A magnetic reconnection origin for the soft X-ray excess in AGN

TL;DR

This paper proposes a magnetic reconnection model in accretion disks to explain the soft X-ray excess observed in Active Galactic Nuclei, linking magnetic activity to X-ray emission.

Contribution

It introduces a novel scenario where magnetic reconnection in accretion disks accelerates electrons, producing soft X-rays via inverse Compton scattering, supported by spectral fitting.

Findings

Magnetic reconnection can produce sufficient luminosity in the inner disk.

The model successfully fits observed AGN spectra with soft X-ray excess.

Magnetic fields in accretion disks are estimated to support the scenario.

Abstract

We present a new scenario to explain the soft X-ray excess in Active Galactic Nucleus. The magnetic reconnection could happen in a thin layer on the surface of accretion disk. Electrons are accelerated by shock wave and turbulence triggered by magnetic reconnection, then they take place inverse Compton scattering above accretion disk which contributes soft X-rays. Based on standard disk model, we estimate the magnetic field strength and the energy released by magnetic reconnection along accretion disk, and find that the luminosity caused by magnetic reconnection mainly emits in the inner disk which is dominated by radiation pressure. We then apply the model to fit the spectra of AGNs with strong soft X-ray excess.