GRB 190103A

A.Ursi (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A.
Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F.
Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli,
V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN
Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team:

The AGILE Mini-CALorimeter (MCAL) detected a burst at T0 = 2019-01-03
16:42:15.05 +/- 0.01 s (UTC).

The event lasted about 4.7 s and released a total number of ~5426 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of about 700 Hz. The light curve shows two peak episodes.

The GRB is clearly detected also by the AGILE scientific ratemeters; in
particular, by the Super-AGILE (20-60 keV), Anti-Coincidence (50-200 keV),
and MCAL (0.4-100 MeV) ratemeters.

Further analysis is still in progress.

The AGILE-MCAL detector has a full solid angle acceptance, and is
operational in the range 0.4 - 100 MeV.

T. Khanam, V. Sharma and A. Vibhute (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 a long GRB 190103A, which was also detected by AGILE/MCAL (Ursi A. et al., GCN 23600
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 ).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 16:42:16.500 UT, ~ 1 s after AGILE/MCAL trigger. The measured peak count rate is 2221 cts/s above the background in combined data of four quadrants, with a total of 10698 cts. The local mean background count rate was 486.7 cts/s. Using cumulative rates, we measure a T90 of 25.4 s. In preliminary analysis, we find that 927 compton events are associated with this event.

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.

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

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

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

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

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 190103A (AGILE (MCAL) detection:
Ursi et al., GCN Circ. 23600
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 ; AstroSat (CZTI) detection:
Khanam et al., GCN Circ. 23609
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 ) was detected by Konus-Wind,
INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), AGILE (MCAL),
AstroSat (CZTI), and Swift (BAT) at about 60113 s UT (16:41:53).
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:
   251.409 (16h 45m 38s) +17.382 (+17d 22' 54")
  Corners:
   251.079 (16h 44m 19s) +18.134 (+18d 08' 01")
   251.470 (16h 45m 53s) +18.711 (+18d 42' 41")
   251.734 (16h 46m 56s) +16.622 (+16d 37' 21")
   251.342 (16h 45m 22s) +16.027 (+16d 01' 37")
  ---------------------------------------------
The error box area is about 0.93 sq. deg, and its maximum
dimension is 2.69 deg (the minimum one is 26.4 arcmin).
The Sun distance was about 51 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB190103_T60113/IPN/

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

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

The long-duration, intense GRB 190103A
(AGILE/MCAL detection: Ursi et al., GCN 23600
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 ;
AstroSat CZTI detection: Khanam et al., GCN 23609
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 ;
IPN triangulation: Hurley et al., GCN 23646
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 )
triggered Konus-Wind at T0=60113.215 s UT (16:41:53.215).

The burst light curve shows two emission episodes
with a total duration of ~33 s.
The emission is seen up to ~16 MeV.

As observed by Konus-Wind, the burst
had a fluence of 7.14(-0.65,+0.68)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+21.648 s,
of 2.00(-0.30,+0.32)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+32.512 s)
is best fit in the 20 keV - 16 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.90(-0.07,+0.07),
the high energy photon index beta = -2.41(-0.24,+0.16),
the peak energy Ep = 304(-26,+28) keV,
chi2 = 85/97 dof.

The spectrum near the peak count rate
(measured from T0+21.504 to T0+24.320 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.76(-0.08,+0.09),
the high energy photon index beta = -2.39(-0.31,+0.20),
the peak energy Ep = 396(-46,+50) keV,
chi2 = 49/62 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190103_T60113/

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