RECENT STAR FORMATION IN THE LEADING ARM OF THE MAGELLANIC STREAM
RECENT STAR FORMATION IN THE LEADING ARM OF THE MAGELLANIC STREAM
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DOI：
10.1088/2041-8205/784/2/l37
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发表时间：
2014-03
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影响因子：
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通讯作者：
D. Casetti-Dinescu;C. M. Bidin;T. Girard;R. Mendez;K. Vieira;V. Korchagin;W. V. van Altena
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作者：
D. Casetti-Dinescu;C. M. Bidin;T. Girard;R. Mendez;K. Vieira;V. Korchagin;W. V. van Altena
强相互作用的星系经历一个短暂但戏剧性的演化阶段，其特征是增强的恒星形成、潮汐尾、桥梁和其他形态特征。一对相互作用的星系最近的例子是麦哲伦星云，其动态相互作用产生了被称为麦哲伦流的气态特征，它尾随这对星系围绕银河系的轨道，是云团和前臂（LA）之间的桥梁，前臂是引导轨道的宽阔且不规则的特征。众所周知，桥中存在年轻的、新形成的恒星，这见证了云层之间最近的相互作用。然而，人们对云层与银河系 (MW) 的相互作用还不太了解。特别是，LA 必须有潮汐起源；然而，没有纯粹的引力模型能够重现其形态和运动学。正如一些模型所表明的那样，与银河系的气态热晕和盘之间的流体动力学相互作用是合理的，并支持中性氢（H i）观测。在这里，我们首次表明，年轻的、最近形成的恒星存在于洛杉矶，这表明云层和银河系之间的相互作用足够强大，足以触发洛杉矶某些区域的恒星形成——这些区域位于MW盘的郊区(R∼18 kpc)，远离云层和桥。
Strongly interacting galaxies undergo a short-lived but dramatic phase of evolution characterized by enhanced star formation, tidal tails, bridges, and other morphological peculiarities. The nearest example of a pair of interacting galaxies is the Magellanic Clouds, whose dynamical interaction produced the gaseous features known as the Magellanic Stream trailing the pair's orbit about the Galaxy, the bridge between the Clouds, and the leading arm (LA), a wide and irregular feature leading the orbit. Young, newly formed stars in the bridge are known to exist, giving witness to the recent interaction between the Clouds. However, the interaction of the Clouds with the Milky Way (MW) is less well understood. In particular, the LA must have a tidal origin; however, no purely gravitational model is able to reproduce its morphology and kinematics. A hydrodynamical interaction with the gaseous hot halo and disk of the Galaxy is plausible as suggested by some models and supporting neutral hydrogen (H i) observations. Here we show for the first time that young, recently formed stars exist in the LA, indicating that the interaction between the Clouds and our Galaxy is strong enough to trigger star formation in certain regions of the LA—regions in the outskirts of the MW disk (R ∼ 18 kpc), far away from the Clouds and the bridge.