Dark matter in the Milky Way: Measurements up to 3 kpc from the Galactic plane above the Sun

¹ Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, 11 rue de l’Université, F-67000 Strasbourg, France
² Institut Utinam, CNRS UMR 6213, Université de Franche-Comté, OSU THETA Franche-Comté-Bourgogne, Observatoire de Besançon, BP 1615, 25010 Besançon Cedex, France

Received: 11 April 2024
Accepted: 19 June 2024

Abstract

We probe the gravitational force perpendicular to the Galactic plane at the position of the Sun based on a sample of red giants, with measurements taken from the DR3 Gaia catalogue. Measurements far out of the Galactic plane up to 3.5 kpc allow us to determine directly the total mass density, where dark matter is dominant and the stellar and gas densities are very low. In a complementary way, we have also used a new determination of the local baryonic mass density to help determine the density of dark matter in the Galactic plane at the solar position. For the local mass density of dark matter, we obtained ρ_dm = 0.0128 ± 0.0008 M_⊙ pc⁻³ = 0.486 ± 0.030 Gev cm⁻³. For the flattening of the gravitational potential of the dark halo, it is q_ϕ, h = 0.843 ± 0.035. For its density, q_ρ, h = 0.781 ± 0.055.