Morphometry as a probe of the evolution of jellyfish galaxies

TL;DR

This study uses morphometric analysis of Hubble images to identify and characterize jellyfish galaxies undergoing ram pressure stripping, revealing distinctive surface brightness features and trail vectors that indicate structural evolution.

Contribution

It introduces a novel morphometry-based method using extsc{morfometryka} to determine trail vectors and analyze galaxy morphology for ram pressure stripping detection.

Findings

Ram pressure stripping candidates show concave surface brightness profiles.

These galaxies have lower Sersic indices than typical star-forming galaxies.

Morphometric trail vectors can help identify and study ram pressure effects.

Abstract

We explore the morphometric properties of a group of 73 ram pressure stripping candidates in the A901/A902 multi-cluster system, at z$\sim$0.165, to characterise the morphologies and structural evolution of jellyfish galaxies. By employing a quantitative measurement of morphometric indicators with the algorithm \textsc{morfometryka} on Hubble Space Telescope (F606W) images of the galaxies, we present a novel morphology-based method for determining trail vectors. We study the surface brightness profiles and curvature of the candidates and compare the results obtained with two analysis packages, \textsc{morfometryka} and \textsc{iraf/ellipse} on retrieving information of the irregular structures present in the galaxies. Our morphometric analysis shows that the ram pressure stripping candidates have peculiar concave regions in their surface brightness profiles. Therefore, these profiles are less concentrated (lower S\'ersic indices) than other star forming galaxies that do not show morphological features of ram pressure stripping. In combination with morphometric trail vectors, this feature could both help identify galaxies undergoing ram-pressure stripping and reveal spatial variations in the star formation rate.