English

Milky Way dark matter distribution or MOND test from vertical stellar kinematics with Gaia DR3

Astrophysics of Galaxies 2024-12-16 v1

Abstract

Vertical stellar kinematics+density can be used to trace the dark matter distribution [or the equivalent phantom mass in a Modified Newtonian Dynamics (MOND) scenario] through Jeans equations. In this paper, we want to improve this type of analysis by making use of the recent data of the 6D information from the Gaia-DR3 survey in the anticenter and the Galactic poles to obtain the dynamical mass distribution near plane regions, including extended kinematics over a wide region of 8 kpc<R<<R<22 kpc, z<3|z|<3 kpc. Our conclusions are as follows: (i) the model of the spherical dark matter halos and the MOND model are compatible with the data; (ii) the model of the disky dark matter (with density proportional to the gas density) is excluded; (iii) the total lack of dark matter (there is only visible matter) within Newtonian gravity is compatible with the data; for instance, at solar Galactocentric radius, we obtained Σ=39±18\Sigma=39\pm 18 M_\odot pc2^{-2} for z=1.05z=1.05 kpc, compatible with the expected value for visible matter alone of 44 M_\odot pc2^{-2}, thus allowing zero dark matter. Similarly, for R>RR>R_\odot, z=1.05z=1.05 kpc: Σ=28.7±9.6\Sigma=28.7\pm 9.6, 23.0±5.723.0\pm 5.7, 16.9±5.816.9\pm 5.8, 11.4±6.611.4\pm 6.6 M_\odot pc2^{-2}, respectively, for R=10,13,16,19R=10,13,16,19 kpc, compatible with visible matter alone. Larger error bars in comparison with previous works are not due to worse data or a more awkward technique but to a stricter modeling of the stellar distribution.

Keywords

Cite

@article{arxiv.2412.09665,
  title  = {Milky Way dark matter distribution or MOND test from vertical stellar kinematics with Gaia DR3},
  author = {Martin Lopez-Corredoira},
  journal= {arXiv preprint arXiv:2412.09665},
  year   = {2024}
}

Comments

21 pages, 15 figures, accepted to be published in ApJ