TY - JOUR
T1 - BREAKING the CURVE with CANDELS
T2 - A Bayesian APPROACH to REVEAL the NON-UNIVERSALITY of the DUST-ATTENUATION LAW at HIGH REDSHIFT
AU - Salmon, Brett
AU - Papovich, Casey
AU - Long, James
AU - Willner, S. P.
AU - Finkelstein, Steven L.
AU - Ferguson, Henry C.
AU - Dickinson, Mark
AU - Duncan, Kenneth
AU - Faber, S. M.
AU - Hathi, Nimish
AU - Koekemoer, Anton
AU - Kurczynski, Peter
AU - Newman, Jeffery
AU - Pacifici, Camilla
AU - Pérez-González, Pablo G.
AU - Pforr, Janine
N1 - Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved.
PY - 2016/8/10
Y1 - 2016/8/10
N2 - Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant universe. Here, we model the spectral energy distributions of galaxies at z ∼ 1.5-3 from CANDELS with rest-frame UV to near-IR imaging under different assumptions about the dust law, and compare the amount of inferred attenuated light with the observed infrared (IR) luminosities. Some individual galaxies show strong Bayesian evidence in preference of one dust law over another, and this preference agrees with their observed location on the plane of infrared excess (IRX, LTIR/ LUV) and UV slope (β). We generalize the shape of the dust law with an empirical model, where k λis the dust law of Calzetti et al., and show that there exists a correlation between the color excess and tilt δ with δ = (0.62 ± 0.05)log (E(B-V))+ (0.26 ± 0.02). Galaxies with high color excess have a shallower, starburst-like law, and those with low color excess have a steeper, SMC-like law. Surprisingly, the galaxies in our sample show no correlation between the shape of the dust law and stellar mass, star formation rate, or β. The change in the dust law with color excess is consistent with a model where attenuation is caused by scattering, a mixed star-dust geometry, and/or trends with stellar population age, metallicity, and dust grain size. This rest-frame UV-to-near-IR method shows potential to constrain the dust law at even higher redshifts (z > 3).
AB - Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant universe. Here, we model the spectral energy distributions of galaxies at z ∼ 1.5-3 from CANDELS with rest-frame UV to near-IR imaging under different assumptions about the dust law, and compare the amount of inferred attenuated light with the observed infrared (IR) luminosities. Some individual galaxies show strong Bayesian evidence in preference of one dust law over another, and this preference agrees with their observed location on the plane of infrared excess (IRX, LTIR/ LUV) and UV slope (β). We generalize the shape of the dust law with an empirical model, where k λis the dust law of Calzetti et al., and show that there exists a correlation between the color excess and tilt δ with δ = (0.62 ± 0.05)log (E(B-V))+ (0.26 ± 0.02). Galaxies with high color excess have a shallower, starburst-like law, and those with low color excess have a steeper, SMC-like law. Surprisingly, the galaxies in our sample show no correlation between the shape of the dust law and stellar mass, star formation rate, or β. The change in the dust law with color excess is consistent with a model where attenuation is caused by scattering, a mixed star-dust geometry, and/or trends with stellar population age, metallicity, and dust grain size. This rest-frame UV-to-near-IR method shows potential to constrain the dust law at even higher redshifts (z > 3).
KW - galaxies: evolution
KW - galaxies: general
KW - galaxies: high-redshift
KW - galaxies: statistics
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U2 - 10.3847/0004-637X/827/1/20
DO - 10.3847/0004-637X/827/1/20
M3 - Article
AN - SCOPUS:84982179485
SN - 0004-637X
VL - 827
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 20
ER -