar
Transient Factory (iPTF) collaboration:
Upon receiving the final GBM localization for GRB 131231A, we
selected ten fields to observe with the Palomar 48-inch Oschin
telescope (P48) covering 62 deg^2, most of the 1-sigma GBM error
circle. Due to the short remaining visibility window at Palomar, we
obtained only one epoch of images of five of the ten fields covering
30 deg^2. This includes ~90% of the LAT error localization (Sonbas et
al., GCN 15640).
Sifting through 50 candidate variable sources near the LAT error
circle using standard iPTF vetting procedures, at 1.45 hours after
the burst we identify multiple uncatalogued sources, including
iPTF13ekl at R=15.7 mag, at the coordinates
RA(J2000) = 00h 42m 21.67s
DEC(J2000) = -01d 39' 11.0"
This position coincides with the Nanshan optical afterglow candidate
at 7.91 hours after the burst (Xu et al., GCN 15641). There are no
coincident sources in SDSS and no associated minor planets in the IAU
Minor Planet Center database at this location.
Despite the low ecliptic latitude of -5.7 deg, the two coincident
optical detections separated by 6.46 hours strongly disfavor a solar
system origin. These two observations fit a power-law decay with an
index of alpha=-1.03, suggesting that the source is indeed associated
with the GRB trigger.
See <http://www.its.caltech.edu/~lsinger/iptf/Fermi410157919.pdf> for
a depiction of the LAT error circle in relation to the P48 optical
candidates, with iPTF13ekl highlighted, and a selection of the P48
fields observed.
GCN Circular 15642
Subject
GRB 131231A: afterglow confirmation from the NOT
Date
2013-12-31T23:02:02Z (12 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
D. Malesani, D. Xu (DARK/NBI), I. R. Losada (Stockholm), F. Duval
(Stockholm), report on behalf of a larger collaboration:
We observed the afterglow candidate of GRB 131231A (Sonbas et al., GCN
15640; Xu et al., GCN 15641) using the 2.56m Nordic Optical Telescope
(NOT) equipped with MOSCA. Observations started at 22:05:40 UT on 2013
Dec 31 (i.e., 17.3 hr after the Fermi trigger).
The afterglow candidate noted by Xu et al. (GCN 15641) has decayed to
R=18.6, using the same calibration. We thus suggest that this source is
very likely the afterglow of GRB 131231A. The coordinates of the
afterglow can be refined to
R.A. = 00:42:21.665
Dec. = -01:39:10.61
with an error of 0.3".
We also wish a happy new year to everyone.
GCN Circular 15641
Subject
GRB 131231A: Nanshan afterglow candidate
Date
2013-12-31T21:39:24Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), H.-B. Niu, X. Zhang, A. Esamdin, L. Ma (XAO) report:
We observed the LAT field of GRB 131231A (Sonbas et al., GCN 15640)
using the 1m telescope located on Mt. Nanshan, Xinjiang, China,
equipped with a 1.2x1.2 deg^2 CCD camera. We obtained a series of 120s
and 300s frames at the mean time 12:40 UT on 2013-12-31 (i.e., 7.91 hr
after the Fermi trigger).
Within the LAT error circle (RA, Dec 10.585, -1.845 with an error
radius of 0.149 deg, error statistical only) reported in Sonbas et al.
(GCN 15640), no new prominent uncatalogued source is found and the
depth of the Nanshan image is similar to that of DSS II. Given that
the above LAT error is statistical only, we thus inspect that
surrounding region the LAT error circle and discovered a bright
source, not present in both DSS II and SDSS, at coordinates
R.A.=00:42:21.66
Dec.=-01:39:10.79
Err Radius: ~1.5 arcsec
with a magnitude of R~17.6, calibrated with nearby USNO B1 stars.
Follow-up observations are encouraged to check whether the source is
the afterglow of the burst.
GCN Circular 15640
Subject
GRB 131231A: Fermi-LAT detection of a burst
Date
2013-12-31T18:38:00Z (12 years ago)
From
Eda Sonbas at NASA/GSFC <edasonbas@gmail.com>
E. Sonbas (Adiyaman Univ.), J. L. Racusin (NASA/GSFC), D. Kocevski
(NASA/GSFC) and J. McEnery (NASA/GSFC), report on behalf of the Fermi-LAT
team:
At 04:45:16.08 on Dec 31, 2013, Fermi LAT detected high energy emission
from GRB 131231A, which was also detected by Fermi-GBM (trigger
410157919/131231198).
The best LAT on-ground location is found to be RA, Dec 10.585,
-1.845 (J2000) with an error radius of 0.149 deg (90% containment,
statistical error only), this was 40 deg from the LAT boresight at the time
of the trigger. The GRB was detected at high enough peak flux in the GBM
detectors to trigger an autonomous repoint of the spacecraft, which kept
the source in the LAT field of view for 900 seconds.
The data from the Fermi LAT are temporally correlated with the GBM emission
with high significance. More than 37 photons above 100 MeV and more than
11 photons above 1 GeV are observed within 900 seconds. The highest energy
photon is a 9.7 GeV event which is observed at 700 seconds after the GBM
trigger.
A Swift ToO request has been submitted.
The Fermi LAT point of contact for this burst is Eda Sonbas (
edasonbas@yahoo.com).
The Fermi LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S. and many
scientific institutions across France, Italy, Japan and Sweden.