A deeper look at the dust attenuation law of star-forming galaxies at high redshift. Issue 2 (8th July 2019)

• Record Type: Journal Article
• Authors: Tress, M; Ferreras, I; Pérez-González, P G; Bressan, A; Barro, G; Domínguez-Sánchez, H; Eliche-Moral, C
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 488:Issue 2(2019)
• Page Start: 2301
• Page End: 2311
• Publication Date: 2019-07-08
• Subjects: dust, extinction -- galaxies: ISM -- galaxies: stellar content; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz1851
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: A diverse range of dust attenuation laws is found in star-forming galaxies. In particular, Tress et al. (2018 ) studied the SHARDS survey to constrain the NUV bump strength ( B ) and the total-to-selective ratio ( RV ) of 1753 star-forming galaxies in the GOODS-N field at 1.5 < z < 3. We revisit here this sample to assess the implications and possible causes of the correlation found between RV and B . The UVJ bicolour plot and main sequence of star formation are scrutinized to look for clues into the observed trend. The standard boundary between quiescent and star-forming galaxies is preserved when taking into account the wide range of attenuation parameters. However, an additional degeneracy – regarding the effective attenuation law – is added to the standard loci of star-forming galaxies in the UVJ diagram. A simple phenomenological model with an age-dependent extinction (at fixed dust composition) is compatible with the observed trend between RV and B, whereby the opacity decreases with the age of the populations, resulting in a weaker NUV bump when the overall attenuation is shallower (greyer). In addition, we compare the constraints obtained by the SHARDS sample with dust models from the literature, supporting a scenario where geometry could potentially drive the correlation between RV and B .