标题： 星系的尘埃校正恒星形成率 I. H-α和红外示踪剂的组合 显示英文标题

标题： Dust-Corrected Star Formation Rates of Galaxies. I. Combinations of H-alpha and Infrared Tracers

摘要： 我们将附近星系的两组样本的氢阿尔法发射线和红外连续谱测量值结合起来，以推导出修正了尘埃消光的恒星形成率（SFR）。我们使用了一种基于简单能量平衡的方法，该方法之前已被应用于斯皮策红外近邻星系调查（SINGS）中的电离氢区（HII区域），并将该方法扩展到星系的整体测量中。我们发现，我们的复合氢阿尔法+红外基恒星形成率与从整体光谱测量得到的修正了尘埃消光的恒星形成率非常一致，涵盖了研究范围内的所有恒星形成率（0.01至80个太阳质量每年）和消光值（0至2.5星等）。我们发现，氢阿尔法和总红外亮度的结合提供了最可靠的恒星形成率测量，但氢阿尔法测量与24微米和8微米单色亮度的组合表现几乎同样好。这些校准值与电离氢区得到的校准值显著不同，这种差异可归因于更进化的恒星群体加热了尘埃。我们的结果与弥散尘埃（‘红外云’成分）的一个重要组成部分一致，该部分由非恒星形成群体加热。同样的方法也可以应用于[OII]$\lambda$3727发射线测量，并且当后者不可用时，可以使用星系的射电连续谱流量代替红外流量。我们评估了所有这些复合方法的精确性和系统可靠性。 显示英文摘要

摘要： We combine H-alpha emission-line and infrared continuum measurements of two samples of nearby galaxies to derive dust attenuation-corrected star formation rates (SFRs). We use a simple energy balance based method that has been applied previously to HII regions in the Spitzer Infrared Nearby Galaxies Survey (SINGS), and extend the methodology to integrated measurements of galaxies. We find that our composite H-alpha+IR based SFRs are in excellent agreement with attenuation-corrected SFRs derived from integrated spectrophotometry, over the full range of SFRs (0.01 -- 80 solar mass per year) and attenuations (0 -- 2.5 mag) studied. We find that the combination of H-alpha and total infrared luminosities provides the most robust SFR measurements, but combinations of H-alpha measurements with monochromatic luminosities at 24 micron and 8 micron perform nearly as well. The calibrations differ significantly from those obtained for HII regions (Calzetti et al. 2007), with the difference attributable to a more evolved population of stars heating the dust. Our results are consistent with a significant component of diffuse dust (the `IR cirrus' component) that is heated by a non-star-forming population. The same methodology can be applied to [OII]$\lambda$3727 emission-line measurements, and the radio continuum fluxes of galaxies can be applied in place of IR fluxes when the latter are not available. We assess the precision and systematic reliability of all of these composite methods.