Supernova Remnants in the Large Magellanic Clouds IX: Multiwavelength Analysis of the Physical Structure of N49

TL;DR

This study provides a detailed multiwavelength analysis of supernova remnant N49 in the Large Magellanic Cloud, revealing its morphology, kinematics, and shock interactions through optical and X-ray observations.

Contribution

It offers new insights into the physical structure and shock dynamics of N49 by combining high-resolution optical imaging, spectroscopy, and X-ray data.

Findings

Detection of emission offset indicating complex shock interactions

Measurement of remnant expansion velocity around 250 km/s

Identification of high-velocity cloudlets up to 350 km/s

Abstract

We present a multiwavelength analysis of the supernova remnant N49 in the Large Magellanic Cloud. Using high-resolution Hubble Space Telescope WFPC2 images of H-alpha, [S II] and [O III] emission, we study the morphology of the remnant and calculate the rms electron densities in different regions. We detect an offset of [O III] and H-alpha emission of about 0.5 arcsec, and discuss possible scenarios that could give rise to such high values. The kinematics of the remnant is analyzed by matching individual filaments to the echelle spectra obtained at CTIO. We detect narrow H-alpha emission component which we identify as the diffuse post-shock recombination radiation, and discrete broad emission features that correspond to the shocked gas in filaments. The overall expansion of the remnant is about 250 km/s. The dense clouds are shocked up to line-of-sight velocities of 250 km/s and the less dense gas up to 300 km/s. A few cloudlets have even higher radial velocities, reaching up to 350 km/s. We confirm the presence of the cavity in the remnant, and identify the center of explosion. Using archival Chandra and XMM-Newton data, we observe the same trends in surface brightness distribution for the optical and X-ray images. We carry out the spectral analysis of three regions that represent the most significant optical features.