A kilonova from an ultra-quick merger of a neutron star binary
| Autor: | Lei Lei, Xiang Li, Zhi-Ping Jin, Hao Zhou, P. D'Avanzo, Da-Ming Wei, Neng-Hui Liao, Stefano Covino, Yi-Zhong Fan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Metallicity Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Kilonova Redshift Afterglow Neutron star Supernova Spectral energy distribution Astrophysics - High Energy Astrophysical Phenomena Gamma-ray burst Astrophysics::Galaxy Astrophysics |
| Zdroj: | INSPIRE-HEP |
| DOI: | 10.48550/arxiv.2109.07694 |
| Popis: | GRB 060505 was the first well-known nearby (at redshift 0.089) "hybrid" gamma-ray burst that has a duration longer than 2 seconds but without the association of a supernova down to very stringent limits. The prompt $\gamma-$ray flash lasting $\sim 4$ sec could consist of an intrinsic short burst and its tail emission, but the sizable temporal lag ($\sim 0.35$ sec) as well as the environment properties led to the widely-accepted classification of a long duration gamma-ray burst originated from the collapse of a massive star. Here for the $ first$ time we report the convincing evidence for a thermal-like optical radiation component in the spectral energy distribution of the early afterglow emission. In comparison to AT2017gfo, the thermal radiation is $\sim 2$ times brighter and the temperature is comparable at similar epochs. The optical decline is much quicker than that in X-rays, which is also at odds with the fireball afterglow model but quite natural for the presence of a blue kilonova. Our finding reveals a neutron star merger origin of the hybrid GRB 060505 and strongly supports the theoretical speculation that some binary neutron stars can merge ultra-quickly (within $\sim 1$ Myr) after their formation when the surrounding region is still highly star-forming and the metallicity remains low. Gravitational wave and electromagnetic jointed observations are expected to confirm such scenarios in the near future. Comment: 20 pages, 7 figures, 2 tables |
| Databáze: | OpenAIRE |
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