Differential attenuation in star-forming galaxies at 0.3 $\lesssim$ $z$ $\lesssim$ 1.5 in the SHARDS/CANDELS field

TL;DR

This study investigates how dust affects nebular emission differently from stellar light in galaxies at redshifts 0.3 to 1.5, revealing a correlation with UV attenuation and supporting a dust attenuation curve similar to local starbursts.

Contribution

It provides new measurements of differential dust attenuation factors in intermediate-redshift galaxies using a large, infrared-selected sample.

Findings

The nebular to stellar color excess ratio is approximately 0.55 to 0.69.

The differential attenuation correlates with UV attenuation but not strongly with stellar mass or SFR.

Results support a dust attenuation curve similar to local starburst galaxies.

Abstract

We use a sample of 706 galaxies, selected as [OII]$\lambda$3727 ([OII]) emitters in the Survey for High-$z$ Absorption Red and Dead Sources (SHARDS) on the CANDELS/GOODS-N field, to study the differential attenuation of the nebular emission with respect to the stellar continuum. The sample includes only galaxies with a counterpart in the infrared and $\mathrm{log}_{10}(M_{*}/\mathrm{M}_{\odot})$ $>$ 9, over the redshift interval 0.3 $\lesssim$ $z$ $\lesssim$ 1.5. Our methodology consists in the comparison of the star formation rates inferred from [OII] and H$\alpha$ emission lines with a robust quantification of the total star-forming activity (${SFR}_{\mathrm{TOT}}$) that is independently estimated based on both infrared and ultraviolet (UV) luminosities. We obtain $f$$=$$E(B-V)_{\mathrm{stellar}}$/$E(B-V)_{\mathrm{nebular}}$ $=$ 0.69$^{0.71}_{0.69}$ and 0.55$^{0.56}_{0.53}$ for [OII] and H$\alpha$, respectively. Our resulting $f$-factors display a significant positive correlation with the UV attenuation and shallower or not-significant trends with the stellar mass, the $SFR_{\mathrm{TOT}}$, the distance to the main sequence, and the redshift. Finally, our results favour an average nebular attenuation curve similar in shape to the typical dust curve of local starbursts.