//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32373 SUBJECT: IPN triangulation of GRB 220711C (short) DATE: 22/07/12 15:50:56 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The short-duration GRB 220711C was detected by Fermi (GBM trigger 679248723), INTEGRAL (SPI-ACS), Konus-Wind, and Swift (BAT) at about 58318 s UT (16:11:58). 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: 79.625 -47.309 Corners: 64.292 -35.777 64.270 -36.123 94.188 -53.124 93.862 -52.805 ------------------------------ The error box area is 5.5 sq. deg, and its maximum dimension is 27 deg (the minimum one is 12 arcmin). The Sun distance was 72 deg. This box may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM final localization (glg_healpix_all_bn220711675_v00). A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB220711_T58317/IPN The time history and spectrum will be given in forthcoming GCN Circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32382 SUBJECT: Konus-Wind detection of GRB 220711C DATE: 22/07/13 14:24:59 GMT FROM: Anna Ridnaia at Ioffe Institute A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The short-duration GRB 220711C (IPN triangulation: Svinkin et al., GCN Circ 32373) triggered Konus-Wind at T0=58317.557 s UT (16:11:57.557). The burst light curve shows a single emission pulse, which starts at T0-0.3 s and has a total duration of ~0.4 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/GRB220711_T58317/ As observed by Konus-Wind, the burst had a fluence of 2.01(-0.37,+0.43)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0+0.066 s, of 1.27(-0.49,+0.52)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+0.128 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = 0.06(-0.41,+0.55) and Ep = 736(-169,+251) keV (chi2 = 19/26 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 = 19/25 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32384 SUBJECT: GRB 220711C: Swift/BAT-GUANO detection outside the coded FOV DATE: 22/07/13 15:42:38 GMT FROM: Aaron Tohuvavohu at U Toronto Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), James DeLaunay (UAlabama), Jamie A. Kennea (PSU), report: Swift/BAT did not localize GRB 220711C onboard (T0: 2022-07-11T16:11:58 UTC, IPN GCN 32373, KONUS GCN 32382). The INTEGRAL and Fermi notices, 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 10.9 in a 0.256 s analysis time bin. NITRATES results are consistent with a burst coming from outside the 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. 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/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32389 SUBJECT: GRB 220711C: Fermi GBM Observation DATE: 22/07/13 21:56:21 GMT FROM: Stephen Lesage at Fermi-GBM Team S. Lesage (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 16:11:58.54 UT on 11 July 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220711C (trigger 679248723/220711675) which was also detected by Konus-Wind (A. Ridnaia, et al. 2022, GCN 32382), Swift/BAT-GUANO (G. Raman et al. 2022, GCN 32384), and localized by IPN (D. Svinkin et al. 2022, GCN 32373). The on-ground calculated location, using the GBM trigger data, is RA = 81.06, DEC = -48.16 (J2000 degrees, equivalent to 05h 24m, -48d 10'), with an uncertainty of 3.5 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 Fermi GBM on-ground location is consistent with the IPN triangulation. The angle from the Fermi LAT boresight is 130 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 0.3 s (10-1000 keV). The time-averaged spectrum from T0-0.06 to T0+0.26 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.1 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 972.6 +/- 136.0 keV. The event fluence (10-1000 keV) in this time interval is (1.51 +/- 0.08)E-06 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0 s in the 10-1000 keV band is 13.6 +/- 1.4 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/"