The Star Formation Efficiency within Galaxies
The Star Formation Efficiency within Galaxies
复制标题
星系内的恒星形成效率
DOI：
10.1086/300957
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
J. Young
中科院分区：
文献类型：
--
作者：
B. Rownd;J. Young
利用联合收割机Hα成像和“五院射电天文台河外CO巡天”的CO线观测资料，在45″分辨率下研究了121个星系中568个区域的分子气体与大质量星星形成的关系.我们的研究发现，当在星系内局部采样时，这些量之间存在很强的相关性，这与最近对全球平均量的研究一致。对于螺旋星系，在恒星形成盘上的星星形成效率没有很强的径向梯度，尽管在中等大小星系的最外层区域（R > 9 kpc）测量的星星形成效率往往系统性地较低。此外，与较小的星系相比，大星系（D0 > 60 kpc）中的星星形成效率在所有半径上都很低。作为形态和环境的函数，星系内星星形成效率的行为与我们以前对全局量的研究结果是一致的。在螺旋星系中，星星的形成效率并不取决于哈勃类型，每种类型的效率范围相似，不同类型之间的平均差异小于25%。最后，相对于一个孤立的星系样本，星星的形成效率被发现是敏感的，只有极端的变化，在星系环境。随着室女座星系团螺旋中H I亏损的增加，星星形成效率逐渐降低，在强相互作用和合并中，恒星形成效率得到增强.
We combine Hα imaging with the CO-line observations of the Five College Radio Astronomy Observatory Extragalactic CO Survey to study the relationship between molecular gas and high-mass star formation for 568 regions in 121 galaxies at 45″ resolution. Our study finds a strong correlation between these quantities when sampled locally within galaxies, consistent with recent studies of globally averaged quantities. For spiral galaxies, there are no strong radial gradients in the star formation efficiency across the star-forming disk, although star formation efficiencies measured in the outermost regions (R > 9 kpc) of midsized galaxies tend to be systematically low. Additionally, star formation efficiencies in large (D0 > 60 kpc) galaxies are uniformly low at all radii compared with smaller galaxies. As a function of morphology and environment, the behavior of the star formation efficiency within galaxies is consistent with the results of our previous investigation of the global quantities. Among spirals the star formation efficiency does not depend on Hubble type, with a similar range of efficiencies within each type and less than 25% variation in the mean from type to type. Finally, relative to an isolated galaxy sample, the star formation efficiency is found to be sensitive only to extreme variations in the galaxy environment. The star formation efficiency decreases steadily with increasing H I deficiency among Virgo cluster spirals, and it is enhanced in strong interactions and mergers.