English

Deep Potential: Recovering the gravitational potential and local pattern speed in the solar neighborhood with GDR3 using normalizing flows

Astrophysics of Galaxies 2025-08-05 v2

Abstract

The gravitational potential of the Milky Way encodes information about the distribution of all matter -- including dark matter -- throughout the Galaxy. Gaia data release 3 has revealed a complex structure that necessitates flexible models of the Galactic gravitational potential. We make use of a sample of 5.6 million upper-main-sequence stars to map the full 3D gravitational potential in a one-kiloparsec radius from the Sun using a data-driven approach called ``Deep Potential''. This method makes minimal assumptions about the dynamics of the Galaxy -- that the stars are a collisionless system that is statistically stationary in a rotating frame (with pattern speed to be determined). We model the distribution of stars in 6D phase space using a normalizing flow and the gravitational network using a neural network. We recover a local pattern speed of Ωp=28.2±0.1km/s/kpc\Omega_p = 28.2\pm0.1\mathrm{\,km/s/kpc}, a local total matter density of ρ=0.086±0.010M/pc3\rho=0.086\pm0.010\mathrm{\,M_\odot/pc^3} and local dark matter density of ρDM=0.007±0.011M/pc3\rho_\mathrm{DM}=0.007\pm0.011\mathrm{\,M_\odot/pc^3}. The full 3D model exhibits spatial fluctuations, which may stem from the model architecture and non-stationarity in the Milky Way.

Keywords

Cite

@article{arxiv.2507.03742,
  title  = {Deep Potential: Recovering the gravitational potential and local pattern speed in the solar neighborhood with GDR3 using normalizing flows},
  author = {Taavet Kalda and Gregory M. Green},
  journal= {arXiv preprint arXiv:2507.03742},
  year   = {2025}
}

Comments

24 pages, 13 figures