Microlensing evidence for super-Eddington disk accretion in quasars

TL;DR

This paper uses gravitational microlensing observations of quasars to investigate accretion disk structures, finding evidence that some quasars exhibit larger-than-expected emission regions consistent with super-Eddington accretion models.

Contribution

It provides observational evidence supporting the presence of super-Eddington accretion in quasars through microlensing data, challenging standard thin disk models.

Findings

Some quasars match standard accretion disk predictions.

Others show larger emission regions independent of wavelength.

Evidence suggests super-Eddington accretion with outflows.

Abstract

Gravitational microlensing by the stellar population of lensing galaxies provides an important opportunity to spatially resolve the accretion disk structure in strongly lensed quasars. Some of the objects (like Einstein's cross) are reasonably consistent with the predictions of the standard accretion disk model. In other cases, the size of the emitting region is larger than predicted by the standard thin disk theory and practically independent on wavelength. This may be interpreted as an observational manifestation of an optically-thick scattering envelope possibly related to super-Eddington accretion with outflows.