Impact of stellar rotation on type II supernova progenitor masses from pre-explosion imaging

TL;DR

This study evaluates how stellar rotation influences the initial mass estimates of type II supernova progenitors derived from pre-explosion imaging, finding only modest effects within current uncertainties.

Contribution

It demonstrates that incorporating observed stellar rotation distributions results in only slight adjustments to progenitor mass estimates compared to non-rotating models.

Findings

Rotating models slightly shift progenitor mass distributions towards lower masses.

The upper initial-mass limit for SN II progenitors is about 20.4 solar masses.

Stellar rotation has a modest impact on mass estimates within current uncertainties.

Abstract

The initial masses of red supergiant (RSG) type II supernova (SN II) progenitors are commonly inferred from pre-explosion imaging by converting the progenitor luminosity into an initial mass estimate using non-rotating stellar evolution models. However, stellar rotation affects the evolution and may influence these estimates. We investigate how the observed distribution of rotational velocities in massive stars influences the progenitor initial masses of SNe II inferred from pre-SN imaging. We compare initial mass estimates obtained from non-rotating models with those derived from rotating models, where the initial rotational velocities of the stellar models are sampled from the observed distribution. We analyse the inferred progenitor initial masses by (i) comparing the results for each SN individually, (ii) examining the overall probability density function, (iii) constructing the cumulative distribution function, and (iv) determining the upper initial-mass boundary. In all cases, the distributions obtained from rotating models are slightly shifted towards lower masses, although the differences remain smaller than the typical uncertainties. When using the observed distribution of initial rotational velocities for massive stars, we infer an upper initial-mass limit for SN II progenitors of 20.4$^{+2.3}_{-1.9} M_{\odot}$. Taken together, these analyses demonstrate that stellar rotation has only a modest impact on progenitor mass estimates from pre-SN imaging within the current observational and model uncertainties when the observed distribution of initial rotational velocities is taken into account. Therefore, adopting this distribution leads to small differences compared to non-rotating models.