Environmental dependence of the molecular cloud lifecycle in 54 main-sequence galaxies
學年 111
學期 1
出版（發表）日期 2022-08-22
作品名稱 Environmental dependence of the molecular cloud lifecycle in 54 main-sequence galaxies
作品名稱（其他語言）
著者 Jaeyeon Kim; Mélanie Chevance; J M Diederik Kruijssen;..., Hsi-An Pan et al.
單位
出版者
著錄名稱、卷期、頁數 Monthly Notices of the Royal Astronomical Society 516(2), p.3006-3028
摘要 The processes of star formation and feedback, regulating the cycle of matter between gas and stars on the scales of giant molecular clouds (GMCs; ∼100 pc), play a major role in governing galaxy evolution. Measuring the time-scales of GMC evolution is important to identify and characterize the specific physical mechanisms that drive this transition. By applying a robust statistical method to high-resolution CO and narrow-band H α imaging from the PHANGS survey, we systematically measure the evolutionary timeline from molecular clouds to exposed young stellar regions on GMC scales, across the discs of an unprecedented sample of 54 star-forming main-sequence galaxies (excluding their unresolved centres). We find that clouds live for about 1−3 GMC turbulence crossing times (5−30 Myr) and are efficiently dispersed by stellar feedback within 1−5 Myr once the star-forming region becomes partially exposed, resulting in integrated star formation efficiencies of 1−8 per cent. These ranges reflect physical galaxy-to-galaxy variation. In order to evaluate whether galactic environment influences GMC evolution, we correlate our measurements with average properties of the GMCs and their local galactic environment. We find several strong correlations that can be physically understood, revealing a quantitative link between galactic-scale environmental properties and the small-scale GMC evolution. Notably, the measured CO-visible cloud lifetimes become shorter with decreasing galaxy mass, mostly due to the increasing presence of CO-dark molecular gas in such environment. Our results represent a first step towards a comprehensive picture of cloud assembly and dispersal, which requires further extension and refinement with tracers of the atomic gas, dust, and deeply embedded stars.
關鍵字 stars: formation;ISM:clouds;ISM:structure;galaxies:ISM,galaxies: star formation
語言 en_US
ISSN 1365-2966;0035-8711
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 是
國別 GBR
公開徵稿
出版型式 ,電子版
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/123361 )