Density Distribution of Plasmas Resembling Dark Matter Halo Due to Ionization lag and Ambipolar Electric Field

TL;DR

This paper models a plasma with ionization lag and electric fields, showing its density distribution resembles dark matter halos and suggesting baryons could replace dark matter in galaxies.

Contribution

It introduces a plasma-based model explaining dark matter-like density profiles through ionization lag and ambipolar electric fields, a novel approach in astrophysics.

Findings

Density distribution resembles pseudo-isothermal halos

Ion collision cross-section is reduced by three orders of magnitude

Baryons may replace dark matter in massive galaxies

Abstract

In a spherically symmetric plasma constrained by its own gravity, the ionization degree lags behind changes in temperature and density. The ambipolar electric field accelerates ions radially and cools electrons. Ions lose energy and angular momentum in collisions with low-temperature electrons. The angular momentum of ions decreases much faster than their energy in cycles. The trajectories of ions are close to radial, and the density distribution resembles pseudo-isothermal. The velocity distributions of baryons moving outward and inward in galaxies tend to approach independent Maxwell distributions. This characteristic suppresses small-angle scattering of ions, reducing the ion collision cross-section by three orders of magnitude. In the massive galaxies, baryons can replace all dark matter.