The Frequency of Polarized Broad Emission Lines in Type 2 Seyfert Galaxies

Abstract

We have discovered polarized broad emission lines in five type 2 Seyfert galaxies (NGC 424, NGC 591, NGC 2273, NGC 3081, and NGC 4507), establishing that these objects are type 1 Seyferts obscured by dense circumnuclear material. The galaxies are part of a distance-limited sample of 31 Seyfert 2s, for which spectropolarimetric observations are now complete. Combined with published reports, our results indicate that at least 11 of the galaxies in this sample, or > 35%, possess hidden broad-line regions. This represents the first reliable estimate of the frequency of polarized broad emission lines in type 2 Seyferts, which has important implications for the general applicability of Seyfert unification models.

13 pages, including 5 figures. Accepted for publication in ApJ Letters

References in corpus (2)

• Radio Continuum Morphology of Southern Seyfert Galaxies
• Polarized Broad-Line Emission from Low-Luminosity Active Galactic Nuclei

Cited by in corpus (101)

• The star formation history of Seyfert 2 nuclei
• The Megamaser Cosmology Project. III. Accurate Masses of Seven Supermassive Black Holes in Active Galaxies with Circumnuclear Megamaser Disks
• First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN
• The dusty heart of nearby active galaxies -- II. From clumpy torus models to physical properties of dust around AGN
• The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas
• Hidden Broad Line Seyfert 2 Galaxies in the CfA and 12micron Samples
• "Hidden" Seyfert 2 Galaxies and the X-ray Background
• Unabsorbed Seyfert 2 galaxies
• A Hubble Space Telescope Survey of Extended [OIII]5007A Emission in a Far-Infrared Selected Sample of Seyfert Galaxies: Observations
• Empirical diagnostics of the starburst-AGN connection
• Seyferts on the edge: polar scattering and orientation-dependent polarization in Seyfert 1 nuclei
• Parsec-scale dust emission from the polar region in the type 2 nucleus of NGC 424
• The Unified Model & Evolution of Active Galaxies: Implications from a Spectropolarimetric Study
• Kinematics of the Narrow-Line Region in the Seyfert 2 Galaxy NGC 1068: Dynamical Effects of the Radio Jet
• The subarcsecond mid-infrared view of local active galactic nuclei: III. Polar dust emission
• Mid-infrared emission of galactic nuclei: TIMMI2 versus ISO observations and models
• An Imaging Survey of Early-Type Barred Galaxies
• On The Nature of Low Luminosity Narrow Line AGN
• The NuSTAR View of Nearby Compton-thick AGN: The Cases of NGC 424, NGC 1320 and IC 2560
• The Link Between the Hidden Broad Line Region and the Accretion Rate in Seyfert 2 Galaxies
• On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei
• Near-infrared spectroscopy of nearby Seyfert galaxies. I. First results
• Statistical Properties of Radio Emission from the Palomar Seyfert Galaxies
• Chandra High Energy Grating Observations of the Fe Ka Line Core in Type 2 Seyfert Galaxies: A Comparison with Type 1 Nuclei
• On the relation of optical obscuration and X-ray absorption in Seyfert galaxies
• The Unified Model of Active Galactic Nuclei: II. Evolutionary Connection
• A compendium of AGN inclinations with corresponding UV/optical continuum polarization measurements
• Investigating on the nuclear obscuration in two types of Seyfert 2 galaxies
• Low-Mass Seyfert 2 Galaxies in the Sloan Digital Sky Survey
• Unobscured Type 2 AGNs
• Near-infrared spectroscopy of nearby Seyfert galaxies - II. Molecular content and coronal emission
• Infrared Spectral Energy Distributions of Seyfert Galaxies: Spitzer Space Telescope Observations of the 12 micron Sample of Active Galaxies
• The accretion ratios in Seyfert 2 galaxies with and without hidden broad-line regions
• Feeding and feedback in the active nucleus of Mrk 1157 probed with Gemini Near-Infrared Integral-Field Spectrograph
• Probing the Physics of Narrow Line Regions in Active Galaxies II: The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)
• Are Most Low-Luminosity AGN Really Obscured?
• STIS Echelle Observations of the Seyfert Galaxy NGC 4151: Physical Conditions in the Ultraviolet Absorbers
• Spectropolarimetry of Seyfert 1 galaxies with equatorial scattering: Black hole masses and Broad Line Region characteristics
• Are there reliable methods to estimate the nuclear orientation of Seyfert galaxies?
• The Unified Model of Active Galactic Nuclei: I. Non-hidden Broad Line Region Seyfert 2 and Narrow Line Seyfert 1 Galaxies
• Seyfert 2 Galaxies with Spectropolarimetric Observations
• A Composite Seyfert 2 X-ray Spectrum: Implications for the Origin of the Cosmic X-ray Background
• X-ray spectral variability of Seyfert 2 galaxies
