Constraints on core-collapse supernova progenitors from explosion site integral field spectroscopy

Abstract

Context. Observationally, supernovae are divided into subclasses pertaining to their distinct characteristics. This diversity naturally reflects the diversity in the progenitor stars. It is not entirely clear however, how different evolutionary paths leading massive stars to become a supernova are governed by fundamental parameters such as progenitor initial mass and metallicity. Aims. This paper places constraints on progenitor initial mass and metallicity in distinct core-collapse supernova subclasses, through a study of the parent stellar populations at the explosion sites. Methods. Integral field spectroscopy (IFS) of 83 nearby supernova explosion sites with a median distance of 18 Mpc has been collected and analysed, enabling detection and spectral extraction of the parent stellar population of supernova progenitors. From the parent stellar population spectrum, the initial mass and metallicity of the coeval progenitor are derived by means of comparison to simple stellar population models and strong-line methods. Additionally, near-infrared IFS was employed to characterise the star formation history at the explosion sites. Results. No significant metallicity differences are observed among distinct supernova types. The typical progenitor mass is found to be highest for supernova type Ic, followed by type Ib, then types IIb and II. Type IIn is the least associated with young stellar populations and thus massive progenitors. However, statistically significant differences in progenitor initial mass are observed only when comparing supernovae IIn with other subclasses. Stripped-envelope SN progenitors with initial mass estimate lower than 25 M are found; these are thought to be the result of binary progenitors. Confirming previous studies, these results support the notion that core-collapse supernova progenitors cannot arise from single-star channel only, and both single and binary channels are at play in the production of core-collapse supernovae. Near-infrared IFS suggests that multiple stellar populations with different ages may be present in some of the supernova sites. As a consequence, there could be a non-negligible amount of contamination from old populations, and therefore the individual age estimates are effectively lower limits.

The 50–100 pc scale parent stellar populations of Type II supernovae and limitations of single star evolution models

“…1 (third Table 2), consistent with the general disassociation between SN II and star formation (e.g. Anderson et al 2012;Galbany et al 2018;Kuncarayakti et al 2018).…”

“…Kuncarayakti et al (2018) considered only single star evolution models in their analysis, and used the Starburst99 SPS models (Leitherer et al 1999). Differences between SPS models that assume single star evolution are relatively minor (Kuncarayakti et al 2016), and indeed the largest inconsistencies between the results in Kuncarayakti et al (2018) for the sample of overlapping SNe, and our single star model results originate from differences in the Hα EW measured at the SN position. These differences are likely related to the relatively large uncertainty in the SN position (1 -1.…”

“…There is evidence to show that SN type Ib originate from binary systems (Leloudas et al 2011;Eldridge et al 2013;Kuncarayakti et al 2013a;Folatelli et al 2016;Galbany et al 2016;Lyman et al 2016;Kangas et al 2017;Kuncarayakti et al 2018;Taddia et al 2018;Prentice et al 2019), whereby the SN progenitor loses its hydrogen envelope through mass transfer to its companion star rather than through stellar winds. It is also thought that at least some SNe Ic are the result of binary star interactions, although single star progenitor channels may also exist.…”

“…As mentioned in the introduction, the use of Hα EW to trace the SN progenitor age, and subsequently M 0 (env), has been extensively used, most recently by Kuncarayakti et al (2018), which includes many of the SNe studied here (9/11). Kuncarayakti et al (2018) considered only single star evolution models in their analysis, and used the Starburst99 SPS models (Leitherer et al 1999). Differences between SPS models that assume single star evolution are relatively minor (Kuncarayakti et al 2016), and indeed the largest inconsistencies between the results in Kuncarayakti et al (2018) for the sample of overlapping SNe, and our single star model results originate from differences in the Hα EW measured at the SN position.…”

The radial distribution of supernovae compared to star formation tracers

“…However, some research suggests Type II SNe cannot arise solely from single stars (e.g. Kuncarayakti et al 2018). There are only a few direct detections of Type IIL SN progenitors (Van Dyk 2017) and these support slightly more massive progenitors for some Type IIL SNe (Fraser et al 2014;Groh et al 2013b, but see Valenti et al 2016).…”