An FMOS Survey of Moderate-luminosity, Broad-line AGNs in COSMOS, SXDS, and E-CDF-S

<jats:title>Abstract</jats:title> <jats:p>We present near-IR spectroscopy in the <jats:italic>J</jats:italic>- and <jats:italic>H</jats:italic>-bands for a large sample of 243 X-ray-selected, moderate-luminosity Type 1 active galactic nuclei (AGNs) in the COSMOS, SXDS, and E-CDF-S survey fields using the multi-object spectrograph <jats:italic>Subaru</jats:italic>/FMOS. Our sample covers the redshift range 0.5 ≲ <jats:italic>z</jats:italic> ≲ 3.0 and X-ray luminosity range of 10<jats:sup>43</jats:sup> ≲ <jats:inline-formula> <jats:tex-math> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsaae82fieqn1.gif" xlink:type="simple"/> </jats:inline-formula> ≲ 10<jats:sup>45</jats:sup> erg s<jats:sup>−1</jats:sup>. We provide emission-line properties and derived virial black hole mass estimates, bolometric luminosities, and Eddington ratios, based on H<jats:italic>α</jats:italic> (211), H<jats:italic>β</jats:italic> (63), and Mg <jats:sc>ii</jats:sc> (4). We compare line widths, luminosities, and black hole mass estimates from H<jats:italic>α</jats:italic> and H<jats:italic>β</jats:italic>, and augment these with commensurate measurements of Mg <jats:sc>ii</jats:sc> and C <jats:sc>iv</jats:sc> detected in optical spectra. We demonstrate the robustness of using H<jats:italic>α</jats:italic>, H<jats:italic>β</jats:italic>, and Mg <jats:sc>ii</jats:sc> as reliable black hole mass estimators for high-<jats:italic>z</jats:italic> moderate-luminosity AGNs, while the use of C <jats:sc>iv</jats:sc> is prone to large uncertainties (≳0.4 dex). We extend a recently proposed correction based on the C <jats:sc>iv</jats:sc> blueshift to lower luminosities and black hole masses. While our sample shows an improvement in their C <jats:sc>iv</jats:sc> black hole mass estimates, the deficit of high blueshift sources reduces its overall importance for moderate-luminosity AGNs compared to the most luminous quasars. In addition, we revisit luminosity correlations between <jats:italic>L</jats:italic> <jats:sub>bol</jats:sub>, <jats:inline-formula> <jats:tex-math> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjsaae82fieqn2.gif" xlink:type="simple"/> </jats:inline-formula>, <jats:italic>L</jats:italic> <jats:sub>[O <jats:sc>iii</jats:sc>]</jats:sub>, <jats:italic>L</jats:italic> <jats:sub>5100</jats:sub>, and <jats:italic>L</jats:italic> <jats:sub>H<jats:italic>α</jats:italic> </jats:sub> and find them to be consistent with a simple empirical model, based on a small number of well-established scaling relations. Finally, we highlight our highest redshift AGN, CID 781, at <jats:italic>z</jats:italic> = 4.6, which has the lowest black hole mass (∼10<jats:sup>8</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) among current near-IR samples at this redshift and is in a state of fast growth.</jats:p>