论文标题
Starburst矮人星系CGCG 007-025的空间分辨化学动力学：金属贫困气体近期积聚的证据
Spatially-resolved chemodynamics of the starburst dwarf galaxy CGCG 007-025: Evidence for recent accretion of metal-poor gas
论文作者
论文摘要
附近的金属贫困的星爆矮星系是一个独特的机会，可以探究高密度恒星形成物理的细节和灵敏度，这是任何观察到高Z宇宙的观察。在这里，我们介绍了附近的富含气体的矮小矮人CGCG 007-025的化学动力学研究。我们使用VLT/Muse积分田间光谱法来表征从金属含量到运动学的恒星形成（SF）气体的性质。恒星形成率（SFR）表面密度呈现出块状分布，最明亮的结容有5 Myr Young，WOLF射线（WR）种群（通过具有5808Å〜WR凹凸的特征性的存在）。离子气体运动学以无序运动为主。狭窄（$σ\ $ 50 km s $^{ - 1} $），中间体（150 km s $^{ - 1} $）和宽（1000 km s $ s $^{ - 1} $）的运动组件才能模拟最明亮的SF区域中的发射线，从而使质量超出质量的质量效果，则需要叠加（150 km s $^{ - 1} $）和宽（1000 km s $^{ - 1} $），表明较狭窄的叠加（150 km s $^{ - 1} $），建议从最亮的群体上模仿：星系的气相金属性跨度为0.6 DEX，并显示出SFR表面密度的强抗相关性，在中央SF结中降至12+log（O/H）= 7.7。空间分辨的BPT表明气体纯粹是通过SF过程电离的。最后，SFR与气体金属性之间的抗相关性指出，金属贫困气体是最近偏心的Starburst的起源，其中插入物质点燃了SF发作。
Nearby metal-poor starburst dwarf galaxies present a unique opportunity to probe the physics of high-density star formation with a detail and sensitivity unmatched by any observation of the high-z Universe. Here we present the first results from a chemodynamical study of the nearby, gas-rich starburst dwarf CGCG 007-025. We use VLT/MUSE integral field spectroscopy to characterise the properties of the star-forming (SF) gas, from its metal content to its kinematics. The star formation rate (SFR) surface density presents a clumpy distribution, with the brightest knot hosting a 5 Myr young, Wolf-Rayet (WR) population (revealed by the presence of the characteristic 5808Å~WR bump). The ionised gas kinematics are dominated by disordered motions. A superposition of a narrow ($σ\approx$ 50 km s$^{-1}$), intermediate (150 km s$^{-1}$) and broad (1000 km s$^{-1}$) kinematic components are needed to model the emission line profiles in the brightest SF region, suggesting the presence of energetic outflows from massive stars. The gas-phase metallicity of the galaxy spans 0.6 dex and displays a strong anti-correlation with SFR surface density, dropping to 12+log(O/H) = 7.7 in the central SF knot. The spatially-resolved BPTs indicates the gas is being ionised purely by SF processes. Finally, the anti-correlation between the SFR and the gas metallicity points out to accretion of metal-poor gas as the origin of the recent off-centre starburst, in which the infalling material ignites the SF episode.
