The Fundamental Plane for early-type galaxies. Dependence on the magnitude range

TL;DR

This study investigates how the Fundamental Plane relations for early-type galaxies vary with the magnitude range, revealing that galaxy distribution in key parameters depends on luminosity, affecting the plane's coefficients and dispersion.

Contribution

It demonstrates the dependence of Fundamental Plane coefficients and dispersion on the magnitude range, highlighting luminosity's role in galaxy parameter distribution.

Findings

Coefficients of the Fundamental Plane depend on magnitude range.

Intrinsic dispersion varies with the width of the magnitude interval.

Galaxy distribution in parameter space depends on luminosity.

Abstract

Studying 3 samples of early-type galaxies, which include approximately 8800 galaxies and cover a relatively ample magnitude range ($<\Delta M>$ $\sim 5$ $mag$), we find that the coefficients as well as the intrinsic dispersion of the Fundamental Plane depend on the width of the magnitude range within which the galaxies are distributed. We analyse this dependence and the results show that it could be due to the fact that the distribution of galaxies in the space defined by the variables $\log (r_{e}), <\mu>_{e}, \log(\sigma)$ depends on the luminosity.