General information
GRB 260603C was reported by the AstroSat CZTI collaboration as a long-duration GRB detected in AstroSat CZTI data. The strongest CZT peak occurred at 2026-06-03 20:22:40.3, with a closely matching Veto peak at 2026-06-03 20:22:40.2.
Wavelength coverage
- Hard X-ray / gamma-ray: CZT detectors clearly detected the burst in the 20-200 keV range, with multiple peaks and a measured T90 of 71 (+25, -13) s.
- Gamma-ray: The CsI anticoincidence Veto detector faintly detected the burst in the 100-500 keV range, with a single emission episode and T90 of 5 (+4, -2) s.
No observations are mentioned in optical, infrared, radio, UV, X-ray afterglow, neutrino, or gravitational-wave bands.
Lightcurve and spectrum
- CZT 20-200 keV light curve: multiple peaks; strongest peak at 2026-06-03 20:22:40.3.
- CZT peak count rate: 83 (+25, -18) counts/s above background in two quadrants, with total counts of 1141 (+467, -343).
- CZT local mean background rate: 150 (+0.7, -2) counts/s.
- CZT T90: 71 (+25, -13) s.
- Veto 100-500 keV light curve: single burst of emission peaking at 2026-06-03 20:22:40.2.
- Veto peak count rate: 250 (+71, -36) counts/s above background in all quadrants, with total counts of 822 (+283, -302).
- Veto local mean background rate: 1204 (+8, -8) counts/s.
- Veto T90: 5 (+4, -2) s, much shorter than CZT and attributed to likely unfavorable angle from the boresight for Veto detectors.
Redshift
What’s special vs typical