Lopsidedness in WHISP galaxies

TL;DR

This paper presents a statistical analysis of lopsidedness in 76 HI disc galaxies from the WHISP survey, using Fourier analysis to quantify asymmetries and explore their dependence on galaxy type and environment.

Contribution

It is the first large-scale statistical study quantifying morphological lopsidedness in HI discs and analyzing its radial variation and environmental dependence.

Findings

Lopsidedness varies with galaxy type and environment.

Fourier analysis effectively quantifies asymmetry in HI discs.

Radial dependence of asymmetry is characterized.

Abstract

Observations of the stellar and gaseous components in disc galaxies often reveal asymmetries in the morphological and kinematic distribution. However, the origin of this effect is not well known to date, and quantitative studies are rare. Here, we present the first statistical investigation of a sample of 76 HI discs using the WHISP survey. We perform a Fourier analysis to study the morphological lopsidedness. This allows to trace the degree of asymmetry with radius. We further investigate the dependence on, e.g., the morphological type and the environment.