Variability of Late-time Radio Emission in SLSN PTF10hgi
| Autor: | Hatsukade, Bunyo, Tominaga, Nozomu, Morokuma, Tomoki, Morokuma-Matsui, Kana, Tamura, Yoichi, Niinuma, Kotaro, Hayashi, Masao, Matsuda, Yuichi, Motogi, Kazuhiro |
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| Rok vydání: | 2021 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/2041-8213/abef03 |
| Popis: | We report the time variability of the late-time radio emission in a Type-I superluminous supernova (SLSN), PTF10hgi, at z = 0.0987. The Karl G. Jansky Very Large Array 3 GHz observations at 8.6 and 10 years after the explosion both detected radio emission with a ~40% decrease in flux density in the second epoch. This is the first report of a significant variability of the late-time radio light curve in a SLSN. Through combination with previous measurements in two other epochs, we constrained both the rise and decay phases of the radio light curve over three years, peaking at approximately 8-9 years after the explosion with a peak luminosity of L(3GHz) = 2 x 10^21 W/Hz. Possible scenarios for the origin of the variability are an active galactic nucleus (AGN) in the host galaxy, an afterglow caused by the interaction between an off-axis jet and circumstellar medium, and a wind nebula powered by a newly-born magnetar. Comparisons with models show that the radio light curve can be reproduced by both the afterglow model and magnetar wind nebula model. Considering the flat radio spectrum at 1-15 GHz and an upper limit at 0.6 GHz obtained in previous studies, plausible scenarios are a low-luminosity flat-spectrum AGN or a magnetar wind nebula with a shallow injection spectral index. Comment: 9 pages, 4 figures, accepted for publication in ApJ Letters |
| Databáze: | arXiv |
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