astropy/astropy — pull request #3153 by astrofrog (2014-11-26 22:10:24+00:00)
Title: Removed a few spectral density equivalencies which do not make sense.

I don't think the equivalencies removed here make sense for spectral density.

@mdboom - since you originally added these, can you comment on this?

cc @pllim @mhvk

(originally discussed in https://github.com/astropy/astropy/pull/692)