A low-luminosity type-1 QSO sample. V. Overluminous host spheroids and
  their excitation mechanisms
  We present near-infrared (NIR) $H+K$-band longslit spectra of eleven galaxies
which are obtained with SOFI at the NTT (ESO). The galaxies are chosen from the
low-luminosity type-1 quasi-stellar object (LLQSO) sample which comprises the
99 closest ($z\leq 0.06$) QSOs from the Hamburg/ESO survey for bright UV-excess
QSOs. These objects are ideal targets to study the gap between local Seyfert
galaxies and high-redshift quasars, since they show much stronger AGN activity
compared to local objects but are still close enough for a detailed structural
analysis.
  We fit hydrogen recombination, molecular hydrogen, and [FeII] lines after
carefully subtracting the continuum emission. From the broad Pa$\alpha$
components, we estimate black hole masses and enlarge the sample of LLQSOs that
show a deviation from the $M_\mathrm{BH}-L_\mathrm{bulge}$ relations of
inactive galaxies from 12 to 16 objects.
  All objects show emission from hot dust ($T\sim 1200\,\mathrm{K}$) as well as
stellar contribution. However, the particular fractions vary a lot between the
objects. More than half of the objects show H$_2$ emission lines that are
indicating a large reservoir of molecular gas which is needed to feed the AGN
and star formation.
  In the NIR diagnostic diagram all objects lie in the location of AGN
dominated objects. However, most of the objects show indications of star
formation activity, suggesting that their offset location with respect to
$M_\mathrm{BH}-L_\mathrm{bulge}$ relations of inactive galaxies may be a
consequence of overluminous bulges.
