Cr-K Emission Line as a Constraint on the Progenitor Properties of Supernova Remnants

TL;DR

This study analyzes Cr, Mn, and Fe-K emission lines in young supernova remnants using Suzaku data to constrain progenitor types and explosion mechanisms, revealing correlations and line ratio thresholds indicative of supernova origins.

Contribution

It provides the first detection of Cr and Mn lines in some SNRs and establishes the correlation of line energies, offering a new method to determine supernova progenitor types based on emission line ratios.

Findings

Cr line energies correlate with Fe and Mn energies.

The EW ratio of Cr to Fe distinguishes Type Ia from core-collapse supernovae.

Line ratio > 2% suggests Type Ia origin; < 2% indicates core-collapse or carbon-deflagration Ia.

Abstract

We perform a survey of the Cr, Mn and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite {\sl Suzaku}. The Cr and/or Mn emission lines are detected in 3C\,397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B and Cas A. We derive the line parameters (i.e., the line centroid energy, flux and equivalent width [EW]) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn and Fe-K line parameters were available in the literature through {\sl Suzaku} observations. We find that the line center energies of Cr correlates very well with that of Fe and that of Mn. This confirms our previous findings that the Cr, Mn and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleo-synthesis. We find that the ratio of the EW of the Cr emission line to that of Fe ($\EWR\equiv \EWCr/\EWFe$) provides useful constraints on the SNR progenitors and on the SN explosion mechanisms: for SNRs with $\EWR > 2%$, a type Ia origin is favored (e.g., N103B, G344.7-0.1, 3C\,397 and 0519-69.0); for SNRs with $\EWR < 2%$, they could be of either core-collpase origin or carbon-deflagration Ia origin.