Work

X-Ray Weak Active Galactic Nuclei from Super-Eddington Accretion onto Infant Black Holes

Year: 2024

Type: article

Abstract: A simple model for the X-ray weakness of James Webb Space Telescope–selected broad-line active galactic nuclei (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 Γ ≃ 2.8–4.0, making high-z super-Eddington AGNs largely undetectable by Chandra.

Source: The Astrophysical Journal Letters

DOI: 10.3847/2041-8213/ad90e1

Authors: Piero Madau, Francesco Haardt

Institutions: University of California, Santa Cruz, University of Milano-Bicocca, University of Insubria, Brera Astronomical Observatory, Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca

Language: English

Topic: Astrophysical Phenomena and Observations

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,400

Funders: National Science Foundation, National Aeronautics and Space Administration, Dipartimenti di Eccellenza, Kavli Institute for Theoretical Physics, University of California, Santa Barbara