The Accretion History of AGN: The Spectral Energy Distributions of X-Ray-luminous Active Galactic Nuclei
Connor Auge, D. B. Sanders, Ezequiel Treister, C. M. Urry, Allison Kirkpatrick, N. Cappelluti, Tonima Tasnim Ananna, M. Boquien, Mislav Baloković, F. Civano, Brandon Coleman, Aritra Ghosh, Jeyhan S. Kartaltepe, Michael Koss, Stephanie LaMassa, Stefano Marchesi, Alessandro Peca, Meredith C. Powell, Benny Trakhtenbrot, T. J. Turner
Abstract
Abstract Spectral energy distributions (SEDs) from X-ray to far-infrared (FIR) wavelengths are presented for a sample of 1246 X-ray-luminous active galactic nuclei (AGNs; L 0.5–10 keV > 10 43 erg s −1 ), with z spec < 1.2, selected from Stripe 82X, COSMOS, and GOODS-N/S. The rest-frame SEDs show a wide spread (∼2.5 dex) in the relative strengths of broad continuum features at X-ray, ultraviolet (UV), mid-infrared (MIR), and FIR wavelengths. A linear correlation (log–log slope of 0.7 ± 0.04) is found between L MIR and L X . There is significant scatter in the relation between the L UV and L X owing to heavy obscuration; however, the most luminous and unobscured AGNs show a linear correlation (log–log slope of 0.8 ± 0.06) in the relation above this scatter. The relation between L FIR and L X is predominantly flat, but with decreasing dispersion at L X > 10 44 erg s −1 . The ratio between the “galaxy-subtracted” bolometric luminosity and the intrinsic L X increases from a factor of ∼10 to 70 from log L bol /(erg s −1 ) = 44.5 to 46.5. Characteristic SED shapes have been determined by grouping AGNs based on relative strengths of the UV and MIR emission. The average L 1 μ m is constant for the majority of these SED shapes, while AGNs with the strongest UV and MIR emission have elevated L 1 μ m , consistent with the AGN emission dominating their SEDs at optical and near-infrared wavelengths. A strong correlation is found between the SED shape and both the L X and L bol , such that L bol / L X = 20.4 ± 1.8, independent of the SED shape. This is consistent with an evolutionary scenario of increasing L bol with decreasing obscuration as the AGN blows away circumnuclear gas.