ar X iv : a st ro - p h / 00 08 21 5 v 1 1 5 A ug 2 00 0 Evolution of the buoyant bubbles in M 87
نویسندگان
چکیده
The morphology of the X–ray and radio emitting features in the central ∼ 50 kpc region around the galaxy M87 strongly suggests that buoyant bubbles of cosmic rays (inflated by an earlier nuclear active phase of the galaxy) are slowly rising through the cooling gas. In the absence of strong surface tension, an intrinsic property of initially spherical bubbles is their transformation into tori as they rise through an external medium. Such structures can be identified in the radio images of the halo of M87. During their rise the bubbles uplift relatively cool X–ray emitting ambient gas from the central regions of the cooling flow to larger distances. This gas is colder than the ambient gas and has a higher volume emissivity. As a result, rising " radio " bubbles may be trailed by elongated X–ray features as indeed is observed in M87. We performed simple hydrodynamical simulations in order to qualitatively illustrate the evolution of the buoyant bubbles in the M87 environment.
منابع مشابه
ar X iv : a st ro - p h / 00 08 21 5 v 2 6 F eb 2 00 1 Evolution of Buoyant Bubbles in M 87
The morphology of the X–ray and radio emitting features in the central ∼ 50 kpc region around the galaxy M87 strongly suggests that buoyant bubbles of cosmic rays (inflated by an earlier nuclear active phase of the galaxy) rise through the cooling gas at roughly half the sound speed. In the absence of strong surface tension, initially spherical bubbles will transform into tori as they rise thro...
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