A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016
A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016
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中央分子区云中的风吹气泡 G0.253 0.016
DOI：
10.1093/mnras/stab3039
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发表时间：
2021
影响因子：
4.8
通讯作者：
Bally, John
中科院分区：
文献类型：
--
作者：
Henshaw, Jonathan D.;Krumholz, Mark R.;Butterfield, Natalie O.;Mackey, Jonathan;Ginsburg, Adam;Haworth, Thomas J.;Nogueras-Lara, Francisco;Barnes, Ashley T.;Longmore, Steven N.;Bally, John
G0.253+0.016，通常被称为“砖”，位于中央分子区，是银河系中密度最大（≈103-4cm−3）的分子云之一，缺乏广泛恒星形成的特征。我们开始约束位于云内的弧形分子线发射特征的起源。我们确定，圆弧，为中心，有一个半径为1.3 pc和运动学表明存在一个壳扩展到。延长的射电连续发射充满电弧腔，复合线发射峰值与电弧的速度相似，这表明分子气体和电离气体在物理上是相关的。推断的Lyman连续体光子率为nlyc = 1046.0 - 1047.9个光子s−1，与光谱型为1b - o8.5的恒星相一致，对应的质量为≈12-20 M⊙。我们探索了弧的起源的两种情况：(i)部分壳被一个闯入的大质量恒星的风卷走；（ii）部分壳被由一个独立恒星形成产生的恒星反馈卷走。我们倾向于后一种情况，在它的形态、动力学和能量学与那些由大质量恒星的风驱动的膨胀气泡之间找到了合理的（少数因素）一致性。直接的含义是，G0.253+0.016可能不像人们普遍接受的那样是静止的。我们推测该星云可能在约0.4 Myr以前产生了一个约103M⊙的星团，并证明在G0.253+0.016附近观测到的高消光和恒星拥挤可能有助于掩盖这样一个星团的探测。
G0.253+0.016, commonly referred to as ‘the Brick’ and located within the Central Molecular Zone, is one of the densest (≈103–4cm−3) molecular clouds in the Galaxy to lack signatures of widespread star formation. We set out to constrain the origins of an arc-shaped molecular line emission feature located within the cloud. We determine that the arc, centred on, has a radius of 1.3 pc and kinematics indicative of the presence of a shell expanding at. Extended radio continuum emission fills the arc cavity and recombination line emission peaks at a similar velocity to the arc, implying that the molecular gas and ionized gas are physically related. The inferred Lyman continuum photon rate isNLyC= 1046.0–1047.9photons s−1, consistent with a star of spectral type B1-O8.5, corresponding to a mass of ≈12–20 M⊙. We explore two scenarios for the origin of the arc: (i) a partial shell swept up by the wind of an interloper high-mass star and (ii) a partial shell swept up by stellar feedback resulting fromin situstar formation. We favour the latter scenario, finding reasonable (factor of a few) agreement between its morphology, dynamics, and energetics and those predicted for an expanding bubble driven by the wind from a high-mass star. The immediate implication is that G0.253+0.016 may not be as quiescent as is commonly accepted. We speculate that the cloud may have produced a ≲103M⊙star cluster ≳0.4 Myr ago, and demonstrate that the high-extinction and stellar crowding observed towards G0.253+0.016 may help to obscure such a star cluster from detection.