Galaxy formation and evolution

Abstract:

We present the results of deep VLT-ISAAC Ks-band imaging of four z∼1.5 flat-spectrum quasars selected from the Parkes half-Jansky flat spectrum sample. We find that the hosts of these flat-spectrum quasars are consistent with lying on the K-z Hubble relation for radio galaxies. This implies that the flat-spectrum quasar hosts fall in line with the expectations from orientation based unified schemes and also that they contain black holes of similar mass. Moreover, the width of the Hβ broad emission line in these objects tends to be narrower than in their misaligned (low-frequency selected quasar) counterparts, implying that the width of the Hβ broad emission line depends on source inclination, at least for radio-loud quasars, in line with previous studies. © 2003 Elsevier B.V. All rights reserved.

Abstract:

We have measured the two-dimensional kinematics and line-strength distributions of 72 representative nearby early-type galaxies, out to approximately one effective radius, with our panoramic integral-field spectrograph SAURON. The resulting maps reveal a rich variety in kinematical structures and linestrength distributions, indicating that early-type galaxies are more complex systems than often assumed. We are building detailed dynamical models for these galaxies, to derive their intrinsic shape and dynamical structure, and to determine the mass of the supermassive central black hole. Here we focus on two examples, the compact elliptical M32 and the E3 galaxy NGC4365. These objects represent two extreme cases: M32 has very regular kinematics which can be represented accurately by an axisymmetric model in which all stars rotate around the short axis, while NGC4365 is a triaxial galaxy with a prominent kinematically decoupled core, with an inner core that rotates about an axis that is nearly perpendicular to the rotation axis of the main body of the galaxy. Our dynamical models for these objects demonstrate that two-dimensional observations are essential for deriving the intrinsic orbital structure and dark matter content of galaxies.