An estimate of the mass of the Milky Way from the Magellanic Stream
An estimate of the mass of the Milky Way from the Magellanic Stream
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根据麦哲伦流对银河系质量的估计
DOI：
10.1093/mnras/stac2308
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发表时间：
2022
影响因子：
4.8
通讯作者：
Lewis, Benjamin T.
中科院分区：
文献类型：
--
作者：
Craig, Peter A.;Chakrabarti, Sukanya;Baum, Stefi;Lewis, Benjamin T.
我们提出了一个模型的形成麦哲伦流（MS）由于冲压压力剥离。我们模型的历史，在最近的宇宙学过去的小和大麦哲伦云在一个静态的银河系（MW）潜在的扩散晕气体，使用观测动机的麦哲伦云的轨道来自HST适当的运动在潜在的MW。该模型能够再现拖臂，但不能再现前导臂特征，前导臂特征对于包括冲压压力剥离效应的流形成的模型是常见的。虽然我们的模型在匹配MS中的可观测量方面没有优于其他模型，但它足够接近我们的最终目标-使用MS来估计MW质量。通过分析我们的模型网格，我们发现在我们的模拟中观察到的流长度与MW的质量之间存在直接相关性。对于观测到的MS长度，推断的MW质量为1.5 ± 0.32 × 1012，这与其他独立的MW质量测量结果非常一致。我们还讨论了MS的背景下，在星系团中的Histreams，并发现MS位于低质量端的连续体从希克森集团的室女座星系团。作为外晕动力学质量的示踪物，MS是MW潜力的特别有价值的探测器。
We present a model for the formation of the Magellanic Stream (MS) due to ram pressure stripping. We model the history of the Small and Large Magellanic Clouds in the recent cosmological past in a static Milky Way (MW) potential with diffuse halo gas, using observationally motivated orbits for the Magellanic Clouds derived fromHSTproper motions within the potential of the MW. This model is able to reproduce the trailing arm but does not reproduce the leading arm feature, which is common for models of the stream formation that include ram pressure stripping effects. While our model does not outperform other models in terms of matching the observable quantities in the MS, it is close enough for our ultimate goal – using the MS to estimate the MW mass. By analysing our grid of models, we find that there is a direct correlation between the observed stream length in our simulations and the mass of the MW. For the observed MS length, the inferred MW mass is 1.5 ± 0.32 × 1012, which agrees closely with other independent measures of the MW mass. We also discuss the MS in the context of Histreams in galaxy clusters, and find that the MS lies on the low-mass end of a continuum from Hickson groups to the Virgo cluster. As a tracer of the dynamical mass in the outer halo, the MS is a particularly valuable probe of the MW’s potential.