Sérsic Galaxy with Sérsic Halo Models of Earlytype Galaxies: A Tool for Nbody Simulations
Abstract
We present spherical, nonrotating, isotropic models of earlytype galaxies with stellar and darkmatter components both described by deprojected Sérsic density profiles and prove that they represent physically admissible stable systems. Using empirical correlations and recent results of Nbody simulations, all the free parameters of the models are expressed as functions of one single quantity: the total (Bband) luminosity of the stellar component. We analyze how to perform discrete Nbody realizations of Sérsic models. To this end, an optimal smoothing length is derived, defined as the softening parameter minimizing the error on the gravitational potential for the deprojected Sérsic model. It is shown to depend on the Sérsic index n and on the number of particles of the Nbody realization. A software code allowing the computations of the relevant quantities of one and twocomponent Sérsic models is provided. Both the code and the results of the present work are primarily intended as tools to perform Nbody simulations of earlytype galaxies, where the structural nonhomology of these systems (i.e., the variation of the shape parameter along the galaxy sequence) might be taken into account.
 Publication:

Publications of the Astronomical Society of the Pacific
 Pub Date:
 May 2009
 DOI:
 10.1086/599288
 arXiv:
 arXiv:0903.4758
 Bibcode:
 2009PASP..121..437C
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Instrumentation and Methods for Astrophysics
 EPrint:
 14 pages, 9 figures, 1 table, accepted for publication in PASP