Star formation and AGN activity in galaxies classified using the 1.6 µm bump and PAH features at z = 0.4-2
Por:
Hanami H., Ishigaki T., Fujishiro N., Nakanishi K., Miyaji T., Krumpe M., Umetsu K., Ohyama Y., Shim H., Im M., Lee H.M., Lee M.G., Serjeant S., White G.J., Willmer C.N., Goto T., Oyabu S., Takagi T., Wada T., Matsuhara H.
Publicada:
25 ago 2012
Resumen:
We studied the star-formation and AGN activity of massive galaxies in the redshift range z = 0.4-2, which were detected in a deep survey field using the AKARI InfraRed (IR) astronomical satellite and Subaru telescope toward the North Ecliptic Pole (NEP). The AKARI/IRC Mid-InfraRed (MIR) multiband photometry was used to trace the starforming activities with Polycyclic Aromatic Hydrocarbon (PAH) emission, which is effective not only to distinguish between star-forming and AGN galaxies, but also to estimate the Star Formation Rate (SFR) with converting its flux to the total emitting IR (TIR) luminosity. In combination with the analyses of the stellar components, we studied the MIR SED features of star-forming and AGN-harboring galaxies, which we summarize below: (1) The rest-frame 7.7-µm and 5-µm luminosities are good tracers of star-forming and AGN activities from their PAH and dusty tori emissions, respectively. (2) For dusty star-forming galaxies without AGN, their SFR shows a correlation that is nearly proportional to their stellar mass, and their specific SFR (sSFR) per unit stellar mass increases with redshift. Extinctions estimated from their TIR luminosities are larger than those from their optical SED fittings, which may be caused by geometric variations of dust in them. (3) Even for dusty star-forming galaxies with AGN, SFRs can be derived from their TIR luminosities with subtraction of the obscured AGN contribution, which indicates that their SFRs were possibly quenched around z ? 0.8 compared with those without AGN. (4) The AGN activity from their rest-frame 5-µm luminosity suggests that their Super Massive Black Holes (SMBHs) could already have grown to ? 3 × 108M? in most massive galaxies with 10 11M? at z > 1.2, and the mass relation between SMBHs and their host galaxies has already become established by z ? 1-2. © 2012. Astronomical Society of Japan.
Filiaciones:
Hanami H.:
Physics Section, Iwate University, 3-18-34 Ueda, Morioka, Iwate 020-8550, Japan
Ishigaki T.:
Physics Section, Iwate University, 3-18-34 Ueda, Morioka, Iwate 020-8550, Japan
Asahikawa National College of Technology, 2-2 Syunkodai, Asahikawa, Hokkaido 071-8142, Japan
Fujishiro N.:
Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555, Japan
Nakanishi K.:
ALMA/NAOJ Office, Calle Joaquin Montelro 3000, Oficina 702, Vitacura, Santiago, Chile
Miyaji T.:
Univ Nacl Autonoma Mexico, Inst Astron, Ensenada, Baja California, Mexico
Krumpe M.:
University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, San Diego, CA 92093-0424, United States
ESO Headquarters, Karl-Schwarzschild-Straße 2, 85748, Garching, Germany
Umetsu K.:
Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan
Ohyama Y.:
Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan
Shim H.:
School of Science Education, Kyungpook National University, Daegu 702-701, South Korea
Im M.:
Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
Lee H.M.:
Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
Lee M.G.:
Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
Serjeant S.:
Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
White G.J.:
Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
Space Science and Technology Division, STFC Rutherford Appleton Laboratory, Chilton, Didcot, United Kingdom
Willmer C.N.:
Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, United States
Goto T.:
Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, United States
Oyabu S.:
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
Takagi T.:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara 252-5210, Japan
Wada T.:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara 252-5210, Japan
Matsuhara H.:
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara 252-5210, Japan
Hybrid Gold
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