Michele Cappellari

Abstract:

By incorporating spatial coverage with the spectral dimension, integral-field spectroscopy is uniquely suited for exploiting the capabilities of adaptive optics (AO) systems. OASIS is a lenslet-based integral-field spectrograph designed to perform high-resolution observations on AO-corrected sources, operating at visible wavelengths. This instrument was commissioned at the William Herschel Telescope, La Palma, in July 2003 to work with the ING's AO system, NAOMI. Here we present an overview of the capabilities of the OASIS+NAOMI system, and show results obtained using this technique. The science presented here is a small preview of what will be possible for a large number of objects when the GLAS laser guide system is operational.

Abstract:

We present a summary of high-spatial resolution follow-up observations of the elliptical (E) and lenticular (SO) galaxies in the SAURON survey using the OASIS integral field spectrograph. The OASIS observations explore the central 8" x 10" regions of these galaxies using a spatial sampling four times higher than SAURON, often revealing previously undiscovered features. Around 75% (31/48) of the SAURON E/SOs with central velocity dispersion greater than or similar to 120 kin s(-1) were observed with OASIS, covering well the original SAURON representative sample. We present here an overview of this follow-up survey, and some preliminary results on individual objects, including a previously unreported counter-rotating core in NGC4382; the decoupled stellar and gas velocity fields of NGC 2768; and the strong age gradient towards the centre of NGC 3489.

Abstract:

We have developed a method to construct realistic triaxial dynamical models for elliptical galaxies, allowing us to derive best-fitting parameters, such as the mass-to-light ratio and the black hole mass, and to study the orbital structure. We use triaxial theoretical Abel models to investigate the robustness of the method.