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

Abstract

We use a sample of 706 galaxies, selected as [O II]λ3727 ([O II]) 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 log<SUB>10</SUB>(M<SUB>*</SUB>/M<SUB>⊙</SUB>) > 9, over the redshift interval 0.3 ≲ z ≲ 1.5. Our methodology consists in the comparison of the star formation rates inferred from [O II] and Hα emission lines with a robust quantification of the total star-forming activity (SFR <SUB>TOT</SUB>) that is independently estimated based on both infrared and ultraviolet (UV) luminosities. We obtain $f\, =\, E(B-V)_{\mathrm{stellar}}$/E(B - V)<SUB>nebular</SUB> = 0.69$^{0.71}_{0.69}$ and 0.55$^{0.56}_{0.53}$ for [O II] and Hα, 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<SUB>TOT</SUB>, 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.