Constraining Axion Dark Matter with Galactic-Centre Resonant Dynamics

Abstract

We study the influence of fuzzy-dark-matter cores on the orbits of stars at the Galactic centre. This dark matter candidate condenses into dense, solitonic cores, and, if a super-massive black hole is present at the centre of such a core, its central part forms a `gravitational atom'. Here, we calculate the atom's contribution to the gravitational potential felt by a Galactic-centre star, for a general state of the atom. We study the angular-momentum dynamics this potential induces, and show that it is similar to vector resonant relaxation. Its influence is found to be potentially sufficiently strong that such a dynamical component should be accounted for in Galactic-centre modelling. For the Milky Way, the atom is expected to have some spherical asymmetry, and we use this to derive a stability condition for the disc of young, massive stars at the Galactic centre - if the atom's mass is too large, then the disc would be destroyed. Thus, the existence of this disc constrains the mass of the particles comprising the solitonic core. We study an example model of the core, where all of the rotation of the core's inner region is assumed to come from an $l=1$ state, and its amplitude is determined by the halo's spin parameter; such a core is found to be in tension with the stability of the clockwise stellar disc for $4.2\times 10^{-20}\text{eV}\le m_a\le 5.4\times 10^{-20}\text{eV}$ at $2\sigma$. Other core models would vary the constrained values of $m_a$ somewhat. These constraints will tighten significantly with future, improved data.

Submitted, comments welcome

References in corpus (28)

• Ultralight scalars as cosmological dark matter
• Cosmic Structure as the Quantum Interference of a Coherent Dark Wave
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Understanding the Core-Halo Relation of Quantum Wave Dark Matter, $\psi$DM, from 3D Simulations
• Wave Dark Matter
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• The Milky Way's nuclear star cluster: Old, metal-rich, and cuspy
• A numerical study of vector resonant relaxation
• Black Hole Hair from Scalar Dark Matter
• The young stars in the Galactic Center
• Black hole in quantum wave dark matter
• Soliton Oscillations and Revised Constraints from Eridanus II of Fuzzy Dark Matter
• Growth of accretion driven scalar hair around Kerr black holes
• Dwarf galaxies imply dark matter is heavier than $2.2\times 10^{-21}\mathbf{eV}$
• Using the motion of S2 to constrain scalar clouds around SgrA*
• Bounding the mass of ultralight bosonic Dark Matter particles with the motion of the S2 star around Sgr A*
• Constraining ultralight bosonic dark matter with Keck observations of S2's orbit and kinematics
• A first estimate of the Milky Way dark matter halo spin
• Relaxation in a Fuzzy Dark Matter Halo. II. Self-consistent kinetic equations
• Two-body relaxation driven evolution of the young stellar disc in the Galactic Centre
• Narrowing the allowed mass range of ultralight bosons with the S2 star
• Ejection of supermassive black holes and implications for merger rates in fuzzy dark matter haloes
• Angular Momentum and the Absence of Vortices in the Cores of Fuzzy Dark Matter Haloes
• A numerical study of stellar discs in galactic nuclei
• Dynamical friction in self-interacting ultralight dark matter
• Secular Dynamics around a Supermassive Black Hole via Multipole Expansion
• Resonant Dynamical Friction Around a Super-Massive Black Hole: Analytical Description
• Angular-momentum pairs in spherical systems: applications to the Galactic centre