Spatial Decorrelation of Young Stars and Dense Gas as a Probe of the Star Formation–Feedback Cycle in Galaxies
Spatial Decorrelation of Young Stars and Dense Gas as a Probe of the Star Formation–Feedback Cycle in Galaxies
复制标题
年轻恒星和致密气体的空间去相关作为星系中恒星形成反馈循环的探针
作者：
V. Semenov;A. Kravtsov;N. Gnedin
在邻近星系中观测到的致密分子气体与年轻恒星在空间上的解相关（约1 kpc尺度）表明恒星形成区域通过恒星反馈迅速扩散。我们在一系列模拟中探索了这种去相关对不同过程的敏感性，这些过程控制着星际介质的结构、分子气体的丰度、恒星的形成和反馈，这些过程具有类似于NGC 300的结构特性，能够自我一致地模拟辐射传递和分子化学。我们的基准模拟再现了NGC 300中测量到的去相关程度及其尺度依赖性，并且我们表明这种一致性是由于反馈的不同方面，包括H2解离，局部变紫外场的气体加热，早期机械反馈和超新星。特别是，早期的辐射反馈和力学反馈在> 100 pc尺度上影响相关性，而超新星在> 100 pc尺度上起重要作用。相关性对每自由落体时间的局部恒星形成效率的选择也很敏感，当全球恒星形成速率与它的值无关时，这就提供了一个很强的观测约束。最后，我们明确地表明，分子气体峰值与恒星形成密度之间的相关程度与恒星形成区域的寿命分布直接相关。
The spatial decorrelation of dense molecular gas and young stars observed on ≲1 kpc scales in nearby galaxies indicates rapid dispersal of star-forming regions by stellar feedback. We explore the sensitivity of this decorrelation to different processes controlling the structure of the interstellar medium, the abundance of molecular gas, star formation, and feedback in a suite of simulations of an isolated dwarf galaxy with structural properties similar to NGC 300 that self-consistently model radiative transfer and molecular chemistry. Our fiducial simulation reproduces the magnitude of decorrelation and its scale dependence measured in NGC 300, and we show that this agreement is due to different aspects of feedback, including H2 dissociation, gas heating by the locally variable UV field, early mechanical feedback, and supernovae. In particular, early radiative and mechanical feedback affects the correlation on ≲100 pc scales, while supernovae play a significant role on ≳ 100 pc scales. The correlation is also sensitive to the choice of the local star formation efficiency per free fall time, ϵ ff, which provides a strong observational constraint on ϵ ff when the global star formation rate is independent of its value. Finally, we explicitly show that the degree of correlation between the peaks of molecular gas and star formation density is directly related to the distribution of the lifetimes of star-forming regions.
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影响因子：
38.5
作者：
M. Vogelsberger;F. Marinacci;P. Torrey;E. Puchwein
通讯作者：
M. Vogelsberger;F. Marinacci;P. Torrey;E. Puchwein
DOI：
10.3847/1538-4357/ab0085
发表时间：
2018-10
期刊：
The Astrophysical Journal
影响因子：
--
作者：
F. Munshi;A. Brooks;C. Christensen;Elaad Applebaum;K. Holley-Bockelmann;T. Quinn;J. Wadsley
通讯作者：
F. Munshi;A. Brooks;C. Christensen;Elaad Applebaum;K. Holley-Bockelmann;T. Quinn;J. Wadsley
NGC 628 恒星形成效率的 50 片比例视图
DOI：
10.3847/2041-8213/aad77d
发表时间：
2018
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Kreckel, K.;Faesi, C.;Kruijssen, J. M.;Schruba, A.;Groves, B.;Leroy, A. K.;Bigiel, F.;Blanc, G. A.;Chevance, M.;Herrera, C.
通讯作者：
Herrera, C.
影响因子：
4.9
作者：
Agertz, Oscar;Kravtsov, Andrey V.
通讯作者：
Kravtsov, Andrey V.
DOI：
10.3847/1538-4357/abe934
发表时间：
2020-11
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Jeong-Gyu Kim;E. Ostriker;N. Filippova
通讯作者：
Jeong-Gyu Kim;E. Ostriker;N. Filippova