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GRB 220128A

GCN Circular 31536

Subject

IPN triangulation of GRB 220128A (long)

Date

2022-01-31T17:40:47Z (3 years ago)

From

Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars-Odyssey team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
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, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, and

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

The long-duration GRB 220128A
was detected by Konus-Wind, Swift (BAT), INTEGRAL (SPI-ACS),
and Mars-Odyssey (HEND) at about 11897 s UT (03:18:17).
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:
   350.191 (23h 20m 46s) -49.734 (-49d 44' 02")
  Corners:
   349.616 (23h 18m 28s) -46.520 (-46d 31' 11")
   350.856 (23h 23m 25s) -52.699 (-52d 41' 57")
   350.687 (23h 22m 45s) -52.865 (-52d 51' 53")
   349.478 (23h 17m 55s) -46.702 (-46d 42' 08")
  ---------------------------------------------
The error box area is 2688 sq. arcmin, and its maximum
dimension is 6.38 deg (the minimum one is 7 arcmin).
The Sun distance was 42 deg.

This box may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220128_T11896/IPN/

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

GCN Circular 31537

Subject

Konus-Wind detection of GRB 220128A

Date

2022-01-31T17:46:00Z (3 years ago)

From

Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 220128A (IPN localization: Kozyrev et al., GCN 31536Loading...
 
 )
triggered Konus-Wind (KW) at T0=11896.619 s UT (03:18:16.619).

The burst light curve shows a multi-peaked structure,
which starts at ~T0-10 s and has a total duration of ~47 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220128_T11896/

As observed by Konus-Wind, the burst had
a fluence of (3.2 �� 0.7)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 10.496 s,
of (5.9 �� 1.1)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+24.832 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.92 (-0.18,+0.28),
the high energy photon index beta = -2.19 (-1.92,+0.32),
the peak energy Ep = 406 (-135,+174) keV,
chi2 = 88/97 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.

GCN Circular 31539

Subject

GRB 220128A: AstroSat CZTI detection

Date

2022-02-01T16:15:59Z (3 years ago)

From

Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>

V. Prasad (IUCAA), G. Waratkar (IITB), A. Suresh (IITB), A. Vibhute
(IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao
(IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat
CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al.,
2021, JApA, 42, 73) showed detection of a long GRB 220128A, which was
also detected by Konus-Wind (Frederiks et al. GCN 31537Loading...
 
 ) with IPN
localization (Kozyrev et al., GCN 31536Loading...
 
 ).

The source was clearly detected in the CsI anticoincidence (Veto)
detector in the 100-500 keV energy range. The light curve showed
multiple peaks of emission with the strongest peak at 2022-01-28
03:18:22.65 UT. The measured peak count rate is 617 (+71, -81) cts/s
above the background in the combined Veto data of four quadrants, with a
total of 4281 (+424, -589) cts. The local mean background count rate was
1477 (+4, -4) cts/s. We measure a T90 of 26 (+4, -4) s from the
cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at
http://astrosat.iucaa.in/czti/?q=grb [1]. 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. 

Links:
------
[1] http://astrosat.iucaa.in/czti/?q=grb