The Turbulent Gas Structure in the Centers of NGC 253 and the Milky Way
The Turbulent Gas Structure in the Centers of NGC 253 and the Milky Way
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DOI：
10.3847/1538-4357/aba903
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发表时间：
2020-08
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影响因子：
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通讯作者：
N. Krieger;A. Bolatto;E. Koch;A. Leroy;E. Rosolowsky;F. Walter;A. Weiss;D. Eden;R. C. Levy-
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文献类型：
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作者：
N. Krieger;A. Bolatto;E. Koch;A. Leroy;E. Rosolowsky;F. Walter;A. Weiss;D. Eden;R. C. Levy-
我们使用树状图以及CO(1-0)和CO(3-2)中分辨率、面积和噪声匹配的数据集，在∼1-100PC的尺度上比较了NGC253恒星爆发中心和银河系中心(GC)的分子气体性质。我们发现，NGC253和GC的谱线宽关系具有相似的斜率，但NGC253的谱线宽度比∼2-3大。σ2/R对柱密度的依赖关系表明，在10-100pC尺度上，N>；3×1021 cm−2上气体的运动与引力束缚结构是相容的。在NGC253中，这只是柱密度N>；3×1022 cm−2的情况。在NGC253中增加的线宽源于较低的柱密度气体。这种高速弥散，而不是重力自束缚气体，很可能是在由高平均密度和星暴中的反馈相结合而产生的瞬变结构中。高密度使气体分子贯穿整个星暴体积，通过反馈注入的能量和动量显著增加了在给定空间尺度上的速度色散。
We compare molecular gas properties in the starbursting center of NGC 253 and the Milky Way Galactic center (GC) on scales of ∼1–100 pc using dendrograms and resolution-, area-, and noise-matched data sets in CO (1–0) and CO (3–2). We find that the size–line width relations in NGC 253 and the GC have similar slope, but NGC 253 has larger line widths by factors of ∼2–3. The σ2/R dependency on column density shows that, in the GC, on scales of 10–100 pc the kinematics of gas over N > 3 × 1021 cm−2 are compatible with gravitationally bound structures. In NGC 253 this is only the case for column densities N > 3 × 1022 cm−2. The increased line widths in NGC 253 originate in the lower column density gas. This high velocity dispersion, not gravitationally self-bound gas, is likely in transient structures created by the combination of high average densities and feedback in the starburst. The high densities turn the gas molecular throughout the volume of the starburst, and the injection of energy and momentum by feedback significantly increases the velocity dispersion at a given spatial scale over what is observed in the GC.