Formation and evolution of S0 galaxies: a SAURON case study of NGC 7332

• DOI: 10.1111/j.1365-2966.2004.07704.x
• Publication Date: 2004-04-21T14:06:25Z
• Authors: Jesús Falcón-Barroso; Reynier F. Peletier; Eric Emsellem; Harald Kuntschner; Kambiz Fathi; Martin Bureau; Roland Bacon; Michele Cappellari; Yannick Copin; Roger L. Davies; Tim de Zeeuw
• Keywords: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; Astrophysics (astro-ph); 0103 physical sciences; FOS: Physical sciences; Astrophysics; 530; 01 natural sciences; 520

We present SAURON integral-field observations of the S0 galaxy NGC7332. Existing broad-band ground-based and HST photometry reveals a double disk structure and a boxy bulge interpreted as a bar viewed close to edge-on. The SAURON two-dimensional stellar kinematic maps confirm the existence of the bar and inner disk but also uncover the presence of a cold counter-rotating stellar component within the central 250 pc. The Hbeta and [OIII] emission line maps show that the ionised gas has a complex morphology and kinematics, including both a component counter-rotating with respect to the stars and a fainter co-rotating one. Analysis of the absorption line-strength maps show that NGC7332 is young everywhere. The presence of a large-scale bar can explain most of those properties, but the fact that we see a significant amount of unsettled gas, together with a few peculiar features in the maps, suggest that NGC7332 is still evolving. Interactions as well as bar-driven processes must thus have played an important role in the formation and evolution of NGC7332, and presumably of S0 galaxies in general.<br/>12 pages, 12 figures, accepted for publication in MNRAS<br/>