The Ejecta Distributions of the Heavy Elements in the Cygnus Loop

TL;DR

This study maps the distribution of heavy elements in the Cygnus Loop supernova remnant, revealing asymmetries and estimating the progenitor star's mass through spectral analysis of X-ray observations.

Contribution

It provides detailed metal distribution maps and estimates the progenitor star's mass, highlighting asymmetries in ejecta distribution using combined Suzaku and XMM-Newton data.

Findings

Si and Fe distributions are offset toward the southwest.

Estimated progenitor mass is between 12 and 15 solar masses.

Metal mixing is suggested by similar results from different regions.

Abstract

We analyzed the metal distribution of the Cygnus Loop using 14 and 7 pointings observation data obtained by the \textit{Suzaku} and the \textit{XMM-Newton} observatories. The spectral analysis shows that all the spectra are well fitted by the two-$kT_e$ non-equilibrium ionization plasma model as shown by the earlier observations. From the best-fit parameters of the high-$kT_e$ component, we calculated the emission measures about various elements and showed the metal distribution of the ejecta component. We found that the distributions of Si and Fe are centered at the southwest of the geometric center toward the blow-out region. From the best-fit parameters, we also estimated the progenitor mass of the Cygnus Loop from our field of view and the metal rich region with a radius of 25 arcmin from the metal center. The result from the metal circle is similar to that from our entire FOV, which suggests the mixing of the metal. From the results, we estimated the mass of the progenitor star at 12-15\MO.