GRB220527A

This page lists all entries on GRB220527A in GRBweb

Summary Fermi GBM IPN GCN 32129 GCN 32130 GCN 32131 GCN 32132 GCN 32133 GCN 32135 GCN 32136 GCN 32138 GCN 32139 GCN 32140 GCN 32141 GCN 32143 GCN 32144 GCN 32145 GCN 32146 GCN 32152 GCN 32158 GCN 32159 GCN 32169

Summary table
Variable Value Source
GRB_name_Fermi GRB220527387
T0 9:17:15.730 UTC GCN_circulars,Fermi GBM Det
ra 323.5708° IPN
decl 21.5667° IPN
pos_error 8.33e-02° IPN
T90 10.496 s Fermi_GBM
T90_error 0.362 s Fermi_GBM
T90_start 9:17:18.355 UTC Fermi_GBM
fluence 5.18e-05 erg/cm² Fermi_GBM
fluence_error 3.26e-08 erg/cm² Fermi_GBM
redshift 0.8570 GCN_circulars,Optical
T100 13.121 s
GBM_located False
mjd 59726.38698761574 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB220527387
trigger_name bn220527387
ra 323.5700°
decl -14.9000°
pos_error 2.55e+00°
datum 2022-05-27
t_trigger 9:17:15.731 UTC
T90 10.496 s
T90_error 0.362 s
T90_start 9:17:18.355 UTC
fluence 5.18e-05 erg/cm²
fluence_error 3.26e-08 erg/cm²
flux_1024 9.26e+01 erg/cm²/s
flux_1024_error 6.91e-01 erg/cm²/s
flux_1024_time 7.36e+00 erg/cm²/s
flux_64 1.18e+02 erg/cm²/s
flux_64_error 3.02e+00 erg/cm²/s
IPN table
GRB_name GRB220527A
ra 323.5708°
decl 21.5667°
pos_error 8.33e-02°
redshift 0.8570
GCN 32129 table
GRB_name GRB220527A
GCN_number 32129
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32129 SUBJECT: GRB 220527A: AGILE detection DATE: 22/05/27 12:18:27 GMT FROM: Alessandro Ursi at INAF/IAPS A. Ursi, G. Piano (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano, E. Menegoni (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, A. Di Piano, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), F. Longo (Univ. Trieste and INFN Trieste), and P. Tempesta (TeleSpazio), report on behalf of the AGILE Team: The AGILE satellite detected a burst at T0 = 2022-05-27 09:17:14.55 (UTC). The event is clearly visible in the AGILE scientific ratemeters of the SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 15 s and it released a total number of 1860 counts in the SA detector (above a background rate of 50 Hz), 27875 counts in the MCAL detector (above a background rate of 1380 Hz), and 67515 counts in the AC detector (above a background rate of 3470 Hz). The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB220527A_AGILE_RM.png . The event also triggered a high time resolution MCAL data acquisition, where it released 12500 counts in the detector, above a background rate of 630 Hz. We notice that most of the signal is revealed in the E < 1.4 MeV energy channels. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB220527A_078464_580727834.552109.png . Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN 32130 table
GRB_name GRB220527A
GCN_number 32130
Detection_method Fermi GBM Other
ra 323.8000°
decl -10.6000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32130 SUBJECT: GRB 220527A: Fermi GBM Final Localization DATE: 22/05/27 14:55:26 GMT FROM: Joe Mangan at UCD The Fermi GBM team reports the detection of a likely Long GRB. At 09:17:15.73 UT on 27 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 220527A (trigger 675335840 / 220527387). The on-ground calculated location, using the GBM trigger data, is RA = 323.8, DEC = -10.6 (J2000 degrees, equivalent to 21 h 35 m, -10 d 34 '), with a statistical uncertainty of 1 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 43 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220527387/quicklook/glg_skymap_all_bn220527387.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220527387/quicklook/glg_healpix_all_bn220527387.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220527387/quicklook/glg_lc_medres34_bn220527387.gif
GCN 32131 table
GRB_name GRB220527A
GCN_number 32131
Detection_method Fermi LAT Det
t_trigger 9:17:15.730 UTC
ra 323.5700°
