91̽»¨

Abstract:

We present a flexible and efficient method to construct triaxial dynamical models of galaxies with a central black hole, using Schwarzschild's orbital superposition approach. Our method is general and can deal with realistic luminosity distributions, which project to surface brightness distributions that may show position angle twists and ellipticity variations. The models are fit to measurements of the full line-of-sight velocity distribution (wherever available). We verify that our method is able to reproduce theoretical predictions of a three-integral triaxial Abel model. In a companion paper by Ven, de Zeeuw & van den Bosch, we demonstrate that the method recovers the phase-space distribution function. We apply our method to two-dimensional observations of the E3 galaxy NGC 4365, obtained with the integral-field spectrograph SAURON, and study its internal structure, showing that the observed kinematically decoupled core is not physically distinct from the main body and the inner region is close to oblate axisymmetric. © 2008 RAS.

Abstract:

Motivated by recent progress in the study of early-type galaxies owing to technological advances, the launch of new space telescopes, and large ground-based surveys, we attempt a short review of our current understanding of the recent star formation activity in such intriguing galactic systems.

Abstract:

A deep H I survey of nearby early-type galaxies carried out with the Westerbork Radio Synthesis telescope has shown that, contrary to expectation, neutral hydrogen is a significant constituent of the ISM in this type of objects located in low density environment. The studied galaxies are part of a representative sample of nearby E and SO for which integral-field spectroscopy using the SAURON spectrograph is available. We present preliminary results on the comparison of the characteristics of the H I with those of the molecular and ionised gas as well as the stellar dynamics and population.