OI and CaII observations in intermediate redshift quasars
  We present an unprecedented spectroscopic survey of the CaII triplet + OI for
a sample of 14 luminous ($-$26 $\gtrsim$ M$_V$ $\gtrsim$ $-$29), intermediate
redshift (0.85 $\lesssim$ $z$ $\lesssim$ 1.65) quasars. The ISAAC spectrometer
at ESO VLT allowed us to cover the CaII NIR spectral region redshifted into the
H and K windows. We describe in detail our data analysis which enabled us to
detect CaII triplet emission in all 14 sources (with the possible exception of
HE0048-2804) and to retrieve accurate line widths and fluxes of the triplet and
OI $\lambda$8446. The new measurements show trends consistent with previous
lower $z$ observations, indicating that CaII and optical FeII emission are
probably closely related. The ratio between the CaII triplet and the optical
FeII blend at $\lambda$4570 $\AA$ is apparently systematically larger in our
intermediate redshift sample relative to a low-$z$ control sample. Even if this
result needs a larger sample for adequate interpretation, higher CaII/optical
FeII should be associated with recent episodes of star formation in the
intermediate redshift quasars and, at least in part, explain an apparent
correlation of CaII triplet equivalent width with $z$ and $L$. The CaII triplet
measures yield significant constraints on the emitting region density and
ionization parameter, implying CaII triplet emission from log n$_H$ $\gtrsim$
11 [cm$^{-3}$] and ionization parameter log $U$ $\lesssim$ 1.5. Line width and
intensity ratios suggest properties consistent with emission from the outer
part of a high density broad line region (a line emitting accretion disk?).
