Self-similar spherical collapse with tidal torque

Journal Article · Mon Nov 15 04:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.104044· OSTI ID:21509938

Zukin, Phillip; Bertschinger, Edmund ^[1]

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1. Department of Physics, MIT, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

N-body simulations have revealed a wealth of information about dark matter halos; however, their results are largely empirical. Using analytic means, we attempt to shed light on simulation results by generalizing the self-similar secondary infall model to include tidal torque. In this first of two papers, we describe our halo formation model and compare our results to empirical mass profiles inspired by N-body simulations. Each halo is determined by four parameters. One parameter sets the mass scale and the other three define how particles within a mass shell are torqued throughout evolution. We choose torque parameters motivated by tidal torque theory and N-body simulations and analytically calculate the structure of the halo in different radial regimes. We find that angular momentum plays an important role in determining the density profile at small radii. For cosmological initial conditions, the density profile on small scales is set by the time rate of change of the angular momentum of particles as well as the halo mass. On intermediate scales, however, {rho}{proportional_to}r{sup -2}, while {rho}{proportional_to}r{sup -3} close to the virial radius.

• OSTI ID: 21509938
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 10 Vol. 82; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTRONOMY AND ASTROPHYSICS
ANGULAR MOMENTUM
COMPARATIVE EVALUATIONS
CONFIGURATION
DENSITY
EVALUATION
MASS
MATTER
NONLUMINOUS MATTER
PHYSICAL PROPERTIES
SIMULATION
SPHERICAL CONFIGURATION
TORQUE