We present the result of systematic AKARI IRC infrared 2.5−5 μm spectroscopy of >100 nearby luminous infrared galaxies, to investigate the energetic roles of starbursts and optically-elusive buried AGNs. Based on (1) the equivalent widths of the 3.3μm PAH emission features, (2) the optical depths of absorption features, and (3) continuum slopes, we can disentangle emission from starbursts and AGNs. We find that the energetic importance of buried AGNs increases with increasing galaxy infrared luminosities, suggesting that the AGN-starburst connections (and thereby possible AGN feedback to host galaxies) are luminosity dependent.

ABSTRACT
1. INTRODUCTION
2. RESULTS AND DISCUSSION
REFERENCES

• MASATOSHI IMANISHI(Subaru Telescope, Department of Astronomy, School of Science, Graduate University for Advanced Studies (SOKENDAI))
• TAKAO NAKAGAWA(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)
• MAI SHIRAHATA(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)
• YOICHI OHYAMA(Institute of Astronomy and Astrophysics Academia Sinica)
• TAKASHI ONAKA(Department of Astronomy, Graduate School of Science, University of Tokyo)