SDSS-IV MaNGA: Understanding Ionized Gas Turbulence Using Integral Field Spectroscopy of 4500 Star-forming Disk Galaxies
SDSS-IV MaNGA: Understanding Ionized Gas Turbulence Using Integral Field Spectroscopy of 4500 Star-forming Disk Galaxies
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DOI：
10.3847/1538-4357/ac5620
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发表时间：
2021-12
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通讯作者：
D. Law;F. Belfiore;M. Bershady;M. Cappellari;N. Drory;K. Masters;K. Westfall;D. Bizyaev;K. Bundy-K.-Bu
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作者：
D. Law;F. Belfiore;M. Bershady;M. Cappellari;N. Drory;K. Masters;K. Westfall;D. Bizyaev;K. Bundy-K.-Bu
斯隆数字巡天漫画计划现在已经获得了附近宇宙中超过10,000个星系的积分场光谱。我们利用最终发布的漫画数据DR17研究了电离气体速度弥散与银河系恒星形成率之间的关系，发现来自星系HⅡ区的σHα从∼18-30 km S−1开始显著增加，与前人的研究基本一致。相反，来自扩散电离气体的σHα从20-60公里S−1开始增长得更快。我们利用漫画的统计能力，用多条发射线更详细地研究了这些关联，确定了观测到的σHα与局地恒星形成率表面密度的相关性主要是由在较高的总恒星形成率时速度弥散增加的全球关系驱动的，与恒星质量也有明显的相关性。假定HⅡ区模型与我们发现的σ[O III]<；σHα<；σ[O i]一致，我们估计了嵌入H II区的分子气体的速度色散，得到的数值σMol=5-30 KM S−1与ALMA在相似质量范围内的观测结果一致。最后，我们利用电离气体σz/σr=0.84±0.0 3和σϕ/σr=0.91±0.0 3与银盘中年轻恒星的速度色散椭球的关系随倾角和盘方位角的变化来约束其速度色散椭球。我们的结果与现代星系盘中的湍流主要由恒星形成反馈驱动的理论模型最为一致。
The Sloan Digital Sky Survey MaNGA program has now obtained integral field spectroscopy for over 10,000 galaxies in the nearby universe. We use the final MaNGA data release DR17 to study the correlation between ionized gas velocity dispersion and galactic star formation rate, finding a tight correlation in which σ Hα from galactic H ii regions increases significantly from ∼18–30 km s−1, broadly in keeping with previous studies. In contrast, σ Hα from diffuse ionized gas increases more rapidly from 20–60 km s−1. Using the statistical power of MaNGA, we investigate these correlations in greater detail using multiple emission lines and determine that the observed correlation of σ Hα with local star formation rate surface density is driven primarily by the global relation of increasing velocity dispersion at higher total star formation rate, as are apparent correlations with stellar mass. Assuming H ii region models consistent with our finding that σ [O III] < σ Hα < σ [O I], we estimate the velocity dispersion of the molecular gas in which the individual H ii regions are embedded, finding values σ Mol = 5–30 km s−1 consistent with ALMA observations in a similar mass range. Finally, we use variations in the relation with inclination and disk azimuthal angle to constrain the velocity dispersion ellipsoid of the ionized gas σ z /σ r = 0.84 ± 0.03 and σ ϕ /σ r = 0.91 ± 0.03, similar to that of young stars in the Galactic disk. Our results are most consistent with the theoretical models in which turbulence in modern galactic disks is driven primarily by star formation feedback.