Molecular gas in supernova local environments unveiled by EDGE

Abstract

CO observations allow estimations of the gas content of molecular clouds, which trace thereservoir of cold gas fuelling star formation, as well as to determine extinction via H2col-umn density, N(H2). Here, we studied millimetric and optical properties at 26 supernovae(SNe) locations of different types in a sample of 23 nearby galaxies by combining molecular12C16O (J=1→0) resolved maps from the EDGE survey and optical Integral Field Spec-troscopy from the CALIFA survey. We found an even clearer separation between type II andtype Ibc SNe in terms of molecular gas than what we found in the optical using Hαemissionas a proxy for current SF rate, which reinforces the fact that SNe Ibc are more associated withSF-environments. While AVat SN locations is similar for SNe II and SNe Ibc, and highercompared to SNe Ia, N(H2) is significantly higher for SNe Ibc than for SNe II and SNe Ia.When compared to alternative extinction estimations directly from SN photometry and spec-troscopy, we find that our SNe Ibc have also redder color excess but showed standard Na ID absorption pseudo-equivalent widths (∼1 Å). In some cases we find no extinction whenestimated from the environment, but high amounts of extinction when measured from SN ob-servations, which suggests that circumstellar material or dust sublimation may be playing arole. This work serves as a benchmark for future studies combining last generation millimeterand optical IFS instruments to reveal the local environmental properties of extragalactic SNe.