Black Hole Accretion: From Quasars to Nano-Quasars

TL;DR

This review discusses recent evidence supporting the significance of sub-Keplerian components in black hole accretion, emphasizing their role in spectral and timing properties and advocating for the advective disk paradigm as a comprehensive model.

Contribution

It provides a comprehensive overview of the sub-Keplerian accretion model and argues for its correctness based on recent observational signatures.

Findings

Sub-Keplerian components are significant in black hole accretion.

The advective disk paradigm explains spectral and timing properties.

Signatures of sub-Keplerian motion are increasingly observed in literature.

Abstract

In this review we shall comment on a few recent findings which strengthen the view that the black hole accretion has substantial amount of sub-Keplerian component. The manifestation of this component is many fold. We discuss some of them. A general outline of the complex structure that emerges from the multitude of observations is presented. A detailed outline of what might be going on in outburst sources is also discussed. The relationship amount the spectral and timing properties can be best understood by this picture. We claim that the sub-Keplerian advective disk paradigm is a complete package. Since signatures of sub-Keplerian motion is already increasing in the literature, the whole package must be correct.