X-ray and Radio Observations of the gamma Cygni Supernova Remnant G78.2+2.1

TL;DR

This study combines X-ray and radio observations to analyze the gamma Cygni supernova remnant, revealing its structure, distance, age, and possible stellar wind bubble, providing detailed insights into its physical properties.

Contribution

It presents new multi-wavelength imaging and spectral analysis of G78.2+2.1, including a refined distance estimate and identification of a stellar wind bubble, advancing understanding of its evolution.

Findings

Distance of 1.7 to 2.6 kpc established

X-ray temperature of 0.6-1.2 keV determined

Age estimated between 6800-10000 years

Abstract

We analyse \textit{ROSAT} and \textit{Chandra} ACIS X-ray observations and HI absorption spectra of the $\gamma$ Cygni supernova remnant (G78.2+2.1, DR4). The \textit{ROSAT} All-Sky-Survey image shows G78.2+2.1 has an adjacent limb-brightened shell north of it. A new \textit{ROSAT} mosaic shows details of the X-ray emission over the entire face of G78.2+2.1. We also create \textit{Chandra} mosaics which cover much of the northern rim and central regions of G78.2+2.1. HI absorption spectra result in association of G78.2+2.1 with the $\gamma$ Cygni nebula, with distance 1.7 to 2.6 kpc. Chandra spectra for G78.2+2.1 give an X-ray temperature of 0.6-1.2 keV (90% error), and that a Sedov model has age of 6800-10000 yr. A compact power-law X-ray source in G78.2+2.1 is consistent with the same distance as G78.2+2.1. The northern X-ray shell is identified with a B3 star at distance of 980 pc and is proposed as a stellar wind bubble.