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arXiv · 1707.09805

Characterizing the UV-to-NIR shape of the dust attenuation curve of IR luminous galaxies up to z$\sim$2

B. Lo Faro·V. Buat·Y. Roehlly·J. Álvarez-Márquez·D. Burgarella·L. Silva·A. Efstathiou
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Abstract

In this work we investigate the far-UV to NIR shape of the dust attenuation curve of a sample of IR selected dust obscured (U)LIRGs at z$\sim$2. The spectral energy distributions (SEDs) are fitted with CIGALE, a physically-motivated spectral synthesis model based on energy balance. Its flexibility allows us to test a wide range of different analytical prescriptions for the dust attenuation curve, including the well-known Calzetti and Charlot & Fall curves, and modified versions of them. The attenuation curves computed under the assumption of our reference double power-law model are in very good agreement with those derived, in previous works, with radiative transfer (RT) SED fitting. We investigate the position of our galaxies in the IRX-$\beta$ diagram and find this to be consistent with grayer slopes, on average, in the UV. We also find evidence for a flattening of the attenuation curve in the NIR with respect to more classical Calzetti-like recipes. This larger NIR attenuation yields larger derived stellar masses from SED fitting, by a median factor of $\sim$ 1.4 and up to a factor $\sim$10 for the most extreme cases. The star formation rate appears instead to be more dependent on the total amount of attenuation in the galaxy. Our analysis highlights the need for a flexible attenuation curve when reproducing the physical properties of a large variety of objects.

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B. Lo Faro, V. Buat, Y. Roehlly, J. Álvarez-Márquez, D. Burgarella, L. Silva, A. Efstathiou. 2017-07-31. Characterizing the UV-to-NIR shape of the dust attenuation curve of IR luminous galaxies up to z$\sim$2. https://doi.org/10.1093/mnras/stx1901

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