Infrared and hard X-ray diagnostics of AGN identification from the Swift/BAT and AKARI all-sky surveys

Abstract

We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides an unbiased, flux-limited selection of hard X-ray detected AGN. Cross-correlating the 22-month hard X-ray survey with the AKARI all-sky survey, we studied 158 AGN detected by the AKARI instruments. We find a strong correlation for most AGN between the infrared (9, 18, and 90 micron) and hard X-ray (14-195 keV) luminosities, and quantify the correlation for various subsamples of AGN. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution. The correlation for radio galaxies has a slope and normalization identical to that for Seyfert 1s, implying similar hard X-ray/infrared emission processes in both. In contrast, Compton-thick sources show a large deficit in the hard X-ray band, because high gas column densities diminish even their hard X-ray luminosities. We propose two photometric diagnostics for source classification: one is an X-ray luminosity vs. infrared color diagram, in which type 1 radio-loud AGN are well isolated from the others in the sample. The other uses the X-ray vs. infrared color as a useful redshift-independent indicator for identifying Compton-thick AGN. Importantly, Compton-thick AGN and starburst galaxies in composite systems can also be differentiated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new and upcoming surveys such as WISE and NuSTAR.

17 pages, 5 figures, 5 tables. Accepted for publication in the Astrophysical Journal

References in corpus (18)

• Swift BAT Survey of AGN
• Radiative Transfer Modeling of Three-Dimensional Clumpy AGN Tori and its Application to NGC 1068
• Spitzer Quasar and ULIRG evolution study (QUEST): I. The origin of the far infrared continuum of QSOs
• Three-dimensional radiative transfer models of clumpy tori in Seyfert galaxies
• A Spitzer IRS Low-Resolution Spectroscopic Search for Buried AGNs in Nearby Ultraluminous Infrared Galaxies - A Constraint on Geometry between Energy Sources and Dust -
• Mid-Infrared Spectral Diagnostics of Nuclear and Extra-Nuclear Regions in Nearby Galaxies
• Study on X-ray Spectra of Obscured AGNs based on Monte Carlo simulation - an interpretation of observed wide-band spectra
• The Toroidal Obscuration of Active Galactic Nuclei
• The mid IR -- hard X-ray correlation in AGN and its implications for dusty torus models
• Calibration of [O IV] 26 micron as a Measure of Intrinsic AGN Luminosity
• A description of sources detected by INTEGRAL during the first 4 years of observations
• A deep X-ray observation of M82 with XMM-Newton
• The small dispersion of the mid IR -- hard X-ray correlation in AGN
• XMM-Newton observations of the diffuse X-ray emission in the starburst galaxy NGC 253
• Mid-infrared imaging of 25 local AGN with VLT-VISIR
• A broad-band spectral analysis of eight radio loud type 1 AGN selected in the hard X-ray band
• 4C 39.29 - extended emission around a powerful Type 2 quasar
• AKARI-CAS --- Online Service for AKARI All-Sky Catalogues

Cited by in corpus (36)

• The subarcsecond mid-infrared view of local active galactic nuclei: II. The mid-infrared--X-ray correlation
• Revisiting the relationship between 6 μm and 2-10 keV continuum luminosities of AGN
• The Complete Infrared View of Active Galactic Nuclei from the 70-month Swift/BAT Catalog
• Mid and Far Infrared Properties of a Complete Sample of Local AGNs
• SALT Long-slit Spectroscopy of Luminous Obscured Quasars: An Upper Limit on the Size of the Narrow-Line Region?
• Sizes and Kinematics of Extended Narrow-Line Regions in Luminous Obscured AGN Selected by Broadband Images
• Luminosity and Redshift Dependence of the Covering Factor of AGNs viewed with WISE and SDSS
• Polar Dust, Nuclear Obscuration and IR SED Diversity in Type-1 AGNs
• NuSTAR Reveals Extreme Absorption in z < 0.5 Type 2 Quasars
• Gemini Long-slit Observations of Luminous Obscured Quasars: Further Evidence for an Upper Limit on the Size of the Narrow-Line Region
• NuSTAR Observations of Heavily Obscured Quasars at z ~ 0.5
• The NuSTAR Serendipitous Survey: The 40 month Catalog and the Properties of the Distant High Energy X-ray Source Population
• Suzaku Observations of Moderately Obscured (Compton-thin) Active Galactic Nuclei Selected by Swift/BAT Hard X-ray Survey
• The NuSTAR Serendipitous Survey: Hunting for The Most Extreme Obscured AGN at >10 keV
• Herschel Far-Infrared Photometry of the Swift Burst Alert Telescope Active Galactic Nuclei Sample of the Local Universe. I. PACS Observations
• Search for Molecular Outflows in Local Volume AGN with Herschel-PACS
• Does the mid-infrared-hard X-ray luminosity relation for active galactic nuclei depend on Eddington ratio?
• Herschel Far-Infrared Photometry of the Swift Burst Alert Telescope Active Galactic Nuclei Sample of the Local Universe. II. SPIRE Observations
• The nuclear and extended mid-infrared emission of Seyfert galaxies
• GBT Detection of Polarization-dependent HI Absorption and HI Outflows in Local ULIRGs and Quasars
• A Compton thick AGN in the barred spiral NGC 4785
• The infrared to X-ray correlation spectra of unobscured type 1 active galactic nuclei
• Mid-Infrared Diagnostics of the Circumnuclear Environments of the Youngest Radio Galaxies
• Investigating the Covering Fraction Distribution of Swift/BAT AGN with X-ray and IR Observations
• Infrared colour properties of nearby radio-luminous galaxies
• Reflection-dominated nuclear X-ray emission in the early-type galaxy ESO 565--G019
• A Generalized Power-Law Diagnostic for Infrared Galaxies at z>1: Active Galactic Nuclei and Hot Interstellar Dust
• A New Sample of Obscured AGNs Selected from the XMM-Newton and AKARI Surveys
• Suzaku Follow-up of Heavily Obscured Active Galactic Nuclei Detected in Swift/BAT Survey: NGC 1106, UGC 03752, and NGC 2788A
• Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26
• Active Galactic Nuclei and their Role in Galaxy Evolution: The Infrared Perspective
• eROSITA Final Equatorial-Depth Survey (eFEDS): eFEDS X-ray view of WERGS Radio Galaxies selected by the Subaru/HSC and VLA/FIRST survey
• Infrared Colours and Spectral Energy Distributions of Hard X-ray Selected Obscured and Compton-thick AGN
• Mid-Infrared and X-ray luminosity correlations of X-ray point sources in NGC 1399
• X-ray and infrared diagnostics of nearby active galactic nuclei with MAXI and AKARI
• The X-ray statistical properties of dust-obscured galaxies detected by eROSITA