May 15 – 17, 2026
College of Hakka Studies at NYCU, Zhubei, Hsinchu County 國立陽明交通大學客家學院(竹北六家校區)
Asia/Taipei timezone

Exploring the spectral characteristics of Type Ia supernovae and their relationship with host galaxies

May 15, 2026, 5:30 PM
15m
International Conference Hall, College of Hakka Studies, NYCU 國立陽明交通大學客家文化學院國際會議廳

International Conference Hall, College of Hakka Studies, NYCU 國立陽明交通大學客家文化學院國際會議廳

Speaker

Cheng-Han Lai (Institute of Astronomy, National Central University)

Description

The progenitor systems and explosion mechanisms of Type Ia supernovae (SNe Ia) are not yet fully understood. We aim to constrain them by analyzing the properties of their host galaxies, from which we can infer key information about the progenitors. In this study, we analyze the maximum light spectra of SNe Ia using data from ePESSTO+ from 2019 to 2023. We investigate the relationship between the SN ejecta velocities and pseudo-equivalent widths (pEW) of the Si II λ6355 and Si II λ5972 absorption lines and the physical properties of their host galaxies, including stellar mass, star formation rate, and specific star formation rate. We test how different SN Ia classification schemes correlate with their host galaxy environments. Our results show that the conventional subtype classification provides the clearest distinctions among host properties. Furthermore, High-velocity (HV) events correlate with host properties suggestive of sub-Chandrasekhar mass explosions, whereas Normal-velocity (NV) events likely arise from multiple channels. For these subtypes, the pEW of the Si II λ6355 line appears to be a more effective indicator than its velocity for distinguishing between their explosion mechanisms.

Participate the oral/poster presentation award competition Yes

Author

Cheng-Han Lai (Institute of Astronomy, National Central University)

Co-author

Prof. Ting-Wan Chen (Institute of Astronomy, National Central University)

Presentation materials

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