An FMOS Survey of moderate-luminosity broad-line AGN in COSMOS, SXDS and
  E-CDF-S
  We present near-IR spectroscopy in J- and H-band for a large sample of 243
X-ray selected moderate-luminosity type-1 AGN in the COSMOS, SXDS and E-CDF-S
survey fields using the multi-object spectrograph Subaru/FMOS. Our sample
covers the redshift range 0.5<z<3.0 and an X-ray luminosity range of
$10^{43}\lesssim L_X \lesssim 10^{45}$~erg s$^{-1}$. We provide emission-line
properties and derived virial black hole mass estimates, bolometric
luminosities and Eddington ratios, based on H$\alpha$ (211), H$\beta$ (63) and
MgII (4). We compare line widths, luminosities and black hole mass estimates
from H$\alpha$ and H$\beta$ and augment these with commensurate measurements of
MgII and CIV detected in optical spectra. We demonstrate the robustness of
using H$\alpha$, H$\beta$ and MgII as reliable black hole mass estimators for
high-z moderate-luminosity AGN, while the use of CIV is prone to large
uncertainties (>0.4 dex). We extend a recently proposed correction based on the
CIV blueshift to lower luminosities and black hole masses. While our sample
shows an improvement in their CIV black hole mass estimates, the deficit of
high blueshift sources reduces its overall importance for moderate-luminosity
AGN, compared to the most luminous quasars. In addition, we revisit luminosity
correlations between $L_{\rm{bol}}$, $L_X$, $L_{\rm{[OIII]}}$, $L_{5100}$ and
$L_{\rm{H}\alpha}$ and find them to be consistent with a simple empirical
model, based on a small number of well-established scaling relations. We
finally highlight our highest redshift AGN, CID 781, at z=4.6 which shows the
lowest black hole mass ($\sim10^8$M$_\odot$) among current near-IR samples at
this redshift, and is in a state of fast growth.
