Observed fractions of core-collapse supernova types and initial masses of their single and binary progenitor stars

Abstract

We analyse the observed fractions of core-collapse supernova (SN) types from the Lick Observatory Supernova Search (LOSS), and we discuss the corresponding implications for massive star evolution. For a standard initial mass function, observed fractions of SN types cannot be reconciled with the expectations of single-star evolution. The mass range of Wolf-Rayet (WR) stars that shed their hydrogen envelopes via their own mass-loss accounts for less than half of the observed fraction of Type Ibc supernovae (SNe Ibc). The true progenitors of SNe Ibc must extend to a much lower range of initial masses than classical WR stars, and we argue that most SN Ibc and SN IIb progenitors must arise from binary Roche lobe overflow. In this scenario, SNe Ic would still trace higher initial mass and metallicity, because line-driven winds in the WR stage remove the helium layer and propel the transition from SN Ib to Ic. Less massive progenitors of SNe Ib and IIb may not be classical WR stars; they may be underluminous with weak winds, possibly hidden by overluminous mass-gainer companions that could appear as B[e] supergiants or related objects having aspherical circumstellar material. The remaining SN types (II-P, II-L and IIn) need to be redistributed across the full range of initial masses, so that even some very massive single stars retain H envelopes until explosion. We consider the possibility of direct collapse to black holes without visible SNe, but find this hypothesis difficult to accommodate in most scenarios. Major areas of remaining uncertainty are (1) the detailed influence of binary separation, rotation and metallicity; (2) mass differences in progenitors of SNe IIn compared to SNe II-L and II-P; and (3) the fraction of SNe Ic arising from single stars with the help of eruptive mass-loss, how this depends on metallicity and how it relates to diversity within the SN Ic subclass. Continued studies of progenitor stars and their environments in nearby galaxies, accounting for SN types, may eventually test these ideas.

On the formation of galactic black hole low-mass X-ray binaries

“…The latter prescription is under the assumption that the BH formation is controlled by the compactness of the stellar core at the time of collapse: low compactness stars are more likely to explode as SNe and produce NSs, while high-compactness stars are more likely to evolve to failed SNe that produce BHs (O'Connor & Ott 2011). In this case we assume MBH = MHe or MCO, where MHe is the He core masses prior to core collapse (e.g., Smith et al 2011;Smith & Arnett 2014;Shiode & Quataert 2014;Sukhbold & Woosley 2014;Clausen et al 2015;Kochanek 2014Kochanek , 2015. The value of MHe is determined as follows (Hurley et al 2000, for a detailed description).…”

Supernovae and their host galaxies – II. The relative frequencies of supernovae types in spirals

“…(e.g. Bressan et al 2002;Eldridge, Izzard & Tout 2008;Eldridge, Langer & Tout 2011;Smith et al 2011). To qualitatively examine the relationship between this ratio and metallicity, we use the extracted global galaxy metallicities 8 available for only 196 CC SNe hosts from the SDSS DR10.…”

Inferring supernova IIb/Ib/Ic ejecta properties from light curves and spectra: correlations from radiative-transfer models

“…While the close-binary evolution scenario offers an attractive solution to both core-collapse SN statistics (see, e.g., Podsiadlowski et al 1992;Eldridge et al 2008;Smith et al 2011) and inferred ejecta properties (Ensman & Woosley 1988;Woosley et al 1995), it is not clear today what fraction arises from the explosion of stars that evolve in isolation. The diversity of massive close binaries can qualitatively explain the observed diversity of SNe IIb (Claeys et al 2011), but for moderate main-sequence masses, the binary channel seems to favour the production of SNe ‹ email: Luc.Dessart@oca.eu Ib (Yoon et al 2010).…”