Characterising “Box/Peanut” Galactic Bulges

Abstract

Owing to the inability of standard fitting functions to fully account for the observed 2D luminosity distributions within the non—thin disc regions of galaxies displaying “box” or “peanut” bulge morphology (Shaw et al.,in preparation), we have sought to identify which of a range of readily measurable photometric parameters best describe these isophotal shapes. Principal component analyses (PCA’s) have been undertaken with a view to identi-fying the minimal range of observational parameters required to fully describe this morphology, and thereby to define the optimal constraints to be placed on theoretical simulations of such systems.