Research & Projects

While electron-capture supernovae (ECSNe) are important as the lowest-mass core-collapse supernovae (CCSNe), their observations are elusive. In this my first leading author paper, to reveal robust observational differences between ECSNe and normal low-mass iron-core-collpase supernovae (FeCCSNe), we calculated their light curves with the one-dimensional multi-group radiation hydrodynamical code, STELLA (Blinnikov and Bartunov 1993), with various progenitor and explosion properties. We found that ECSNe show bluer light-curve plateaus than low-mass FeCCSNe because of their degenerate oxgen-neon-magnesium cores and low-density hydrogen-rich (H-rich) envelopes. Since the low-density H-rich envelope results in a low-density H-rich ejecta, the photosphere of ECSN goes deep and the photospheric temperature becomes high, resulting in the blue color. Moreover, we proposed a new diagnostic method to identify ECSNe with the blue color. This work is the first study that reveals a robust observational difference between ECSNe and low-mass FeCCSNe and shows a concrete diagnostic method to identify ECSNe that opens a new door for observational research of ECSNe.