Chris Lin (ASIAA), Po-Sheng Ou (ASIAA), Chuan-Jui Li (ASIAA), You-Hua Chu (ASIAA)
Type Ia supernovae (SNe) have been used as standard candles to discover the accelerated expansion of the Universe. It is vital to understand the origin and nature of Type Ia SNe. We have been studying Type Ia SNRs in order to gain insights into their SNe. We are particularly interested in the population of Type Ia SNe in a galaxy, and intend to expand our study from the Large Magellanic Cloud (LMC) to the spiral galaxy M33, since M33 is also one of the closest galaxy in Local Group with nearly face-on inclination to make it easy to be observed. We assume that young Type Ia SNRs in M33 are similar to those in the LMC, and used the criteron Lx > 1036 erg/s to search for candidates of young Type Ia SNRs in M33. The Chandra catalog of X-ray sources in M33 provided 31 candidates. We then used archival KPNO 4m wide-band and narrow band images to search for optical counterparts of these X-ray sources. To our dismay, no Balmer-dominated young Type Ia SNRs were found. Considering that M33 and the LMC have comparable stellar masses, the contrast of 5 Balmer-dominated Type Ia SNRs in the LMC and none in M33 is surprising. In this poster we report our search for Type Ia SNRs in M33 and speculate possible causes for the difference in young Type Ia SNRs between M33 and the LMC.