论文标题
依赖环境的IMF对宇宙历史上恒星的形成和金属性的影响
The effect of the environment-dependent IMF on the formation and metallicities of stars over the cosmic history
论文作者
论文摘要
最近的观察性研究和理论研究表明，恒星初始质量函数（IMF）随环境（星形形成速率-SFR，金属性）的系统变化。尽管IMF对这些特性的确切依赖性可能会随着观察限制的改善而发生变化，但IMF形状的报告趋势似乎很健壮。我们提出了第一个旨在评估IMF变化对测得的宇宙SFR密度（SFRD）的影响的研究，这是金属性和红移的函数，$ f _ {\ rm sfr} $（z，z，z）。我们还研究了不同的IMF假设下的白矮人，中子星和黑洞祖细胞的预期数量和金属性。应用综合银河IMF（IGIMF）理论所描述的经验驱动的IMF变体，我们纠正了Chruslinska＆Nelemans（2019）获得的$ f _ {\ rm sfr} $（z，Z），并在高红色高点及以上的金属po＆after and Metal-Poor Stars is组定的较高水平的情况下找到较低的SFRD。在本地宇宙中，我们使用IGIMF理论的计算表明，与通用IMF场景相比，更多的白矮人和中子星祖细胞，而黑洞祖细胞的数量仍然不受影响。
Recent observational and theoretical studies indicate that the stellar initial mass function (IMF) varies systematically with the environment (star formation rate - SFR, metallicity). Although the exact dependence of the IMF on those properties is likely to change with improving observational constraints, the reported trend in the shape of the IMF appears robust. We present the first study aiming to evaluate the effect of the IMF variations on the measured cosmic SFR density (SFRD) as a function of metallicity and redshift, $f_{\rm SFR}$(Z,z). We also study the expected number and metallicity of white dwarf, neutron star and black hole progenitors under different IMF assumptions. Applying the empirically driven IMF variations described by the integrated galactic IMF (IGIMF) theory, we correct $f_{\rm SFR}$(Z,z) obtained by Chruslinska & Nelemans (2019) and find lower SFRD at high redshifts as well as a higher fraction of metal-poor stars being formed. In the local Universe, our calculation applying the IGIMF theory suggests more white dwarf and neutron star progenitors in comparison with the universal IMF scenario, while the number of black hole progenitors remains unaffected.
