Using 3D Spectroscopy to Probe the Orbital Structure of Composite Bulges

Peter Erwin, Roberto Saglia, Jens Thomas, Maximilian Fabricius, Ralf Bender, Stephanie Rusli, Nina Nowak, John E. Beckman, Juan Carlos Vega Beltrán

Published 2014-09-28Version 1

Detailed imaging and spectroscopic analysis of the centers of nearby S0 and spiral galaxies shows the existence of "composite bulges", where both classical bulges and disky pseudobulges coexist in the same galaxy. As part of a search for supermassive black holes in nearby galaxy nuclei, we obtained VLT-SINFONI observations in adaptive-optics mode of several of these galaxies. Schwarzschild dynamical modeling enables us to disentangle the stellar orbital structure of the different central components, and to distinguish the differing contributions of kinematically hot (classical bulge) and kinematically cool (pseudobulge) components in the same galaxy.