Far-Ultraviolet Spectral Images of the Vela Supernova Remnant: Supplements and Comparisons with other Wavelength Images

TL;DR

This study provides detailed far-ultraviolet emission-line images of the Vela supernova remnant, revealing interactions with surrounding media and potential links to the nearby Vela Jr. SNR, enhancing understanding of SNR structures across wavelengths.

Contribution

It offers the first FUV detection associated with Vela Jr. SNR and improves the imaging data of Vela SNR, enabling better analysis of shock interactions and SNR environment.

Findings

FUV emissions suggest interaction with Vela Jr. SNR.

FUV and X-ray images reveal boundary features of the SNR.

Hα features indicate contact with the SNR's shell.

Abstract

We present the improved far-ultraviolet (FUV) emission-line images of the entire Vela supernova remnant (SNR) using newly processed SPEAR/FIMS data. The incomplete C III {\lambda}977 and O VI {\lambda}{\lambda}1032, 1038 images presented in the previous study are updated to cover the whole region. The C IV {\lambda}{\lambda}1548, 1551 image with a higher resolution and new images at Si IV {\lambda}{\lambda}1394, 1403, O IV] {\lambda}1404, He II {\lambda}1640.5, and O III] {\lambda}{\lambda}1661, 1666 are also shown. Comparison of emission line ratios for two enhanced FUV regions reveals that the FUV emissions of the east enhanced FUV region may be affected by nonradiative shocks of another very young SNR, the Vela Jr. SNR (RX J0852.0-4622, G266.6-1.2). This result is the first FUV detection that is likely associated with the Vela Jr. SNR, supporting previous arguments that the Vela Jr. SNR is close to us. The comparison of the improved FUV images with soft X-ray images shows that a FUV filamentary feature forms the boundary of the northeast-southwest asymmetrical sections of the X-ray shell. The southwest FUV features are characterized as the region where the Vela SNR is interacting with slightly denser ambient medium within the dim X-ray southwest section. From a comparison with the H{\alpha} image, we identify a ring-like H{\alpha} feature overlapped with an extended hot X-ray feature of similar size and two local peaks of C IV emission. Their morphologies are expected when the H{\alpha} ring is in direct contact with the near or far side of the Vela SNR.