James Webb Space Telescope Feed Post

Harvard ADS: X-Ray Weak AGNs from Super-Eddington Accretion onto Infant Black Holes

Paper abstract: A simple model for the X-ray weakness of JWST-selected broad-line AGNs is proposed under the assumption that the majority of these sources are fed at super-Eddington accretion rates. In these conditions, the hot inner corona above the geometrically thin disk that is responsible for the emission of X-rays in "normal" AGNs will be embedded instead in a funnel-like reflection geometry. The coronal plasma will Compton upscatter optical/UV photons from the underlying thick disk as well as the surrounding funnel walls, and the high soft-photon energy density will cool down the plasma to temperatures in the range 30-40 keV. The resulting X-ray spectra are predicted to be extremely soft, with power-law photon indices Gamma=2.8-4.0, making high-z super-Eddington AGNs largely undetectable by Chandra.