Collaborative Research:The Supernova Rate and Delay Time Distribution in the Local Group

Michigan State University, East Lansing MI

Investigators

Abstract

Supernovae are violent stellar explosions that can briefly outshine the cumulative light from all the stars in a galaxy. Supernovae are important because they return heavy elements to the empty space in the galaxy, thus seeding the next generation of stars and planets. The rate at which supernovae occur is crucial to our understanding of the evolution of galaxies and the Universe as a whole. This proposal will investigate two important quantities related to supernovae by observing the objects that are left behind after a supernova explosions and modeling the brightness of these supernova remnants. The goal of this proposal is to investigate the supernova (SN) rate and the delay time distribution (DTD) of supernovae (SNe). The DTD is a quantity that describes how the SN rate varies with the age of a stellar population. The project will impact our understanding of two key questions regarding SNe, namely: What are the progenitors of Type Ia SNe?, and What is the range of masses for progenitors of core collapse SNe? The PIs propose an innovative approach to determining the SN rate and DTD that involves: (1) compiling a deep sample of SN remnants from four galaxies in the Local Group, (2) measuring the density and distribution of the interstellar medium in these galaxies, and (3) using calibrated models for the luminosity of the SN remnants to determine the SN rate and DTD. The study of the properties (i.e. size and luminosity) of supernova remnant populations will be broadly relevant to questions of galaxy evolution and cosmic ray origins. The project will communicate its results to the general public through lectures and hands-on astronomy activities for audiences of all ages. Both PI's are heavily involved in the education and training of graduate and undergraduate students, and the proposed work will further strengthen the students' exposure to astronomical research into supernovae.