论文标题
恒星质量是星系恒星种群特性的“全球”驱动力
Stellar mass as the "glocal" driver of galaxies' stellar population properties
论文作者
论文摘要
已知星系中恒星种群的特性与恒星质量的数量和分布相关。 We take advantage of the maps of light-weighted mean stellar age Agewr and metallicity Z*wr for a sample of 362 galaxies from the integral-field spectroscopic survey CALIFA (summing up to >600,000 individual regions of approximately 1 kpc linear size), produced in our previous works, to investigate how these local properties react to the local stellar-mass surface density mu* and to the global total stellar mass M* and mean恒星质量表面密度<mu> e。我们确定了i）双重mu*-agewr关系的存在，导致了年轻的序列和一个旧的山脊，以及ii）Mu*-z*wr关系，总体上与地区年龄无关。全局质量参数（M*，可能是<mu> e）确定在星系中Mu*的分布，并设置最大可达到的Mu*，以M*增加。 M*会影响局部关系的形状和归一化，直到阈值质量为$ \ sim 10^{10.3} $ msun，而它们在上面保持不变。我们得出的结论是，恒星质量是恒星种群特性的“全球”（即同时全球和本地）驱动因素。我们考虑如何将本地和全球质量和金属关系关系连接，特别是讨论从单个局部关系，分别为静态和恒星形成星系产生两种不同的全球质量金属关系，如文献中所报道。这两个类别的星系中的结构差异是解释全球缩放关系双重性的关键，并且对于对星系的重型循环进行建模至关重要。
The properties of the stellar populations in a galaxy are known to correlate with the amount and the distribution of stellar mass. We take advantage of the maps of light-weighted mean stellar age Agewr and metallicity Z*wr for a sample of 362 galaxies from the integral-field spectroscopic survey CALIFA (summing up to >600,000 individual regions of approximately 1 kpc linear size), produced in our previous works, to investigate how these local properties react to the local stellar-mass surface density mu* and to the global total stellar mass M* and mean stellar-mass surface density <mu>e. We establish the existence of i) a dual mu*-Agewr relation, resulting in a young sequence and an old ridge, and ii) a mu*-Z*wr relation, overall independent of the age of the regions. The global mass parameters (M* and, possibly secondarily, <mu>e) determine the distribution of mu* in a galaxy and set the maximum attainable mu*, which increases with M*. M* affects the shape and normalization of the local relations up to a threshold mass of $\sim 10^{10.3}$ MSun, above which they remain unchanged. We conclude that stellar mass is a "glocal" (i.e. simultaneously global and local) driver of the stellar population properties. We consider how the local and global mass-age and mass-metallicity relations are connected, and in particular discuss how it is possible, from a single local relation, to produce two different global mass-metallicity relations for quiescent and star-forming galaxies respectively, as reported in the literature. Structural differences in these two classes of galaxies are key to explain the duality in global scaling relations and appear as essential in modelling the baryonic cycle of galaxies.
