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		| Paper: | 
		High-Velocity Gas from the Galactic Dark Halo | 
	 
	
		| Volume: | 
		166, Stromlo Workshop on High-Velocity Clouds | 
	 
	
		| Page: | 
		269 | 
	 
	
		| Authors: | 
		Walker, Mark; Wardle, Mark | 
	 
	
	
		| Abstract: | 
		We present the germ of a new model for High Velocity Clouds, derived from the idea that the dark matter halo of our Galaxy is in the form of cold, planetary-mass gas clouds. In this picture HVCs arise as a result of disruptive collisions between dark matter clouds: high velocity atomic gas is a natural consequence of the dark halo kinematics, and is intimately associated with assembly of the visible Galaxy. Quasi-spherical halo models predict a broad 21 cm line background, together with a number of individually detectable, low-mass HVCs conforming to a particular velocity field. A halo model which incorporates satellite substructure -- after the fashion of the current paradigm of hierarchical structure formation -- includes both these components and, in addition, some massive HVCs. These latter HVCs are simply the wakes of the orbiting satellite halos, and each may have a mass up to 0.3% of the mass of the satellite. | 
	 
	
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