| 摘要: | 已知Ia型超新星被視為標準燭光，拿來作為探測星系距離以及宇宙膨脹的工具。但它
們爆炸的前身系統直到了現今都不確定，而宿主星系為其前身系統的環境且已證明是
探知前身系統的途徑。 本研究主要利用泛星深度巡天計畫，找出約兩百多顆高紅移
的Ia型超新星的宿主星系(紅移的中位數在0.3)。 我們研究了這些超新星整體與區域的
宿主星系性質(區域為超新星爆炸位置半徑1.5”的範圍)，例如恆星質量、恆星形成率和特徵恆星形成率，藉由這些參數來跟超新星光變曲線的寬度、超新星的顏色和超新星哈伯常數殘數做比較，並與先前的低紅移宿主星系研究(紅移中位數在0.05)來做比較。我們發現在宿主星系的整體環境中，星系的恆星質量和特徵恆星形成率與Ia型超新星的光度曲線寬有明顯趨勢 (在恆星質量上有6.9個標準差以及線性擬合出100%的負斜率，在特徵恆星形成率上有8.139個標準差及線性擬合出100%的正斜率)，這些趨勢與先前低紅移星系的研究一致。 而在超新星Ia的顏色跟整體宿主星系恆星形成率的趨勢則與先前低紅移研究不同，低紅移研究並無發現趨勢，但本研究有發現微弱的趨勢，本研究線性擬合給出星系的恆星形成率與超新星顏色有95.5%的負斜率趨勢。 而在哈伯殘數跟Ia型超新星的關係上也跟先前的研究一致，不管是整體宿主星系的恆星質量、恆星形成率和特徵恆星形成率與哈伯殘數都沒有趨勢。 除了整體宿主星系的性質，宿主星系區域的恆星形成率與Ia超新星的顏色及哈伯殘數有趨勢，其顏色的線性擬合有100%為負而哈伯殘數有98.75%為負的，在區域的特徵恆星形成率則與Ia的光度曲線寬和顏色有趨勢，(光度曲線寬有4.227個標準差及線性擬合出99.5%正的斜率，顏色有3.196個標準差以及線性擬合出100%的負斜率)。 在區域宿主星系的參數與Ia的哈伯殘數比較中，區域星系的恆星形成率可以看到有相關聯性，由線性擬合出來有98.75%的負斜率，這些結果顯示區域宿主星系的參數可能在未來有機會取代整體宿主星系的參數來作為了解Ia型超新星前身的一個重要工具。;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. |
