Variable AGN in the GALEX Time Domain Survey

Abstract

We searched the Northern Hemisphere Fields of the GALEX Time-Domain Survey (TDS) for galaxies with UV variability indicative of active galactic nuclei (AGNs). We identified 48 high-probability candidate AGNs from a parent sample of 1819 galaxies in the NASA Sloan Atlas (NSA) catalog. We further characterized these systems using optical spectroscopic diagnostics, WISE IR color selection criteria, and spectral energy distribution (SED) modeling. Of the 48 candidates, eight were identified as AGNs from optical emission lines, two were identified by their IR colors, and 28 were identified through spectral energy decomposition. Observational biases of each selection method are discussed in connecting these AGNs subsamples to another. By selecting AGNs based on UV variability, we also identified six low-mass AGNs candidates, all of which would have been missed by spectroscopic selection.

arXiv commentResubmitted to The Astrophysical Journal

References in corpus (63)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• The Seventh Data Release of the Sloan Digital Sky Survey
• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• The Host Galaxies of AGN
• A Relationship Between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
• Theoretical Modeling of Starburst Galaxies
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Host Galaxies and Classification of Active Galactic Nuclei
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies
• On characterising the variability properties of X-ray light curves from active galaxies
• The Palomar Transient Factory: System Overview, Performance and First Results
• The First Data Release (DR1) of the LAMOST general survey
• The Zwicky Transient Facility: Science Objectives
• Estimating Black Hole Masses in Active Galaxies Using the Halpha Emission Line
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• Formation of Supermassive Black Holes
• Intermediate-Mass Black Holes
• Obscured and unobscured active galactic nuclei in the Spitzer Space Telescope First Look Survey
• Dwarf Galaxies with Optical Signatures of Active Massive Black Holes
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• Physical properties and environments of nearby galaxies
• unWISE: unblurred coadds of the WISE imaging
• The evolution of massive black hole seeds
• Active Galactic Nuclei with Candidate Intermediate-Mass Black Holes
• Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns
• Emission-line Diagnostics of Low Metallicity AGN
• A New Sample of (Wandering) Massive Black Holes in Dwarf Galaxies from High Resolution Radio Observations
• A ~50,000 solar mass black hole in the nucleus of RGG 118
• Intermediate-mass black holes in dwarf galaxies out to redshift $\sim$ 2.4 in the Chandra COSMOS Legacy Survey
• The role of star-formation and AGN in dust heating of z = 0.3-2.8 galaxies - I. Evolution with redshift and luminosity
• The Biases of Optical Line-Ratio Selection for Active Galactic Nuclei, and the Intrinsic Relationship between Black Hole Accretion and Galaxy Star Formation
• Black Holes at the Centers of Nearby Dwarf Galaxies
• The Intrinsic Properties of SDSS Galaxies
• Optical variability of AGN in the PTF/iPTF survey
• A Uniformly Selected Sample of Low-mass Black Holes in Seyfert 1 Galaxies
• Identifying AGNs in low-mass galaxies via long-term optical variability
• Variability-Selected Quasars in MACHO Project Magellanic Cloud Fields
• X-ray Detected Active Galactic Nuclei in Dwarf Galaxies at $0<z<1$
• Quasar Selection Based on Photometric Variability
• A search for optical AGN variability in 35,000 low-mass galaxies with the Palomar Transient Factory
• A comprehensive and uniform sample of broad-line active galactic nuclei from the SDSS DR7
• Mid-Infrared Colors of Dwarf Galaxies: Young Starbursts Mimicking Active Galactic Nuclei
• X-ray Properties of Intermediate-mass Black Holes in Active Galaxies
• A Sample of Massive Black Holes in Dwarf Galaxies Detected via [Fe X] Coronal Line Emission: Active Galactic Nuclei and/or Tidal Disruption Events
• Stellar Populations of Elliptical Galaxies in the Local Universe
• The Limitations of Optical Spectroscopic Diagnostics in Identifying AGNs in the Low Mass Regime
• X-ray Properties of Intermediate-Mass Black Holes in Active Galaxies. II. X-ray-Bright Accretion and Possible Evidence for Slim Disks
• The GALEX Time Domain Survey I. Selection and Classification of Over a Thousand UV Variable Sources
• The UV Properties of SDSS Selected Quasars
• A Large Population of Obscured AGN in Disguise as Low Luminosity AGN in Chandra Deep Field South
• A Large Population of Luminous Active Galactic Nuclei Lacking X-ray Detections: Evidence for Heavy Obscuration?
• On the AGN Nature of Broad Balmer Emission in Four Low-Redshift Metal-Poor Galaxies
• The UV Emission of Stars in LAMOST Survey I. Catalogs
• A transition mass for black holes to show broad emission lines
• The GALEX Time Domain Survey. II. Wavelength-Dependent Variability of Active Galactic Nuclei in the Pan-STARRS1 Medium Deep Survey

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