Black hole mass estimates in quasars. A comparative analysis of high- and low-ionization lines

Marziani, P. ; Olmo, A. del ; Martínez-Carballo, M.A. (Universidad de Zaragoza) ; Martínez-Aldama, M.L. ; Stirpe, G.M. ; Negrete, C.A. ; Dultzin, D. ; D’Onofrio, M. ; Bon, E. ; Bon, N.

Resumen: Context: The interline comparison between high- and low-ionization emission lines has yielded a wealth of information on the structure and dynamics of the quasar broad line region (BLR), including perhaps the earliest unambiguous evidence in favor of a disk + wind structure in radio-quiet quasars.
Aims: We carried out an analysis of the C IVλ1549 and Hβ line profiles of 28 Hamburg-ESO high-luminosity quasars and of 48 low-z, low-luminosity sources in order to test whether the width of the high-ionization line C IVλ1549 could be correlated with Hβ and be used as a virial broadening estimator.
Methods: We analyze intermediate- to high-S/N, moderate-resolution optical and near-infrared (NIR) spectra covering the redshifted C IVλ1549 and Hβ over a broad range of luminosity log L ∼ 44 − 48.5 [erg s−1] and redshift (0 − 3), following an approach based on the quasar main sequence.
Results: The present analysis indicates that the line width of C IVλ1549 is not immediately offering a virial broadening estimator equivalent to Hβ. At the same time a virialized part of the BLR appears to be preserved even at the highest luminosities. We suggest a correction to FWHM(C IVλ1549) for Eddington ratio (using the C IVλ1549 blueshift as a proxy) and luminosity effects that can be applied over more than four dex in luminosity.
Conclusions: Great care should be used in estimating high-L black hole masses MBH from C IVλ1549 line width. However, once a corrected FWHM C IVλ1549 is used, a C IVλ1549-based scaling law can yield unbiased MBH values with respect to the ones based on Hβ with sample standard deviation ≈0.3 dex.

Idioma: Inglés

DOI: 10.1051/0004-6361/201935265

Año: 2019

Publicado en: Astronomy & astrophysics 627 (2019), A88 [20 pp]
ISSN: 0004-6361

Factor impacto JCR: 5.636 (2019)

Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 11 / 68 = 0.162 (2019) - Q1 - T1

Factor impacto SCIMAGO: 2.174 - Space and Planetary Science (Q1) - Astronomy and Astrophysics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA-FEDER/E24-17R
Financiación: info:eu-repo/grantAgreement/ES/MINECO/AYA2016-76682-C3-1-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/MTM2015-64095-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO/SEV-2017-0709

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Matemática Aplicada (Dpto. Matemática Aplicada)