Tully-Fisher relation, galactic rotation curves and dissipative mirror dark matter

R. Foot

doi:10.1088/1475-7516/2014/12/047

paper

Tully-Fisher relation, galactic rotation curves and dissipative mirror dark matter

arXiv:1307.1755 · doi:10.1088/1475-7516/2014/12/047

Abstract

If dark matter is dissipative then the distribution of dark matter within galactic halos can be governed by dissipation, heating and hydrostatic equilibrium. Previous work has shown that a specific model, in the framework of mirror dark matter, can explain several empirical galactic scaling relations. It is shown here that this dynamical halo model implies a quasi-isothermal dark matter density, $ρ (r) = ρ_{0} r_{0}^{2} / (r^{2} + r_{0}^{2})$ , where the core radius, $r_{0}$ , scales with disk scale length, $r_{D}$ , via $r_{0} / kpc = 1.4 (r_{D} / kpc)$ . Additionally, the product $ρ_{0} r_{0}$ is roughly $co n s t an t$ , i.e. independent of galaxy size (the $co n s t an t$ is set by the parameters of the model). The derived dark matter density profile implies that the galactic rotation velocity satisfies the Tully-Fisher relation, $L_{B} \propto v_{ma x}^{3}$ , where $v_{ma x}$ is the maximal rotational velocity. Examples of rotation curves resulting from this dynamics are given.

About 12 pages

Tully-Fisher relation, galactic rotation curves and dissipative mirror dark matter

Abstract

References in corpus (8)

Cited by in corpus (18)