decl -14.9000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32131 SUBJECT: GRB 220527A: Fermi-LAT detection DATE: 22/05/27 16:25:14 GMT FROM: Magnus Axelsson at Stockholm U. E. Bissaldi (Politecnico and INFN Bari), L. Scotton (CNRS/IN2P3/LUPM) and M. Axelsson (KTH & Stockholm Univ.) report on behalf of the Fermi-LAT team: On May 27, 2022, Fermi-LAT detected high-energy emission from GRB 220527A, which was also detected by Fermi-GBM (trigger 675335840 / 220527387, GCN 32130) and AGILE (Ursi et al. 2022. GCN 32129). The best LAT on-ground location is found to be RA, Dec = 323.57, -14.9 (degrees, J2000) with an error radius of 0.08 deg (90 % containment, statistical error only). This was 49 deg from the LAT boresight at the time of the GBM trigger: T0 = 09:17:15.73 UT. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0-1000 s after the GBM trigger is (6.0 +/- 1.4)E-06 ph/cm2/s. The estimated photon index above 100 MeV is -2.0 +/- 0.2. The highest-energy photon is a 12 GeV event which is observed 89 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN 32132 table
GRB_name GRB220527A
GCN_number 32132
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32132 SUBJECT: GRB 220527A: Swift ToO observations DATE: 22/05/27 17:38:33 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/LAT GRB 220527A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021503 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/LAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team.
GCN 32133 table
GRB_name GRB220527A
GCN_number 32133
Detection_method Fermi GBM Det
t_trigger 9:17:15.730 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 32133 SUBJECT: GRB 220527A: Fermi GBM Observation DATE: 22/05/27 18:13:27 GMT FROM: Joe Mangan at UCD J. Mangan (UCD), R. Dunwoody (UCD), and C.Meegan (UAH) report on behalf of the Fermi GBM Team: At 09:17:15.73 UT on 27 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 220527A (trigger 675335840 / 220527387), which was also detected by the Fermi LAT (Bissaldi et al. 2022, GCN 32131) and AGILE (Ursi et al 2022, GCN 32129). The Fermi GBM Final Real-time Localization (GCN 32130) is consistent with the Fermi LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 49 degrees. The GBM light curve consists of a double peak emission with a duration (T90) of about 10.5 s (50-300 keV). The time-averaged spectrum from T0-0.13 s to T0+21.38 s is best fit by a Band function with Epeak = 151.6 +/- 2.7 keV, alpha = -0.75 +/- 0.02, and beta = -2.55 +/- 0.05. The event fluence (10-1000 keV) in this time interval is (5.69 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+7.4 s in the 10-1000 keV band is 92.6 +/- 0.7 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 32135 table
GRB_name GRB220527A
GCN_number 32135
Detection_method Swift-XRT Other
ra 323.5281°
decl -14.9718°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32135 SUBJECT: GRB 220527A: Swift-XRT afterglow detection DATE: 22/05/28 01:10:03 GMT FROM: Phil Evans at U of Leicester B. Sbarufatti (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , D.N. Burrows (PSU), J. D. Gropp (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 220527A (Bissaldi et al. GCN Circ. 32131), collecting 1.7 ks of Photon Counting (PC) mode data between T0+30.1 ks and T0+31.9 ks. Two uncatalogued X-ray sources are detected, of which one ("Source 2") is above the RASS 3-sigma upper limit at this position, and is therefore likely the GRB afterglow. Using 1733 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 323.52805, -14.97183 which is equivalent to: RA (J2000): 21h 34m 06.73s Dec(J2000): 14d 58' 18.6" with an uncertainty of 2.6 arcsec (radius, 90% confidence). This position is 4.9 arcmin from the Fermi/LAT position. The light curve is consistent with a constant source of mean count rate 3.9e-01 ct/sec. A power-law fit gives an index of 0.6 (+2.5, -1.1). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.83 (+0.21, -0.20). The best-fitting absorption column is 9.8 (+6.1, -3.5) x 10^20 cm^-2, consistent with the Galactic value of 6.2 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 9.8 (+6.1, -3.5) x 10^20 cm^-2 Galactic foreground: 6.2 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.83 (+0.21, -0.20) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021503. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021503. This circular is an official product of the Swift-XRT team.
