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T.S. Hamilton (NRC, NASA/GSFC), S. Casertano (STScI), D.A. Turnshek (U. Pittsburgh)
We present results from an archival study of 71 medium-redshift QSOs observed with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. The QSOs have magnitudes MV\leq -23 (total nuclear plus host light) and redshifts 0.06\leq z\leq 0.46.
We find a weak correlation between the nuclear and host luminosities, after accounting for certain selection effects. Their central black hole masses do not appear to be a fixed fraction of the host bulge mass. Overall, black hole mass shows very little correlation with bulge luminosity, although this may be a result of the small range of black hole masses considered, and a relationship does exist for radio-quiet QSOs. QSO nuclear luminosity shows only a weak correlation with black hole mass.
A much closer relationship is found by examining multiple parameters at once. A principal components analysis shows that 3 nuclear and host properties are related in a kind of fundamental plane: nuclear luminosity, and the size and effective surface magnitude of the host. Using optical nuclear luminosity, this relationship explains 95.8% of the variance in the overall sample and 98.0% in one subsample (radio-loud QSOs in elliptical hosts). Another version of the relationship uses x-ray nuclear luminosity and explains 94.9--98.7% of the variance.
The form of this QSO fundamental plane shows similarities to the well-studied fundamental plane of elliptical galaxies, and we examine the possible relationship between them as well as the difficulties involved in establishing this connection. The key to the relationship might lie in the fueling mechanism of the central black hole.
This work has been supported by funding from the Space Telescope Science Institute, the University of Pittsburgh, and the National Research Council.
The author(s) of this abstract have provided an email address for comments about the abstract: hamilton@milkyway.gsfc.nasa.gov
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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.