Mid-Infrared Selected Quasars I: Virial Black Hole Mass and Eddington Ratios

Abstract

We provide a catalog of 391 mid-infrared-selected (MIR, 24$\mu$m) broad-emission-line (BEL, type 1) quasars in the 22 deg${}^2$ SWIRE Lockman Hole field. This quasar sample is selected in the MIR from Spitzer MIPS with $S_{24}>400\mu$Jy, jointly with an optical magnitude limit of r (AB) $<$ 22.5 for broad line identification. The catalog is based on MMT and SDSS spectroscopy to select BEL quasars, extends the SDSS coverage to fainter magnitudes and lower redshifts, and recovers a more complete quasar population. The MIR-selected quasar sample peaks at $z\sim$1.4, and recovers a significant and constant (20\%) fraction of extended objects with SDSS photometry across magnitudes, which was not included in the SDSS quasar survey dominated by point sources. This sample also recovers a significant population of $z<3$ quasars at $i>19.1$. We then investigate the continuum luminosity and line profiles of these MIR quasars, and estimate their virial black hole masses and the Eddington ratios. The SMBH mass shows evidence of downsizing, though the Eddington ratios remain constant at $1<z<4$. Compared to point sources in the same redshift range, extended sources at $z<1$ show systematically lower Eddington ratios. The catalog and spectra are publicly available online.

72 pages, 27 figures, 16 tables; ApJ accepted

References in corpus (20)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• A Catalog of Quasar Properties from SDSS DR7
• Biases in Virial Black Hole Masses: An SDSS Perspective
• The Sloan Digital Sky Survey Quasar Catalog IV. Fifth Data Release
• The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements
• Photometric redshift and classification for the XMM-COSMOS sources
• Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral Energy Distributions of Palomar-Green Quasars
• The Luminosity Function of X-ray Selected Active Galactic Nuclei: Evolution of Supermassive Black Holes at High Redshift
• How Mergers May Affect The Mass Scaling Relations Between Black Holes, Galaxies, and Other Gravitationally Bound Systems
• CIV 1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei
• Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey
• The Intrinsic Fraction of Broad Absorption Line Quasars
• Spitzer Reveals Hidden Quasar Nuclei in Some Powerful FR II Radio Galaxies
• The FIRST-2MASS Red Quasar Survey
• Widespread and Hidden Active Galactic Nuclei in Star-Forming Galaxies at Redshift > 0.3
• Narrow associated QSO absorbers: clustering, outflows and the line-of-sight proximity effect
• Luminosity Function Constraints on the Evolution of Massive Red Galaxies Since z~0.9
• Mid-Infrared Diagnostics of LINERs
• Galaxy Counts at 24 Microns in the SWIRE Fields
• Spectrophotometry with Hectospec, the MMT's Fiber-Fed Spectrograph

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