Optical and UV properties of a radio-loud and a radio-quiet Population A
  quasar at high redshift
  Different properties of quasars may be observed and analysed through the many
ranges of the electromagnetic spectrum. Pioneering studies showed that an "H-R
diagram" for quasars was needed to organize these data, and that more than two
dimensions were necessary: a four dimensional Eigenvector (4DE1) parameter
space was proposed. The 4DE1 makes use of independent observational properties
obtained from the optical and UV emission lines, as well as from the soft-X
rays. The 4DE1 "optical plane", also known as the quasar Main Sequence (MS),
identifies different spectral types in order to describe a consistent picture
of QSOs. In this work we present a spectroscopic analysis focused on the
comparison between two sources, one radio-loud (PKS2000-330, z = 3.7899) and
one radio-quiet (Q1410+096, z = 3.3240), both showing Population A quasar
spectral properties. Optical spectra were observed in the infrared with
VLT/ESO, and the additional measures in UV were obtained through the fitting of
archive spectra. The analysis was performed through a non-linear
multi-component decomposition of the emission line profiles. Results are shown
in order to highlight the effects of the radio-loudness on their emission line
properties. The two quasars share similar optical spectroscopic properties and
are very close on the MS classification while presenting significant
differences on the UV data. Both sources show significant blueshifts in the UV
lines but important differences in their UV general behaviour. While the
radio-quiet source Q1410+096 shows a typical Pop A UV spectrum with similar
intensities and shapes on both CIV1549 and SiIV1392, the UV spectrum of the
strong radio-loud PKS2000-330 closely resembles the one of population B of
quasars.
