论文标题
宇宙背景辐射对金属贫困星的初始质量功能的影响
Impact of the cosmic background radiation on the initial mass function of metal-poor stars
论文作者
论文摘要
我们使用三维流体动力学仿真以$ z/z_ \ odot = 10^{ - 4} $ - $ z__ \ odot = 10^{ - 4} $ - $ z/z_ \ odot = 10^{ - 4} $研究星团形成。特别强调恒星质量分布如何受到宇宙微波背景辐射（CMB）的影响，该辐射将温度底部设置为气体。从湍流云的崩溃开始，我们遵循Protostellar系统的形成，这些系统可以解决$ \ sim $ au量表。在相对富含$ z/z_ \ odot \ gtrsim 10^{ - 2} $的相对富含的情况下，其中质量函数类似于当今的功能，在没有CMB的情况下，高温CMB抑制了云碎片，并减少了低质量的星星的数量，使质量不含CMB $ zby $ zby $ zby $ zmb the $ zmb。在$ z/z_ \ odot \ Lessim 10^{ - 3} $的低金属案例中，由于冷却效率低下，气体温度高于CMB值，CMB对质量分布的影响只有很小的影响，无论红移无关。在$ z/z_ \ odot \ lyssim 10^{ - 2} $的低金属性或高红移$ z \ gtrsim10 $的情况下，质量频谱由低质量的salpeter型组成，由$ 0.1〜m_ \ odot $ use $ 10 $ 50- $ 50-50-50-50〜- $ 50〜MO.后者随着红移的增加而增加。在形成$ z \ gtrsim10 $的星系中，包括JWST在内的未来仪器的主要目标，CMB的供暖使恒星质量显着高度发挥，使超新星爆炸的数量增加了$ 1.4 $（$ 2.8 $）的$ 1.4 $（$ 2.8 $），$ z = 10 $（$ 20 $）与CHABRIAL BAIND相比， $ z/z_ \ odot = 0.1 $。
We study star cluster formation at low metallicities of $Z/Z_\odot=10^{-4}$--$10^{-1}$ using three-dimensional hydrodynamics simulations. Particular emphasis is put on how the stellar mass distribution is affected by the cosmic microwave background radiation (CMB), which sets the temperature floor to the gas. Starting from the collapse of a turbulent cloud, we follow the formation of a protostellar system resolving $\sim$au scale. In relatively metal-enriched cases of $Z/Z_\odot \gtrsim 10^{-2}$, where the mass function resembles the present-day one in the absence of the CMB, high temperature CMB suppresses cloud fragmentation and reduces the number of low-mass stars, making the mass function more top-heavy than in the cases without CMB heating at $z\gtrsim10$. In lower-metallicity cases with $Z/Z_\odot \lesssim 10^{-3}$, where the gas temperature is higher than the CMB value due to inefficient cooling, the CMB has only a minor impact on the mass distribution, which is top-heavy regardless of the redshift. In cases either with a low metallicity of $Z/Z_\odot \lesssim 10^{-2}$ or at a high redshift $z\gtrsim10$, the mass spectrum consists of a low-mass Salpeter-like component, peaking at $0.1~M_\odot$, and a top-heavy component with $10$--$50~M_\odot$, with the fraction in the latter increasing with increasing redshift. In galaxies forming at $z\gtrsim10$, the major targets of the future instruments including JWST, CMB heating makes the stellar mass function significantly top-heavy, enhancing the number of supernova explosions by a factor of $1.4$ ($2.8$) at $z=10$ ($20$, respectively) compared to the prediction by Chabrier initial mass function when $Z/Z_\odot=0.1$.
