The properties of active galaxies at the extreme of eigenvector 1

Eigenvector one is the formal parameter which allows to introduce some order in the properties of the unobscured type 1 active galaxies. We aim at the understanding of the nature of this parameter, and with this purpose we analyse the most extreme examples of quasars with the highest possible values of the corresponding eigenvalues R_Fe. We selected the appropriate sources from the SDSS and we perform a detailed modelling, including various templates for the Fe II pseudo-continuum and the starlight contribution to the spectrum. Out of 9 sources with the R_Fe larger than 2 selected from the SDSS quasar catalog only one quasar was confirmed to have a high value of R_Fe, equal 4.1. All other sources have R_Fe about 1. The high R_Fe object has an extremely narrow Hbeta line, as in Seyfert 2 galaxies, but the [OIII] in this object is very weak in comparison with Hbeta. Careful reanalysis of a larger sample from SDSS is needed to make stronger conclusions about the properties of the extreme eigenvector 1 sources.