GRB 240115B
GCN Circular 35540
Subject
GRB 240115B: Fermi GBM Final Real-time Localization
Date
2024-01-15T16:56:08Z (a year ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 16:45:37 UT on 15 Jan 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240115B (trigger 727029942.62324 / 240115698).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 188.3, Dec = -34.8 (J2000 degrees, equivalent to J2000 12h 33m, -34d 47'), with a statistical uncertainty of 4.7 degrees.
The angle from the Fermi LAT boresight is 98.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240115698/quicklook/glg_skymap_all_bn240115698.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240115698/quicklook/glg_healpix_all_bn240115698.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240115698/quicklook/glg_lc_medres34_bn240115698.gif
GCN Circular 35541
Subject
GRB 240115B: A long GRB detected by INTEGRAL
Date
2024-01-15T19:53:08Z (a year ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
Via
Web form
S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report:
a gamma ray burst lasting about 190 s has been detected by IBAS in the IBIS/ISGRI data at 16:43:30 UT of 2024 Jan 15. The burst was detected at a large off-axis angle (about 13 degrees) resulting in a low significance and large uncertainties. We note that the brightest part of the burst was also detected by the Fermi/GBM (GCN circ. 35540)
The refined coordinates (J2000) are:
R.A.= 191.894 deg
DEC.= -35.566 deg
with an uncertainty of 3.5 arcmin (90% c.l.).
The burst had a fluence of about 4e-6 erg/cmq in the 20-200 keV range.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 35542
Subject
Fermi GRB 240115B: Global MASTER-Net observations report
Date
2024-01-15T20:45:42Z (a year ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
legacy email
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240115B ( Fermi GBM team, GCN 35540) errorbox 12811 sec after notice time and 12818 sec after trigger time at 2024-01-15 20:19:16 UT, with upper limit up to 16.3 mag. The observations began at zenith distance = 87 deg. The sun altitude is -26.0 deg.
The galactic latitude b = 28 deg., longitude l = 299 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2356581
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
12909 | 2024-01-15 20:19:16 | MASTER-SAAO | (12h 43m 33.54s , -35d 23m 00.7s) | C | 180 | 16.3 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 35549
Subject
GRB 240115B: Fermi GBM Detection
Date
2024-01-16T20:10:53Z (a year ago)
From
sumanbala2210@gmail.com
Via
Web form
R. Hamburg (CNRS/IN2P3), S. Bala (USRA), and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 16:45:37.62 UT on 15 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240115B (trigger 727029942/240115698). GRB 240115B
was also localized by INTEGRAL (S. Mereghetti et al. 2024, GCN 35541).
The angle from the Fermi LAT boresight is 97 degrees.
The GBM light curve consists of multiple peaks of emission
with a duration (T90) of about 163 s (50-300 keV).
The time-averaged spectrum from T0-26.63 s to T0+47.11 s
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.73 +/- 0.11,
and the cutoff energy parameterized as Epeak, is 125 +/- 10.
The event fluence (10-1000 keV) in this time interval is
(5.13 +/- 0.26)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+17.6 s in the 10-1000 keV band is 2.6 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular 35551
Subject
GRB 240115B: AstroSat CZTI detection
Date
2024-01-17T07:19:29Z (a year ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>
Via
Web form
J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/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 the detection of a long-duration GRB 240115B which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35540), and INTEGRAL (S.Mereghetti et al., GCN Circ. 35541).
The source was detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-01-15 16:45:40.50 UTC. The measured peak count rate associated with the burst is 80 (+42, -5) counts/s above the background in the combined data of three quadrants (out of four), with a total of 2052 (+489, -339) counts. The local mean background count rate was 280 (+1, -4) counts/s. Using cumulative rates, we measure a T90 of 47 (+7, -4) s.
The source was also 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 2024-01-15 16:46:04.75 UTC. The measured peak count rate associated with the burst is 127 (+72, -1) counts/s above the background in the combined data of three quadrants (out of four), with a total of 1941 (+685, -748) counts. The local mean background count rate was 1168 (+5, -5) counts/s. We measure a T90 of 36 (+6, -10) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb