Narrow lines correlations in an SDSS sample of type 1 quasars
  Investigation of quasar emission line properties and relationships between
spectral parameters is important for understanding the physical mechanisms that
originate inside different regions of the active galactic nuclei. In this
paper, we investigate the optical spectral parameters of type 1 quasars taken
from the Sloan Digital Sky Survey Data Release 7 Quasar Catalog
(arXiv:1006.5178 [astro-ph.CO]). Spectral parameters, such are equivalent
widths and full widths at half maximum of both narrow and broad lines are taken
into account. We perform the analysis of correlation matrix and principal
component analysis of our sample. We obtain that the narrow line Baldwin effect
is significant enough and deserves further investigation. We provide the
correlation coefficients and slope values for Baldwin effect in several narrow
lines.
