Gas-phase metallicity gradients of TNG50 star-forming galaxies
Gas-phase metallicity gradients of TNG50 star-forming galaxies
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DOI：
10.1093/mnras/stab1803
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发表时间：
2020-07
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通讯作者：
Z. Hemler;P. Torrey;J. Qi;L. Hernquist;M. Vogelsberger;Xiangcheng Ma;L. Kewley;D. Nelson;A. Pillepich;R. Pakmor;F. Marinacci
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作者：
Z. Hemler;P. Torrey;J. Qi;L. Hernquist;M. Vogelsberger;Xiangcheng Ma;L. Kewley;D. Nelson;A. Pillepich;R. Pakmor;F. Marinacci
我们提出的径向气相，质量加权金属丰度的配置文件和梯度的TNG 50恒星形成星系人口测量的红移$z=$0 - 3。我们研究梯度的红移演化，并研究梯度陡度和星系性质之间的关系。我们发现，TNG 50梯度主要是负的，在所有的红移，虽然我们观察到显着的差异，这些负梯度。我们确定，所有星系的梯度陡度增加近似单调的红移在一个大致恒定的速率。这个速率并不随星系质量而显著变化。我们观察到一个弱的梯度陡度和星系恒星质量之间的负相关性在红移$z\leq2$。然而，当我们规范化的银河系星星形成分布所定义的特征半径的梯度，我们发现，这些规范化的梯度保持不变的恒星质量和红移。我们将我们的结果在以前的模拟的背景下，并表明，TNG 50高红移梯度是陡峭的比具有突发反馈的模型，这可能进一步突出高红移梯度作为重要的鉴别星系形成模型。我们还发现，红移$z=0$和$z=0.5$TNG 50梯度与在这些红移星系中观察到的梯度是一致的，虽然在红移$z\gtrsim 1 $星系中观察到的平坦梯度的偏好是不存在的TNG 50。如果未来的JWST和ELT观测证实了这些平坦的梯度，则可能表明需要模拟模型来实现ISM内更强大的径向气体混合，可能通过湍流和/或强风
We present the radial gas-phase, mass-weighted metallicity profiles and gradients of the TNG50 star-forming galaxy population measured at redshifts $z=$ 0--3. We investigate the redshift evolution of gradients and examine relations between gradient steepness and galaxy properties. We find that TNG50 gradients are predominantly negative at all redshifts, although we observe significant diversity among these negative gradients. We determine that the gradient steepness of all galaxies increases approximately monotonically with redshift at a roughly constant rate. This rate does not vary significantly with galaxy mass. We observe a weak negative correlation between gradient steepness and galaxy stellar mass at redshifts $z\leq2$. However, when we normalize gradients by a characteristic radius defined by the galactic star formation distribution, we find that these normalized gradients remain invariant with both stellar mass and redshift. We place our results in the context of previous simulations and show that TNG50 high-redshift gradients are steeper than those of models featuring burstier feedback, which may further highlight high-redshift gradients as important discriminators of galaxy formation models. We also find that redshift $z=0$ and $z=0.5$ TNG50 gradients are consistent with the gradients observed in galaxies at these redshifts, although the preference for flat gradients observed in redshift $z\gtrsim1$ galaxies is not present in TNG50. If future JWST and ELT observations validate these flat gradients, it may indicate a need for simulation models to implement more powerful radial gas mixing within the ISM, possibly via turbulence and/or stronger winds