TITLE: GCN CIRCULAR NUMBER: 36646 SUBJECT: Konus-Wind detection of GRB 240606B DATE: 24/06/08 09:47:59 GMT FROM: Anna Ridnaia at Ioffe Institute ridnaia@mail.ioffe.ru
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 240606B (Swift/BAT-GUANO arcminute localization: DeLaunay et al., GCN 36628; GECAM-B detection: Wang et al., GCN 36633; Fermi-GBM detection: Bala & Meegan, GCN 36640) triggered Konus-Wind at T0=48787.583 s UT (13:33:07.583).
The burst light curve shows a multipeaked structure which starts at ~T0-53.0 s and has a total duration of ~58.4 s. The emission is seen up to ~4 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB240606_T48787/
As observed by Konus-Wind, the burst had a fluence of 5.07(-0.10,+1.54)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.318 s, of 1.68(-0.34,+0.61)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
Since the bulk of the burst emission was detected before the trigger, the spectral analysis was performed using the KW 3-channel light curve data.
Modelling the KW 3-channel time-integrated spectrum (measured from T0-53.014 s to T0+5.360 s) by a power law with exponential cutoff (CPL) model, dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), yields alpha = -0.55(-0.83,+3.21) and Ep = 116(-21,+62) keV.
A CPL fit to the spectrum near the peak count rate, measured from T0-0.400 s to T0+0.816 s, gives alpha -1.20(-0.14,+0.14), and Ep = 475(-128,+239) keV.
All the quoted errors are at the 68% confidence level. All the quoted values are preliminary.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36646. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...