Triggered Population III star formation: the effect of H2 self-shielding
Triggered Population III star formation: the effect of H2 self-shielding
复制标题
触发星族III恒星形成：H2自屏蔽效应
DOI：
10.1093/mnras/stad433
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发表时间：
2023
影响因子：
4.8
通讯作者：
Wise, John H.
中科院分区：
文献类型：
--
作者：
Chiaki, Gen;Wise, John H.
无金属恒星（星族III）的多样性可能会影响它们在宿主暗物质晕内的反馈效率，从而影响随后的金属富集和向星系形成的过渡。来自大质量恒星的辐射反馈可以在密集的自屏蔽云中触发附近恒星的形成。在模型辐射自屏蔽中，必须精确计算h2柱密度。在本研究中，我们比较了两种基于密度梯度和沿射线柱密度直接积分的Jeans长度的局部近似。在主质量恒星形成后，我们发现无论是直接积分法还是密度梯度法，都没有形成副质量恒星。近似方法将计算时间减少了1 / 2。Jeans长度近似值将H2column密度高估了10倍，导致5个数值增强的自屏蔽恒星形成团块。我们的结论是，密度梯度近似对于更大体积的星系模拟是足够精确的，尽管人们仍然必须注意，近似不能完全再现直接积分的结果。
The multiplicity of metal-free (Population III) stars may influence their feedback efficiency within their host dark matter haloes, affecting subsequent metal enrichment and the transition to galaxy formation. Radiative feedback from massive stars can trigger nearby star formation in dense self-shielded clouds. In model radiation self-shielding, the H2column density must be accurately computed. In this study, we compare two local approximations based on the density gradient and Jeans length with a direct integration of column density along rays. After the primary massive star forms, we find that no secondary stars form for both the direct integration and density gradient approaches. The approximate method reduces the computation time by a factor of 2. The Jeans length approximation overestimates the H2column density by a factor of 10, leading to five numerically enhanced self-shielded, star-forming clumps. We conclude that the density gradient approximation is sufficiently accurate for larger volume galaxy simulations, although one must still caution that the approximation cannot fully reproduce the result of direct integration.