{
  "submittedHow": "email-legacy",
  "createdOn": 1702751231076,
  "subject": "Konus-Wind detection of GRB 231215A",
  "circularId": 35377,
  "bibcode": "2023GCN.35377....1F",
  "body": "D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,\nA. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long, bright GRB 231215A (Swift detection: D'Avanzo et al., GCN 35343;\nAstroSat CZTI detection: Navaneeth et al., GCN 35352;\nCALET Gamma-Ray Burst Monitor detection: Cannady et al., GCN 35368;\nAGILE detection: Verrecchia et al., GCN 35361;\nFermi GBM detection: Lesage et al., GCN 35369)\ntriggered Konus-Wind (KW) at T0=35239.795 s UT (09:47:19.795).\n\nThe burst light curve shows a single multi-peaked pulse,\nwhich starts at ~T0-1 s, peaks at ~T0+9.5 s,\nand has a total duration of ~25 s.\nThe emission is seen up to ~10 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB231215_T35239/\n\nAs observed by Konus-Wind, the burst had\na fluence of (1.02 ± 0.09)x10^-4 erg/cm^2 and\na 64-ms peak energy flux, measured from T0 + 28.352 s,\nof (1.14 ± 0.12)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+24.320 s)\nis best fit in the 20 keV - 15 MeV range\nby a GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.67 (-0.07,+0.08),\nthe high energy photon index beta = -2.49 (-0.43,+0.22),\nthe peak energy Ep = 612 (-63,+74) keV,\nchi2 = 80/97 dof.\n\nThe spectrum near the peak count rate (measured from T0+6.400s to T0+9.984s)\nis best fit in the 20 keV - 15 MeV range\nby a GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.49 (-0.09,+0.09),\nthe high energy photon index beta = -3.07 (-2.04,+0.44),\nthe peak energy Ep = 582 (-54,+58) keV,\nchi2 = 69/80 dof.\n\nAssuming the redshift z=2.305 (Thoene et al., GCN 35373)\nand a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,\nand Omega_Lambda = 0.685 (Planck Collaboration, 2014),\nwe estimate the burst isotropic energy release E_iso to (1.35 ± 0.12)x10^54 erg,\nthe isotropic peak luminosity L_iso to (4.93 ± 0.49)x10^53 erg/s,\nthe rest-frame peak energy of the time-integrated spectrum Ep,i,z to ~2023 keV,\nand the rest-frame peak energy at the peak of the emission Ep,p,z to ~1924 keV.\nWith the obtained estimates, GRB 230818A is inside 68% prediction band for\nboth 'Amati' and 'Yonetoku' relations derived for the sample of >300 long\nKW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021),\nsee http://www.ioffe.ru/LEA/GRBs/GRB231215_T35239/GRB231215A_rest_frame.pdf\n\nAll the quoted errors are estimated at the 68% confidence level.\nAll the presented results are preliminary.\n\n",
  "submitter": "Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>",
  "eventId": "GRB 231215A"
}