# The resolved stellar populations around 12 Type IIP supernovae

## TL;DR

This study uses Bayesian modeling of stellar populations around 12 Type IIP supernovae to better understand progenitor stars, revealing complex age structures and improved estimates of progenitor masses compared to previous methods.

## Contribution

It introduces a Bayesian mixture model approach to analyze resolved stellar populations around supernovae, providing more accurate progenitor mass estimates and insights into local stellar environments.

## Key findings

- Multiple age components found in most supernova environments
- Progenitors often not from the youngest stellar populations
- Bayesian approach matches progenitor masses within ±3 solar masses

## Abstract

Core-collapse supernovae are found in regions associated with recent massive star formation. The stellar population observed around the location of a SN can be used as a probe of the origins of the progenitor star. We apply a Bayesian mixture model to fit isochrones to the massive star population around twelve Type IIP SNe, for which constraints on the progenitors are also available from fortuitous pre-explosion images. Using the high-resolution Hubble Space Telescope Advanced Camera for Surveys and Wide Field Camera 3, we study the massive star population found within 100pc of each our target SNe. For most of the SNe in our sample, we find that there are multiple age components in the surrounding stellar populations. In the cases of SNe~2003gd and 2005cs, we find that the progenitor does not come from the youngest stellar population component and, in fact, these relatively low mass progenitors ($\sim 8M_{\odot}$) are found in close proximity to stars as massive as $15$ and $50-60M_{\odot}$, respectively. Overall, the field extinction (Galactic and host) derived for these populations is $\sim 0.3\,\mathrm{mags}$ higher than the extinction that was generally applied in previously reported progenitor analyses. We also find evidence, in particular for SN~2004dj, for significant levels of differential extinction. Our analysis for SN~2008bk suggests a significantly lower extinction for the population than the progenitor, but the lifetime of the population and mass determined from pre-explosion images agree. Overall, assuming that the appropriate age component can be suitably identified from the multiple stellar population components present, we find that our Bayesian approach to studying resolved stellar populations can match progenitor masses determined from direct imaging to within $\pm 3M_{\odot}$.