Infrared 3-4μm Spectroscopy of Nearby PG QSOs and AGN-Nuclear Starburst Connections in High-luminosity AGN Populations
Abstract
We present the results of infrared L-band (3-4μm) slit spectroscopy of 30 PG QSOs at z < 0.17, a representative sample of local high-luminosity, optically selected AGNs. The 3.3μm polycyclic aromatic hydrocarbon (PAH) emission feature is used to probe nuclear (< a few kpc) starburst activity and to investigate the connections between AGNs and nuclear starbursts in PG QSOs. The 3.3μm PAH emission is detected in the individual spectra of 5/30 of the observed PG QSOs. We constructed a composite spectrum of PAH-undetected PG QSOs and discerned the presence of the 3.3μm PAH emission therein. We estimated the nuclear-starburst and AGN luminosities from the observed 3.3μm PAH emission and 3.35μm continuum luminosities, respectively, and found that the nuclear-starburst-to-AGN luminosity ratios in PG QSOs are similar to those of previously studied AGN populations with lower luminosities, suggesting that AGN-nuclear starburst connections are valid over a wide luminosity range of AGNs in the local universe. The observed nuclear-starburst-to-AGN luminosity ratios in PG QSOs with available supermassive black-hole masses are comparable to a theoretical prediction based on the assumption that the growth of a supermassive black hole is controlled by starburst-induced turbulence.
- Publication:
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Publications of the Astronomical Society of Japan
- Pub Date:
- March 2011
- DOI:
- 10.1093/pasj/63.sp2.S447
- arXiv:
- arXiv:1101.1970
- Bibcode:
- 2011PASJ...63S.447I
- Keywords:
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- galaxies: active;
- galaxies: nuclei;
- galaxies: starburst;
- infrared: galaxies;
- quasars: general;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 10 pages, 5 figures, accepted for publication in PASJ (No. 63, 2011 March, Subaru special issue)