High-ionization Fe K emission from luminous infrared galaxies

Abstract

The Chandra component of the Great Observatories All-Sky LIRG Survey (GOALS) presently contains 44 luminous and ultraluminous infrared galaxies with log (Lir/Lsun) = 11.73-12.57. Omitting 15 obvious AGNs, the other galaxies are, on average, underluminous in the 2-10 keV band by 0.7 dex at a given far-infrared luminosity, compared to nearby star-forming galaxies with lower star formation rates. The integrated spectrum of these hard X-ray quiet galaxies shows strong high-ionization Fe K emission (Fe XXV at 6.7 keV), which is incompatible with X-ray binaries as its origin. The X-ray quietness and the Fe K feature could be explained by hot gas produced in a starburst, provided that the accompanying copious emission from high-mass X-ray binaries is somehow suppressed. Alternatively, these galaxies may contain deeply embedded supermassive black holes that power the bulk of their infrared luminosity and only faint photoionized gas is visible, as seen in some ULIRGs with Compton-thick AGN.

4 pages, 2 figures, ApJ Letters in press

References in corpus (23)

• Star Formation in Galaxies Along the Hubble Sequence
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• The IRAS Revised Bright Galaxy Sample (RBGS)
• High Mass X-ray Binaries as a Star Formation Rate Indicator in Distant Galaxies
• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• The 2-10 keV luminosity as a Star Formation Rate indicator
• Diagnostics of irradiated gas in galaxy nuclei. I: A Far-ultraviolet and X-ray dominated region code
• Iron line and diffuse hard X-ray emission from the starburst galaxy M82
• Lx-SFR relation in star forming galaxies
• Arp 299: a second merging system with two active nuclei?
• SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity
• Black hole in the West Nucleus of Arp 220
• Millimeter Interferometric HCN(1-0) and HCO+(1-0) Observations of Luminous Infrared Galaxies
• A deep X-ray observation of M82 with XMM-Newton
• Fe K emission in the ultraluminous infrared galaxy Arp220
• Galactic star-formation rates gauged by stellar end-products
• Tracing the Mass-Dependent Star Formation History of Late-Type Galaxies using X-ray Emission: Results from the Chandra Deep Fields
• Chandra Observations of Arp 220: The Nuclear Source
• Chandra-SDSS Normal and Star-Forming Galaxies I: X-ray Source Properties of Galaxies Detected by Chandra in SDSS DR2
• The MicroJansky Radio Galaxy Population
• Resolving the buried starburst in Arp299
• High-resolution HNC 3-2 SMA observations of Arp220
• An XMM-Newton study of Hyper-Luminous Infrared Galaxies

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• C-GOALS: Chandra observations of a complete sample of luminous infrared galaxies from the IRAS Revised Bright Galaxy Survey
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• Investigation of Dual Active Nuclei, Outflows, Shock-Heated Gas, and Young Star Clusters in Markarian 266
• Comprehensive Broadband X-ray and Multiwavelength Study of Active Galactic Nuclei in Local 57 Ultra/luminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT
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• Diffuse Hard X-ray Emission in Starburst Galaxies as Synchrotron from Very High Energy Electrons
• A 33 GHz Survey of Local Major Mergers: Estimating the Sizes of the Energetically Dominant Regions from High Resolution Measurements of the Radio Continuum
• Fast and Furious: Shock Heated Gas as the Origin of Spatially Resolved Hard X-ray Emission in the Central 5 kpc of the Galaxy Merger NGC 6240
• The Buried Starburst in the Interacting Galaxy II Zw 096 as Revealed by the Spitzer Space Telescope
• C-GOALS II. Chandra Observations of the Lower Luminosity Sample of Nearby Luminous Infrared Galaxies in GOALS
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• Heavily Obscured AGN in High Redshift Luminous Infrared Galaxies
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• The role of bars in AGN fueling in disk galaxies over the last seven billion years
• The Radio - X-ray relation as a star formation indicator: Results from the VLA--E-CDFS Survey
• Linking the X-ray and infrared properties of star-forming galaxies at z<1.5
• Evidence for Black Hole Growth in Local Analogs to Lyman Break Galaxies
• A search for AGN in the most extreme UV-selected starbursts using the European VLBI Network
• NuSTAR unveils a heavily obscured low-luminosity Active Galactic Nucleus in the Luminous Infrared Galaxy NGC 6286
• A Focused, Hard X-ray Look at Arp 299 with NuSTAR
• X-ray emission from the nuclear region of Arp 220
• An Iwasawa-Taniguchi Effect for Compton-thick Active Galactic Nuclei
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• X-ray supernova remnants in the starburst region of M82
• The Large Deficit of HMXB Emission from Luminous Infrared Galaxies: the Case of the Circumnuclear Starburst Ring in NGC 7552
• Molecular lines as tracers of Compton-thick AGN ?
• Iron emission line from the spiral galaxy M101