Black Hole Accretion is all about Sub-Keplerian Flows

TL;DR

This paper emphasizes the importance of sub-Keplerian flows in black hole accretion, demonstrating through simulations that they are fundamental regardless of the binary system's mass, and highlighting the effectiveness of the Two Component Advective Flow model.

Contribution

The paper introduces the TCAF model with four physical parameters and shows that sub-Keplerian flows are essential for understanding spectral and timing properties in black hole accretion.

Findings

Sub-Keplerian flows are dominant in black hole accretion across different binary systems.

The TCAF model effectively explains spectral and timing phenomena.

Sub-Keplerian component is crucial for disk-jet connection understanding.

Abstract

We review the advantages of fitting with a Two Component Advective Flow (TCAF) which uses only four physical parameters. We then present the results of hydrodynamic simulations to highlight the fact that the primary component of a black hole accretion remains the sub-Keplerian or the low angular momentum flow independent of whether we have a high, intermediate or low mass X-ray binary. Every aspect of spectral and timing properties, including the disk-jet connection could be understood well only if such a component is present along with a Keplerian component of variable size and accretion rate.