Building the Largest Pure Sample of Narrow-Line Seyfert 1 Galaxies with FORS2 Spectroscopy

Narrow-Line Seyfert 1 (NLS1) galaxies exhibit narrow permitted Hß lines (FWHM < 2000 km/s) and strong Fe II multiplets with low black hole (BH) masses (< 10^8 M?) and high Eddington ratio. The BH masses and predominantly disk-like hosts suggest that NLS1s are an early-stage Active Galactic Nuclei (AGN). They host the lowest mass super massive BHs that can launch relativistic jets and offer insight into the conditions necessary for jet formation. But classifying NLS1s in large samples is challenging due to low S/N ratio. We use FORS2 observations of ~100 candidate NLS1s to classify the sources and perform detailed spectral modelling of Hß, [OIII], and the Fe II pseudo-continuum using the Voigt profile. We found 16 Changing-look AGN and a contamination factor of ~28% in our data. We study how the line profile of the broad Hß line changes from Lorentzian to Keplerian motion-dominated Gaussian with the BH mass to determine if the changing line profile is an essential part of intraclass evolution. We also measure the parameters of ionized gas like electron density and temperature to compare with other AGN classes. Studying NLS1s in the local universe, which resembles high-z, AGN allows us to explore BH growth in the early universe.