Using vo tools to iNvestIgate Quasar Spectra (UNIQS)

TL;DR

This study investigates the drivers of the Quasar Main Sequence by analyzing spectral energy distributions and black hole masses, challenging the Eddington ratio hypothesis and proposing the maximum disk temperature as a key factor.

Contribution

The paper introduces a refined sample and a new hypothesis that the maximum accretion disk temperature drives the Quasar Main Sequence, supported by detailed spectral modeling.

Findings

RFeII correlates with the maximum disk temperature.

Black hole mass distributions differ when using the new virial factors.

Analysis of an extreme source supports the new hypothesis.

Abstract

The work initially started as a test to retrace the Shen & Ho (2014) Quasar Main Sequence diagram where they (and references therein) claimed that the parameter RFeII, which defines the Eigenvector 1 (EV1) is driven by the Eddington ratio alone. We subsequently construct a refined (error and redshift limited) sample from the original Shen et. al (2011) QSO catalogue. Based on our hypothesis - the main driver of the Quasar Main Sequence is the maximum of the accretion disk temperature defined by the Big Blue Bump on the Spectral Energy Distribution. We select five extreme sources that have RFeII >= 4.0 and use the SED modelling code CIGALE to fit the multi-band photometric data for these sources. Incorporating the prescription for broad emission-line species dependent virial factors, we derive the black hole masses for the entire Shen+11 catalogue and compare their distribution with the black hole masses in the original catalogue. Here, we show the results of our analysis for one of the 5 extreme sources, SDSSJ082358.30+213545.2. We also show the detailed modelling, including the Fe II pseudo-continuum to estimate and compare the value of RFeII for this object.