Year: 2020
Type: article
Abstract: We present dust attenuation properties of spectroscopically confirmed star forming galaxies on the main sequence at a redshift of ∼4.4 − 5.8. Our analyses are based on the far infrared continuum observations of 118 galaxies at rest-frame 158 μ m obtained with the Atacama Large Millimeter Array (ALMA) Large Program to INvestigate [CII] at Early times (ALPINE). We study the connection between the ultraviolet (UV) spectral slope ( β ), stellar mass ( M ⋆ ), and infrared excess (IRX = L IR / L UV ). Twenty-three galaxies are individually detected in the continuum at > 3.5 σ significance. We perform a stacking analysis using both detections and nondetections to study the average dust attenuation properties at z ∼ 4.4 − 5.8. The individual detections and stacks show that the IRX– β relation at z ∼ 5 is consistent with a steeper dust attenuation curve than typically found at lower redshifts ( z < 4). The attenuation curve is similar to or even steeper than that of the extinction curve of the Small Magellanic Cloud. This systematic change of the IRX– β relation as a function of redshift suggests an evolution of dust attenuation properties at z > 4. Similarly, we find that our galaxies have lower IRX values, up to 1 dex on average, at a fixed mass compared to previously studied IRX– M ⋆ relations at z ≲ 4, albeit with significant scatter. This implies a lower obscured fraction of star formation than at lower redshifts. Our results suggest that dust properties of UV-selected star forming galaxies at z ≳ 4 are characterised by (i) a steeper attenuation curve than at z ≲ 4, and (ii) a rapidly decreasing dust obscured fraction of star formation as a function of redshift. Nevertheless, even among this UV-selected sample, massive galaxies (log M ⋆ / M ⊙ > 10) at z ∼ 5 − 6 already exhibit an obscured fraction of star formation of ∼45%, indicating a rapid build-up of dust during the epoch of reionization.
Source: Astronomy and Astrophysics
Authors: Y. Fudamoto, P. A. Oesch, A. Faisst, M. Béthermin, M. Ginolfi, Y. Khusanova, F. Loiacono, O. Le Fèvre, P. Capak, D. Schaerer, J. D. Silverman, P. Cassata, L. Yan, R. Amorin, S. Bardelli, M. Boquien, A. Cimatti, M. Dessauges-Zavadsky, S. Fujimoto, C. Gruppioni, N. P. Hathi, E. Ibar, G. C. Jones, A. M. Koekemoer, G. Lagache, B. C. Lemaux, R. Maiolino, D. Narayanan, F. Pozzi, D. A. Riechers, G. Rodighiero, M. Talia, S. Toft, L. Vallini, D. Vergani, G. Zamorani, E. Zucca
Institutions: University of Geneva, California Institute of Technology, Infrared Processing and Analysis Center, Centre National de la Recherche Scientifique, Aix-Marseille Université, Laboratoire d’Astrophysique de Marseille, Osservatorio di Astrofisica e Scienza dello Spazio, University of Bologna, University of Copenhagen, Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, University of Padua, University of La Serena, Universidad de Antofagasta, Arcetri Astrophysical Observatory, Space Telescope Science Institute, University of Valparaíso, University of Cambridge, University of California, Davis, University of Florida, Cornell University, Max Planck Institute for Astronomy, Osservatorio Astronomico di Padova, National Institute for Astrophysics, Leiden University, Leiden Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, Alexander von Humboldt-Stiftung, National Radio Astronomy Observatory, European Commission, National Research Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Danmarks Grundforskningsfond, National Science Council, Ministero dell’Istruzione, dell’Università e della Ricerca, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Science and Technology Facilities Council, National Institutes of Natural Sciences
Awards: G1461837398, Support of the astronomical research of the Cavendish Astrophysics Group, G15967578, G3456374072, G434337789, G4915654406, The Cold Gas History of the Universe, Galaxy Build-up at Cosmic Dawn, Deep Investigation on Molecular Processes At early Cosmic Times, G6687328476, Studies of Flows, Turbulence and Transport in the Large Plasma Device, G710816533, G8252591933, G8931419319
OpenAlex ID: W4288079453