标题： 从集群恒星形成中获得的恒星质量上限的基本证据及其一些相关影响 显示英文标题

标题： Evidence for a fundamental stellar upper mass limit from clustered star formation, and some implications therof

摘要： 理论考虑使人们预期恒星的质量不应超过大约m_{最大值}=60-120Msun，而观测证据一直存在歧义。 只有在最近，由于现代高分辨率观测本地星暴星团，才出现了接近150Msun的物理恒星质量极限。 但这一极限似乎并不依赖于金属丰度，这与理论相矛盾。 不过仍存在重要的不确定性。 现在也逐渐发现，星团限制了其组成恒星的质量，使得星团中最重恒星的质量与星团质量之间存在明确的关系，m_{最大值}=F(M_ecl) \le m_{最大值}\approx 150Msun。 一个相当引人注目的发现是，观测数据强烈支持星团是由连续形成更重的恒星构建而成，直到最重的恒星终止进一步的恒星形成。 这一关系还意味着，由许多星团组成的复合种群，其中大部分可能已经溶解，必须比单个星团中发现的简单恒星种群具有更陡的复合初始质量函数。 因此，例如，10^5个Taurus--Auriga恒星形成群体，每个群体有20颗恒星，将只能采样大约1Msun以下的初始质量函数。 因此，这个初始质量函数不会与一个拥有2×10^6颗恒星的星团的初始质量函数相同。 这意味着，星系的恒星形成历史关键地决定了其综合星系初始质量函数，从而决定了每颗恒星的超新星总数及其化学富集历史。 依赖于不变初始质量函数的星系形成和演化模型将是错误的。 显示英文摘要

摘要： Theoretical considerations lead to the expectation that stars should not have masses larger than about m_{max*}=60-120Msun, while the observational evidence has been ambiguous. Only very recently has a physical stellar mass limit near 150Msun emerged thanks to modern high-resolution observations of local star-burst clusters. But this limit does not appear to depend on metallicity, in contradiction to theory. Important uncertainties remain though. It is now also emerging that star-clusters limit the masses of their constituent stars, such that a well-defined relation between the mass of the most massive star in a cluster and the cluster mass, m_{max}=F(M_ecl) \le m_{max*}\approx 150Msun, exists. One rather startling finding is that the observational data strongly favour clusters being built-up by consecutively forming more-massive stars until the most massive stars terminate further star-formation. The relation also implies that composite populations, which consist of many star clusters, most of which may be dissolved, must have steeper composite IMFs than simple stellar populations such as are found in individual clusters. Thus, for example, 10^5 Taurus--Auriga star-forming groups, each with 20 stars, will ever only sample the IMF below about 1Msun. This IMF will therefore not be identical to the IMF of one cluster with 2 times 10^6 stars. The implication is that the star-formation history of a galaxy critically determines its integrated galaxial IMF and thus the total number of supernovae per star and its chemical enrichment history. Galaxy formation and evolution models that rely on an invariant IMF would be wrong.