English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We derive black hole masses for a sample of about 300 AGNs in the redshiftrange 0 < z < 2.5. We use the same virial velocity measure (FWHM Hbeta broadcomponent) for all sources which represents a significant improvement overprevious studies. We review methods and caveats for determining AGN black holemasses via the virial assumption for motions in the gas producing lowionization broad emission lines. We derive a corrected FWHM measure for thebroad component of H-beta that better estimates the virialized line emittingcomponent by comparing our FWHM measures with a sample of reverberated sourceswith H-beta radial velocity dispersion measures. We also consider the FWHM ofthe FeII 4570 blend as a potential alternative velocity estimator. We find arange of black hole mass between log M ~ 6 - 10, where the black hole mass M isin solar masses. Estimates using corrected FWHM, as well as FWHM(Fe II)measures, reduce the number of sources with log M > 9.5 and suggest thatextremely large M values (log M >~ 10) may not be realistic. Derived Eddingtonratio values values show no evidence for a significant population ofsuper-Eddington radiators especially after correction is made for sources withextreme orientation to our line of sight. Sources with FWHM(Hbeta broadcomponent) <~ 4000 km/s show systematically higher Eddington ratio and lower Mvalues than broader lined AGNs (including almost all radio-loud sources).Comment: Accepted for publication in Astronomy & Astrophysic

VLT/ISAAC spectra of the Hβregion in intermediate-redshift quasars