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Angel Castro,Takamitsu Miyaji, Mai Shirahata, Kohei Ichikawa, Shinki Oyabu, David M. Clark, Masatoshi Imanishi, Takao Nakagawa, Yoshihiro Ueda 1Instituto de Astronomia, Universidad Nacional Autonoma de Mexico (UNAM), Ensenada, Baja California, Mexico (mailing address: PO Box 439027, San Diego, CA 92143-9027, USA) 2University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093-0424, USA 3National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 4Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara 252-5210 5Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 6Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan 7Subaru Telescope, 650 North Aohoku Place, Hilo, Hawaii, 96720, USA acastro@astrosen.unam.mx

We utilize AKARI’s slitless spectroscopic capability to detect the 3.3 „m polycyclic aromatic hydrocarbons (PAHs) emission and measure star formation (SF) activity for various AKARI programs. First, we obtain 2»5 „m spectra of 20 flux-limited galaxies with mixed SED classes in order to calibrate the 3.3 „m PAH luminosity (LPAH3:3) as a star formation rate (SFR) indicator. We find that LPAH3:3 correlates with LIR as well as with the 6.2 „m PAH luminosity (LPAH6:2). The correlations does not depend on SED classes. We find that ULIRGs deviate from the correlation between PAH luminosities and LIR, while they do not for the correlation between PAH luminosities. We suggest possible eects to cause this deviation. On the other hand, how AGN activity is linked to SB activity is one of the most intriguing questions. While it is suggested that AGN luminosity of quasars correlates with starburst (SB) luminosity, it is still unclear how AGN activity is connected to SF activity based on host galaxy properties. We are measuring SFRs for the LQSONG sample consisting of reverberation mapped AGNs and PG-QSOs. This is an extension of the ASCSG program by which we investigated the connection between SB and AGN activities for Seyferts type 1s at z » 0.36. While we found no strong correlation between LPAH3:3 and AGN luminosity for these Seyferts 1s, LPAH3:3 measured from the central part of galaxies correlates with AGN luminosity, implying that SB and AGN activities are directly connected in the nuclear region.

Accepted: 2012-08-02, 資料番号: SA1004453000

We present the result of our near infrared J(λ = 1.25 μm), H(λ = 1.63 μm), and Ksband (λ = 2.14 μm) imaging of ultraluminous (LIR >10 L ) and luminous (LIR = 1011−12 L ) infrared galaxies (ULIRGs and LIRGs), to investigate their relationship through properties of their host galaxies. We find that (1) for single-nucleus ULIRGs and LIRGs, their spheroidal host galaxies have similar properties, but ULIRGs display a substantially higher level of nuclear activity than LIRGs, suggesting that their infrared luminosity difference comes primarily from the different level of current nuclear activity. We infer that LIRGs and ULIRGs have similar progenitor galaxies, follow similar evolutionary processes, and may evolve into optically-selected QSOs. (2) Largely-separated multiple-nuclei ULIRGs have significantly brighter host galaxies than single-nucleus ULIRGs and LIRGs in Ks-band, indicating that multiple-nuclei ULIRGs have a bias towards mergers of intrinsically large progenitor galaxies, in order to produce high infrared luminosity (LIR >10 L ) even at the early merging stage. (3) We derive dust extinction of host galaxies of ULIRGs and LIRGs to be AV ∼ 14 mag in the optical or equivalently AK ∼ 0.8 mag in the near-infrared Ks-band, based on the comparison of host galaxy’s luminosities in the J-, H-, and Ks-bands.