We present the results of an optical imaging survey of 73 luminous early-type galaxies directed to study the properties of their interstellar medium. We have found that a large fraction of E (72%) and S0 (85%) galaxies in our sample contain a measurable amount of ionized gas. The gas morphology appears to be rather smooth; however 12% of the sample

Not Available

We present a detailed stellar population analysis for a sample of 24 early-type galaxies (ETGs) belonging to the rich cluster RX J0152.7-1357 at z = 0.83. We have derived the age, metallicity, abundance pattern, and star formation history (SFH) for each galaxy individually to further characterize this intermediate-z reference cluster. We then study

We present a kinematical study of the optical ejecta of GK Per. It is based on proper-motion measurements of 282 knots from ~20 images spanning 25 years. Doppler shifts are also computed for 217 knots. The combination of proper motions and radial velocities allows a unique three-dimensional view of the ejecta to be obtained. The main results are as

Optical and radio data from the 1989 minimum are analyzed to examine the implications of the light curves for the spectrum. The optical spectrum increases between maximum and minimum with a sharp peak in the continuum, and a normal shape is noted at the minimum. The data are suggestive of a self-absorbed synchrotron component in the accretion disk

We analyse age-velocity dispersion relations (AVRs) from kinematics of individual stars in eight Local Group galaxies ranging in mass from Carina (M* ˜ 106 M⊙) to M31 (M* ˜ 1011 M⊙). Observationally the σ versus stellar age trends can be interpreted as dynamical heating of the stars by giant molecular clouds, bars/spiral arms or merging subhaloes