Computer modelling of accretion processes in binary systems with black holes and neutron stars

TL;DR

This dissertation employs advanced numerical simulations to model accretion disks in X-ray binaries with black holes and neutron stars, revealing new disk structures and explaining observed spectral and temporal features.

Contribution

It introduces the concept of puffy accretion disks based on numerical simulations and advances the modeling of X-ray variability and oscillations.

Findings

Discovery of puffy accretion disks

Modeling of X-ray variability and QPOs

Implications for observational data

Abstract

This dissertation is written as an annotated collection of selected articles. The dissertation focuses on the modelling of accretion disks in X-ray binaries with a black hole or neutron star. The main objective is to use advanced numerical methods to reveal the fundamental processes that influence the observed spectral and temporal features. Among the significant results of this modelling is the recognition of the puffy accretion disk, a novel type of accretion disk based purely on the results of numerical simulations. Furthermore, the work focuses on modelling the X-ray variability and quasi-periodic oscillations using analytical models of accretion disks, but an advanced description of the oscillations, and a discussion of the implications of this modelling for observational data.