Molecular gas properties of UV-luminous star-forming galaxies at low redshift

TL;DR

This study investigates the molecular gas properties of UV-luminous star-forming galaxies at low redshift, revealing their high gas fractions and rapid depletion times, making them comparable to high-redshift galaxies and useful for ISM studies.

Contribution

First detailed CO(1-0) survey of LBAs showing their molecular gas properties and similarities to high-redshift star-forming galaxies.

Findings

LBAs follow the Schmidt-Kennicutt law.

They have high gas fractions up to 66%.

Gas depletion times are below 1 Gyr.

Abstract

Lyman break analogues (LBAs) are a population of star-forming galaxies at low redshift (z ~ 0.2) selected in the ultraviolet (UV). These objects present higher star formation rates and lower dust extinction than other galaxies with similar masses and luminosities in the local universe. In this work we present results from a survey with the Combined Array for Research in Millimetre-wave Astronomy (CARMA) to detect CO(1-0) emission in LBAs, in order to analyse the properties of the molecular gas in these galaxies. Our results show that LBAs follow the same Schmidt-Kennicutt law as local galaxies. On the other hand, they have higher gas fractions (up to 66%) and faster gas depletion time-scales (below 1 Gyr). These characteristics render these objects more akin to high-redshift star-forming galaxies. We conclude that LBAs are a great nearby laboratory for studying the cold interstellar medium in low-metallicity, UV-luminous compact star-forming galaxies.