TY - JOUR

T1 - Dust Attenuation Curves at z ~ 0.8 from LEGA-C

T2 - Precise Constraints on the Slope and 2175Å Bump Strength

AU - Barisic, Ivana

AU - Pacifici, Camila

AU - Wel, Arjen van der

AU - Straatman, Caroline

AU - Bell, Eric F.

AU - Bezanson, Rachel

AU - Brammer, Gabriel

AU - D'Eugenio, Francesco

AU - Franx, Marijn

AU - Houdt, Josha van

AU - Maseda, Michael V.

AU - Muzzin, Adam

AU - Sobral, David

AU - Wu, Po-Feng

N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi: 10.3847/1538-4357/abba37

PY - 2020/11/12

Y1 - 2020/11/12

N2 - We present a novel approach to measure the attenuation curves of 485 individual star-forming galaxies with M* > 1010 M⊙ based on deep optical spectra from the VLT/VIMOS LEGA-C survey and multi-band photometry in the COSMOS field. Most importantly, we find that the attenuation curves in the rest-frame 3000-4500 Å range are typically almost twice as steep as the Milky Way, LMC, SMC, and Calzetti attenuation curves, which is in agreement with recent studies of the integrated light of present-day galaxies. The attenuation at 4500 Å and the slope strongly correlate with the galaxy inclination: face-on galaxies show less attenuation and steeper curves compared to edge-on galaxies, suggesting that geometric effects dominate observed variations in attenuation. Our new method produces 2175 Å UV bump detections for 260 individual galaxies. Even though obvious correlations between UV bump strength and global galaxy properties are absent, strong UV bumps are most often seen in face-on, lower-mass galaxies (10 < log10(M*/M⊙) < 10.5) with low overall attenuation. Finally, we produce a typical attenuation curve for star-forming galaxies at z ~ 0.8; this prescription represents the effect of dust on the integrated spectral energy distributions of high-redshift galaxies more accurately than commonly used attenuation laws.

AB - We present a novel approach to measure the attenuation curves of 485 individual star-forming galaxies with M* > 1010 M⊙ based on deep optical spectra from the VLT/VIMOS LEGA-C survey and multi-band photometry in the COSMOS field. Most importantly, we find that the attenuation curves in the rest-frame 3000-4500 Å range are typically almost twice as steep as the Milky Way, LMC, SMC, and Calzetti attenuation curves, which is in agreement with recent studies of the integrated light of present-day galaxies. The attenuation at 4500 Å and the slope strongly correlate with the galaxy inclination: face-on galaxies show less attenuation and steeper curves compared to edge-on galaxies, suggesting that geometric effects dominate observed variations in attenuation. Our new method produces 2175 Å UV bump detections for 260 individual galaxies. Even though obvious correlations between UV bump strength and global galaxy properties are absent, strong UV bumps are most often seen in face-on, lower-mass galaxies (10 < log10(M*/M⊙) < 10.5) with low overall attenuation. Finally, we produce a typical attenuation curve for star-forming galaxies at z ~ 0.8; this prescription represents the effect of dust on the integrated spectral energy distributions of high-redshift galaxies more accurately than commonly used attenuation laws.

KW - astro-ph.GA

U2 - 10.3847/1538-4357/abba37

DO - 10.3847/1538-4357/abba37

M3 - Journal article

VL - 903

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 146

ER -