Original language | English |
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Journal | Monthly Notices of the Royal Astronomical Society |
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DOIs | |
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Publication status | Published - 22 Feb 2018 |
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We present the results of a new study of dust attenuation at redshifts 3
<z <4 based on a sample of 236 star-forming galaxies from the
VANDELS spectroscopic survey. Motivated by results from the First
Billion Years (FiBY) simulation project, we argue that the intrinsic
spectral energy distributions (SEDs) of star-forming galaxies at these
redshifts have a self-similar shape across the mass range 8.2 ≤
log(M⋆/M⊙) ≤ 10.6 probed by our
sample. Using FiBY data, we construct a set of intrinsic SED templates
which incorporate both detailed star formation and chemical abundance
histories, and a variety of stellar population synthesis (SPS) model
assumptions. With this set of intrinsic SEDs, we present a novel
approach for directly recovering the shape and normalization of the dust
attenuation curve. We find, across all of the intrinsic templates
considered, that the average attenuation curve for star-forming galaxies
at z ≃ 3.5 is similar in shape to the commonly-adopted Calzetti
starburst law, with an average total-to-selective attenuation ratio of
RV = 4.18 ± 0.29. In contrast, we find that an average
attenuation curve as steep as the SMC extinction law is strongly
disfavoured. We show that the optical attenuation (AV) versus
stellar mass (M⋆) relation predicted using our method is
consistent with recent ALMA observations of galaxies at 2 <z <3
in the HubbleUltraDeepField (HUDF), as well as empirical AV -
M⋆ relations predicted by a Calzetti-like law. In fact,
our results, combined with other literature data, suggest that the
AV - M⋆ relation does not evolve over the
redshift range 0 <z <5, at least for galaxies with
log(M⋆/M⊙) ≳ 9.5. Finally, we
present tentative evidence which suggests that the attenuation curve may
become steeper at lower masses log(M⋆/M⊙)
≲ 9.0.
- galaxies: dust, galaxies: high redshift, galaxies: evolution, galaxies: star-forming
ID: 57768713