The End of Amnesia: A New Method for Measuring the Metallicity of Type Ia Supernova Progenitors Using Manganese Lines in Supernova Remnants

TL;DR

This paper introduces a novel X-ray spectral method to determine the metallicity of Type Ia supernova progenitors by analyzing Mn and Cr lines, providing insights into their initial composition.

Contribution

The study establishes a correlation between Mn/Cr mass ratio and progenitor metallicity, applying it to real data to estimate the progenitor's metallicity.

Findings

Proposed a new X-ray spectral technique for metallicity measurement.

Applied method to Tycho supernova remnant, estimating progenitor metallicity.

Confirmed metallicity is at least solar, ruling out very low values.

Abstract

We propose a new method to measure the metallicity of Type Ia supernova progenitors using Mn and Cr lines in the X-ray spectra of young supernova remnants. We show that the Mn to Cr mass ratio in Type Ia supernova ejecta is tightly correlated with the initial metallicity of the progenitor, as determined by the neutron excess of the white dwarf material before thermonuclear runaway. We use this correlation, together with the flux of the Cr and Mn Kalpha X-ray lines in the Tycho supernova remnant recently detected by Suzaku (Tamagawa et al. 2008) to derive a metallicity of log(Z) = -1.32 (+0.67,-0.33) for the progenitor of this supernova, which corresponds to log(Z/Zsun)= 0.60 (+0.31,-0.60) according to the latest determination of the solar metallicity by Asplund et al. (2005). The uncertainty in the measurement is large, but metallicities much smaller than the solar value can be confidently discarded. We discuss the implications of this result for future research on Type Ia supernova progenitors.