Isolating an outflow component in single-epoch spectra of quasars
  Gaseous outflows appear to be a universal property of type-1 and type-2
active galactic nuclei (AGN). The main diagnostic is provided by emission
features shifted to higher frequency via the Doppler effect, implying that the
emitting gas is moving toward the observer. However, beyond the presence of
blueshift, the observational signatures of the outflows are often unclear, and
no established criteria exist to isolate the outflow contribution in the
integrated, single-epoch spectra of type-1 AGN. The emission spectrum collected
with the typical apertures of long-slit spectroscopy or of fiber optics sample
contributions over a broad range of spatial scales, making it difficult to
analyze the line profiles in terms of different kinematic components.
Nevertheless, hundred of thousands of quasars spectra collected at moderate
resolution demand a proper analysis of the line profiles for proper dynamical
modelling of the emitting regions. In this small contribution we shall analyze
several profiles of the HI Balmer line H\b{eta} from composite and individual
optical spectra of sources radiating at moderate Eddington ratio (Population B
following Sulentic et al. 2000). Features and profile shapes that might be
traced to outflow due to narrow-line region gas are detected over a wide range
of luminosity.
