Cosmological Simulations of Elliptical Galaxy Formation in LCDM and LWDM Cosmologies

Abstract

We present the results of a series of gas dynamical cosmological simulations of the formation of individual massive field galaxies in the standard concordance \LCDM and in a \LWDM cosmology. The galaxies form in an initial burst of star formation followed by accretion of small satellites. The simulated galaxies are old ($\approx$ 10 $Gyrs$) hot stellar systems with masses of $\approx 1.7 \times 10^{11} M_{\odot}$. Baryonic matter dominates the mass in the luminous part of the galaxies up to $\approx 5$ effective radii. The \LCDM galaxy is a slowly rotating spheroidal stellar system (E2) with predominantly disky isophotes. The line-of-sight velocity distributions deviate from Gaussian shape and $h_3$ is anticorrelated with $v_{los}$. The corresponding \LWDM galaxy is more elongated (E3 - E4) and rotates faster. The anisotropy parameter $(v/σ)^*$ is close to unity. Within the uncertainties of $M/L$ both galaxies follow the Fundamental Plane. We conclude that the properties of the two galaxies simulated in the \LCDM and \LWDM cosmology are in good agreement with observations of intermediate mass elliptical or S0 galaxies (abstract abbreviated).