演講資訊

摘要：

Type Ia supernovae (SNe) have been used to discover the accelerated expansion of the universe; however, it is not clear whether they originate from white dwarfs accreting too much material from their companions or mergers of two white dwarfs. If a surviving companion of a Type Ia SN can be identified and confirmed, an origin of a white dwarf with a companion can be affirmed.
We have used two methods to search for surviving companions of Type Ia SN progenitors in five Balmer-dominated SN remnants (SNRs) in the Large Magellanic Cloud: 0509-67.5, 0519-69.0, N103B, DEM L71, and 0548-70.4. In the first method, we use the Hubble Space Telescope photometric measurements of stars to construct color-magnitude diagrams (CMDs), and compare positions of stars in the CMDs with those expected from theoretical post-impact evolution of surviving main sequence or helium star companions. In the second method, we use Multi-Unit Spectroscopic Explorer (MUSE) observations to carry out spectroscopic analyses of stars in order to use large peculiar radial velocities as diagnostics of surviving companions. In both methods, we find stars with unexpected behaviors that could be candidates of surviving companions of the SN progenitors.