Dissipative dark matter explains rotation curves
  Dissipative dark matter, where dark matter particles interact with a massless
(or very light) boson, is studied. Such dark matter can arise in simple hidden
sector gauge models, including those featuring an unbroken $U(1)'$ gauge
symmetry, leading to a dark photon. Previous work has shown that such models
can not only explain the LSS and CMB, but potentially also dark matter
phenomena on small scales, such as the inferred cored structure of dark matter
halos. In this picture, dark matter halos of disk galaxies not only cool via
dissipative interactions but are also heated via ordinary supernovae
(facilitated by an assumed photon - dark photon kinetic mixing interaction).
This interaction between the dark matter halo and ordinary baryons, a very
special feature of these types of models, plays a critical role in governing
the physical properties of the dark matter halo. Here, we further study the
implications of this type of dissipative dark matter for disk galaxies.
Building on earlier work, we develop a simple formalism which aims to describe
the effects of dissipative dark matter in a fairly model independent way. This
formalism is then applied to generic disk galaxies. We also consider specific
examples, including NGC 1560 and a sample of dwarf galaxies from the LITTLE
THINGS survey. We find that dissipative dark matter, as developed here, does a
fairly good job accounting for the rotation curves of the galaxies considered.
Not only does dissipative dark matter explain the linear rise of the rotational
velocity of dwarf galaxies at small radii, but it can also explain the observed
wiggles in rotation curves which are known to be correlated with corresponding
features in the disk gas distribution.
