Physical morphology and triggers of starburst galaxies

Abstract

We present a method of determining the likely triggering mechanisms for luminous, nearby starbursts based on their optical asymmetry and (B-V) color -- what we term as indices of `physical morphology.' By comparing the starbursts' locations in a color-asymmetry diagram to an independent, nearby galaxy sample, we identify which starbursts are likely triggered by an interaction/merger. We confirm our morphological interpretation based on a comparison to 20% and 50% HI velocity-width ratios. We further explain how this use of physical morphology can put constraints on the dynamical history of other galaxies, including star-forming galaxies at high redshifts.