The Wide Field Planetary Camera 2 of the Hubble Space T elescope has been used to obtain highresolution images of NGC 4038/4039 that go roughly 3 mag deeper in V than previous observations made during cycle 2. These new images allow us to measure the luminosity functions (LFs) of clusters and stars over a range of 8 mag To Ðrst order, the LF is a power law, with expo-. nent a \ [2.12^0.04. However, using a variety of di †erent techniques to decouple the cluster and stellar LFs, which overlap in the range we Ðnd an apparent bend in the young cluster 9^0.1, and is dominated by young red and blue supergiants. The star clusters of the Antennae appear slightly resolved, with median e †ective radii of 4^1 pc, similar to or perhaps slightly larger than those of globular clusters in our Galaxy. However, the radial extents of some of the very young clusters (ages less than 10 Myr) are much larger than those of old globular clusters (e.g., the outer radius of knot S exceeds 450 pc). This may indicate that the tidal forces from the galaxies have not had time to remove some of the outer stars from the young clusters. A combination of the UBV I colors, Ha morphology, and Goddard High Resolution Spectrograph (GHRS) spectra enables us to age date the clusters in different regions of the Antennae. Star clusters around the edge of the dust overlap region appear to be the youngest, with ages Myr, while clusters in the western loop appear to be 5È10 Myr old. Many star [5 clusters in the northeastern star formation region appear to be D100 Myr old, with an LF in V that has shifted faintward by D1.0 mag relative to the younger (0È20 Myr) clusters that dominate over most of the rest of the galaxy. A third cluster population consists of intermediate-age clusters (D500 Myr) that probably formed during the initial encounter responsible for ejecting the tails. A handful of old globular clusters from the progenitor galaxies are also identiÐed. Most of these lie around NGC 4039, where the lower background facilitates their detection. Age estimates derived from GHRS spectroscopy yield 3^1 Myr for knot K (just south of the nucleus of NGC 4038) and 7^1 Myr for knot S in the western loop, in good agreement with ages derived from the UBV I colors. E †ective gas outÑow velocities from knots S and K are estimated to be about 25È30 km s~1, based on the above cluster ages and the sizes of the surrounding Ha bubbles. However, the measured widths of the interstellar absorption lines suggest dispersion velocities of D400 km s~1 along the lines of sight to knots S and K.

We present the stellar kinematics of 48 representative elliptical and lenticular galaxies obtained with our custom-built integral-field spectrograph SAURON operating on the William Herschel Telescope. The data were homogeneously processed through a dedicated reduction and analysis pipeline. All resulting SAURON data cubes were spatially binned to a constant minimum signal-to-noise ratio. We have measured the stellar kinematics with an optimized (penalized pixel-fitting) routine which fits the spectra in pixel space, via the use of optimal templates, and prevents the presence of emission lines to affect the measurements. We have thus generated maps of the mean stellar velocity V, the velocity dispersion σ , and the Gauss-Hermite moments h 3 and h 4 of the line-of-sight velocity distributions. The maps extend to approximately one effective radius. Many objects display kinematic twists, kinematically decoupled components, central stellar discs, and other peculiarities, the nature of which will be discussed in future papers of this series.

A new integral‐field spectrograph, SAURON, is described. It is based on the TIGER principle, and uses a lenslet array. SAURON has a large field of view and high throughput, and allows simultaneous sky subtraction. Its design is optimized for studies of the stellar kinematics, gas kinematics, and line‐strength distributions of nearby early‐type galaxies. The instrument design and specifications are described, as well as the extensive analysis software which was developed to obtain fully calibrated spectra, and the associated kinematic and line‐strength measurements. A companion paper will report on the first results obtained with SAURON on the William Herschel Telescope.

Early results are reported from the SAURON survey of the kinematics and stellar populations of a representative sample of nearby E, S0 and Sa galaxies. The survey is aimed at determining the intrinsic shape of the galaxies, their orbital structure, the mass-tolight ratio as a function of radius, the age and metallicity of the stellar populations, and the frequency of kinematically decoupled cores and nuclear black holes. The construction of the representative sample is described, and its properties are illustrated. A comparison with long-slit spectroscopic data establishes that the SAURON measurements are comparable to, or better than, the highest-quality determinations. Comparisons are presented for NGC 3384 and NGC 4365 where stellar velocities and velocity dispersions are determined to a precision of 6 km s −1 , and the h 3 and h 4 parameters of the lineof-sight velocity distribution to a precision of better than 0.02. Extraction of accurate gas emission-line intensities, velocities and line widths from the datacubes is illustrated for NGC 5813. Comparisons with published line-strengths for NGC 3384 and NGC 5813 reveal uncertainties of ∼ < 0.1Å on the measurements of the Hβ, Mg b and Fe5270 indices. Integral-field mapping uniquely connects measurements of the kinematics and stellar populations to the galaxy morphology. The maps presented here illustrate the rich stellar kinematics, gaseous kinematics, and line-strength distributions of early-type galaxies. The results include the discovery of a thin, edge-on, disk in NGC 3623, confirm the axisymmetric shape of the central region of M32, illustrate the LINER nucleus and surrounding counter-rotating star-forming ring in NGC 7742, and suggest a uniform stellar population in the decoupled core galaxy NGC 5813.

We present the results of a Hubble Space Telescope WFPC2 F555W and F814W survey of 69 dwarf elliptical galaxies (dEs) in the Virgo and Fornax Clusters and Leo Group. The V − I colors of the dE globular clusters, nuclei, and underlying field star populations are used to trace the dE star-formation histories. We find that the dE globular cluster candidates are as blue as the metal-poor globular clusters of the Milky Way. The observed correlation of the dE globular cluster systems' V − I color with the luminosity of the host dE is strong evidence that the globular clusters were formed within the the halos of dEs and do not have a pre-galactic origin. Assuming the majority of dE clusters are old, the mean globular cluster color-host galaxy luminosity correlation implies a cluster metallicity − galaxy luminosity relation of Z GC ∝ L 0.22±0.05 B, which is significantly shallower than the field star metallicity -host galaxy luminosity relationship observed in Local Group dwarfs ( Z F S ∝ L 0.4 ). The dE stellar envelopes are 0.1 − 0.2 magnitudes redder in V − I than their globular clusters and nuclei. This color offset implies separate star-formation episodes within the dEs for the clusters and field stars, while the very blue colors of two dE nuclei trace a third star-formation event in those dEs less than a Gyr ago.