K-band versus I-band surface brightness fluctuations as distance indicators

We evaluate the method of optical and infrared Surface Brightness Fluctuati ons (SBF) as a distance indicator and its application on 8-m class telescop es, such as the Very Large Telescope (VLT). The novelty of our approach res ides in the development of Monte Carlo simulations of SBF observations inco rporating realistic elliptical galaxy stellar population models, the effect s induced by globular clusters and background galaxies, instrumental noise, sky background and PSF blurring. We discuss, for each band and in differen t observational conditions, the errors on distance measurements arising fro m stellar population effects, data treatment and observational constraints. With 8-m class telescopes, one can extend I-band SBF measurements out to 6 000-10 000 km s(-1). Integration times in the K-band are too expensive from the ground, due to the high infrared background for large-scale distance d etermination projects. Nevertheless ground-based K-band measurements are ne cessary to understand stellar population effects on the SBF calibration, an d to prepare future space{based observations, where this band is more effic ient.