Double Neutron Star Mergers: Are Late-time Radio Signals Overestimated?
| Autor: | Li, Shao-Ze, Yu, Yun-Wei, Gao, He, Lan, Lin |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | The coalescence of binary neutron stars can yield the expulsion of a fast-moving, quasi-isotropic material, which may induce thermal radiation and give rise to kilonova emission. Moreover, the interaction between the ejected material and the surrounding environment generates an external shock, which can result in a long-lasting radio signal that persists for several decades following the merger. In contrast to supernova ejecta, kilonova ejecta exhibits a relatively lesser mass and higher velocity, and its expansion may ultimately result in the ejecta density becoming so low that the medium particle can freely pass through the ejecta. Thereby it would lead to a kind of incomplete sweeping on the interstellar medium. Employing a toy model, our investigation reveals that such incomplete sweeping may considerably diminish the late-time radio radiation power, irrespective of whether the binary neutron star merger results in the formation of a black hole or a neutron star. Our findings, thus, imply that the previously reported radio upper limits for certain short gamma-ray bursts may not necessarily place stringent constraints on the presence of a long-lived magnetar remnant in these short GRBs. Comment: 8 pages, 7 figures, accepted for publication in ApJ |
| Databáze: | arXiv |
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