GRB211120B

This page lists all entries on GRB211120B in GRBweb

Summary Fermi GBM GCN 31101 GCN 31131

Summary table
Variable Value Source
GRB_name_Fermi GRB211120548
T0 13:09:43.510 UTC Fermi_GBM
ra 47.9400° Fermi_GBM
decl 47.1400° Fermi_GBM
pos_error 4.05e+00° Fermi_GBM
T90 36.097 s Fermi_GBM
T90_error 2.534 s Fermi_GBM
T90_start 13:09:43.510 UTC Fermi_GBM
fluence 7.65e-06 erg/cm² Fermi_GBM
fluence_error 5.47e-08 erg/cm² Fermi_GBM
T100 36.097 s
GBM_located True
mjd 59538.54842025463 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB211120548
trigger_name bn211120548
ra 47.9400°
decl 47.1400°
pos_error 4.05e+00°
datum 2021-11-20
t_trigger 13:09:46.838 UTC
T90 36.097 s
T90_error 2.534 s
T90_start 13:09:43.510 UTC
fluence 7.65e-06 erg/cm²
fluence_error 5.47e-08 erg/cm²
flux_1024 6.55e+00 erg/cm²/s
flux_1024_error 2.41e-01 erg/cm²/s
flux_1024_time 1.28e+00 erg/cm²/s
flux_64 8.47e+00 erg/cm²/s
flux_64_error 1.08e+00 erg/cm²/s
GCN 31101 table
GRB_name GRB211120B
GCN_number 31101
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 31101 SUBJECT: GRB 211120B: Swift/BAT-GUANO detection outside the coded FOV DATE: 21/11/21 14:44:02 GMT FROM: Aaron Tohuvavohu at U Toronto James DeLaunay (UAlabama), Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), report: Swift/BAT did not successfully trigger on GRB 211120B (T0: 2021-11-20 13:09:46.8 UT, Fermi Trigger: 659106591). The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu, arXiv:2111.01769), detects the burst with a sqrt(TS) of 23.1 in a 8.192 s analysis time bin. The estimated T90 in the detector is 24.5 s (15-350 keV). NITRATES prefers an origin for this burst coming from outside the coded FOV, with DeltaLLHOut of -6. See Section 9.1 and Figure 20 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. An out of FOV origin is consistent with the Fermi/GBM localization. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/
GCN 31131 table
GRB_name GRB211120B
GCN_number 31131
Detection_method Fermi GBM Det
t_trigger 13:09:46.840 UTC
ra 47.9000°
decl 47.1000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 31131 SUBJECT: GRB 211120548: Fermi GBM observation DATE: 21/11/26 15:39:53 GMT FROM: Rachel Dunwoody at UCD R. Dunwoody (UCD), J.Mangan (UCD) and C.Meegan (UAH) report on behalf of the Fermi GBM Team: "At 13:09:46.84 UT on 20 November 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 211120B (trigger 659106591 / 211120548). which was also detected by the Swift/BAT-GUANO (DeLaunay et al. 2021, GCN 31101) The GBM on-ground calculated location, using the GBM trigger data, is RA = 47.9, DEC = 47.1 (J2000 degrees, equivalent to 03 h 11 m, 47 d 6 '), with a statistical uncertainty of 1.9 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ) The angle from the Fermi LAT boresight at the GBM trigger time is 62 degrees. The GBM light curve consists of a single peak with a duration (T90) of about 36.1 s (50-300 keV). The time-averaged spectrum from T0-6.400 s to T0+33.537 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.99 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 298.2 +/- 26.3 keV The event fluence (10-1000 keV) in this time interval is (1.184 +/- 0.60)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.28 s in the 10-1000 keV band is 6.5 +/- 0.2 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 180.1 +/- 24.3 keV, alpha = -0.79 +/- 0.08 and beta = -1.87 +/- 0.08. 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/"