2012ApJ...761..135K

We present the improved far-ultraviolet (FUV) emission-line images of the entire Vela supernova remnant (SNR) using newly processed Spectroscopy of Plasma Evolution from Astrophysical Radiation/Far-Ultraviolet Imaging Spectrograph (SPEAR/FIMS) data. The incomplete C III λ977 and O VI λλ1032, 1038 images presented in the previous study are updated to cover the whole region. The C IV λλ1548, 1551 image with a higher resolution and new images at Si IV λλ1394, 1403, O IV] λ1404, He II λ1640.5, and O III] λλ1661, 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 an 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 Hα image, we identify a ring-like Hα 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 Hα ring is in direct contact with the near or far side of the Vela SNR.