GRB 190329A

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,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
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,

A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE 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, bright GRB 190329A was detected by
Konus-Wind, Mars-Odyssey (HEND), INTEGRAL (SPI-ACS),
AGILE (MCAL), and CALET (GBM trigger 1237875481),
at about 22910 s UT (06:21:50).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   333.269 (22h 13m 05s) +19.640 (+19d 38' 25")
  Corners:
   333.369 (22h 13m 29s) +19.121 (+19d 07' 16")
   333.043 (22h 12m 10s) +20.087 (+20d 05' 13")
   333.169 (22h 12m 41s) +20.159 (+20d 09' 31")
   333.495 (22h 13m 59s) +19.194 (+19d 11' 38")
  ---------------------------------------------
The error box area is about 492 sq. arcmin, and its maximum
dimension is 1.06 deg (the minimum one is 8.04 arcmin).
The Sun distance was about 37 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB190329_T22905/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.

K. Yamaoka (Nagoya U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), 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 bright GRB 190329A (IPN triangulation: Hurley et al.,
GCN Circ. 24029
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 ) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 06:21:49.627 UTC on 29 March 2019.
The burst signal was seen by all CGBM detectors.

The burst light curve shows two multi-peaked pulses separated by
a quiescent interval. The first pulse starts at T=0.4 sec,
peaks at 1.4 sec and ends at T+2.0 sec; the second starts at T=11.0 sec,
peaks at 11.8 sec and ends at T+16.9 sec.
The T90 and T50 durations measured by the SGM data are 14.2 +- 1.2 sec
and 10.8 +- 0.2 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1237875481/

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

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

The long-duration, bright GRB 190329A
(IPN  triangulation: Hurley et al., GCN Circ. 24029
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 ;
CALET-GBM detection: Yamaoka et al., GCN Circ. 24033
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 )
triggered Konus-Wind at T0=22905.458 s UT (06:21:45.458).

The burst light curve shows two separated multi-peaked emission
episodes. The first episode starts at ~T0-0.3 s and
has a duration of ~2 s; the second starts at ~T0-10.3 s
and has a duration of ~8 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190329_T22905/

As observed by Konus-Wind, the burst
had a fluence of 2.20(-0.14,+0.16)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+11.168 s,
of 1.31(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+15.104 s)
is best fit in the 20 keV - 3 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.15(-0.08,+0.09)
and Ep = 345(-39,+50) keV (chi2 = 73/65 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.0
(chi2 = 73/64 dof).

The spectrum near the maximum count rate
(measured from T0+8.448 to T0+15.104 s)
is best fit in the 20 keV - 3 MeV range
by a power law with exponential cutoff model:
with  alpha = -1.01(-0.11,+0.11)
and Ep = 252(-24,+30) keV (chi2 = 80/67 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.1
(chi2 = 80/66 dof).

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