SDSS-IV MaNGA: stellar population correlates with stellar root-mean-square velocity V-rms gradients or total-density-profile slopes at fixed effective velocity dispersion sigma(e)
SDSS-IV MaNGA: stellar population correlates with stellar root-mean-square velocity V-rms gradients or total-density-profile slopes at fixed effective velocity dispersion sigma(e)
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SDSS-IV ManNGA：恒星数量与恒星均方根速度 Vrms 梯度或固定有效速度色散下的总密度剖面斜率相关
DOI：
10.1093/mnras/staa1481
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发表时间：
2020
影响因子：
4.8
通讯作者：
Li Ran
中科院分区：
文献类型：
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作者：
Lu Shengdong;Cappellari Michele;Mao Shude;Ge Junqiang;Li Ran
银河系的性质与星系的有效恒星速度弥散σe关系最为密切。在这里，我们使用具有积分场光谱数据的漫画(σ)样本中的1339个不同形态的星系(M*≳6×109M⊙)，在固定的星速下寻找额外的趋势。我们重点研究了恒星均方根速度()的梯度(γrms≡σ(Re/4)/σe)，我们发现它跟踪了从动力学模型得到的总质量密度梯度γ，更弱的是，凸起分数。我们证实了γrms随σe、年龄和金属丰度的增加而增加。此外，我们还发现，在固定的σe，这些关联仍然存在，在那里，γrms较大的星系被发现更古老，更富金属。这意味着质量密度梯度包含了σe不能完全解释的恒星数量信息。这一结果对我们理解星系猝灭提出了额外的限制。我们将我们的结果与IllustrisTNG流体动力学模拟中的星系进行了比较，发现在固定的σe下，随着年龄、凸起比例和总质量密度斜率的变化，存在类似的趋势，但与观测不同的是，在模拟中没有检测到与金属丰度的关联。
Galaxy properties are known to correlate most tightly with the galaxy effective stellar velocity dispersion σe. Here, we look foradditionaltrends at fixed σeusing 1339 galaxies (M*≳ 6 × 109M⊙) with different morphologies in the MaNGA (DR14) sample with integral-field spectroscopy data. We focus on the gradients (γrms≡ σ(Re/4)/σe) of the stellar root-mean-square velocity (), which we show traces the total mass density gradient γtotderived from dynamical models and, more weakly, the bulge fraction. We confirm that γrmsincreases with σe, age, and metallicity. We additionally find that these correlations still exist at fixed σe, where galaxies with larger γrmsare found to be older and more metal-rich. It means that mass density gradients contain information of the stellar population which is not fully accounted for by σe. This result puts an extra constraint on our understanding of galaxy quenching. We compare our results with galaxies in the IllustrisTNG hydrodynamical simulations and find that, at fixed σe, similar trends exist with age, the bulge fraction, and the total mass density slope but, unlike observations, no correlation with metallicity can be detected in the simulations.