We have been searching for surviving companions of Type Ia SNe in five young Type Ia SNRs in the LMC in order to assess their explosion mechanism. These young Type Ia SNRs are characterized by shells whose optical spectra are dominated by hydrogen Balmer lines. These Blamer-dominated spectra result from collisionless shocks moving into a partially neutral ambient medium. The five SNRs are 0509-67.5, 0519-69.0, 0548-70.4, DEM L71, and N103B. N103B is known to contain a dense circumstellar medium interior to the SNR shell, suggesting a single-degenerate nature of its SN progenitor.

 

We have used HST photometry of stars projected within the above five young Type Ia SNRs to produce color-magnitude diagrams (CMDs) and compare the stars to the post-impact evolution tracks of surviving companions from Pan et al. (2014) to identify candidates of surviving companions. We have also used VLT/MUSE observations of 0519-69.0, DEM L71, and N103B to extract spectra of stars projected within their SNR shells in order to use stellar radial velocities to identify candidates of surviving companions. In both methods, we find stars with unexpected behaviors that could be candidates of surviving companions of the SN progenitors.