A METHOD FOR MEASURING VARIATIONS IN THE STELLAR INITIAL MASS FUNCTION
A METHOD FOR MEASURING VARIATIONS IN THE STELLAR INITIAL MASS FUNCTION
复制标题
一种测量恒星初始质量函数变化的方法
DOI：
10.1088/2041-8205/719/2/l158
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
B. Whitmore
中科院分区：
文献类型：
--
作者：
D. Calzetti;R. Chandar;J. Lee;B. Elmegreen;R. Kennicutt;B. Whitmore
我们提出了一种方法来调查的恒星初始质量函数（IMF）的上端的变化，通过探测电离光子的生产率在未解决的，紧凑的星星星团的年龄为107年，不同的质量。我们通过对附近星系NGC5194（M51a）中的年轻星系团人口进行试点研究来测试这种方法，哈勃太空望远镜的多波长观测可用。我们的研究结果表明，该方法可以探测位于至少1000万秒差距的星系中IMF的上端，即，比通过计算年轻致密星团中的单个恒星所能计算的要远200倍。我们对NGC5194的研究结果表明，IMF的上质量端对星星团的质量没有明显的依赖性，但需要对低质量团和其他星系进行更广泛的分析来证实这一结论。
We present a method for investigating variations in the upper end of the stellar initial mass function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages ⩽107 yr and with different masses. We test this method by performing a pilot study on the young cluster population in the nearby galaxy NGC5194 (M51a), for which multi-wavelength observations from the Hubble Space Telescope are available. Our results indicate that the proposed method can probe the upper end of the IMF in galaxies located out to at least ∼10 Mpc, i.e., a factor ≈200 further away than what is possible by counting individual stars in young compact clusters. Our results for NGC5194 show no obvious dependence of the upper mass end of the IMF on the mass of the star cluster down to ≈103 M☉, although more extensive analyses involving lower mass clusters and other galaxies are needed to confirm this conclusion.