Since this is a review, conclusions will be short. Already in the early 1980s, a continuum between bright ellipticals, low-luminosity ellipticals, and bright bulges had been demonstrated (Davies et al. 1983). Now, a continuity in the structural and kinematic properties of bright bulges (generally early and R1/4-like) and faint bulges (generally late and exponential-like) also emerges (e.g. Andredakis et al. 1995). A link between faint bulges and disks is even suggested and is the subject of much work (Kormendy 1993, these proceedings). All the observations discussed in this paper concern nearby galaxies, where the internal structure, kinematics, and dynamics can be studied in detail. This shows that so-called near-field cosmology has an essential (and perhaps dominant) role to play in our quest to understand galaxy formation and evolution.
Although it is impossible to be exhaustive, it is essential to discuss current instrumental developments, since they will lead without doubt to the next discoveries. The usual bells and whistles associated with “weather” prediction are however necessary. On nuclear scales, we are unlikely to make great advances from space until the advent of NGST (e.g. Stockman & Mather 2000). HST/ACS does not increase HST’s spatial resolution, and HST/STIS will not be upgraded or replaced, offering few new possibilities for high spatial resolution kinematics. Adaptive optics on large ground-based telescope, particularly in the near-infrared and/or with integral-field spectrographs (IFSs), is very promising (e.g. VLT/SINFONI; Mengel et al. 2000). On intermediate scales, WHT/SAURON has already demonstrated the possibilities of wide-field IFSs, especially when supplemented with data on nuclear scales and proper modeling tools (Fig. 6; de Zeeuw et al. 2002). VLT/VIMOS and other similar instruments will increase this power. On large scales, WHT/PNS will provide much needed data on stellar kinematics in the outskirts of galaxies (using PN as tracers; see Douglas & Taylor 1999), constraining the amount of dark matter present. Astrometric missions such as ESA/GAIA (e.g. Perryman et al. 2001), acting on all scales, will provide the position, colors, type, and radial velocity for a billion stars in the Galaxy (a large fraction with accurate proper motions and parallax). This will revolutionize our view of spirals, providing us with a stereoscopic and kinematic census of the stellar populations. Near-field cosmology at its best!
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Figure 6. SAURON stellar kinematics of the SB0 galaxy NGC3384. Left: Reconstructed intensity map. Center: Velocity. Right: Velocity dispersion. Not shown are the Gauss-Hermite moments h3 and h4 (skewness and kurtosis of the velocity profiles), and the line-strength indices Hβ, Mgb, Fe5015, and Fe5270 (stellar populations). The data clearly reveal a confined, cold kinematic component inside the bulge. Reproduced with permission from de Zeeuw et al. (2002). |
Acknowledgments. Support for this work was provided by NASA through Hubble Fellowship grant HST-HF-01136.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. All figures reproduced by permission of the American Astronomical Society and Blackwell Publishing.