GCN 32136 table
GRB_name GRB220527A
GCN_number 32136
Detection_method Swift-UVOT Det
ra 323.5280°
decl -14.9717°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32136 SUBJECT: GRB 220527A: Swift/UVOT detection DATE: 22/05/28 02:22:50 GMT FROM: Aaron Tohuvavohu at U Toronto The Swift/UVOT began observations of the Fermi/LAT localization (GCN 32131) of GRB 220527A , collecting 1.7 ks of u band data between T0+30.1 ks and T0+31.9 ks after the Fermi GBM detection (32133). A source consistent with the XRT afterglow position (GCN 32135) is detected in the UVOT observation. The preliminary UVOT position is: RA,Dec (J2000): 323.52803, -14.97169 with an estimated u band magnitude of 17.8 +/- 0.07 in the UVOT photometric system.
GCN 32138 table
GRB_name GRB220527A
GCN_number 32138
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 32138 SUBJECT: GRB 220527A: MITSuME Akeno optical observation DATE: 22/05/28 02:37:56 GMT FROM: Yuri Imai at Tokyo Inst of Tech Y. Imai, S. Sato, R. Hosokawa, K. L. Murata, M. Sasada, M. Niwano, N. Ito, Y. Takamatsu, M. Tateda, T. Hattori, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 220527A (A. Ursi et al. GCN Circular #32129, The Fermi GBM team et al. GCN Circular #32130, Bissaldi et al. GCN Circular #32131, Evans et al. GCN Circular #32132, Mangan et al. GCN Circular #32133, Sbarufatti et al. GCN Circular #32135, Tohuvavohu et al. GCN Circular #32136,) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 60 sec exposures started at 2022-05-27 16:05:50 UT (6.8 hours after the AGILE detection). We stacked the images with good conditions. Here we report magnitudes by the forced-photometry at the Swift/XRT position (Sbarufatti et al. GCN Circular #32135). T0+[hour] |MID-UT | T-EXP[sec] | magnitudes of forced-photometry ------------------------------------------------------------------------------------------------ 7.5 | 2022-05-27 16:46:53| 3780 | g'=18.9 +/- 0.2, Rc=18.5 +/- 0.1, Ic=18.3 +/- 0.1 8.7 | 2022-05-27 17:58:38| 3420 | g'=18.9 +/- 0.2, Rc=18.6 +/- 0.1, Ic=18.7 +/- 0.2 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN 32139 table
GRB_name GRB220527A
GCN_number 32139
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 32139 SUBJECT: GRB 220527A: CALET Gamma-Ray Burst Monitor detection DATE: 22/05/28 03:10:53 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The bright long GRB 220527A (AGILE detection: Ursi et al., GCN Circ. 32129; Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 32130; Fermi-LAT detection: Bissaldi et al., GCN Circ. 32131) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:17:14.518 UTC on 27 May 2022 (http://cgbm.calet.jp/cgbm_trigger/flight/1337678064/index.html). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure which starts at T+0.5 sec, peaks at T+9.1 sec, and ends at T+21.9 sec. The T90 and T50 durations measured by the SGM data are 10.2 +/- 1.0 sec and 3.9 +/- 0.1 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1337678064/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
GCN 32140 table
GRB_name GRB220527A
GCN_number 32140
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 32140 SUBJECT: GRB 220527A: AstroSat CZTI detection DATE: 22/05/28 05:23:18 GMT FROM: Gaurav Waratkar at IIT,Bombay R. Gopalakrishnan (IUCAA), V. Prasad (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 detection of a long GRB 220527A which was also reported by AGILE (Ursi et al. GCN 32129), Fermi-GBM (GCN 32130), Fermi-LAT (Bissaldi et al., GCN 32131), Swift-XRT (Sbarufatti et al., GCN 32135), Swift-UVOT (Tohuvavohu et al., GCN 32136) and CALET (Yamaoka et al., GCN 32139). The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2022-05-27 09:17:23.55 UTC. The measured peak count rate associated with the burst is 1879 (+251, -171) counts/s above the background in the combined data of four quadrants, with a total of 5318 (+224, -235) counts. The local mean background count rate was 496 (+4, -5) counts/s. Using cumulative rates, we measure a T90 of 7 (+1, -1) s. It was also clearly 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 2022-05-27 09:17:19.39 UTC. The measured peak count rate is 1880 (+96, -93) counts/s above the background in the combined Veto data of four quadrants, with a total of 11483 (+534, -559) counts. The local mean background count rate was 1644 (+6, -6) counts/s. We measure a T90 of 14 (+3, -2) s from the cumulative Veto light curve. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb [1]. 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. Links: ------ [1] http://astrosat.iucaa.in/czti/?q=grb
