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Title: Review of the fermionic dark matter model applied to galactic structures

Baryonic components (e.g. bulge and disk) of galactic structures are assumed to be embedded in an isothermal dark matter halo of fermionic nature. Besides the Pauli principle only gravitational interaction is considered. Using the underlying Fermi-Dirac phase space distribution, typical of collisionless relaxation processes, it yields an one-parameter family of scaled solutions which reproduces the observed flat rotation curves in galaxies, and additionally predicts a degenerate core through their centers. In order to provide the right DM halo properties of galaxies a set of four parameters (particle mass, degeneracy parameter at the galactic center, central density and the velocity dispersion) is necessary. The more general density profile shows three regimes depending on radius: an almost uniform very dense quantum core followed by a steep fall, a plateau in the diluted regime and a Boltzmannian tail representing the halo. In contrast to purely Boltzmannian configurations the fermionic DM model containing a quantum core allows to determine the particle mass. We show that the quantum core can be well approximated by a polytrope of index n = 3/2, while the halo can be perfectly described by an isothermal sphere with a halo scale length radius equal to approximately 3/4 of the King-radius.
Authors:
 [1] ;  [2] ; ;  [1] ;  [3]
  1. Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 5, I–00185 Rome (Italy)
  2. ICRANet, P.zza della Repubblica 10, I-65122 Pescara (Italy)
  3. (Italy)
Publication Date:
OSTI Identifier:
22494333
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1693; Journal Issue: 1; Conference: 2. ICRANet Cesar Lattes meeting on supernovae, neutron stars and black holes, Rio de Janeiro (Brazil), 13-22 Apr 2015; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; BARYONS; DENSITY; DIAGRAMS; DISTRIBUTION; GALAXIES; GRAVITATIONAL INTERACTIONS; NONLUMINOUS MATTER; PARTICLES; PAULI PRINCIPLE; PHASE SPACE; RELAXATION; SPHERES; VELOCITY