The advent of 8 m-class telescopes and of the forthcoming NGST will soon make it possible to trace observationally the evolution of galaxies up to redshifts of cosmological relevance, and therefore allow a direct comparison between model predictions and observations.
Should however adult galaxies retain some memory of their "infancy'', observations carried out at z=0 would provide important constraints on their evolutionary history. For these nearby objects even the present instrumentation is suitable for extending to intrinsically low luminosity galaxies a detailed determination of their "shape'' and "size'' parameters, such as color, morphology, and brightness profile, or luminosity, radius, and mass, respectively (see Whitmore 1984). These parameters are the constituents of the well known scaling relations of local galaxies: the Fundamental Plane for the Ellipticals (Djorgovski & Davis 1987; Dressler et al. 1987), and the Tully-Fisher relation for the Spiral galaxies (Tully & Fisher 1977).
Over the last two decades we have witnessed an extensive effort in studying these properties, limited however mostly to the optical bands. Less systematic efforts were devoted to Near infrared (NIR) investigations, in spite of these being the most suitable ones for studying the properties of galaxies, because most of a galaxy luminous mass sits in the old stellar population traced by NIR light (Gavazzi et al. 1996c), and because of the greatly reduced dust obscuration at these wavelengths. To fully exploit these two advantages we have made extensive use of NIR panoramic detectors to obtain H (and K') band images of nearby galaxies. We first concentrated on disk galaxies (see Gavazzi et al. 1996a, Paper I; Gavazzi et al. 1996b, Paper II; Boselli et al. 2000, Paper IV; Boselli et al. 1997 (B97)), while later we extended the survey to the early-types (Gavazzi et al. 2000a, Paper III). Using these data Gavazzi et al. (2000b, Paper V) studied the structural properties of galaxies that can be derived from surface-photometry measurements at NIR pass-bands: i.e. their light profiles. The observing sample was selected among members of 5 nearby, rich clusters: namely the Virgo, Coma, A1367, A262 and Cancer clusters, in addition to a significant population of galaxies in the "Great Wall'', the bridge between Coma and A1367. The survey included a representative sample of galaxies spanning all morphological types (including Im and BCDs), except early-type dwarfs (dE, dS0) which were severely undersampled because, due to the their low surface brightness at NIR bandpasses, they could not be observed with 2 m class telescopes. Beside our work, early panoramic NIR observations exist for only 15 dwarf elliptical galaxies in the Virgo cluster, as reported by James (1991, 1994).
To fill this gap, we have obtained NIR imaging observations of 50 dwarf elliptical and dwarf S0 galaxies, of 11 dI galaxies and of 11 giant galaxies from the Virgo Cluster Catalogue (hereafter VCC, Binggeli et al. 1985) and from the Centaurus Cluster Catalogue (hereafter CCC, Jerjen & Dressler 1997). From these observations we derive the azimuthally averaged light profiles, that are fitted using either a de Vaucouleurs r1/4 law, an exponential law, a mixed (bulge+disk) model, or an exponentially truncated model. We derive some relevant photometric parameters, namely: the asymptotic total magnitude, the effective radius (within which half of the total galaxy luminosity is enclosed), the effective mean surface brightness, the light concentration index C31, and the bulge to total flux ratio for the two-component models. Moreover, using observations taken in optical bands, we compare light profiles in B, V and H, and present color profiles. Combining the present results with those given in Paper V, we obtain a nearly complete sample, covering all morphological types and spanning 4 decades in luminosity.
The paper is organized as follows: the sample selection criteria are discussed in Sect. 2. The observations and data reduction are described in Sect. 3. The procedures adopted to derive the light profiles and their fitted models are given in Sect. 4. The results of the present work are given in Sect. 5. Some implications of the present analysis on the structural properties of galaxies are discussed in Sect. 6 and summarized in Sect. 7.
Copyright ESO 2001