English

Cored DARKexp systems with finite size: numerical results

Cosmology and Nongalactic Astrophysics 2018-08-23 v2

Abstract

In the DARKexp framework for collisionless isotropic relaxation of self--gravitating matter, the central object is the differential energy distribution n(E)n(E), which takes a maximum--entropy form proportional to exp[β(EΦ(0))]1\exp[-\beta(E - \Phi(0))] - 1, Φ(0)\Phi(0) being the depth of the potential well and β\beta the standard Lagrange multiplier. Then the first and quite non--trivial problem consists in the determination of an ergodic phase--space distribution which reproduces this n(E)n(E). In this work we present a very extensive and accurate numerical solution of such DARKexp problem for systems with cored mass density and finite size. This solution holds throughout the energy interval Φ(0)E0\Phi(0)\le E\le 0 and is double--valued for a certain interval of β\beta. The size of the system represents a unique identifier for each member of this solution family and diverges as β\beta approaches a specific value. In this limit, the tail of the mass density ρ(r)\rho(r) dies off as r4r^{-4}, while at small radii it always starts off linearly in rr, that is ρ(r)ρ(0)r\rho(r)-\rho(0)\propto r.

Keywords

Cite

@article{arxiv.1806.06413,
  title  = {Cored DARKexp systems with finite size: numerical results},
  author = {Claudio Destri},
  journal= {arXiv preprint arXiv:1806.06413},
  year   = {2018}
}

Comments

33 pages, 16 figures, accepted for publication on JCAP