SN 2018hti: a nearby superluminous supernova discovered in a metal-poor galaxy

Abstract

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 $\sim 3.5\times 10^{44}$ 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 $B=1.8\times 10^{13}$~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 ($Z=0.3Z_{\odot }$), 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 $M_{\mathrm{ZAMS}}\gtrsim 25$ $M_{\odot }$.

26 pages, 12 figures, 7 tables, published in MNRAS

References in corpus (17)

• The Zwicky Transient Facility: System Overview, Performance, and First Results
• Physical Properties of Wolf-Rayet Stars
• The Zwicky Transient Facility: Science Objectives
• New fully empirical calibrations of strong-line metallicity indicators in star forming galaxies
• Magnetorotational Core-Collapse Supernovae in Three Dimensions
• The magnetar model for Type I superluminous supernovae I: Bayesian analysis of the full multicolour light curve sample with MOSFiT
• SOUSA: the Swift Optical/Ultraviolet Supernova Archive
• Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies
• The Unique Type Ib Supernova 2005bf at Nebular Phases: A Possible Birth Event of A Strongly Magnetized Neutron Star
• Optical and Near-Infrared Observations of the Highly Reddened, Rapidly Expanding Type Ia Supernova 2006X in M100
• Hydrogen-Poor Superluminous Supernovae from the Pan-STARRS1 Medium Deep Survey
• Superluminous supernova 2015bn in the nebular phase: evidence for the engine-powered explosion of a stripped massive star
• Superluminous Supernovae Powered by Magnetars: Late-time Light Curves and Hard Emission Leakage
• An ultraviolet excess in the superluminous supernova Gaia16apd reveals a powerful central engine
• A Monte Carlo Approach to Magnetar-powered Transients: I. Hydrogen-deficient Superluminous Supernovae
• Circumstellar Interaction Models for the Bolometric Light Curve of SN 2017egm
• Optical Observations of the Type Ic Supernova 2007gr in NGC 1058 and Implications for the Properties of its Progenitor

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• Pre-maximum spectroscopic diversity of hydrogen-poor superluminous supernovae
• ASASSN-14ms:the Most Energetic Known Explosion of a Type Ibn Supernova and its Physical Origin
• Close, bright and boxy: the superluminous SN 2018hti
• Feeding post core collapse supernova explosion jets with an inflated main sequence companion
• Hard X-ray Observations of the Hydrogen-poor Superluminous Supernova SN 2018hti with NuSTAR
• Exploring GRBs and supernovae connection: does a superluminous hypernova population exist?