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This page lists all entries on GRB230404A in GRBweb

Summary Fermi GBM GCN 33564 GCN 33565

Summary table
Variable	Value	Source
GRB_name_Fermi	GRB230404958
T0	23:00:07 UTC	GCN_circulars,Fermi GBM final loc
ra	139.7800°	Fermi_GBM
decl	-3.4500°	Fermi_GBM
pos_error	4.04e+00°	Fermi_GBM
T90	65.793 s	Fermi_GBM
T90_error	1.81 s	Fermi_GBM
T90_start	23:00:08.095 UTC	Fermi_GBM
fluence	5.43e-06 erg/cm²	Fermi_GBM
fluence_error	3.14e-08 erg/cm²	Fermi_GBM
T100	66.888 s
GBM_located	True
mjd	60038.95841435185	GCN_circulars,Fermi GBM final loc

Fermi GBM table
GRB_name_Fermi	GRB230404958
trigger_name	bn230404958
ra	139.7800°
decl	-3.4500°
pos_error	4.04e+00°
datum	2023-04-04
t_trigger	23:00:07.327 UTC
T90	65.793 s
T90_error	1.81 s
T90_start	23:00:08.095 UTC
fluence	5.43e-06 erg/cm²
fluence_error	3.14e-08 erg/cm²
flux_1024	2.71e+00 erg/cm²/s
flux_1024_error	1.99e-01 erg/cm²/s
flux_1024_time	1.77e+01 erg/cm²/s
flux_64	4.65e+00 erg/cm²/s
flux_64_error	9.38e-01 erg/cm²/s

GCN 33564 table
GRB_name	GRB230404A
GCN_number	33564
Detection_method	Fermi GBM final loc
t_trigger	23:00:07 UTC
ra	139.8000°
decl	-3.5000°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 33564 SUBJECT: GRB 230404A: Fermi GBM Final Real-time Localization DATE: 23/04/04 23:10:23 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 23:00:07 UT on 4 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230404A (trigger 702342012.327256 / 230404958). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 139.8, Dec = -3.5 (J2000 degrees, equivalent to J2000 09h 19m, -3d 30'), with a statistical uncertainty of 3.5 degrees. The angle from the Fermi LAT boresight is 56.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230404958/quicklook/glg_skymap_all_bn230404958.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230404958/quicklook/glg_healpix_all_bn230404958.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230404958/quicklook/glg_lc_medres34_bn230404958.gif

GCN 33565 table
GRB_name	GRB230404A
GCN_number	33565
Detection_method	AstroSat CZTI
Circular_text	TITLE: GCN CIRCULAR NUMBER: 33565 SUBJECT: GRB 230404A: AstroSat CZTI detection DATE: 23/04/05 09:28:55 GMT FROM: Gaurav Waratkar at IIT,Bombay P K. Navaneeth (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 GRB 230404A which was also detected by Fermi (Fermi GBM Team, GCN 33564). The source was detected in the 20-200 keV energy range. The light curve peaks at 2023-04-04 23:00:07.5 UTC. The measured peak count rate associated with the burst is 75 (+30, -10) counts/s above the background in the combined data of two quadrants (out of four), with a total of 753 (+275, -296) counts. The local mean background count rate was 224 (+1, -2) counts/s. Using cumulative rates, we measure a T90 of 29 (+10, -12) s. The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-04-04 23:00:07.0 UTC. The measured peak count rate associated with the burst is 246 (+67, -54) counts/s above the background in the combined data of all quadrants, with a total of 3668 (+1002, -1058) counts. The local mean background count rate was 1491 (+6, -6) counts/s. We measure a T90 of 48 (+7, -12) s from the cumulative Veto light curve. While the two T90 measurements agree within error bars, the difference is higher than typical measurements. There are two possibilities for this: firstly, there may be an intrinsic energy dependence in T90, with it being higher at higher energies. The second is that at the instant of this GRB, AstroSat was relatively close to the South Atlantic Anomaly, which increased the background and hence the uncertainty in our T90 measurements. 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