Facial reconstruction

Search LJMU Research Online

Browse Repository | Browse E-Theses

Supernova 2020wnt: An Atypical Superluminous Supernova with a Hidden Central Engine

Tinyanont, S, Woosley, SE, Taggart, K, Foley, RJ, Yan, L, Lunnan, R, Davis, KW, Kilpatrick, CD, Siebert, MR, Schulze, S, Ashall, C, Chen, TW, De, K, Dimitriadis, G, Dong, DZ, Fremling, C, Gagliano, A, Jha, SW, Jones, DO, Kasliwal, MM , Miao, HY, Pan, YC, Perley, DA, Ravi, V, Rojas-Bravo, C, Sfaradi, I, Sollerman, J, Alarcon, V, Angulo, R, Clever, KE, Crawford, P, Couch, C, Dandu, S, Dhara, A, Johnson, J, Lai, Z and Smith, C (2023) Supernova 2020wnt: An Atypical Superluminous Supernova with a Hidden Central Engine. The Astrophysical Journal, 951 (1). pp. 1-26. ISSN 1538-4357

Supernova 2020wnt An Atypical Superluminous Supernova with a Hidden Central Engine.pdf - Published Version
Available under License Creative Commons Attribution.

Download (20MB) | Preview


We present observations of a peculiar hydrogen- and helium-poor stripped-envelope (SE) supernova (SN) 2020wnt, primarily in the optical and near-infrared (near-IR). Its peak absolute bolometric magnitude of −20.9 mag (L bol, peak = (6.8 ± 0.3) × 1043 erg s−1) and a rise time of 69 days are reminiscent of hydrogen-poor superluminous SNe (SLSNe I), luminous transients potentially powered by spinning-down magnetars. Before the main peak, there is a brief peak lasting <10 days post explosion, likely caused by interaction with circumstellar medium (CSM) ejected ∼years before the SN explosion. The optical spectra near peak lack a hot continuum and O ii absorptions, which are signs of heating from a central engine; they quantitatively resemble those of radioactivity-powered hydrogen/helium-poor Type Ic SESNe. At ∼1 yr after peak, nebular spectra reveal a blue pseudo-continuum and narrow O i recombination lines associated with magnetar heating. Radio observations rule out strong CSM interactions as the dominant energy source at +266 days post peak. Near-IR observations at +200-300 days reveal carbon monoxide and dust formation, which causes a dramatic optical light-curve dip. Pair-instability explosion models predict slow light curve and spectral features incompatible with observations. SN 2020wnt is best explained as a magnetar-powered core-collapse explosion of a 28 M ⊙ pre-SN star. The explosion kinetic energy is significantly larger than the magnetar energy at peak, effectively concealing the magnetar-heated inner ejecta until well after peak. SN 2020wnt falls into a continuum between normal SNe Ic and SLSNe I, and demonstrates that optical spectra at peak alone cannot rule out the presence of a central engine.

Item Type: Article
Uncontrolled Keywords: 0201 Astronomical and Space Sciences; 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics; 0306 Physical Chemistry (incl. Structural); Astronomy & Astrophysics
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: American Astronomical Society
SWORD Depositor: A Symplectic
Date Deposited: 04 Jan 2024 12:26
Last Modified: 04 Jan 2024 12:30
DOI or ID number: 10.3847/1538-4357/acc6c3
URI: https://researchonline.ljmu.ac.uk/id/eprint/22173
View Item View Item