The optical emission lines of type 1 X-ray bright Active Galactic Nuclei
  A strong X-ray emission is one of the defining signatures of nuclear activity
in galaxies. According to the Unified Model for Active Galactic Nuclei (AGN),
both the X-ray radiation and the prominent broad emission lines, characterizing
the optical and UV spectra of Type 1 AGNs, are originated in the innermost
regions of the sources, close to the Super Massive Black Holes (SMBH), which
power the central engine. Since the emission is concentrated in a very compact
region (with typical size $r < 0.1\,$pc) and it is not possible to obtain
resolved images of the source, spectroscopic studies of this radiation
represent the only valuable key to constrain the physical properties of matter
and its structure in the center of active galaxies. Based on previous studies
on the physics of the Broad Line Region (BLR) and on the X-ray spectra of broad
(FWHMH$_{\rm H\beta}$ > 2000 km/s) and narrow line (1000 km/s < FWHMH$_{\rm
H\beta}\, \leq$ 2000 km/s) emitting objects, it has been observed that the
kinematic and ionization properties of matter close to the SMBHs are related
together, and, in particular, that ionization is higher in narrow line sources.
Here we report on the study of the optical and X-ray spectra of a sample of
Type 1 AGNs, selected from the Sloan Digital Sky Survey (SDSS) database, within
an upper redshift limit of z = 0.35, and detected at X-ray energies. We present
analysis of the broad emission line fluxes and profiles, as well as the
properties of the X-ray continuum and Fe K$\alpha$ emission and we use these
parameters to assess the consistency of our current AGN understanding.
