| 摘要: | 2002es-like 與 2003fg-like Ia 型超新星為 Ia 型超新星中的特殊類型。儘管其前身系統與爆炸機制尚未明確確定，但過去研究結果普遍認為兩者源自不同的環境。然而，近期針對其紫外光變曲線的分析顯示，兩者在紫外波段具有高度相似性，並推測可能擁有共同的起源。本研究旨在透過分析其宿主星系環境，深入探討這些特殊超新星的爆炸特性與前身系統。本研究將比較 2002es-like 與 2003fg-like Ia 型超新星的宿主星系性質，以辨識其環境上的差異與共通點。本研究樣本包含 13 個 2002es-like 與 42 個 2003fg-like Ia 型超新星的紫外光至紅外線影像，資料來源包含 GALEX、PS1、SDSS、SkyMapper、2MASS 與 WISE 巡天望遠鏡，並額外使用 SDSS 巡天望遠鏡資料中的 463 個一般 Ia 型超新星作為參考樣本。本研究提取宿主星系的整體光度，並推導其恆星質量、年齡、金屬量、恆星形成率與特徵恆星形成率。結果顯示，兩類型之間的宿主星系環境存在顯著差異：2002es-like Ia 型超新星通常位於質量較大、年齡較老、恆星形成活動較低的星系；相反地，2003fg-like 超新星則多出現在質量較小、年齡較年輕、且恆星形成較為活躍的星系。這些環境趨勢暗示其前身系統與爆炸機制可能有所不同。本研究結論指出，儘管兩類型皆可能被富含碳的環星物質所環繞，但 2002es-like Ia 型超新星較符合具有較長延遲時間的雙簡併模型中的暴力併合情境（violent merger）；而 2003fg-like Ia 型超新星則更符合延遲時間較短的核心簡併模型（core degenerate）。;The 2002es-like and 2003fg-like supernovae (SNe) are among the most peculiar members of the SNe Ia population. While their progenitor systems and explosion mechanisms remain uncertain, past observations believed that they originate from different channels. However, recent studies of their UV light curves indicate that they are remarkably similar in the UV and may even share a common origin. In this work, we investigate these peculiar explosions and their progenitor systems through an analysis of their host-galaxy environments. We examine and compare the host-galaxy properties of 2002es-like and 2003fg-like SNe Ia to identify their environmental differences and similarities. Our sample consists of UV-to-IR imaging for 13 2002es-like and 42 2003fg-like SNe Ia collected from the GALEX, PS1, SDSS, SkyMapper, 2MASS, and WISE surveys, along with an additional 463 normal SNe Ia from SDSS photometry used as a reference sample. We extract global host-galaxy photometry and derive their stellar masses, ages, metallicities, star-formation rates, and specific star-formation rates. Our results reveal clear environmental differences between the two subtypes: 2002es-like SNe Ia preferentially reside in more massive, older, and less star-forming galaxies, whereas 2003fg-like events are found in relatively lower-mass, younger, and more actively star-forming hosts. These environmental trends imply distinct progenitor systems and explosion mechanisms. We conclude that although the progenitor systems of both subtypes may be associated with a carbon-rich circumstellar medium, the 2002es-like SNe Ia are consistent with a longer-delay-time, double-degenerate violent merger scenario, while the 2003fg-like SNe Ia are more consistent with a shorter-delay-time, core-degenerate origin. |
