Baryonic Dark Halos: A Cold Gas Component?
Baryonic Dark Halos: A Cold Gas Component?
复制标题
重子暗晕：冷气体成分？
DOI：
10.1086/178039
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
J. Silk
中科院分区：
文献类型：
--
作者：
O. Gerhard;J. Silk
我们认为星系晕中的一些暗物质可能以寒冷、致密的气体云的形式存在。许多观测和动力学论证都表明星系周围存在迄今为止未被观测到的冷气体。如果冷气体嵌入无碰撞物体或粒子的暗小团簇中，或者如果气体的热平衡由气体颗粒加热主导，则冷气体可能会稳定。典型的云质量为 ∼1 M☉，气体温度为 ≲10 K。我们讨论了晕冷气体含量的演变，并在简单的二元模型框架内导出了对微型星团的约束。人们给出了各种预测来检验这样的假设：这些云可能对星系外晕的质量有很大贡献。如果晕确实部分是重子的，并且含有大量的冷气体，那么它们在星系形成和演化中可能发挥比通常认为的更积极的作用。
We consider the possibility that some of the dark matter in the halos of galaxies may be in the form of cold, dense gas clouds. A number of observational and dynamical arguments point to the existence of hitherto unobserved cold gas around galaxies. The cold gas may be stabilized if it is embedded within dark miniclusters of collisionless objects or particles, or if the thermal balance of the gas is dominated by gas-grain heating. Typical cloud masses are ∼1 M☉, and the gas temperature is ≲10 K. We discuss the evolution of the halo cold gas content and derive constraints on the miniclusters within the framework of a simple two-component model. Various predictions are given for testing the hypothesis that such clouds could contribute substantially to the mass in the outer halos of galaxies. If halos are indeed partly baryonic and contain significant amounts of cold gas, they are likely to play a much more active role in galaxy formation and evolution than is commonly supposed.