GCN 32141 table
GRB_name GRB220527A
GCN_number 32141
Detection_method Optical
redshift 0.8570
Circular_text TITLE: GCN CIRCULAR NUMBER: 32141 SUBJECT: GRB 220527A: NOT optical photometry and spectroscopic redshift DATE: 22/05/28 06:34:21 GMT FROM: Dong Xu at NAOC/CAS D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), L. Izzo (DARK/NBI), S.Y. Fu, X. Liu (NAOC), M. Aron (NOT), report on behalf of a larger collaboration: We observed the field of GRB 220527A detected by AGILE (Ursi et al., GCN 32129), Fermi (Fermi GBM team, GCN 32130; Bissaldi et al., GCN 32131), CALET (Yamaoka et la., GCN 32139), and AstroSat (Gopalakrishnan et al., GCN 32140), using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFSOC camera. We carried out 3x120 s Sloan r-band photometry starting at 03:55:22 UT on 2022-05-28, i.e., 18.6 hr since the Fermi/GBM trigger, followed by 2x1800 s spectroscopy covering wavelength of ~ 3600 - 9000 AA. The previously reported optical afterglow (Tohuvavohu et al., GCN 32136; Imai et al., GCN 32138) is clearly detected in each single r-band image, and has decayed to r = 19.55 +/- 0.02 mag, calibrated with the PAN-STARRS field. A blue continuum is throughout the spectrum, superimposed with a few relatively prominent absorption features, among which we identify as Ni II, Fe II, Mn II, Mg II, all at a common redshift of z =0.857, using old calibrations. A weak emission feature might also be detected, interpreted as due to [O II] at the same redshift. We thus conclude z =0.857 is the redshift of the burst.
GCN 32143 table
GRB_name GRB220527A
GCN_number 32143
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32143 SUBJECT: GRB 220527A: MeerLICHT afterglow observations DATE: 22/05/28 08:11:28 GMT FROM: Simon de Wet at UCT S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) and P.M. Vreeswijk (Radboud) report on behalf of the MeerLICHT consortium: Following the detection of GRB 220527A by AGILE (Ursi et al., GCN 32129), Fermi/GBM (Fermi GBM Team, GCN 32130) and Fermi/LAT (Bissaldi et al., GCN 32131), the 0.6m wide-field MeerLICHT telescope, located at Sutherland, South Africa, obtained 2x600 s exposures in the q-band and a single 300 s exposure in each of the g and r bands covering the entire Fermi/LAT error region beginning 17.68 hours after the GRB trigger. We detect the previously reported afterglow to GRB 220527A (Sbarufatti et al., GCN 32135; Tohuvavohu, GCN 32136; Imai et al., GCN 32138; Xu et al., GCN 32141) at the UVOT position with AB magnitudes: g = 19.72 +/- 0.04 r = 19.55 +/- 0.06 q = 19.57 +/- 0.02 MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN 32144 table
GRB_name GRB220527A
GCN_number 32144
Detection_method Swift-XRT Other
redshift 0.8570
Circular_text TITLE: GCN CIRCULAR NUMBER: 32144 SUBJECT: GRB DATE: 22/05/28 10:32:22 GMT FROM: Andrea Saccardi at Observatoire de Paris A. Saccardi (GEPI, Observatoire de Paris), L. Izzo (DARK/NBI), and D. Xu (NAOC) report on behalf of the Stargate collaboration: We observed the afterglow counterpart of GRB 220527A detected by Swift-XRT (B. Sbarufatti et al. GCN Circ. 32135) during the follow-up observations of the Fermi/LAT-detected burst GRB 220527A (E. Bissaldi et al. GCN Circ. 32131) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. A spectrum was acquired covering the wavelength range 3000-21000 AA, and consisting of 4 exposures of 600 s each. The observation started at 06:19:10 UT on 2022-05-28 (0.88 days after the GRB detection by Fermi/GBM). From the detection of several absorption lines, which we identified as due to Al III, Ni II, Fe II, Mn II, Mg II, Mg I, and Ca II we infer a redshift z=0.857, which is in agreement with the redshift reported by the NOT (D. Xu et al. GCN Circ. 32141). We note also the presence of a possible intervening absorber, through the identification of Mg II, at z=0.455 which coincides with the photometric redshift of a nearby source visible in the Pan-STARRS archival images. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Rob van Holstein (ESO fellow) and Felipe Gaete (Telescope operator).
