Determining the Timescale over Which Stellar Feedback Drives Turbulence in the Interstellar Medium: A Study of Four Nearby Dwarf Irregular Galaxies
Determining the Timescale over Which Stellar Feedback Drives Turbulence in the Interstellar Medium: A Study of Four Nearby Dwarf Irregular Galaxies
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DOI：
10.3847/1538-3881/ac4d2c
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发表时间：
2022-01
期刊：
影响因子：
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通讯作者：
Laura Congreve Hunter;L. van Zee;K. McQuinn;Ray Garner;A. Dolphin
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文献类型：
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作者：
Laura Congreve Hunter;L. van Zee;K. McQuinn;Ray Garner;A. Dolphin
恒星反馈是星系演化建模的基础，因为它驱动星系中的湍流和外流。了解所涉及的时间尺度对于限制恒星反馈对星际介质的影响至关重要。我们分析了四个附近的恒星形成矮星系（NGC 4068, NGC 4163， NGC 6789和UGC 9128）的恒星形成历史以及原子和电离气体的空间分布和运动学，以确定恒星反馈驱动湍流的时间尺度。这四个星系都在5 Mpc范围内，它们具有一系列的特性，包括当前恒星形成率为0.0005-0.01 M⊙年−1，log（M */M⊙）在7.2和8.2之间，log（M H i /M⊙）在7.2和8.3之间。他们的彩色星等图得出了过去500迈的恒星形成历史，并将其与原子和电离气体速度色散和作为湍流指标的H能量表面密度进行了比较。Spearman等级相关系数被用来确定它们当前的湍流与它们过去在局部尺度上的恒星形成活动之间的任何相关性（~ 400pc）。发现最强的相关性是在100-200万年前的H湍流测量和恒星形成率之间。这表明在这个时间尺度上恒星形成活动和原子气体之间存在耦合。在5 - 500 Myr之间，电离气体速度弥散与恒星形成活动之间没有很强的相关性。样本和分析是一个更大的项目的基础，该项目旨在了解恒星反馈驱动湍流的时间尺度。
Stellar feedback is fundamental to the modeling of galaxy evolution, as it drives turbulence and outflows in galaxies. Understanding the timescales involved are critical for constraining the impact of stellar feedback on the interstellar medium. We analyzed the resolved star formation histories along with the spatial distribution and kinematics of the atomic and ionized gas of four nearby star-forming dwarf galaxies (NGC 4068, NGC 4163, NGC 6789, and UGC 9128) to determine the timescales over which stellar feedback drives turbulence. The four galaxies are within 5 Mpc and have a range of properties including current star formation rates of 0.0005–0.01 M ⊙ yr−1, log(M */M ⊙) between 7.2 and 8.2, and log(M H i /M ⊙) between 7.2 and 8.3. Their color–magnitude diagram derived star formation histories over the past 500 Myr were compared to their atomic and ionized gas velocity dispersion and H i energy surface densities as indicators of turbulence. The Spearman’s rank correlation coefficient was used to identify any correlations between their current turbulence and their past star formation activity on local scales (∼400 pc). The strongest correlation found was between the H i turbulence measures and the star formation rate 100–200 Myr ago. This suggests a coupling between the star formation activity and atomic gas on this timescale. No strong correlation between the ionized gas velocity dispersion and the star formation activity between 5 and 500 Myr ago was found. The sample and analysis are the foundation of a larger program aimed at understanding the timescales over which stellar feedback drives turbulence.