Presentation 1 : Oral
Structure and Kinematics of Early-Type Galaxies: The SAURON Project
R. Bacon and the SAURON consortium
We present the SAURON project, which is aimed at studying the
morphology, two-dimensional kinematics and stellar populations of a
representative sample of elliptical galaxies and spiral bulges.
SAURON, a dedicated integral-field spectrograph that is optimized for
wide-field observations and has high throughput, was built in Lyon and is now operated at the WHT 4.2m telescope. At present, we have observed
approximately two thirds of the seventy-two sample galaxies with
SAURON. A comparison with published long-slit measurements
demonstrates that the SAURON-data is of equal or better quality,
and provides full two-dimensional coverage. The velocity and velocity
dispersion fields exhibit a large variety of morphologies: from simple
rotating systems to cylindrical, disky and triaxial velocity fields,
bars and decoupled cores. Most of these kinematical signatures do not
have counterparts in the light distribution. While some
galaxies are consistent with axisymmetry, most are more complex
systems than assumed previously. This suggests that the kinematical
properties of nearby E/S0 galaxies do not agree with the often assumed
simplistic two-family model, in which the giant non-rotating triaxial
ellipticals are opposed to the fast-rotating axisymmetric faint
ellipticals and S0s.