GCN 32145 table
GRB_name GRB220527A
GCN_number 32145
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32145 SUBJECT: GRB 220527A: REM optical/NIR observations DATE: 22/05/28 15:04:15 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza, A. Melandri, S. Covino (INAF-OAB) on behalf of the REM team, report: We observed the field of GRB 220527A (Ursi et al., GCN Circ. 32129; Fermi GBM Team, GCN Circ. 32130; Bissaldi et al., GCN Circ. 32131) with the REM 60cm robotic telescope located at the ESO premise of La Silla (Chile). The observations were carried in the g, r, i, z, J and K bands, starting on 2022 May 28 at 07:27:54 UT (i.e. about 22.2 hours after the burst). From preliminary photometry we derive the following magnitudes and upper limits (3sigma c.l.) for the optical afterglow (Tohuvavohu et al., GCN Circ. 32136; Imai et al., GCN Circ. 32138; Xu et al., GCN 32141; de Wet et al., GCN Circ. 32143): g = 20.4 +/- 0.3 (*) r = 19.4 +/- 0.2 i = 19.4 +/- 0.2 z > 18.4 (* marginal detection; AB calibrated against the Pan-STARRS catalogue) J > 17.7 K > 14.9 (Vega; calibrated against the 2MASS catalogue) at a mid time of t-t0 ~ 22.4 hours.
GCN 32146 table
GRB_name GRB220527A
GCN_number 32146
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 32146 SUBJECT: GRB 220527A: AST3-3 Yaoan Optical Observation DATE: 22/05/28 15:20:11 GMT FROM: Tianrui Sun at Purple Mountain Obs,CAS Tianrui Sun (Purple Mountain Observatory), Lei Hu, Maokai Hu, Xuefeng Wu, Lei Liu, Kelai Meng, Xiaoyan Li (Nanjing Institute of Astronomical Observation Technology), Zhengyang Li, Xiangyan Yuan, Lifan Wang (TAMU), Xiaofeng Wang (Tsinghua University), report on behalf the AST3 Team: Following the detection of GRB 220527A detected by AGILE (Ursi et al., GCN 32129), Fermi (Fermi GBM team, GCN 32130; Bissaldi et al., GCN 32131), CALET (Yamaoka et la., GCN 32139), and AstroSat (Gopalakrishnan et al., GCN 32140), we use Antarctic Survey Telescope 3-3 at Yaoan Astronomy Observation (China, Yunnan) to follow up for the afterglow (Sbarufatti et al., GCN 32135; Tohuvavohu, GCN 32136; Imai et al., GCN 32138; Xu et al., GCN 32141; Simon et al. 32143; D'Avanzo et al., 32145). We observed the target position with 14 x 60s exposure in g-band starting from 27 May 2022, UTC 21:11:36.003, about 11.9 hours after the burst. The magnitude detection at the Swift UVOT position (GCN 32136) on the combined images for the GRB afterglow : g=19.3 +/- 0.06 We used the PS1 catalogue as the magnitude reference for calibration.
