Dust attenuation in z ~ 1 galaxies from Herschel and 3D-HST Hα measurements

Journal
Date Issued
2016
Author(s)
•
Rodighiero, G.
•
Franceschini, A.
•
Talia, M.
•
Cimatti, A.
•
Baronchelli, I.
•
Daddi, E.
•
Renzini, A.
•
Schawinski, K.
•
Mancini, C.
•
Silverman, J.
•
•
Lutz, D.
•
Berta, S.
•
Oliver, S. J.
DOI
Abstract
We combined the spectroscopic information from the 3D-HST survey with Herschel data to characterize the Hα dust attenuation properties of a sample of 79 main sequence star-forming galaxies at z ~ 1 in the GOODS-S field. The sample was selected in the far-IR at λ = 100 and/or 160 μm and only includes galaxies with a secure Hα detection (S/N > 3). From the low resolution 3D-HST spectra we measured the redshifts and the Hα fluxes for the whole sample. (A factor of 1/1.2 was applied to the observed fluxes to remove the [NII] contamination.) The stellar masses (M⋆), infrared (LIR), and UV luminosities (LUV) were derived from the spectral energy distributions by fitting multiband data from GALEX near-UV to SPIRE 500 μm. We estimated the continuum extinction Estar(B-V) from both the IRX = LIR/LUV ratio and the UV-slope, β, and found excellent agreement between the two. The nebular extinction was estimated from comparison of the observed SFRHα and SFRUV. We obtained f = Estar(B-V) /Eneb(B-V) = 0.93 ± 0.06, which is higher than the canonical value of f = 0.44 measured in the local Universe. Our derived dust correction produces good agreement between the Hα and IR+UV SFRs for galaxies with SFR ≳ 20M☉/yr and M⋆ ≳ 5 × 1010M☉, while objects with lower SFR and M⋆ seem to require a smaller f-factor (I.e. higher Hα extinction correction). Our results then imply that the nebular extinction for our sample is comparable to extinction in the optical-UV continuum and suggest that the f-factor is a function of both M⋆ and SFR, in agreement with previous studies.
Volume
586
Start page
A83
Uri
Url
Issn Identifier
0004-6361
Ads BibCode
2016A&A...586A..83P
Rights
open.access
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