English

Comparing Hbeta Line Profiles in the 4D Eigenvector 1 Context

Cosmology and Nongalactic Astrophysics 2014-11-20 v1

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.

Cite

@article{arxiv.0911.4220,
  title  = {Comparing Hbeta Line Profiles in the 4D Eigenvector 1 Context},
  author = {J. W. Sulentic and P. Marziani and S. Zamfir},
  journal= {arXiv preprint arXiv:0911.4220},
  year   = {2014}
}

Comments

11 pages, 4 figures

R2 v1 2026-06-21T14:14:35.293Z