The impact of quenching on galaxy profiles in the simba simulation
The impact of quenching on galaxy profiles in the simba simulation
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DOI：
10.1093/mnras/staa1169
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发表时间：
2019-11
影响因子：
4.8
通讯作者：
S. Appleby;R. Dav'e;K. Kraljic;D. Anglés-Alcázar;D. Narayanan
中科院分区：
文献类型：
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作者：
S. Appleby;R. Dav'e;K. Kraljic;D. Anglés-Alcázar;D. Narayanan
在Simba宇宙流体动力学模拟中，我们研究了星星形成星系和绿色谷星系的比星星形成率（sSFR）和气体分布。恒星形成星系的半光半径（$R_{\rmhalf}$）在$z=0$和它们的演化（$\propto（1+z）^{-0.78}$）符合观测。被动星系$R_{\rm half}$同意在高红移的观察，但$z=0$太大，由于数值加热。我们比较辛巴$z=0$ sSFR径向配置文件的星星形成和绿色谷星系的意见。辛巴在绿色谷星系和大质量恒星形成系统的星星形成率（SFR）、sSFR和气体分数方面表现出强烈的中心凹陷，定性地观察到，这是由于黑洞X射线反馈，它将中心气体向外推。关闭X射线反馈导致如在其他模拟中一样的中心峰值sSFR曲线。与观测结果相冲突，辛巴产生绿色谷星系强烈下降sSFR配置文件超过$\gtrsim R_{\rm half}$，无论活动星系核反馈。中心的低气压是由于分子气体含量的降低，而外围的低气压则是由于星星形成效率的降低。辛巴的卫星有较高的中央sSFR和较低的郊区sSFR比中央，在定性协议与观测。在z=2时，辛巴没有显示出大质量恒星形成星系的中心凹陷，这表明辛巴的X射线反馈在高z时应该更活跃。高分辨率测试表明，中央sSFR抑制是不敏感的数值分辨率。在$z=0$绿色谷星系中再现中央sSFR凹陷代表了辛巴的独特成功。其余的差异突出了SFR和气体配置文件在约束淬火机制的重要性。
We study specific star formation rate (sSFR) and gas profiles of star forming and green valley galaxies in the Simba cosmological hydrodynamic simulation. Star-forming galaxy half-light radii ($R_{\rm half}$) at $z=0$ and their evolution ($\propto(1+z)^{-0.78}$) agree with observations. Passive galaxy $R_{\rm half}$ agree with observations at high redshift, but by $z=0$ are too large, owing to numerical heating. We compare Simba $z=0$ sSFR radial profiles for star forming and green valley galaxies to observations. Simba shows strong central depressions in star formation rate (SFR), sSFR, and gas fraction in green valley galaxies and massive star-forming systems, qualitatively as observed, owing to black hole X-ray feedback, which pushes central gas outwards. Turning off X-ray feedback leads to centrally peaked sSFR profiles as in other simulations. In conflict with observations, Simba yields green valley galaxies with strongly dropping sSFR profiles beyond $\gtrsim R_{\rm half}$, regardless of AGN feedback. The central depression owes to lowering molecular gas content; the drop in the outskirts owes to reduced star formation efficiency. Simba's satellites have higher central sSFR and lower outskirts sSFR than centrals, in qualitative agreement with observations. At $z=2$ Simba does not show central depressions in massive star-forming galaxies, suggesting Simba's X-ray feedback should be more active at high-$z$. High resolution tests indicate central sSFR suppression is not sensitive to numerical resolution. Reproducing the central sSFR depression in $z=0$ green valley galaxies represents a unique success of Simba. The remaining discrepancies highlight the importance of SFR and gas profiles in constraining quenching mechanisms.