| dc.description.abstract | Type Ia supernovae (SNe Ia) are standardizable candles frequently used to probe cosmic expansion. However, their progenitor system and explosion mechanism remain unclear. The host-galaxy environment has been proven to be a valuable avenue for investigating the nature of SN Ia explosions. In this thesis, we study the host galaxies of approximately 200 high-redshift (medium z=0.3) SNe Ia discovered by the Pan-STARRS1 Medium Deep Survey (PS1-MDS). We determined the global and local (1.5” radius from SNe Ia) host galaxy stellar mass, star-formation rate (SFR), and specific star-formation rate (sSFR), examining their relation to SN Ia properties and compared our results with that of lowredshift research (medium z=0.05). This research aims to explore whether host parameters have a correlation with SNe Ia light-curve width (x1), color, and Hubble residual. We found significant correlations between host-galaxy stellar mass and sSFR with SN x1 (6.9 sigma and 100% negative slope for stellar mass, and 8.139 sigma and 100% positive slope for sSFR), which are consistent with low-redshift studies. For the comparison between SNe Ia color and SFR, we found a mild trend (95.5% negative slope), which is different from the low-redshift studies. For the comparison between Hubble residual and global host parameters, we do not see any trend, which is align with previous research. For the local host-galaxy properties, there is significant trend between local SFR and SN color and Hubble residual (100% negative slope for color, and 98.75% negative slope for Hubble residual). There is trend between local sSFR and x1 (4.227 sigma and 99.5% positive slope), which is consistent with the global result. There is also a trend between local sSFR and color (3.196 sigma and 100% negative slope), but this trend is not seen in the relation between global sSFR and SN color. Notably, we observed a trend between local SFR and the Hubble residual, which was not seen by previous global studies. This may suggest that the local host-galaxy environment may be promising in replacing the global host-galaxy properties to improve the scatter of Hubble diagram in the future. | en_US |