The Type Ia Supernova Rate in Radio and Infrared Galaxies from the CFHT Supernova Legacy Survey

TL;DR

This study examines the rate of Type Ia supernovae in radio and infrared galaxies, finding rates slightly higher than in all early-type galaxies, and explores the role of dust and star formation in these hosts.

Contribution

It combines large supernova and galaxy catalogs to analyze SN Ia rates in radio and infrared galaxies, incorporating star formation into existing models and discussing implications for delay time distributions.

Findings

SN Ia rate in radio/infrared early-type galaxies is 1-5 times higher than in all early-type galaxies.

Rates are consistent with the two-component 'A+B' SN Ia rate model.

Infrared properties suggest dust-obscured star formation in hosts.

Abstract

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, VLA 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ~1-5 times the rate in all early-type galaxies, and that any enhancement is always <~ 2 sigma. Rates in these subsets are consistent with predictions of the two component "A+B" SN Ia rate model. Since infrared properties of radio SN Ia hosts indicate dust obscured star formation, we incorporate infrared star formation rates into the "A+B" model. We also show the properties of SNe Ia in radio and infrared galaxies suggest the hosts contain dust and support a continuum of delay time distributions for SNe Ia, although other delay time distributions cannot be ruled out based on our data.