Cellone, Sergio
Argentina CASLEO (CONICET-UNLP-UNC-UNSJ) & FCAG (UNLP)
Sersic’s Law in dwarf elliptical galaxies: a history more than 30 years long
Driven by the widespread use of CCD detectors starting in the mid eighties of last century, surface photometry of galaxies experimented a noticeable expansion, alongside a significant increase in precision. This allowed, for the first time, detailed studies of low-surface brightness objects, such as dwarf elliptical galaxies (dE). While the surface brightness profiles of luminous elliptical galaxies (E) used to be fit with a de Vaucouleurs law, the Exponential Law was used for dEs, in analogy to stellar disks. It was soon evident that both mathematical expressions gave adequate fits just for particular cases of profiles that, in reality, display a continuous curvature distribution. Sersic’s Law was thus rescued from oblivion, showing its powerful ability to properly quantify different profile curvatures, in a
way that opened the possibility of studying, on a firm basis, the relationships between different structural parameters of early-type galaxies. We present here a brief review of our work with Sersic’s Law and dwarf galaxies along 30 years, including the controversy that arised regarding its usefulness as a distance indicator.