The ALMaQUEST Survey. XII. Dense Molecular Gas as Traced by HCN and HCO+ in Green Valley Galaxies
學年 112
學期 2
出版（發表）日期 2024-03-05
作品名稱 The ALMaQUEST Survey. XII. Dense Molecular Gas as Traced by HCN and HCO+ in Green Valley Galaxies
作品名稱（其他語言）
著者 Pan, Hsi-an
單位
出版者
著錄名稱、卷期、頁數 The Astrophysical Journal 963(2),　115
摘要 We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of two dense gas tracers, HCN (1−0) and HCO+ (1-0) for three galaxies in the green valley and two galaxies on the star-forming main sequence with comparable molecular gas fractions as traced by the CO (1−0) emissions, selected from the ALMaQUEST survey. We investigate whether the deficit of molecular gas star formation efficiency (SFEmol) that leads to the low specific star formation rate (sSFR) in these green valley galaxies is due to a lack of dense gas (characterized by the dense gas fraction fdense) or the low star formation efficiency of dense gas (SFEdense). We find that SFEmol as traced by the CO emissions, when considering both star-forming and retired spaxels together, is tightly correlated with SFEdense and depends only weakly on fdense. The sSFR on kiloparsec scales is primarily driven by SFEmol and SFEdense, followed by the dependence on fmol, and is least correlated with fdense or the dense-gas-to-stellar mass ratio (Rdense). When compared with other works in the literature, we find that our green valley sample shows lower global SFEmol and lower SFEdense while exhibiting similar dense gas fractions when compared to star-forming and starburst galaxies. We conclude that the star formation of the three green valley galaxies with a normal abundance of molecular gas is suppressed, mainly due to the reduced SFEdense rather than the lack of dense gas.
關鍵字
語言 en
ISSN 1538-4357
期刊性質 國外
收錄於 SCI
產學合作
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審稿制度 是
國別 USA
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出版型式 ,電子版
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