论文标题

高Z圆盘星系中结块存活的条件

Conditions for Clump Survival in High-z Disc Galaxies

论文作者

Dekel, Avishai, Tziperman, Offek, Sarkar, Kartick, Ginzburg, Omri, Mandelker, Nir, Ceverino, Daniel, Primack, Joel

论文摘要

我们通过针对模拟测试测试的分析建模,研究了高红移圆盘星系中巨大团块的存活率与破坏巨大团块的生存率。我们根据预测性生存能力参数$ s $制定了有或没有气体的团块生存的标准。它比较了超新星反馈和重力收缩的能源,与流出和湍流耗散的结块结合能量和损失。团块的性质源自Toomre不稳定性,接近病毒和牛仔裤平衡,超新星能量矿床基于最新的气泡分析。对于中等反馈级别,我们发现L团块存在圆速度$ \ sim \!50 \,km \,s^{ - 1} $和Masses $ \ geq \!10^8 \,m_ \ odot $。它们可能在具有圆速度的星系中,$ \ geq \!200 \,km \,s^{ - 1} $,在$ z \ sim 2 $中保持一致,带有圆盘的偏爱恒星质量,$ \ geq \!10^{9.3}} \,m_ \ odot $。 l团块偏爱光盘气体分数$ \ geq \!0.3 $,低质量凸起和红移$ z \!\ sim \! 2 $。如果反馈更加弹出,例如,如果超新星是最佳聚类,如果辐射反馈非常强,则降低了l团块的可能性,如果散发出色的初始质量质量功能最高,或者恒星形成率效率特别高。 LS(LS)的子类型在几个自由下降时失去气体,但保留了结合的恒星成分,可以通过较小的收缩因子和更强的外部重力效应来解释,其中团块合并提高了SFR效率。较大的L团块(LL)以数十个自由落体的时间保留了大部分的重量,并以大致恒定的恒星形成速率保留。

We study the survival versus disruption of the giant clumps in high-redshift disc galaxies, short-lived (S) versus long-lived (L) clumps and two L sub-types, via analytic modeling tested against simulations. We develop a criterion for clump survival, with or without their gas, based on a predictive survivability parameter $S$. It compares the energy sources by supernova feedback and gravitational contraction to the clump binding energy and losses by outflows and turbulence dissipation. The clump properties are derived from Toomre instability, approaching virial and Jeans equilibrium, and the supernova energy deposit is based on an up-to-date bubble analysis. For moderate feedback levels, we find that L clumps exist with circular velocities $\sim\!50\, km\, s^{-1}$ and masses $\geq\!10^8\, M_\odot$. They are likely in galaxies with circular velocities $\geq \!200\, km\, s^{-1}$, consistent at $z \sim 2$ with the favored stellar mass for discs, $\geq\!10^{9.3}\, M_\odot$. L clumps favor disc gas fractions $\geq\!0.3$, low-mass bulges and redshifts $z\!\sim\! 2$. The likelihood of L clumps is reduced if the feedback is more ejective, e.g., if the supernovae are optimally clustered, if radiative feedback is very strong, if the stellar initial mass function is top-heavy, or if the star-formation-rate efficiency is particularly high. A sub-type of L clumps (LS), which lose their gas in several free-fall times but retain bound stellar components, may be explained by a smaller contraction factor and stronger external gravitational effects, where clump mergers increase the SFR efficiency. The more massive L clumps (LL) retain most of their baryons for tens of free-fall times with a roughly constant star-formation rate.

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