Emission line models for the lowest-mass core collapse supernovae. I: Case study of a 9 $M_{\odot }$ one-dimensional neutrino-driven explosion

Abstract

A large fraction of core-collapse supernovae (CCSNe), 30-50%, are expected to originate from the low-mass end of progenitors with $M_{\mathrm{ZAMS}}=8-12M_{\odot }$. However, degeneracy effects make stellar evolution modelling of such stars challenging, and few predictions for their supernova light curves and spectra have been presented. Here we calculate synthetic nebular spectra of a 9 $M_{\odot }$ Fe CCSN model exploded with the neutrino mechanism. The model predicts emission lines with FWHM$\sim$1000 km/s, including signatures from each deep layer in the metal core. We compare this model to observations of the three subluminous IIP SNe with published nebular spectra; SN 1997D, SN 2005cs, and SN 2008bk. The prediction of both line profiles and luminosities are in good agreement with SN 1997D and SN 2008bk. The close fit of a model with no tuning parameters provides strong evidence for an association of these objects with low-mass Fe CCSNe. For SN 2005cs, the interpretation is less clear, as the observational coverage ended before key diagnostic lines from the core had emerged. We perform a parameterised study of the amount of explosively made stable nickel, and find that none of these three SNe show the high ${}^{58}$Ni/${}^{56}$Ni ratio predicted by current models of electron capture SNe (ECSNe) and ECSN-like explosions. Combined with clear detection of lines from O and He shell material, these SNe rather originate from Fe core progenitors. We argue that the outcome of self-consistent explosion simulations of low-mass stars, which gives fits to many key observables, strongly suggests that the class of subluminous Type IIP SNe is the observational counterpart of the lowest mass CCSNe.

Resubmitted to MNRAS after referee comments

References in corpus (22)

• Nucleosynthesis and Remnants in Massive Stars of Solar Metallicity
• The Supernova Channel of Super-AGB Stars
• Three-Dimensional Simulations of Core-Collapse Supernovae: From Shock Revival to Shock Breakout
• Super and massive AGB stars - IV. Final fates - Initial to final mass relation
• SN 2005cs in M51 II. Complete Evolution in the Optical and the Near-Infrared
• The Landscape of the Neutrino Mechanism of Core-Collapse Supernovae: Neutron Star and Black Hole Mass Functions, Explosion Energies and Nickel Yields
• The Status of Multi-Dimensional Core-Collapse Supernova Models
• Neutrino-driven supernova of a low-mass iron-core progenitor boosted by three-dimensional turbulent convection
• Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh
• Using Quantitative Spectroscopic Analysis to Determine the Properties and Distances of Type II-Plateau Supernovae: SNe 2005cs and 2006bp
• A Spitzer Space Telescope Study of SN 2003gd: Still No Direct Evidence that Core-Collapse Supernovae are Major Dust Factories
• Dynamics of shock propagation and nucleosynthesis conditions in O-Ne-Mg core supernovae
• Progenitor mass of the type IIP supernova 2005cs
• VLT detection of a red supergiant progenitor of the type IIP supernova 2008bk
• Electron-capture supernovae exploding within their progenitor wind
• Supersolar Ni/Fe production in the Type IIP SN 2012ec
• Distance estimate and progenitor characteristics of SN 2005cs in M51
• Ruling out a massive-assymptoic giant-branch star as the progenitor of supernova 2005cs
• Radiation-hydrodynamical modelling of underluminous type II plateau Supernovae
• A study of the low-luminosity Type II-Plateau supernova 2008bk
• Constraints on explosive silicon burning in core-collapse supernovae from measured Ni/Fe ratios
• Ejecta and progenitor of the low-luminosity Type IIP supernova 2003Z

Cited by in corpus (1)

• Remnants and ejecta of thermonuclear electron-capture supernovae: Constraining oxygen-neon deflagrations in high-density white dwarfs