2022/03/14 by Zhijie Xu, Xu, Zhijie
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2203.06899
openalex publication_date 2022/03/14 · openalex created_date 2022/04/03 · openalex updated_date 2026/08/01
The relation between properties of galaxies and dark matter halos they reside in can be valuable for structure formation and evolution. This paper focus on the baryonic-to-halo mass ratio (BHMR) and its evolution. We first review unique properties of self-gravitating collisionless dark matter flow (SG-CFD), followed by their application to derive BHMR. To maximize system entropy, the long-range interaction requires a broad size of halos to be formed. These halos facilitate inverse mass and energy cascade from small to large scales with a constant rate of energy cascade εu. In addition, dark matter flow exhibits scale-dependent flow behaviors that is incompressible on small scale and irrotational on large scale. With these properties and considering a given halo with a total baryonic mass mb, halo mass mh, halo virial size rh, and flat rotation speed vf, BHMR can be analytically derived by combining the baryonic Tully-Fisher relation and constant εu in small and large halos. A maximum BHMR ratio ~0.076 is found for halos with a critical mass mhc∼ 1012M\odot at z=0. That ratio is much lower for both smaller and larger halos such that two regimes can be identified: i) for incompressible small halos with mass mhmhc, we have εu∝ vf3/rh, vf∝ rh1/3, and mb∝ mh4/9. Combined with double-λ halo mass function, the average BHMR ratio in all halos (~0.024 at z=0) can be analytically derived, along with its redshift evolution. The fraction of total baryons in all galaxies is ~7.6% at z=0 and increases with time ∝ t1/3. The SPARC (Spitzer Photometry & Accurate Rotation Curves) data with 175 late-type galaxies were used for derivation and comparison.