Techniques for profile binning and analysis of eigenvector composite spectra: Comparing H beta and MgII lambda 2800 as virial estimators

Titulo: 
Techniques for profile binning and analysis of eigenvector composite spectra: Comparing H beta and MgII lambda 2800 as virial estimators
Autores: 
Sulentic, JW; Marziani, P; del Olmo, A; Plauchu-Frayn, I
Resumen: 
We review the basic techniques for extracting information about quasar structure and kinematics from the broad emission lines in quasars. We consider which lines can most effectively serve as virial estimators of black hole mass. At low redshift the Balmer lines, particularly broad H beta, are the lines of choice. For redshifts greater than 0.7 - 0.8 one can follow H beta into the IR windows or find an H beta surrogate. We explain why UV CIV lambda 1549 is not a safe virial estimator and how MgII lambda 2800 serves as the best virial surrogate for H beta up to the highest redshift quasar known at z approximate to 7. We show how spectral binning in a parameter space context (4DE1) makes possible a more effective comparison of H beta and MgII. It also helps to derive more accurate mass estimates from appropriately binned spectra and, finally, to map the dispersion in M-BH and Eddington ratio across the quasar population. FWHM MgII is about 20% smaller than FWHM H beta in the majority of type 1 AGN requiring correction when comparing MBH estimates from these two lines. The 20% of sources showing narrowest FWHM H beta (< 4000 km s(-1)) and strongest FeII (R-Fe greater than or similar to 1.0) emission (we call them bin A3-4 sources) do not show this FWHM difference and a blueshift detected in MgII for these sources suggests that FWHM H beta is the safer virial estimator for these extreme Eddington emitters. (C) 2013 COSPAR. Published by Elsevier Ltd. All rights reserved.
Autor principal: 
Sulentic, JW
Autor/es del IAA: 
Sulentic, Jack W.; del Olmo, Ascension; Plauchu-Frayn, Ilse
DOI: 
10.1016/j.asr.2013.09.039
Revista: 
ADVANCES IN SPACE RESEARCH
Fecha de publicación: 
2014/10/01
Volumen: 
54
Issue: 
7
Páginas: 
1406-1413
Tipo de documento: 
Article
Palabras clave: 
Line:formation; Line: profile; Quasars: emission lines; Quasars: general