近邻恒星形成星系中星云与恒星尘埃消光曲线的比较
Comparing the Nebular and Stellar Dust Attenuation Curves in Nearby Star-Forming Galaxies
AI总结：
本研究以90958个近邻恒星形成星系为样本，发现星云尘埃消光曲线比典型恒星消光曲线更浅，二者存在差异但相关，可通过源-尘埃几何效应定性解释。
AI中文摘要：
星系中恒星与电离气体相对于尘埃的空间分布存在差异，这意味着恒星与星云尘埃消光曲线未必完全相同。尽管恒星消光曲线已被广泛研究，但星云消光曲线的探索仍较少。本研究利用斯隆数字巡天中90958个具有良好约束恒星消光曲线的近邻恒星形成星系样本，通过巴尔末线比率研究星云消光曲线。在Hα/Hβ与Hα/Hγ的关系图中，星云消光曲线平均而言比典型恒星消光曲线显著更浅，这种差异可通过源-尘埃几何效应定性重现。星云消光曲线斜率与恒星消光曲线斜率呈弱正相关，且对星系属性的依赖关系大致遵循恒星消光曲线斜率的依赖规律。这些结果表明，星云消光曲线与恒星消光曲线存在差异，但二者仍具有一致性关联。
英文摘要：
Differences in the spatial distributions of stars and ionized gas relative to dust in galaxies imply that stellar and nebular dust attenuation curves need not be identical. Although stellar attenuation curves have been extensively studied, nebular attenuation curves remain less explored. In this work, we investigate nebular attenuation curves using Balmer line ratios for a sample of 90,958 nearby star-forming galaxies from the Sloan Digital Sky Survey with well-constrained stellar attenuation curves. In the H$α$/H$β$ versus H$α$/H$γ$ diagram, the nebular attenuation curves are, on average, significantly shallower than typical stellar attenuation curves, which can be qualitatively reproduced by source-dust geometric effects. The nebular attenuation curve slopes show weak positive correlations with the stellar attenuation curve slopes and weak dependences on galaxy properties that broadly follow those of the stellar attenuation curve slopes. These results suggest that nebular attenuation curves are distinct from stellar attenuation curves, while remaining consistent with a connection between them.
