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)
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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. |