I am interested in understanding the progenitors of thermonuclear and core-collapse supernovae using supernova remnant (SNR) populations in the Local Group, i.e. Magellanic Clouds, Andromeda (M31) and Triangulum (M33) galaxies. My goal is to estimate the SN delay time distribution (DTD) - the hypothetical SN rate following a brief (delta-function) burst of star-formation - in the Local Group. The SN DTD is effectively the age distribution, or the distribution of evolutionary timescales, of SN progenitors and therefore serves as a direct observational constraint on theoretical progenitor models. An accurately measured DTD is crucial to understanding systematic uncertanties in supernova cosmology, binary stellar evolution and the structure and chemical evolution of galaxies.
Traditionally, DTD has been measured using extragalactic SN surveys, but this approach had to rely on star-formation histories derived from the integrated spectra of galaxies, which can be dominated mostly by the younger stellar population. Instead in our Local Group, we can take advantage of more accurate star-formation histories derived from resolved stellar populations, and treat the population of SNRs as an effective SN survey.
I have led efforts to model the evolution of SNR populations by combining physical models of the interstellar medium and shock-induced particle acceleration along with rich multi-wavelength datasets available for Local Group galaxies. This produces a statistical estimate of the visibility times of SNRs in a survey, which is a key-ingredient in calculating SN rates and subsequently the DTD. I am also assisting observation, data reduction and compilation of radio-continuum selected SNRs in Local Group galaxies. These SNR surveys will combined with our visibility time model and star-formation history maps to estimate the Local Group DTD.