Shape and evolution of wind-blown bubbles of massive stars: on the effect of the interstellar magnetic field
Shape and evolution of wind-blown bubbles of massive stars: on the effect of the interstellar magnetic field
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DOI：
10.1051/0004-6361/201425230
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发表时间：
2015-09
影响因子：
6.5
通讯作者：
A. J. Marle;Z. Meliani;A. Marcowith
中科院分区：
文献类型：
--
作者：
A. J. Marle;Z. Meliani;A. Marcowith
大质量恒星的恒星风在其祖先周围产生了大（>10 pc）的气泡。当这些气泡膨胀时，它们会遇到星际相干磁场，根据其强度，可以影响气泡的形状。我们希望研究星际磁场是否以及在多大程度上对大质量星星周围的膨胀的星周气泡的形状有贡献。我们使用MPI-AMRVAC代码，使磁流体动力学模拟的气泡，使用一个单一的星星模型，结合几个不同的磁场强度：B = 5，10，和20 μ G的星际磁场。这涵盖了在银盘和凸起中发现的星际磁场的典型场强。此外，我们提出了两个模拟，包括5 μ G的星际磁场和10，000 K的星际介质和两个不同的ISM密度，以演示磁场如何与其他外部因素联合收割机影响拱星气泡的形态。我们的研究结果表明，低磁场，发现在银盘，抑制的拱星气泡在垂直于该领域的方向上的增长。结果，气泡变成卵形，而不是球形。强的星际场，如银河系凸起所观察到的，可以完全阻止气泡在垂直于场的方向上的膨胀，导致管状气泡的形成。当与温暖的高密度ISM相结合时，气泡的尺寸大大减小，导致气泡内部临时特征的演变发生戏剧性的变化。星际介质的磁场会影响星周气泡的形状。这种效应可能会对星周星云和超新星遗迹的形状和演化产生影响，这些星云和超新星遗迹是在主风吹气泡内形成的。
The winds of massive stars create large (>10 pc) bubbles around their progenitors. As these bubbles expand they encounter the interstellar coherent magnetic field which, depending on its strength, can influence the shape of the bubble. We wish to investigate if, and how much, the interstellar magnetic field can contribute to the shape of an expanding circumstellar bubble around a massive star. We use the MPI-AMRVAC code to make magneto-hydrodynamical simulations of bubbles, using a single star model, combined with several different field strengths: B = 5, 10, and 20 muG for the interstellar magnetic field. This covers the typical field strengths of the interstellar magnetic fields found in the galactic disk and bulge. Furthermore, we present two simulations that include both a 5 muG interstellar magnetic field and a 10,000 K interstellar medium and two different ISM densities to demonstrate how the magnetic field can combine with other external factors to influence the morphology of the circumstellar bubbles. Our results show that low magnetic fields, as found in the galactic disk, inhibit the growth of the circumstellar bubbles in the direction perpendicular to the field. As a result, the bubbles become ovoid, rather than spherical. Strong interstellar fields, such as observed for the galactic bulge, can completely stop the expansion of the bubble in the direction perpendicular to the field, leading to the formation of a tube-like bubble. When combined with a warm, high-density ISM the bubble is greatly reduced in size, causing a dramatic change in the evolution of temporary features inside the bubble. The magnetic field of the interstellar medium can affect the shape of circumstellar bubbles. This effect may have consequences for the shape and evolution of circumstellar nebulae and supernova remnants, which are formed within the main wind-blown bubble.