Decoding the IRX-β dust attenuation relation in star-forming galaxies at intermediate redshift

Abstract

We aim to understand what drives the IRX-βdust attenuation relation at intermediate redshift (0.5 < z < 0.8) in star-forming galaxies. We investigate the role of various galaxy properties in shaping this observed relation. We use robust [O ii] λ3727, [O iii] λλ4959, 5007, and Hβline detections of our statistical sample of 1049 galaxies to estimate the gas-phase metallicities. We derive key physical properties that are necessary to study galaxy evolution, such as the stellar masses and the star formation rates, using the spectral energy distribution fitting tool CIGALE. Equivalently, we study the effect of galaxy morphology (mainly the Sérsic index n and galaxy inclination) on the observed IRX-βscatter. We also investigate the role of the environment in shaping dust attenuation in our sample. We find a strong correlation of the IRX-βrelation on gas-phase metallicity in our sample, and also strong correlation with galaxy compactness characterized by the Sérsic indexes. Correlations are also seen with stellar masses, specific star formation rates and the stellar ages of our sources. Metallicity strongly correlates with the IRX-βscatter, this also results from the older stars and higher masses at higher beta values. Galaxies with higher metallicities show higher IRX and higher beta values. The correlation with specific dust mass strongly shifts the galaxies away from the IRX-βrelation towards lower \b{eta} values. We find that more compact galaxies witness a larger amount of attenuation than less compact galaxies. There is a subtle variation in the dust attenuation scatter between edge-on and face-on galaxies, but the difference is not statistically significant. Galaxy environments do not significantly affect dust attenuation in our sample of star-forming galaxies at intermediate redshift.

14 pages, 13 figures, accepted for publication in A&A