The Baryonic Mass–Halo Mass Relation of Extragalactic Systems
Abstract
Abstract We combine data for extragalactic systems to quantify a relation between the observed baryonic mass M b and the enclosed dynamical mass M 200 inferred from kinematics or gravitational lensing. Our sample covers 9 orders of magnitude in baryonic mass, including galaxies with kinematic or weak gravitational lensing data and groups and clusters of galaxies with new gravitational lensing data. For rich clusters with M b > 10 14 M ⊙ , the observed baryon fraction is consistent with the cosmic value, f b = 0.157. For lower masses, the baryon fraction decreases systematically with mass. The variation is well described by M b / M 200 = f b tanh ( M b / M 0 ) 1 / 4 with M 0 ≈ 5 × 10 13 M ⊙ . This relation is qualitatively similar to stellar mass–halo mass relations derived from abundance matching, but exhibits less scatter.
Fields of Study & Subjects
Galaxies: Formation
Evolution
Phenomena
Astronomy and Astrophysical Research
Cosmology and Gravitation Theories
Publication details
- Journal / source
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Volume
- 1001
- Issue
- 1
- Pages
- 65–65
- Publication date
- 6 April 2026
- Language
- EN