Dr. Antonio Marin-Franch
UF

University of Florida Astronomy Colloquium - Oct 26th, 2005

Surface-Brightness Fluctuations in Stellar Populations: IAC-Star Models for the Optical and Near-IR Wavelengths

In the surface photometry of a galaxy far enough to remain unresolved, a pixel-to-pixel fluctuation is observed due to the Poisson statistics of the spatial distribution of the stars. These Surface-Brightness Fluctuations (SBF) are an intrinsic property of the observed unresolved stellar population, so they can be used to study some characteristics of the target galaxy, such as its age and metallicity. Several attempts have been done to compute SBF magnitudes using population synthesis. In this colloquium I will present a new SBF theoretical calibration for unresolved stellar populations based on both the Padua (Bertelli et al., 1994; Girardi et al. , 2000) and the Teramo (Pietrinferni et al. , 2004) stellar evolution libraries. As a result, it is shown that SBF studies provide a very powerful tool to study ages and metallicities of unresolved stellar populations.