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arXiv · 0911.4220

Comparing Hbeta Line Profiles in the 4D Eigenvector 1 Context

J. W. Sulentic·P. Marziani·S. Zamfir
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Abstract

We describe a 4D Eigenvector 1 (4DE1) space that serves as a surrogate H-R diagram for quasars. It provides a context for describing and unifying differences between all broad line AGN. Quasar spectra can be averaged in a non-random way using 4DE1 just as stellar spectra can be averaged non-randomly within the OBAFGKM classification sequence. We find that quasars with FWHM H_beta less than (Population A) and greater than (Population B) 4000 km/s show many significant differences that may point to an actual dichotomy. Broad line profile measures and fits reenforce the idea of a dichotomy because they are fundamentally different: Pop.A - Lorentzian-like and Pop.B - double Gaussian. The differences have implications both for BH mass estimation and for inferences about source structure and kinematics.

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J. W. Sulentic, P. Marziani, S. Zamfir. 2009-11-22. Comparing Hbeta Line Profiles in the 4D Eigenvector 1 Context. https://doi.org/10.1016/j.newar.2009.06.001

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