A low-luminosity type-1 QSO sample. III.

Our goal is to enrich our systematic multiwavelength analysis of the AGN/starburst relation in these systems and give a complementary information on this particular sample of LLQSOs from the Hamburg ESO survey. Here, we present results of the analysis of visible wavelength spectroscopy provided by the HES and the 6 Degree Field Galaxy Survey (6dFGS). These surveys use different spectroscopic techniques, long-slit and circular fiber, respectively.

These allow us to assess the influence of different apertures on the activity of the LLQSOs using classical optical diagnostic diagrams. We perform a Gaussian fitting of strong optical emission lines and decompose narrow and broad Balmer components. A small number of our LLQSO present no broad component, which is likely to be present but buried in the noise.

Two sources show double broad components, whereas six comply with the classic NLS1 requirements. As expected in NLR of broad line AGNs, the [SII]-based electron density values range between 100 and 1000N_e_/cm^3^. Using the optical characteristics of Populations A and B, we find that 50% of our sources with H{beta} broad emission are consistent with the radio-quiet sources definition.

The remaining sources could be interpreted as low-luminosity radio-loud quasar. The BPT-based classification renders an AGN/Seyfert activity between 50 to 60%. For the remaining sources, the possible starburst contribution might control the LINER and HII classification.

Finally, we discuss the aperture effect as responsible for the differences found between data sets, although variability in the BLR could play a significant role as well.