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arXiv 2408.13636astro-ph.GA

引力还是湍流？VI. Kennicutt-Schmidt关系背后的物理学

Gravity or turbulence? VI. The physics behind the Kennicutt-Schmidt relations

Javier Ballesteros-Paredes, Manuel Zamora-Avilés, Carlos Román-Zúñiga, Aina Palau, Bernardo Cervantes-Sodi, Karla Gutiérrez-Dávila, Vianey Camacho, Eric Jiménez… 展开作者

Javier Ballesteros-Paredes, Manuel Zamora-Avilés, Carlos Román-Zúñiga, Aina Palau, Bernardo Cervantes-Sodi, Karla Gutiérrez-Dávila, Vianey Camacho, Eric Jiménez-Andrade, Adriana Gazol

备注：
17 pages, one figure. Accepted by MNRAS
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AI总结：

本文通过基本代数推导出单一恒星形成定律，论证其由冷致密分子气体坍缩驱动，解释了多种星系内外恒星形成相关性及斜率变化，并指出恒星反馈仅起关闭作用。

摘要：

我们通过一条可以从恒星形成率的定义和基本代数中推导出的单一简单定律，解释了恒星形成定律的多样性。所得方程 $\SFR = \eff\\ \Mcollapsing/\tauff$ 虽然在其他文献中已有过展示，但在此被解释为云团正在经历坍缩，而非受湍流支撑——这是本世纪不同研究团队所探索的一种观点。在此假设下，可以解释 $\eff$ 的恒定性、在银河系分子云中观测到的不同云内相关性，以及 SFR 与 CO、HCN 和 CO+HI 质量测量值之间已分辨和未分辨的星系外关系。我们还解释了当考虑轨道时间 $\tauorb$ 而非自由落体时间时相关性斜率为何改变，以及为何从星系外观测中估计的自由落体时间会使相关性发生偏斜，从而提供虚假的次线性相关性。我们进一步表明，恒星形成率与星系中面动力学平衡压力 $\PDE$ 之间表观上近乎线性的相关性，仅仅是 $\PDE$ 值由分子气体柱密度变化主导这一事实的必然结果。总而言之，我们论证了恒星形成定律是由冷致密气体的坍缩驱动的，这种气体在当前宇宙中主要是分子态的；而恒星反馈的作用仅仅是关闭恒星形成过程，而非塑造恒星形成定律。

英文摘要：

We explain the large variety of star formation laws in terms of one single, simple law that can be inferred from the definition of the star formation rate and basic algebra. The resulting equation, $\SFR = \eff\ \Mcollapsing/\tauff$, although it has been presented elsewhere, is interpreted in terms of clouds undergoing collapse { rather than being turbulence-supported, an idea that different groups have pursued this century}. Under such assumption, one can explain the constancy of $\eff$, the different intra-cloud correlations observed in Milky Way's molecular clouds, as well as the resolved and unresolved extragalactic relationships between SFR and a measurement of the mass in CO, HCN, and CO+HI. We also explain why the slope of the correlation changes when the orbital time $\tauorb$ is considered instead of the free-fall time, and why estimations of the free-fall time from extragalactic observations skew the correlation, providing a false sublinear correlation. We furthermore show that the apparent nearly linear correlation between the star formation rate and the dynamical equilibrium pressure in the midplane of the galaxies, $\PDE$, is just a consequence of $\PDE$ values being dominated by the variation of the column density of molecular gas. All in all, we argue that the star formation law is driven by the collapse of cold, dense gas, which happens to be primarily molecular in the present Universe, and that the role of stellar feedback is just to shut down the star formation process, not to shape the star formation law.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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