ANALYTICAL DYNAMICAL MODELS FOR DOUBLE POWER-LAW GALACTIC NUCLEI

Authors
Citation
Hs. Zhao, ANALYTICAL DYNAMICAL MODELS FOR DOUBLE POWER-LAW GALACTIC NUCLEI, Monthly Notices of the Royal Astronomical Society, 287(3), 1997, pp. 525-537
Citations number
25
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
00358711
Volume
287
Issue
3
Year of publication
1997
Pages
525 - 537
Database
ISI
SICI code
0035-8711(1997)287:3<525:ADMFDP>2.0.ZU;2-E
Abstract
Motivated by the finding that the observed surface brightness profiles of many galactic nuclei are fitted well by double power laws, we expl ore a range of spherical self-consistent dynamical models with this li ght profile. We, find that the corresponding deprojected volume densit y profile, phase-space density and line-of-sight velocity distribution of these models are fitted well by simple analytic approximations. We illustrate the application of these models by fitting a sample of app roximately 25 galactic nuclei observed by the Hubble Space Telescope ( HST). Without a central black hole and strong anisotropy the models ge nerally predict a negligibly small kurtosis parameter k(4). These mode ls with a simple distribution function are suited to seed N-body simul ations of galactic nuclei with realistic density profiles for studying the evolution of these systems.