GRB 241114B

Chen-Wei Wang, Shao-Lin Xiong, Shi-Jie Zheng and Yan-Ting Zhang report on behalf of the Insight-HXMT team:

At 2024-11-14T11:05:03 (T0), Insight-HXMT/HE detected a long burst, GRB 241114B.

The Insight-HXMT/HE light curve mainly consists of three
episodes with a T90 of 25.0 +0.3/-0.5 s. 
The 1s peak rate, measured from T0+30.5 s, is 7255 cnts/sec. 
The total counts from this burst is 33848 counts.

The HXMT/HE light curve can be found here:
https://www.bursthub.cn//admin/static/hxmtgrb241114B.png

All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.

D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

C. Wang, S. Xiong, S. Zheng and Y. Zhang,
on behalf of the Insight-HXMT team,

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

E. Burns on behalf of the IPN,

and

B. Grefenstette on behalf of the NuSTAR team, report:

The long-duration GRB 241114B
(Insight-HXMT-HE detection: Wang et al., GCN 38284
Loading...
 
 )
was detected by Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT),
NuSTAR (AC), and Insight-HXMT (HE) at about 39904 s UT (11:05:04).
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:
  304.514 (20h 18m 03s) -10.028 (-10d 01' 40")
 Corners:
  302.298 (20h 09m 12s)  -7.588 ( -7d 35' 17")
  303.748 (20h 15m 00s)  -7.242 ( -7d 14' 31")
  306.603 (20h 26m 25s) -12.501 (-12d 30' 04")
  305.164 (20h 20m 39s) -12.843 (-12d 50' 34")
 ---------------------------------------------
The error box area is 8.4 sq. deg, and its maximum
dimension is 6.5 deg (the minimum one is 1.4 deg).
The Sun distance was 70 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB241114_T39903/IPN
The HEALPix triangulation map is the multi-order HEALPix in units of
probability density.

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

V. Panteleeva, 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-duration GRB 241114B 
(Insight-HXMT-HE detection: Wang et al., GCN 38284
Loading...
 
 ; 
IPN triangulation: Svinkin et al., GCN 38341
Loading...
 
 ) 
triggered Konus-Wind at T0=39903.659 s UT (11:05:03.659). 
 
The burst light curve shows a multipeaked structure 
which starts at ~T0-11.7 s and has a total duration of ~45 s. 
The emission is seen up to ~2 MeV. 
 
The Konus-Wind light curve of this GRB is available at 
http://www.ioffe.ru/LEA/GRBs/GRB241114_T39903/ 
 
As observed by Konus-Wind, the burst 
had a fluence of 4.03(-0.38,+0.43)x10^-5 erg/cm2, 
and a 64-ms peak flux, measured from T0+23.648 s, 
of 1.38(-0.22,+0.24)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+32.768 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 = -1.15(-0.10,+0.11), 
the high energy photon index beta = -3.11(-6.89,+0.49), 
the peak energy Ep = 258(-25,+30) keV 
(chi2 = 123/97 dof). 
 
The spectrum near the maximum count rate 
(measured from T0+16.640 s to T0+24.576 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 = -0.76(-0.14,+0.17), 
the high energy photon index beta = -3.08(-6.92,+0.46), 
the peak energy Ep = 272(-30,+31) keV 
(chi2 = 84/77 dof). 
 
All the quoted errors are at the 90% confidence level. 
All the quoted values are preliminary.

A. Bogomolov, V. Bogomolov, A. Iyudin, S. Svertilov, N. Vasiliev 
on behalf of the MSU “Sozvezdie-270” team, report:

At 2024-11-14 ~11:05:04 UT the long-duration GRB 241114B (Insight-HXMT/HE detection: GCN #38284
Loading...
 
 ; Konus-Wind detection: GCN #38398
Loading...
 
 ) was detected by the DeCoR-1 and DeCoR-3 instruments on the cubesat Avion of the Moscow University project “Constellation-270” [1].
  
Total amount of photons detected by Avion is 220 (DeCoR-1, energy band 40-500 keV) and ~145 (DeCoR-3, >30 keV), it corresponds to a fluence of ~9*10^(-7) erg/cm^2 in the range 40-500 keV.

LC in the energy range of 40-500 keV has three main episodes with a maximum flux of ~1.2 phot/(cm^2*s) in the 1st peak with a duration of ~6 s, ~2.7 phot/(cm^2*s) in the 2nd peak with a duration of 2 s and 7.7 phot/(cm^2*s) in the 3rd peak with a duration of 2.5 s.
А total duration (T90) of the burst in ~25 s.

The light curve obtained by Avion is available here:
https://swx.sinp.msu.ru/models/grb_cat/data/pictures/2024_11_14_Avion_LC_s.png

Parameters of GRB 241114B as well as 22 other GRBs detected by Moscow University cubesats are listed at: https://swx.sinp.msu.ru/models/grb_cat/grb.php?lang=en

Avion is one of 5 cubesats of the Moscow University project “Constellation-270” [1] launched on 2023 June 27. The payload of Avion is a set of scintillation gamma-ray detectors DeCoR [2], the energy range is >30 keV, the time resolution is 0.5s. 

[1] Svertilov et al. 2023  https://link.springer.com/chapter/10.1007/978-3-031-50248-4_21
[2] Bogomolov et al. 2022 Universe 8, 282 https://www.mdpi.com/2218-1997/8/5/282