Journal Article

A nearby long gamma-ray burst from a merger of compact objects

Kutyrev, A., Gupta, R., Kumar, A., Misra, K., O’Connor, B., Fryer, C. L., van Eerten, H. J., Hu, Y.-D., Ito, N., Hosokawa, R., Ryan, G., Aryan, A., Norris, J. P., Butler, N. R., Castro-Tirado, A. J., Pandey, S. B., Kawai, N., Murata, K. L., Niwano, M., Dichiara, S., Chase, E. A., Wollaeger, R. T., Troja, E., Caballero-Garcia, M. D.

2022

Overview

Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive stars 1 , and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars 2 . A third class of events with hybrid high-energy properties was identified 3 , but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions 4 – 6 , but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented 7 , 8 . Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 10 42  erg per second) kilonova possibly formed in the ejecta of a compact object merger. A bright, long-duration gamma-ray burst observed by the Swift observatory has hybrid high-energy properties, suggesting that its origin is the merger of a compact binary.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/33/34/4118 / 639/33/34/864 / ASTRONOMY AND ASTROPHYSICS / Ejecta / Energy / Explosions / Gamma ray astronomy / Gamma ray bursts / Gamma rays / Gravitational waves / High energy astronomy / Humanities and Social Sciences / multidisciplinary / Radiation / Science / Science & Technology - Other Topics / Science (multidisciplinary) / Space telescopes / Stars, Celestial / Supernovae