Dust attenuation up to z ≃ 2 in the AKARI North Ecliptic Pole Deep Field

¹ Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
e-mail: veronique.buat@lam.fr
² Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, 229-8510 Kanagawa, Japan
³ Department of Astronomy CSS Bldg., Rm. 1204, Stadium Dr. University of Maryland College Park, MD 20742-2421, USA
⁴ University of Crete, Department of Physics and Institute of Theoretical & Computational Physics, 71003 Heraklion, Greece
⁵ Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, 464-8602 Nagoya, Japan
⁶ National Centre for Nuclear Research, ul. Hoza 69, 00-681 Warszawa, Poland
⁷ Institute of Astronomy, National Tsing Hua University, No. 101, Sect. 2, Kuang-Fu Road, Hsinchu, Taiwan 30013, R.O.C.
⁸ University of California, Los Angeles, CA 90095-1547, USA
⁹ Academia Sinica, Institute of Astronomy and Astrophysics, No.1, Sect. 4, Roosevelt Rd, Taipei 10617, Taiwan, R.O.C.
¹⁰ RAL Space, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, UK
¹¹ The Open University, Milton Keynes, MK7 6AA, UK
¹² Oxford Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Rd, Oxford OX1 3RH, UK
¹³ Instituto de Astronomía sede Ensenada, UNAM, Km 103, Carret. Tijuana-Ensenada, Ensenada, 22860, Mexico
¹⁴ University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Dr., La Jolla, CA 92093-0424, USA
¹⁵ European Southern Observatory, ESO Headquarters, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
¹⁶ Max-Planck-Institut für extraterrestische Physik, Postfach 1312, 85741 Garching, Germany

Received: 24 November 2014
Accepted: 8 March 2015

Abstract

Aims. We aim to study the evolution of dust attenuation in galaxies selected in the infrared (IR) in the redshift range in which they are known to dominate the star formation activity in the universe. The comparison with other measurements of dust attenuation in samples selected using different criteria will give us a global picture of the attenuation at work in star-forming galaxies and its evolution with redshift.

Methods. We selected galaxies in the mid-IR from the deep survey of the North Ecliptic Field performed by the AKARI satellite. Using multiple filters of IRC instrument, we selected more than 4000 galaxies from their rest-frame emission at 8 μm, from z ≃ 0.2 to ~2. We built spectral energy distributions from the rest-frame ultraviolet (UV) to the far-IR by adding ancillary data in the optical-near IR and from GALEX and Herschel surveys. We fit spectral energy distributions with the physically-motivated code CIGALE. We test different templates for active galactic nuclei (AGNs) and recipes for dust attenuation and estimate stellar masses, star formation rates, amount of dust attenuation, and AGN contribution to the total IR luminosity. We discuss the uncertainties affecting these estimates on a subsample of galaxies with spectroscopic redshifts. We also define a subsample of galaxies with an IR luminosity close to the characteristic IR luminosity at each redshift and study the evolution of dust attenuation of this selection representative of the bulk of the IR emission.

Results. The AGN contribution to the total IR luminosity is found to be on average approximately 10%, with a slight increase with redshift. The determination of AGN contribution does not depend significantly on the assumed AGN templates except for galaxies detected in X-ray. The choice of attenuation law has a marginal impact on the determination of stellar masses and star formation rates. Dust attenuation in galaxies dominating the IR luminosity function is found to increase from z = 0 to z = 1 and to remain almost constant from z = 1 to z = 1.5. Conversely, when galaxies are selected at a fixed IR luminosity, their dust attenuation slightly decreases as redshift increases but with a large dispersion, confirming previous results obtained at lower redshift.The attenuation in our mid-IR selected sample is found ~2 mag higher than that found globally in the universe or in UV and Hα line selections in the same redshift range. This difference is well explained by an increase of dust attenuation with the stellar mass, in global agreement with other recent studies. Starbursting galaxies do not systematically exhibit a high attenuation. We conclude that the galaxies selected in IR and dominating the star formation exhibit a higher attenuation than those measured on average in the universe because they are massive systems. Conversely UV selected galaxies exhibit a large range of stellar masses leading in a lower average attenuation than that found in an IR selection.