Stars are among the most fundamental structures of our Universe. They comprise most of the baryonic and luminous mass of galaxies; synthesize heavy elements; and inject mass, momentum, and energy into the interstellar medium. They are also home to the planets. Because stellar properties are primarily decided by their mass, the so-called stellar initial mass function (IMF) is critical to the structuring of our Universe. We review the various physical processes and theories that have been put forward as well as the numerical simulations that have been carried out to explain the origin of the stellar IMF. Key messages from this review include the following: ▪Gravity and turbulence most likely determine the power-law, high-mass part of the IMF.▪Depending of the Mach number and the density distribution, several regimes are possible, including ΓIMF ≃ 0, −0.8, −1, or −1.3, where dN/d log M ∝ M ΓIMF . These regimes are likely universal; however, the transition between these regimes is not.▪Protostellar jets can play a regulating influence on the IMF by injecting momentum into collapsing clumps and unbinding gas.▪The peak of the IMF may be a consequence of dust opacity and molecular hydrogen physics at the origin of the first hydrostatic core. This depends weakly on large-scale environmental conditions such as radiation, magnetic field, turbulence, or metallicity. This likely constitutes one reason for the relative universality of the IMF.

中文翻译：

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恒星初始质量函数的物理起源


恒星是我们宇宙中最基本的结构之一。它们构成了星系的大部分重子和发光质量;合成重元素;并将质量、动量和能量注入星际介质。它们也是行星的家园。因为恒星的性质主要由它们的质量决定，所以所谓的恒星初始质量函数 （IMF） 对于我们宇宙的结构至关重要。我们回顾了已经提出的各种物理过程和理论，以及为解释恒星 IMF 的起源而进行的数值模拟。这篇综述的关键信息包括： ▪重力和湍流最有可能决定 IMF 的幂律，即 IMF 的高质量部分.▪根据马赫数和密度分布，可能有几种状态，包括 ΓIMF ≃ 0、-0.8、-1 或 -1.3，其中 dN/d log M ∝ M ΓIMF 。这些制度可能是普遍的;然而，这些状态之间的过渡并非如此。▪原恒星喷流可以通过向坍塌的团块注入动量和解开结合气体来对 IMF 产生调节作用。▪IMF 的峰值可能是第一个静流体核心起源处的尘埃不透明度和分子氢物理学的结果。这弱依赖于大尺度环境条件，例如辐射、磁场、湍流或金属丰度。这可能构成了 IMF 相对普遍性的一个原因。