CfA OIR Division Lunch Talks
Thursday, August 21, 2008, 12:30 pm, Pratt Conference Room

Mid-IR Spectroscopic Properties of Ultraluminous Infrared Quasars,
and an introduction to Optical Observatories in China

Dr. Chen Cao (Shandong University)

In the first part of my talk, I will report the results of our recent work on the MIR spectral properties of IR QSOs: based on the spectra from IRS on board Spitzer, we analyse mid-infrared spectroscopic properties for 19 ultra-luminous infrared quasars (IR QSOs) in the local universe, and compare them with those of optically-selected PG QSOs and ultra-luminous infrared galaxies (ULIRGs). We found that the average MIR spectral features (including spectral slopes, PAH emission strengths and [NeII] luminosities) of IR QSOs are differ from those of PG QSOs and ULIRGs, which indicate that IR QSOs could be at a transitional stage from ULIRGs to classical QSOs. Correlations between the [NeII], PAH and 60um luminosities for ULIRGs and IR QSOs indicate that both [NeII] and PAH luminosities are approximate star formation rate indicators for IR QSOs and starburst-dominated galaxies. The correlation between the EW (PAH) and outflow velocities suggests that star formation activities are suppressed by feedback from AGNs and/or supernovae.

The second part of the talk will be a brief introduction to optical telescopes in China. I will mainly focus on telescopes settled at Xinglong observatory (the institution where I got my PhD), including its 2.16m and future 4m LAMOST, and the small but modern 1m at Weihai Observatory of Shandong University (my current institution). Some scientific issues and projects related to observations made by these telescopes will also be reviewed.

More information can be found at http://arxiv.org/abs/0807.3653.