Stellar mass, not dynamical mass nor gravitational potential, drives the mass-metallicity relationship
Stellar mass, not dynamical mass nor gravitational potential, drives the mass-metallicity relationship
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恒星质量，而不是动力质量或引力势，驱动着质量-金属丰度关系
DOI：
10.1093/mnras/stad802
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发表时间：
2023
影响因子：
4.8
通讯作者：
Baker W
中科院分区：
文献类型：
--
作者：
Baker W
星系中恒星质量和气体金属丰度之间的关系[质量-金属丰度关系（MZR）]通常被归因于更大质量的系统更有能力保留金属以对抗星系外流的作用。在这种情况下，恒星质量只是动力学质量或引力势的间接代表。我们测试这种情况下，使用的样本超过1000恒星形成星系的MANGA（映射附近Galerkin在阿帕奇点天文台）调查的动力学质量已被准确地确定。通过使用三种不同的方法（平均色散，偏相关系数和随机森林），我们明确地发现，气体金属丰度主要和根本上取决于恒星质量。一旦考虑到对恒星质量的依赖性，对动力学质量或引力势的依赖性就很小或没有（如果有的话，金属丰度对后者的依赖性是颠倒的）。我们的结果表明，MZR不是由金属在更大质量星系中的滞留引起的。金属丰度对恒星质量的直接、基本依赖性表明了一个简单得多的假设，即MZR只是恒星质量与星系中金属生产的积分成正比的结果。
The widely known relation between stellar mass and gas metallicity [mass–metallicity relation (MZR)] in galaxies is often ascribed to the higher capability of more massive systems to retain metals against the action of galactic outflows. In this scenario the stellar mass would simply be an indirect proxy of the dynamical mass or of the gravitational potential. We test this scenario by using a sample of more than 1000 star-forming galaxies from the MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) survey for which dynamical masses have been accurately determined. By using three different methods (average dispersion, partial correlation coefficients, and random forest), we unambiguously find that the gas metallicity depends primarily and fundamentally on the stellar mass. Once the dependence on stellar mass is taken into account, there is little or no dependence on either dynamical mass or gravitational potential (and, if anything, the metallicity dependence on the latter quantities is inverted). Our result indicates that the MZR is not caused by the retention of metals in more massive galaxies. The direct, fundamental dependence of metallicity on stellar mass suggests the much simpler scenario in which the MZR is just a consequence of the stellar mass being proportional to the integral of metals production in the galaxy.