The Red Supergiant Problem: As Seen from the Local Group's Red Supergiant Populations

Abstract: The red supergiant (RSG) problem, which describes the apparent lack of high-luminosity progenitors detected in Type II supernova (SN) pre-images, has been a contentious topic for two decades. We re-assess this problem using a new RSG population of the Milky Way supplemented with RSGs from other galaxies in the Local Group. In particular, we quantify the uncertainties inherent to assumptions made regarding the star's temperature or spectral type and the corresponding bolometric correction. We find that only M3 or later RSGs reproduce the steepness seen from the SN II pre-imaged sample. To assess the significance of the RSG problem, we build a metallicity-weighted cumulative luminosity distribution of M3 or later RSGs and directly compare it to the luminosity distribution of SN II pre-imaged progenitors. We find no evidence of missing high-luminosity pre-imaged progenitors since the uncertainties on the pre-imaged SN progenitors and single-band derived luminosity are too large to meaningfully infer population differences.