Exploring the diversity of Type 1 active galactic nuclei identified in SDSS-IV/SPIDERS

Journal Article · 07 January 2020 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/staa018 · OSTI ID:1595149

Wolf, Julien ^[1]; Salvato, Mara  ^[1]; Coffey, Damien ^[1]; Merloni, Andrea ^[1]; Buchner, Johannes ^[1]; Arcodia, Riccardo ^[1]; Baron, Dalya ^[2]; Carrera, Francisco J. ^[3]; Comparat, Johan ^[1]; Schneider, Donald P. ^[4]; Nandra, Kirpal ^[1]

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1. Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, D-85748 Garching, Germany
2. School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 69978, Israel
3. Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), E-39005 Santander, Spain
4. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA, Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802, USA

ABSTRACT We present a statistical analysis of the optical properties of an X-ray-selected Type 1 active galactic nucleus (AGN) sample, using high signal-to-noise ratio (S/N>20) spectra of the counterparts of the ROSAT/2RXS sources in the footprint of the SDSS-IV/SPIDERS (Spectroscopic IDentification of eROSITA Sources) programme. The final sample contains 2100 sources. It significantly extends the redshift and luminosity ranges (z ∼ 0.01–0.80 and $$L_{\rm 0.1\!-\!2.4 \, keV} \sim \rm 2.0 \times 10^{41}\!-\!1.0 \times 10^{46} \, \, erg \, s^{-1}$$) used so far in this kind of analysis. By means of a principal component analysis, we derive eigenvector (EV) 1 and 2 in an eleven-dimensional optical and X-ray parameter space, which are consistent with previous results. The validity of the correlations of the Eddington ratio L/LEdd with EV1 and the black hole mass with EV2 is strongly confirmed. These results imply that L/LEdd and black hole mass are related to the diversity of the optical properties of Type 1 AGNs. Investigating the relation of the width and asymmetry of H β and the relative strength of the iron emission $$r_{\rm Fe\, \small{II}}$$, we show that our analysis supports the presence of a distinct kinematic region: the very broad line region. Furthermore, comparing sources with a red-asymmetric broad H β emission line to sources for which it is blue asymmetric, we find an intriguing difference in the correlation of the $$\rm Fe\, \small{II}$$ and the continuum emission strengths. We show that this contrasting behaviour is consistent with a flattened, stratified model of the broad-line region, in which the $$\rm Fe\, \small{II}$$-emitting region is shielded from the central source.

• Sponsoring Organization: USDOE
• OSTI ID: 1595149
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 492; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English