Dynamical constraints on a dark matter spike at the Galactic centre from stellar orbits

Thomas Lacroix (1)

1 LUPM - Laboratoire Univers et Particules de Montpellier

In this work I use astrometric and spectroscopic data on the S2 star at the Galactic centre (GC) up to 2016 to derive specific constraints on the size of a dark matter (DM) spike around the central supermassive black hole Sgr A*. These limits are the best direct constraints on a DM spike at the GC for non-annihilating dark matter and exclude a spike with radius greater than a few tens of parsecs for cuspy outer halos and a few hundred parsecs for cored outer halos.

Mots clés: dark matter; Galaxy: center; celestial mechanics; black hole physics

Domaines: Astrophysique [astro-ph]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Physique des Hautes Energies - Phénoménologie [hep-ph]

Thomas Lacroix. Dynamical constraints on a dark matter spike at the Galactic centre from stellar orbits. Astronomy and Astrophysics - A&A, 2018, 619, pp.A46. ⟨10.1051/0004-6361/201832652⟩. ⟨hal-01696137⟩