The first optical light from the supernova remnant G182.4+4.3 located in the Galactic anti-centre region

TL;DR

This paper reports the first optical detection of supernova remnant G182.4+4.3, combining optical, radio, and X-ray observations to analyze its structure, shock-heated gas, and estimate its age and distance.

Contribution

It provides the first optical imaging and spectroscopic analysis of G182.4+4.3, revealing filamentary structures and shock-heated gas, and combines multi-wavelength data to estimate its age and physical properties.

Findings

Optical filaments correlate with radio shell, indicating association.

Shock-heated gas confirmed by [SII]/Halpha ratios of ~0.9-1.1.

Remnant estimated to be ~4400 years old with a radius of ~22 pc.

Abstract

We report the discovery of optical filamentary and diffuse emission from G182.4+4.3 using 1.5-m Russian-Turkish telescope. We present the optical CCD images obtained with Halpha filter revealing the presence of mainly filamentary structure at the northwest, filamentary and diffuse structure at the centre, south and north regions of the remnant. The bright optical filaments located in northwest and south regions are well correlated with the prominent radio shell of the remnant strongly suggesting their association. From the flux-calibrated CCD imaging, the average [SII]/Halpha ratio is found to be ~0.9 and ~1.1 for south and northwest regions, which clearly indicates that the emission originates from the shock heated gas. We also present the results of X-ray data obtained from XMM-Newton that show diffuse emission with a very low luminosity of ~7.3x10^31 erg s^-1 at a distance of 3 kpc in 0.3-10 keV energy band. Furthermore, we find a surprisingly young age of ~4400 yr for this remnant with such a large radius of ~22 pc.