LINE-OF-SIGHT VELOCITY DISTRIBUTIONS OF ELLIPTIC GALAXIES

The line-of-sight velocity distributions (LOSVDs) have been measured t o > R(e)/2 along the major axes of 44 elliptical galaxies (more than 8 0 per cent of all ellipticals north of delta = -10-degrees and brighte r than B(T) = 12.0), together with stellar rotational velocity and vel ocity dispersion profiles. For 19 of these 44 objects, minor axis prof iles are also given. Monte Carlo simulations have been used to estimat e errors. LOSVDs are found to deviate from Gaussians by no more than a lmost-equal-to 10 per cent. If rotation is present, LOSVDs are asymmet ric with the prograde wings being always steeper than the retrograde w ings. The degree of asymmetry (measured by the H-3 Gauss-Hermite coeff icient) correlates with upsilon/sigma. Round and boxy ellipticals have lower asymmetries than flat and discy ones. On the whole, both types must have intrinsically asymmetric velocity distributions. Symmetric d eviations (measured by the H-4 Gauss-Hermite coefficient) are generall y smaller than asymmetric ones. On the basis of the observed LOSVD sha pes, the validity of two-integral models can be ruled out for most of the non-discy objects observed here (discy ellipticals require detaile d modelling before similar conclusions can be drawn). Discy elliptical s have H-3 and H-4 major and minor axis profiles which appear consiste nt with a bulge+disc superposition. The observed H-4 profile in M87 ar gues for radially anisotropic spherical or oblate models. Velocity dis persion profiles show significant individuality, but typically become flat outside R(e)/4. Major and minor axis slopes are mostly correlated one to one. We confirm that, with increasing luminosity, ellipticals become more. anisotropic and that discy ellipticals have more rotation al support. The Fundamental Plane of elliptical galaxies is tighter if total kinetic energy is used instead of central velocity dispersion. Both the small scatter about the Fundamental Plane and the homogenous and systematic properties of the LOSVDs imply that only a small range of dynamical models is realized in elliptical galaxies.