Special issues No. 2,
Pages: 78,
https://doi.org/10.69646/15scslsa49
XV Serbian Conference on Spectral Line Shapes in Astrophysics
Published by: Astronomical Observatory Belgrade

We present the analysis of deep (∼27 hours on-source) VLT/MUSE observations of the supernova remnant SNR 0509-67.5 in the Large Magellanic Cloud. The Hα line profiles were analyzed across the remnant, identifying both narrow and broad components that exhibit azimuthal variations in their parameters – fluxes, centroids, and widths. We compare theoretical predictions of broad-line widths to our measurements at 231 positions along the forward shock, where proper motion was determined using HST images taken 10 years apart. In some locations, the observed broad-line widths are significantly smaller than expected for the measured shock velocities assuming full electron-proton equilibration, suggesting efficient cosmic-ray acceleration in those regions. Also, the broad-line width is found to be larger on the northeastern side, indicating a higher shock velocity; however, this contradicts astrometric measurements. Additionally, the broad-line centroid is blue-shifted on the southwestern side, suggesting that the nearer limb of the supernova remnant appears brighter. The narrow-line centroid displays an east-west gradient, which may reflect a velocity gradient in the ambient medium. In contrast, the narrow-line width reveals a bipolar pattern, with slightly broader values in the southeast and northwest – possibly indicating enhanced cosmic-ray efficiency in these regions.