Michele Cappellari

Abstract:

The panoramic integral-field spectrograph SAURON is currently being used to map the stellar kinematics, gaseous kinematics, and stellar populations of a large number of early-type galaxies and bulges. Here, we describe SAURON observations of cold stellar disks embedded in spheroids (NGC 3384, NGC 4459, NGC 4526), we illustrate the kinematics and ionization state of large-scale gaseous disks (NGC 4278, NGC 7742), and we show preliminary comparisons of SAURON data with barred galaxy N-body simulations (NGC 3623).

Abstract:

A summary of the SAURON project and its current status is presented. SAURON is a panoramic integral-field spectrograph designed to study the stellar kinematics, gaseous kinematics, and stellar populations of spheroids. Here, the sample of galaxies and its properties axe described. The instrument is detailed and its capabilities illustrated through observational examples. These includes results on the structure of central stellar disks, the kinematics and ionization state of gaseous disks, and the stellar populations of galaxies with decoupled cores.

Abstract:

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 observations and has high throughput, was built in Lyon and is now operated at the WHT 4.2m telescope. At present, we have ob served approximately two thirds of the seventy-two sample galaxies with SAURON. A comparison with published long-slit measurements demonstrates that the SAURON-data are 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.