Misclassified type 1 AGNs in the local universe

Abstract

We search for misclassified type 1 AGNs among type 2 AGNs identified with emission line flux ratios, and investigate the properties of the sample. Using 4\,113 local type 2 AGNs at $0.02<z<0.05$ selected from Sloan Digital Sky Survey Data Release 7, we detected a broad component of the \Ha\ line with a Full-Width at Half-Maximum (FWHM) ranging from 1\,700 to 19\,090 \kms\ for 142 objects, based on the spectral decomposition and visual inspection. The fraction of the misclassified type 1 AGNs among type 2 AGN sample is $\sim$3.5%, implying that a large number of missing type 1 AGN population may exist. The misclassified type 1 AGNs have relatively low luminosity with a mean broad \Ha\ luminosity, log L${}_{H\alpha }=40.50\pm 0.35$ \ergs, while black hole mass of the sample is comparable to that of the local black hole population, with a mean black hole mass, log M${}_{\mathrm{BH}}=6.94\pm 0.51$ M${}_{\odot }$. The mean Eddington ratio of the sample is log L${}_{\mathrm{bol}}$/L${}_{\mathrm{Edd}}$ = $-2.00\pm 0.40$, indicating that black hole activity is relatively weak, hence, AGN continuum is too weak to change the host galaxy color. We find that the \OIII\ lines show significant velocity offsets, presumably due to outflows in the narrow-line region, while the velocity offset of the narrow component of the \Ha\ line is not prominent, consistent with the ionized gas kinematics of general type 1 AGN population.

arXiv comment12 pages, 8 figures, JKAS in press

References in corpus (42)

• The Seventh Data Release of the Sloan Digital Sky Survey
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Parametric Recovery of Line-of-Sight Velocity Distributions from Absorption-Line Spectra of Galaxies via Penalized Likelihood
• The Host Galaxies and Classification of Active Galactic Nuclei
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• On the Black Hole Mass - Bulge Mass Relation
• Galaxy Zoo : Morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey
• Revisiting the Scaling Relations of Black Hole Masses and Host Galaxy Properties
• The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• The Low-Luminosity End of the Radius-Luminosity Relationship for Active Galactic Nuclei
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• AGN Black Hole Masses and Bolometric Luminosities
• Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies
• Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the M-sigma Relationship for AGNs
• Dwarf Galaxies with Optical Signatures of Active Massive Black Holes
• A New Sample of Low-mass Black Holes in Active Galaxies
• Active Galactic Nuclei with Candidate Intermediate-Mass Black Holes
• The Lick AGN Monitoring Project: The MBH - sigma Relation For Reverberation-Mapped Active Galaxies
• Accretion and star formation rates in low redshift type-II active galactic nuclei
• On the nature of Seyfert galaxies with high [OIII]5007 blueshifts
• Galaxy Zoo: The fundamentally different co-evolution of supermassive black holes and their early- and late-type host galaxies
• Cosmic Evolution of Black Holes and Spheroids. I: The M_BH-sigma Relation at z=0.36
• Exploring the Low-Mass End of The M-Sigma Relation with Active Galaxies
• A SAURON study of M32: measuring the intrinsic flattening and the central black hole mass
• The Demographics of Broad Line Quasars in the Mass-Luminosity Plane II. Black Hole Mass and Eddington Ratio Functions
• Improved and Quality-assessed Emission and Absorption Line measurements in Sloan Digital Sky Survey galaxies
• Do quiescent and active galaxies have different M_BH-sigma relations?
• Blueshifted [O III] Emission: Indications of a Dynamic NLR
• The FIRST-2MASS Red Quasar Survey
• A Physical Model for the Luminosity Function of High-Redshift Quasars
• Type 1 low z AGN. I. Emission properties
• Galaxy Zoo: The large-scale spin statistics of spiral galaxies in the Sloan Digital Sky Survey
• The Lick AGN Monitoring Project: Recalibrating Single-Epoch Virial Black Hole Mass Estimates
• Radial Velocity Offsets Due to Mass Outflows and Extinction in Active Galactic Nuclei
• The Black Hole-Bulge Relationship in Luminous Broad-Line Active Galactic Nuclei and Host Galaxies
• A Census of Gas Outflows in Type 2 Active Galactic Nuclei
• Chandra-SDSS Normal and Star-Forming Galaxies I: X-ray Source Properties of Galaxies Detected by Chandra in SDSS DR2
• Dust Reddened Quasars in FIRST and UKIDSS: Beyond the Tip of the Iceberg
• Effects of Inclination on Measuring Velocity Dispersion and Implications for Black Holes
• Calibrating stellar velocity dispersions based on spatially-resolved h-band spectra for improving the m-sigma relation
• Tidal disruptions in circumbinary discs (I): Star formation, dynamics, and binary evolution

Cited by in corpus (12)

• The black hole mass - stellar velocity dispersion relation of narrow-line Seyfert 1 galaxies
• A census of ionized gas outflows in type 1 AGNs: gas outflows in AGNs. V
• Are there reliable methods to estimate the nuclear orientation of Seyfert galaxies?
• The flux ratio of the [N II]$\lambda \lambda$ 6548, 6583 Å lines in sample of Active Galactic Nuclei Type 2
• The correlation of outflow kinematics with star formation rate -- Gas outflows in AGNs. VI
• Tracing the outflow kinematics in Type 2 Active Galactic Nuclei
• Outflow kinematics manifested by the H-alpha line: gas outflows in Type 2 AGNs. IV
• An evolutionary missing link? A modest-mass early-type galaxy hosting an over-sized nuclear black hole
• A Polarimetric Method for Measuring Black Hole Masses in Active Galactic Nuclei
• A systematic search for hidden type 1 AGNs: gas kinematics and scaling relations
• Mapping the diffuse interstellar bands $\lambda$5780 and $\lambda$6284 in the luminous infrared galaxy merger NGC 6240
• Search of Intermediate Mass Black Holes at Low Redshift with Intra-night Variability