SN 2018hti: a nearby superluminous supernova discovered in a metal-poor galaxy
| Autor: | Danfeng Xiang, Zhihao Chen, Jun Mo, Hanna Sai, Y Hsiao, Wenxiong Li, T. G. Brink, Gaobo Xi, Liming Rui, Alexei V. Filippenko, Sh. A. Ehgamberdiev, X. F. Wang, Ling-Jun Wang, WeiKang Zheng, Weili Lin, Liang-Duan Liu, Jie Zhang, Shengyu Yan, D. O. Mirzaqulov, E. Baron, Xiaolin Li, Xinghan Zhang, Chengyuan Wu, J. M. Derkacy, J. Zhang, T. Zhang |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) 010308 nuclear & particles physics Astrophysics::High Energy Astrophysical Phenomena Metallicity FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Magnetar Light curve 01 natural sciences Galaxy Redshift Photometry (optics) Supernova Space and Planetary Science 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics - High Energy Astrophysical Phenomena Ejecta 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| DOI: | 10.48550/arxiv.2006.16443 |
| Popis: | SN 2018hti is a Type I superluminous supernova (SLSN~I) with an absolute $g$-band magnitude of $-22.2$ at maximum brightness, discovered in a metal-poor galaxy at a redshift of 0.0612. We present extensive photometric and spectroscopic observations of this supernova, covering the phases from $\sim -35$ days to more than +340 days from the $r$-band maximum. Combining our $BVgri$-band photometry with {\it Swift} UVOT optical/ultraviolet photometry, we calculated the peak luminosity as $\sim 3.5\times10^{44}$ erg s$^{-1}$. Modeling the observed light curve reveals that the luminosity evolution of SN 2018hti can be produced by an ejecta mass of 5.8 $M_\odot$ and a magnetar with a magnetic field of $B=1.8\times10^{13}$~G having an initial spin period of $P_0=1.8$ ms. Based on such a magnetar-powered scenario and a larger sample, a correlation between the spin of the magnetar and the kinetic energy of the ejecta can be inferred for most SLSNe~I, suggesting a self-consistent scenario. Like for other SLSNe~I, the host galaxy of SN 2018hti is found to be relatively faint ($M_{g} = -17.75$ mag) and of low metallicity ($Z=0.3~Z_\odot$), with a star-formation rate of 0.3 $M_\odot$ yr$^{-1}$. According to simulation results of single-star evolution, SN 2018hti could originate from a massive, metal-poor star with a zero-age main sequence (ZAMS) mass of 25--40 $M_\odot$, or from a less massive rotating star with $M_\mathrm{ZAMS} \approx 16$--25 $M_\odot$. For the case of a binary system, its progenitor could also be a star with $M_\mathrm{ZAMS} \gtrsim 25$ $M_\odot$. Comment: 26 pages, 12 figures, 7 tables, published in MNRAS |
| Databáze: | OpenAIRE |
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