Optical and near-UV spectroscopic properties of low-redshift jetted quasars in the main sequence context

TL;DR

This study investigates the optical and near-UV spectral properties of low-redshift jetted quasars, revealing differences in emission line profiles and black hole characteristics compared to radio-quiet quasars, within the context of the quasar main sequence.

Contribution

It provides new spectral measurements of powerful jetted quasars and analyzes their emission line properties in relation to the main sequence, highlighting the impact of radio jets on broad emission lines.

Findings

RL quasars have larger ext{FWHM} of ext{H}eta.

RL quasars exhibit weaker ext{FeII} emission.

RL quasars show higher black hole masses and lower ext{L}/ ext{L}_{ ext{Edd}}.

Abstract

This paper presents new optical and near-UV spectra of 11 extremely powerful jetted quasars, with radio to optical flux density ratio $>$ 10$^3$, that concomitantly cover the low-ionization emission of \mgii\ and \hb\ as well as the \feii\ blends in the redshift range $0.35 \lesssim z \lesssim 1$. We aim to quantify broad emission line differences between radio-loud (RL) and radio-quiet (RQ) quasars by using the 4D eigenvector 1 parameter space and its Main Sequence (MS) and to check the effect of powerful radio ejection on the low ionization broad emission lines. The \hb\ and \mgii\ emission lines were measured by using non-linear multicomponent fittings as well as by analysing their full profile. We found that broad emission lines show large redward asymmetry both in \hb\ and \mgii. The location of our RL sources in a UV plane looks similar to the optical one, with weak \feiiuv\ emission and broad \mgii. We supplement the 11 sources with large samples from previous work to gain some general inferences. We found that, compared to RQ, our extreme RL quasars show larger median \hb\ full width at half maximum (FWHM), weaker \feii\ emission, larger \mbh, lower \lledd, and a restricted bf space occupation in the optical and UV MS planes. The differences are more elusive when the comparison is carried out by restricting the RQ population to the region of the MS occupied by RL sources, albeit an unbiased comparison matching \mbh\ and \lledd\ suggests that the most powerful RL quasars show the highest redward asymmetries in \hb.