Cylindrical model for the dark matter halo of disk galaxies

TL;DR

This paper introduces a cylindrical model for galaxy dark matter halos that aligns with observed velocity dispersions and neutrino mass constraints, offering an alternative to traditional spherical profiles.

Contribution

A novel cylindrical model for dark matter halos is developed, matching observations with less mass than standard profiles and compatible with neutrino constraints.

Findings

Cylindrical model reproduces Milky Way velocity dispersion.

Requires less mass than NFW profile.

Compatible with 1.1 eV neutrinos.

Abstract

A cylindrical model for the dark matter halo of disk galaxies is developed. At the center of the cylinder, in the plane perpendicular to the long axis, the rotation curve is constant for distances much less than the cylinder length and Keplerian at much greater distances. The rotation curve is equivalent to the spherical truncated flat (TF) profile, a model derived empirically from the radial velocity dispersion of the Milky Way dark halo. It is shown that an isothermal, self-gravitating cylinder of length 89 kpc can account for the observed radial velocity dispersion of the Milky Way dark halo with less mass than the NFW profile. Moreover, a cylindrical model of the Milky Way dark halo is consistent with free-streaming neutrinos of mass 1.1 eV.