From Sub-Solar to Super-Solar Chemical Abundances along the Quasar Main Sequence
Paola Marziani,
Alberto Floris,
Alice Deconto-Machado,
Swayamtrupta Panda,
Marzena Sniegowska,
Karla Garnica,
Deborah Dultzin,
Mauro D’Onofrio,
Ascensión Del Olmo,
Edi Bon,
Nataša Bon
Affiliations
Paola Marziani
National Institute for Astrophysics (INAF), Astronomical Observatory of Padova, IT-35122 Padova, Italy
Alberto Floris
Department of Physics and Astronomy, University of Padua, Vicolo dell’ Osservatorio 3, IT-35122 Padova, Italy
Alice Deconto-Machado
Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas (IAA-CSIC), Glorieta de Astronomía s/n, 18008 Granada, Spain
Swayamtrupta Panda
Laboratório Nacional de Astrofísica, Ministério da Ciência, Tecnologia e Inovação (MCTI), R. dos Estados Unidos 154, Nações, Itajubá CEP 37504-364, Brazil
Marzena Sniegowska
School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
Karla Garnica
Institute of Astronomy, National Autonomous University of Mexico (UNAM), Mexico City 04510, Mexico
Deborah Dultzin
Institute of Astronomy, National Autonomous University of Mexico (UNAM), Mexico City 04510, Mexico
Mauro D’Onofrio
National Institute for Astrophysics (INAF), Astronomical Observatory of Padova, IT-35122 Padova, Italy
Ascensión Del Olmo
Instituto de Astrofísica de Andalucía, Consejo Superior de Investigaciones Científicas (IAA-CSIC), Glorieta de Astronomía s/n, 18008 Granada, Spain
Edi Bon
Belgrade Astronomical Observatory, Volgina 7, 11000 Belgrade, Serbia
Nataša Bon
Belgrade Astronomical Observatory, Volgina 7, 11000 Belgrade, Serbia
The 4D (four-dimensional) eigenvector 1 (E1) sequence has proven to be a highly effective tool for organizing observational and physical properties of type-1 active galactic nuclei (AGNs). In this paper, we present multiple measurements of metallicity for the broad line region gas, from new and previously-published data. We demonstrate a consistent trend along the optical plane of the E1 (also known as the quasar main sequence), defined by the line width of Balmer hydrogen Hβ profile and by a parameter measuring the prominence of singly-ionized iron emission. The trend involves an increase from sub-solar metallicity in correspondence with extreme Population B (weak Feii emission, large Hβ FWHM (full width at half maximum)) to metallicity several tens the solar value in correspondence with extreme Population A (strongest Feii optical emission, narrower Hβ profiles). The data establish the metallicity as a correlate of the 4DE1/main sequence. If the considerably high metallicity (Z≳10Z⊙, solar metallicity) gas is expelled from the sphere of influence of the central black hole, as indicated by the widespread evidence of nuclear outflows and disk wind in the case of sources radiating at a high Eddington ratio, then it is possible that the outflows from quasars played a role in chemically enriching the host galaxy.