GCN 32152 table
GRB_name GRB220527A
GCN_number 32152
Detection_method Konus-Wind Det
t_trigger 9:17:21.517 UTC
redshift 0.8570
Circular_text TITLE: GCN CIRCULAR NUMBER: 32152 SUBJECT: Konus-Wind observation of GRB 220527A DATE: 22/05/30 16:59:09 GMT FROM: Alexandra Lysenko at Ioffe Institute A. Lysenko, D. Frederiks, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 220527A (AGILE detection: Ursi et al., GCN Circ. 32129; Fermi-LAT detection: Bissaldi et al., GCN Circ. 32131; Fermi-GBM detection: The Fermi GBM team, GCN Circ. 32130; Mangan et al., GCN Circ. 32133; CALET detection: Yamaoka et al., GCN Circ. 32139; AstroSat CZTI detection: Gopalakrishnan et al., GCN Circ. 32140) triggered Konus-Wind at T0=33441.517 s UT (09:17:21.517). The burst light curve shows a multipeaked structure which starts at ~T0-4.1 s and has a total duration of ~21.3 s. The emission is seen up to ~16 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB220527_T33441/ As observed by Konus-Wind, the burst had a fluence of 5.98(-0.31,+0.32)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+5.152s, of 1.73(-0.21,+0.22)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+13.568 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 = -0.80(-0.12,+0.13), the high energy photon index beta = -2.55(-0.13,+0.10), the peak energy Ep = 154(-10,+10) keV (chi2 = 115/98 dof). The spectrum near the maximum count rate (measured from T0+3.584 to T0+5.376 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 = -0.49(-0.18,+0.21), the high energy photon index beta = -3.24(-0.53,+0.31), the peak energy Ep = 146(-9,+9) keV (chi2 = 72/64 dof). For both spectra, we note a prominent count excess over the model at energies above ~5 MeV. The excess can be modeled by an additional power-law component with a photon index of <~2. Assuming the redshift z=0.857 (Xu et al., GCN Circ. 32141) and a standard cosmology model with H_0 = 67.7 km/s/Mpc, Omega_M = 0.310, and Omega_Lambda = 0.689 (Planck Collab 2018, Paper VI), we estimate the following rest-frame parameters: the isotropic energy release E_iso is 1.22(-0.06,+0.07)x10^53 erg, the peak luminosity L_iso is 6.53(-0.81,+0.84)x10^52 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i,z is 286(-18,+19) keV With the obtained estimates, GRB 220527A lies inside 68% prediction bands for both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB220527_T33441/GRB220527A_rest_frame.pdf All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 32158 table
GRB_name GRB220527A
GCN_number 32158
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 32158 SUBJECT: GRB 220527A: Lick 3m Optical Observations DATE: 22/06/02 23:05:53 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng, Thomas G. Brink and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: We observed the field of GRB 220527A (AGILE detection: Ursi et al., GCN 32129; Fermi detection: Fermi GBM team, GCN 32130, Bissaldi et al., GCN 32131, Mangan et al., 32133; CALET detection: Yamaoka et al., GCN 32139; AstroSat detection: Gopalakrishnan et al., GCN 32140; Konus-Wind detection: Lysenko et al. GCN 32152) with the 3m Shane telescope (located at Lick Observatory) on May 28 and 30 UT. Observations were performed in unfiltered images with the Kast Dual Spectrograph simultaneously in both blue and red side with the d57 dichroic. We detected the optical afterglow (Tohuvavohu et al., GCN 32136; Imai et al., GCN 32138; Xu et al., GCN 32141; de Wet et al., GCN 32143; D'Avanzo et al., GCN 32145; Sun et al., GCN 32146) in our coadd images. We calibrated our blue side images to g band and red side images to I band from the Pan-STARRS1 catalog. We measure its brightness to be the following: 1.09d g = 20.3 +/- 0.2 1.09d I = 19.4 +/- 0.2 3.08d I = 21.2 +/- 0.3
GCN 32159 table
GRB_name GRB220527A
GCN_number 32159
