AAS 201st Meeting, January, 2003
Session 114. Quasars
Poster, Thursday, January 9, 2003, 9:20am-4:00pm, Exhibit Hall AB

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[114.02] Are BALQSOs extreme accretors?

M. J. Yuan, B. J. Wills (University of Texas)

Broad Absorption Line (BAL) QSOs are QSOs with massive absorbing outflows up to 0.2c. Two hypothesis have been suggested in the past about the nature of BALQSOs:


\item Every QSO might have BAL outflow with some covering factor. BALQSOs are those which happen to have outflow along our line of sight.

\item BALQSOs have intrinsically different physical properties than non-BALQSOs. Based on BALQSO's optical emission properties and a large set of correlations linking many general QSO emission line and continuum properties, it has been suggested that BALQSOs might accrete at near Eddington limit with abundant of fuel supplies.


With new BALQSO H\beta region spectroscopic observation conducted at UKIRT and re-analysis of literature data for low and high redshift non-BALQSOs, We confirm that BALQSOs have extreme Fe~II and [O~III] emission line properties.

Using results derived from the latest QSO H\beta region reverberation mapping, we calculated Eddington ratios (\dot{M}/\dot{M}Edd) for our BAL and non-BALQSOs. The Fe~II and [O~III] strengths are strongly correlated with Eddington ratios. Those correlations link Eddington ratio to a large set of general QSO properties through the Boroson & Green Eigenvector 1.

We find that BALQSOs have Eddington ratios close to 1. However, all high redshift, high luminosity QSOs have rather high Eddington ratios. We argue that this is a side effect from selecting the brightest objects. In fact, our high redshift sample might constitute BALQSO's high Eddington ratio orientation parent population.

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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.