Star Formation and Gas Accretion in Nearby Galaxies

TL;DR

This study examines how gas accretion influences star formation in nearby galaxies by comparing radial profiles of star formation indicators with gas content, finding a consistent relationship regardless of accretion evidence.

Contribution

It provides a comparative analysis of star formation and gas content in galaxies with different accretion and interaction states, highlighting the universality of the gas-star formation relationship.

Findings

Gas surface density correlates with star formation surface density.

No significant difference in star formation efficiency among galaxy groups.

Outer disc star formation linked to HI content across groups.

Abstract

In order to quantify the relationship between gas accretion and star formation, we analyse a sample of 29 nearby galaxies from the WHISP survey which contains galaxies with and without evidence for recent gas accretion. We compare combined radial profiles of FUV (GALEX) and IR 24 {\mu}m (Spitzer) characterizing distributions of recent star formation with radial profiles of CO (IRAM, BIMA, or CARMA) and HI (WSRT) tracing molecular and atomic gas contents to examine star formation efficiencies in symmetric (quiescent), asymmetric (accreting), and interacting (tidally disturbed) galaxies. In addition, we investigate the relationship between star formation rate and HI in the outer discs for the three groups of galaxies. We confirm the general relationship between gas surface density and star formation surface density, but do not find a significant difference between the three groups of galaxies.