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 32159 SUBJECT: GRB 220527A: MITSuME Akeno continued optical observation DATE: 22/06/03 10:00:43 GMT FROM: Masafumi Niwano at Tokyo Institute of Tech M. Niwano, S. Sato, M. Tateda, N. Higuchi, T. Hattori, R. Hosokawa, K. L. Murata, M. Sasada, N. Ito, Y. Takamatsu, Y. Imai, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 220527A (A. Ursi et al. GCN Circular #32129, The Fermi GBM team GCN Circular #32130, E. Bissaldi et al. GCN Circular #32131, P. A. Evans et al. GCN Circular #32132, J. Mangan et al. GCN Circular #32133, B. Sbarufatti et al. GCN Circular #32135, Tohuvavohu et al. GCN Circular #32136, Y. Imai et al. GCN Circular #32138, K. Yamaoka et al. GCN Circular #32139, R. Gopalakrishnan et al. GCN Circular #32140, D. Xu et al. GCN Circular #32141, S. de Wet et al. GCN Circular #32143, P. D'Avanzo et al. GCN Circular #32145, T. Sun et al. GCN Circular #32146, A. Lysenko et al. GCN Circular #32152, W. Zheng et al. GCN Circular #32158) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 60 sec exposures started at 2022-05-28 16:06:39 UT (1.3 days after the AGILE detection). We stacked the images with good conditions. The point source was presumably detected at the Swift/XRT position (Sbarufatti et al. GCN Circular #32135) with S/N~3 only in the Rc-band image. Here we report the Rc-band magnitude by the forced-photometry at the position and 5-sigma limits. T0+[days] | MID-UT | T-EXP[sec] | magnitudes of forced-photometry | 5-sigma limits ------------------------------------------------------------------------------------------------ 1.3 | 2022-05-28 17:39:36 | 4980 | Rc=20.5+/-0.3 | g'<18.6, Rc<19.3, Ic<18.5 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN 32169 table
GRB_name GRB220527A
GCN_number 32169
Detection_method CALET
redshift 0.8570
Circular_text TITLE: GCN CIRCULAR NUMBER: 32169 SUBJECT: GRB 220527A: A BdHN I with a clear UPE phase DATE: 22/06/06 15:33:00 GMT FROM: Remo Rufinni at ICRA R. Ruffini, Y. Aimuratov, L. Becerra, C.L. Bianco, Y.-C. Chen, C. Cherubini, S. Eslamzadeh, S. Filippi, M. Karlica, L. Li, G.J. Mathews, R. Moradi, M. Muccino, G.B. Pisani, F. Rastegarnia, J.A. Rueda, N. Sahakyan, Y. Wang, S.-S. Xue, on behalf of the ICRA, ICRANet-INAF team, report: GRB 220527A is observed by AGILE (Ursi et al. 2022, GCN 32129), Fermi (GCN 32130, Bissaldi et al. 2022, GCN 32131, Mangan et al. 2022, GCN 32133), Swift (B. Sbarufatti et al. 2022 GCN 32135, A. Tohuvavohu. 2022, GCN 32136), CALET (Yamaoka et al. 2022, GCN 32139), AstroSat (Gopalakrishnan et al. 2022, GCN 32140), and Konus-Wind (Lysenko et al. 2022, GCN 32152). With the redshift z = 0.857 of GRB 220527A (D. Xu et al. 2022, GCN 32141), the isotropic energy of this GRB in 10 keV - 10 MeV, and 20 keV - 16 MeV ranges are E_iso=(2.60 +\- 0.14)x10^{53} erg, and E_iso=1.22(-0.06,+0.07)x10^{53} erg, respectively (A. Lysenko et al. 2022, GCN 32152). The ultra-relativistic prompt emission phase of this GRB, originating from the over-criticl electric field around the black hole (Moradi et al 2021, Phys. Rev. D 104, 063043) extends from rest-frame time of 3.7s to 5.4s. The UPE phase is best fitted by a cutoff power-law plus blackbody spectrum (CPL+BB) with best fit parameters of: alpha = -0.57, Ep = 109.5 keV, beta = -2.36, kT = 47.8 keV. In addition to the above observations, the following observation of the GeV emission (E. Bissaldi et al. 2022, GCN 32131), originated from the newborn black hole (R. Ruffini et al. 2019 ApJ 886 82) and the afterglow emission (B. Sbarufatti et al. 2022 GCN 32135, A. Tohuvavohu. 2022, GCN 32136) originated from the newborn neutron star (J.A. Rueda et al. 2020 ApJ 893 148), confirm this GRB is a BDHN I. Following Ruffini et al. 2021 (MNRAS, 504, 5301,doi:10.1093/mnras/stab724), we predict the emergence of an optical supernova peak to be detected at (25.1+/-3.5) days after the trigger (June 21th 2022, uncertainty from June 18th 2022 to June 24th 2022), with the bolometric optical luminosity of L_SN,b=(9.0+/-2.7)x10^{42} erg/s. Follow-up optical observations for the SN peak are encouraged.