Fast evolving pair-instability supernova models: evolution, explosion, light curves

Abstract

With an increasing number of superluminous supernovae (SLSNe) discovered the question of their origin remains open and causes heated debates in the supernova community. Currently, there are three proposed mechanisms for SLSNe: (1) pair-instability supernovae (PISN), (2) magnetar-driven supernovae, and (3) models in which the supernova ejecta interacts with a circumstellar material ejected before the explosion. Based on current observations of SLSNe, the PISN origin has been disfavoured for a number of reasons. Many PISN models provide overly broad light curves and too reddened spectra, because of massive ejecta and a high amount of nickel. In the current study we re-examine PISN properties using progenitor models computed with the GENEC code. We calculate supernova explosions with FLASH and light curve evolution with the radiation hydrodynamics code STELLA. We find that high-mass models (200 M⊙ and 250 M⊙) at relatively high metallicity (Z = 0.001) do not retain hydrogen in the outer layers and produce relatively fast evolving PISNe Type I and might be suitable to explain some SLSNe. We also investigate uncertainties in light curve modelling due to codes, opacities, the nickel-bubble effect and progenitor structure and composition.

Studying the Ultraviolet Spectrum of the First Spectroscopically Confirmed Supernova at Redshift Two

“…The power source of SLSNe-I remains unclear, but it is unlikely to be the radioactive decay of 56 Ni that powers the light curves of normal SNe (see Chatzopoulos et al 2009;Chomiuk et al 2011;Inserra et al 2013;Papadopoulos et al 2015). Alternative mechanisms could be the spin down of a rapidly rotating magnetar (e.g., Kasen & Bildsten 2010;Woosley 2010;Bersten et al 2016), a pair-instability SN explosion (e.g., Langer et al 2007;Kasen et al 2011;Kozyreva et al 2017), the interaction of SN ejecta with circumstellar material (e.g., Woosley et al 2007;Chevalier & Irwin 2011;Chatzopoulos et al 2012Chatzopoulos et al , 2013, or the fallback of accreted material onto a compact remnant (Dexter & Kasen 2013).…”

Rapidly Interpreting UV-optical Light Curve Properties Using a “Simple” Modeling Approach

“…Figure 1 shows luminosity versus time for three different models, varying the density profile and temperature for the He130 model in Kozyreva et al (2017). Our simulation better captures the shock breakout than some of the detailed transport calculations, and the breadth of light curve results compares well with the range of results from the different codes in the Kozyreva et al (2017) study.…”

“…These methods range from analytic approaches that focus on specific aspects of the supernova emission (Arnett 1980(Arnett , 1982Chevalier 1992;Arnett et al 2016), to fullscale radiation hydrodynamics calculations (Fryer 2009;Fryer et al 2010;Bersten et al 2011;Morozova et al 2015;Kozyreva et al 2017). Most of the analytic methods make simplifying assumptions.…”

“…In Arnett et al (2016), we found good agreement between analytic type Ia models and our simulations. We have also compared to the pair-instability models of Kozyreva et al (2017). Figure 1 shows luminosity versus time for three different models, varying the density profile and temperature for the He130 model in Kozyreva et al (2017).…”

“…The higher explosion energy results in a higher blackbody temperature, and thus a brighter SN light Figure 1. Luminosity vs. time for three pair-instability models based on the He130 model from Kozyreva et al (2017). We have altered the power in the density profile from 0 (magenta, red) to 1.5 (green).…”