Correlations between SNe Ia Rates and Host Galaxy Properties

TL;DR

This study investigates how type Ia supernova rates relate to host galaxy properties using SDSS-II data, finding a model that fits some data but fails in other aspects, indicating the need for additional parameters.

Contribution

The paper introduces a maximum likelihood method to fit the SNe Ia rate model and reveals that an extra parameter, likely related to galaxy mass, improves the fit.

Findings

Estimated parameters A and B for the rate model.

The model fits some data projections but poorly predicts distributions with host mass and SFR.

Additional model parameter related to host galaxy mass is needed.

Abstract

Studying the correlation of type Ia supernova rates (SNR) with host galaxy properties is an important step in understanding the exact nature of type Ia supernovae. We use SNe Ia from the SDSS-II sample, spectroscopically determined masses and star formation rates, and a new maximum likelihood method, to fit the Scannapieco and Bildsten rate model $SNR = A{\times}M + B{\times}SFR$, where $M$ is galaxy mass and $SFR$ is star formation rate. We find $A = 3.5^{+0.9}_{-0.7}\times10^{-14}(\text{SNe/yr})(M_{\odot})^{-1}$ and $B =1.3^{+0.4}_{-0.3}\times10^{-3}(\text{SNe/yr})(M_{\odot}$yr$^{-1})^{-1}$, assuming overall efficiency of 0.5. This is in reasonable agreement with other determinations. However we find strong evidence that this model is a poor fit to other projections of the data: it fails to correctly predict the distribution of supernovae with host mass or SFR. An additional model parameter is required; most likely this parameter is related to host galaxy mass. Some implications of this result are discussed.