GRB 171102A

**M. Yassine (Univ & INFN Trieste), E. Bissaldi (Politecnico & INFN Bari)
and D. Kocevski (NASA/MSFC) report on behalf of the Fermi-LAT team:

At 2:33:35.99 UT on November 02, 2017, Fermi-LAT detected
high-energy emission from GRB 171102A,
which was also detected by Fermi-GBM (trigger 531282820).

The best LAT on-ground location is found to be

RA, Dec: 188.41, 53.63 (degrees, J2000)

with an error radius of 0.57 deg (90% containment, statistical error only).
This was 43 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase
in the event rate that is spatially and temporally correlated
with the GBM emission with high significance.

More than 17 photons above 100 MeV are observed within 500 seconds.
The highest-energy photon is a 500 MeV event which is
observed��328 seconds after the GBM trigger.

A Swift ToO has been requested for this burst. 

The Fermi-LAT point of contact for this burst is
Manal Yassine (mychbib@gmail.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.

[GCN OPS NOTE(03nov17): Per author's request, the URL link to the Swift ToO page
and the URL link to gmail were removed.]

[GCN OPS NOTE(06nov17): Per author's request, intitutional affiliation
was corrected from INAF to INFN.]

M. Stanbro (UAH), C. Meegan (UAH), and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 02:33:35.99 UT on 02 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171102A (trigger 531282820 / 171102107)
which was also detected by the Fermi-LAT (M. Yassine et al. 2017, GCN 22081
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 )
The GBM on-ground location is consistent with the LAT 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 LAT location is 43 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 35 s (50-300 keV).
The time-averaged spectrum from T0+20.48 s to T0+56.32 s is
best fit by a Band function with Epeak = 171 +/- 6 keV,
alpha = -0.82 +/- 0.02, and beta = -2.59 +/- 0.14.

The event fluence (10-1000 keV) in this time interval is
(2.88 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+49.2 s in the 10-1000 keV band
is 28.7 +/- 0.3 ph/s/cm^2.

A power law function with an exponential high-energy cutoff
fits the spectrum equally well.  The power law index is -0.87 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 187 +/- 4 keV.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, report:

The long-duration GRB 171102A (Yassine et al., GCN Circ. 22081
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 ; Stanbro 
et al., GCN Circ. 22083
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 ) was detected by Konus-Wind, Fermi (GBM trigger 
531282820), INTEGRAL (SPI-ACS), and Swift (BAT) at about 9216 s UT 
(02:33:36). The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3-sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   188.823 (12h 35m 18s) +54.288 (+54d 17' 15")
  Corners:
   180.299 (12h 01m 12s) +53.175 (+53d 10' 31")
   179.157 (11h 56m 38s) +54.095 (+54d 05' 41")
   197.995 (13h 11m 59s) +54.514 (+54d 30' 52")
   198.922 (13h 15m 41s) +53.378 (+53d 22' 41")
  ---------------------------------------------
The error box area is 11.5 sq. deg, and its maximum
dimension is 11.7 deg (the minimum one is ~1 deg).
The Sun distance was about 70 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171102_T09247/IPN

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, intense GRB 171102A
(Fermi-LAT detection: Yassine et al., GCN 22081
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 ;
Fermi GBM detection: Stanbro et al., GCN 22083
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 ;
IPN Triangulation: Kozlova et al., GCN 22091
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 )
triggered Konus-Wind at T0=9247.579 s UT (02:34:07.579).

The burst light curve shows two emission episodes
with a total duration of ~28 s.
The emission is seen up to ~1 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.96(-0.32,+0.27)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+14.608 s,
of 5.87(-0.95,+0.96)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+21.760 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.76(-0.11,+0.11),
the high energy photon index beta = -2.98(-3.40,+0.31),
the peak energy Ep = 174(-12,+16) keV,
chi2 = 90/97 dof.

The spectrum near the peak count rate
(measured from T0+8.448 to T0+16.128 s)
is best fit in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with�� alpha = -0.91(-0.12,+0.12),
and Ep = 203(-17,+21) keV (chi2 = 56/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.52 (chi2 = 56/59 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171102_T09247/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

Y. Kawakubo, A. Yoshida, T. Sakamoto, M. Moriyama, Y. Yamada,
A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (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 171102A (Yassine et al., GCN circ. 21615
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 ;
Stanbro et al., GCN circ. 22083
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 ; Kozlova et al., GCN circ. 22091
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 ;
Tsvetkova et al., GCN circ. 22094
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 ; INTEGRAL SPI-ACS trigger #7955) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 02:33:36.14 on 2 November 2017.
The burst signal was seen by the all CGBM instruments.  Because of a problem
in one of the ground alert processing script, the GCN notice was not distributed
automatically for this event.

The light curve of the SGM shows a complex structure with a precursor around
T0.  The precursor emission starts at T-2 sec and ends at T+2 sec.  The main burst
episode starts at T+30 sec, peaks at T+48 sec and ends at T+60 sec.  The T90
duration measured by the SGM data is 21.9 +- 0.3 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1193625133/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.