Why do we expect WIMPs to be distributed throughout galactic halos, rather than settled into a disk?
A) They are light enough that they have expanded out into the halo.
B) WIMPs were produced at the early stages of galaxy evolution, and objects in the halo, such as globular clusters, were formed at the beginning of the galaxy.
C) Since they do not interact with the electromagnetic force, they do not feel friction or drag and hence do not contract with the rest of the protogalactic cloud.
D) Shock waves from supernovae have blown the WIMPs out into the halo.
E) Jets from the early active stage of a galaxy's life shot out most of the WIMPs from the disk.
C
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