论文标题
Almaquest调查：VI。星系中“退休”区域的分子气体主序列
The ALMaQUEST Survey: VI. The molecular gas main sequence of `retired' regions in galaxies
论文作者
论文摘要
为了研究气体在恒星在KPC尺度上的灭绝中的作用，我们比较了星形区域的分辨分子气体主序列（RMGMS：Sigma_* vs sigma_h2）与已停止形成新恒星的“退休”区域的序列。使用来自Almaquest调查的数据，我们发现退休的Spaxels形成了与恒星形成Spaxels不同的RMGM，在固定的Sigma_*下将Sigma_h2降低到降低sigma_h2的含量〜5。我们根据八个单独的Almaquest星系的星系基础研究星系和退休的Spaxels的RMGM。这些星系中有六个已退休的Spaxels集中在中央少数KPC中。在我们的样品中的八个星系中，在40-100％的退休spaxels中检测到分子气体。星形和退休的RMGM都表现出来自银河系到加拉克斯的标准化的多样性。但是，在任何给定的星系中，都发现退休区域的RMGM与恒星形成序列不同，而退休的Spaxels的气体级数则比恒星形成的Spaxels低一个数量级。我们得出的结论是，淬灭与通常从星系中心开始的机制耗尽（但不存在）分子气体的耗竭（但不存在）。
In order to investigate the role of gas in the demise of star formation on kpc-scales, we compare the resolved molecular gas main sequence (rMGMS: Sigma_* vs Sigma_H2) of star-forming regions to the sequence of `retired' regions that have ceased to form new stars. Using data from the ALMaQUEST survey, we find that retired spaxels form a rMGMS that is distinct from that of star-forming spaxels, offset to lower Sigma_H2 at fixed Sigma_* by a factor of ~5. We study the rMGMS of star-forming and retired spaxels on a galaxy-by-galaxy basis for eight individual ALMaQUEST galaxies. Six of these galaxies have their retired spaxels concentrated within the central few kpc. Molecular gas is detected in 40-100% of retired spaxels in the eight galaxies in our sample. Both the star-forming and retired rMGMS show a diversity in normalization from galaxy-to-galaxy. However, in any given galaxy, the rMGMS for retired regions is found to be distinct from the star-forming sequence and gas fractions of retired spaxels are up to an order of magnitude lower than the star-forming spaxels. We conclude that quenching is associated with a depletion (but not absence) of molecular gas via a mechanism that typically begins in the centre of the galaxy.