• Probing the Physics of Narrow Line Regions in Active Galaxies IV: Full data release of The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)
• Spectropolarimetry of a Complete Infrared Selected Sample of Seyfert 2 Galaxies
• Unveiling the nature of the highly obscured AGN in NGC5643 with XMM-Newton
• Demystifying the coronal line region of active galactic nuclei: spatially resolved spectroscopy with HST
• Feeding and Feedback in NGC3081
• Infrared spectroscopy around 4micron of Seyfert 2 galaxies: Obscured broad line regions and coronal lines
• Upholding the Unified Model for Active Galactic Nuclei: VLT/FORS2 Spectropolarimetry of Seyfert 2 galaxies
• The intrinsic emission of Seyfert galaxies observed with BeppoSAX/PDS I. Comparison of the average spectra of the three classes of Seyfert Galaxies
• The mid-infrared emission of Seyfert galaxies. A new analysis of ISOCAM data
• Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies
• A New Black Hole Mass Estimate for Obscured Active Galactic Nuclei
• Understanding AGN-Host Connection in Partially Obscured Active Galactic Nuclei. Part I: The Nature of AGN+HII Composites
• Chandra Observations of Candidate "True" Seyfert 2 Nuclei
• The infrared luminosity of the torus and the visibility of scattered broad line emission in Seyfert 2 galaxies
• Dust and PAH emission in the star-forming active nucleus of NGC 1097
• Circumnuclear star-formation and AGN activity: Clues from surface brightness radial profile of PAHs and [SIV]
• Galaxies Correlating with Ultra-high Energy Cosmic Rays
• "Hidden" Seyfert 2 Galaxies in the Chandra Deep Field North
• Nuclear obscuration and scattering in Seyfert 2 galaxies
• The Different Nature in Seyfert 2 Galaxies With and Without Hidden Broad-Line Regions
• The K-band properties of Seyfert 2 galaxies
• Chandra observations of NGC4698: a Seyfert-2 with no absorption
• Chandra and XMM-Newton observations of Tololo 0109-383
• UV Imaging Polarimetry of the Seyfert 2 Galaxy Mrk 3
• Measuring the level of nuclear activity in Seyfert galaxies and the unification scheme
• A Search for Optical Variability of Type 2 Quasars in SDSS Stripe 82
• The X-ray spectral signatures from the complex circumnuclear regions in the Compton thick AGN NGC 424
• A complete disclosure of the hidden type-1 AGN in NGC 1068 thanks to 52 years of broadband polarimetric observation
• VISIR/VLT mid-infrared imaging of Seyfert nuclei: Nuclear dust emission and the Seyfert-2 dichotomy
• Constraining the X-ray reflection in low accretion rate AGN using XMM-Newton, NuSTAR and Swift
• Decoupling absorption and continuum variability in the Seyfert 2 NGC 4507
• Optically-Selected BLR-less Active Galactic Nuclei from the SDSS Stripe82 Database I: The Sample
• The X-ray variability of Seyfert 1.8/1.9 galaxies
• Nuclear Infrared Spectral Energy Distribution of Type II Active Galactic Nuclei
• Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy
• Nuclear obscuration in the high-ionization Seyfert 2 galaxy Tol 0109-383
• Low-frequency radio observations of Seyfert galaxies: A test to the unification scheme
• Investigating the central engine of Seyfert 2 galaxies with and without Polarized Broad Lines
• Multiple Flares in the Changing-Look AGN NGC 5273
• Constraints on the densities and temperature of Seyfert 2 NLR
• Hidden Broad-line Regions in Seyfert 2 Galaxies: from the spectropolarimetric perspective
• Constraining Torus Models for AGNs Using X-Ray Observations
• Systematic research of low redshift optically selected SDSS Type-2 AGN but with apparent long-term optical variabilities from Catalina Sky Survey, I: data sample and basic results
• Type 1 Active Galactic Nucleus Fraction in SDSS/FIRST Survey
• XMM Observations of the Seyfert 2 Galaxy NGC 7590: the Nature of X-ray Absorption
• The Impact of the Dusty Torus on Obscured Quasar Halo Mass Measurements
• Are Seyfert 2 Galaxies without Polarized Broad Emission Lines More Obscured?
• The study of Seyfert 2 galaxies with and without infrared broad lines
• Ionization Mechanisms of HBLR and Non-HBLR Seyfert 2 Galaxies
• On the Structure of the AGN Torus through the Fraction of Optically-Selected Type 1 AGNs
• The Awakening Beast in the Seyfert 1 Galaxy KUG 1141+371 I
• Spectropolarimetric measurements of hidden broad lines in nearby megamaser galaxies: a lack of clear evidence for a correlation between black hole masses and virial products
• On a method to resolve the nuclear activity in galaxies as applied to the Seyfert 2 galaxy NGC1358
• OVI Asymmetry and an Accelerated Outflow in an Obscured Seyfert: FUSE and HST STIS Spectroscopy of Markarian533
• Polarization in broad emission lines of Active Galactic Nuclei
• Distant X-ray Galaxies: Insights from the Local Population
• The X-ray Nature of Nucleus in Seyfert 2 Galaxy NGC 7590
• Infrared and Optical Emission-line Diagnostics