A nearby long gamma-ray burst from a merger of compact objects
Abstract
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (>2 s) duration are produced by the core-collapse of massive stars, those of short (< 2 s) duration by the merger of two neutron stars (NSs). A third class of events with hybrid high-energy properties was identified, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented. Here we report observations of the exceptionally bright GRB211211A that classify it as a hybrid event and constrain its distance scale to only 346 Mpc. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (~1E42 erg/s) kilonova possibly formed in the ejecta of a compact binary merger.
Cite
@article{arxiv.2209.03363,
title = {A nearby long gamma-ray burst from a merger of compact objects},
author = {E. Troja and C. L. Fryer and B. O'Connor and G. Ryan and S. Dichiara and A. Kumar and N. Ito and R. Gupta and R. Wollaeger and J. P. Norris and N. Kawai and N. Butler and A. Aryan and K. Misra and R. Hosokawa and K. L. Murata and M. Niwano and S. B. Pandey and A. Kutyrev and H. J. van Eerten and E. A. Chase and Y. -D. Hu and M. D. Caballero-Garcia and A. J. Castro-Tirado},
journal= {arXiv preprint arXiv:2209.03363},
year = {2022}
}
Comments
final version, including supplementary methods