Photoionization Modelling as a Density Diagnostic of Line Emitting/Absorbing Regions in Active Galactic Nuclei

  • Tek Prasad Adhikari

Part of the Springer Theses book series (Springer Theses)

Table of contents

  1. Front Matter
    Pages i-xix
  2. Tek Prasad Adhikari
    Pages 1-13
  3. Tek Prasad Adhikari
    Pages 15-33
  4. Tek Prasad Adhikari
    Pages 35-53
  5. Tek Prasad Adhikari
    Pages 55-81
  6. Tek Prasad Adhikari
    Pages 83-121
  7. Tek Prasad Adhikari
    Pages 123-126

About this book


This book presents timely work on the nature of the physical processes underpinning two of the basic characteristics of the gas structure in the innermost region of Active Galactic Nuclei (AGN): ionized outflows and emission line regions. In addition, it describes physics-based methods for estimating the density of the astrophysical plasma surrounding AGN. All numerical computations of the photoionized gas employ the most advanced codes available (CLOUDY and TITAN). Calculations of the radiative transfer are based on the assumption of thermal and ionization equilibrium. 

Promising preliminary examples of comparison with current observations are included for several individual AGN. All of them suggest that the absorbing/emitting gas should have a density on the order of 1012 cm-3. Future observations will provide more objects to verify these results, and will allow us to put constraints on the launch radius of ionized outflows and therefore on the mass loading and kinetic energy outflow rates. These rates, in turn, are crucial to estimating whether the outflows have a significant feedback impact on star formation and metal enrichment in the interstellar medium of the host galaxy. In closing, the book discusses a representative example of applying powerful photoionization techniques to explain the complex physics of the AGN environment.   


Photoionization Modelling Warm Absorbers TITAN code simulations CLOUDY code simulations Absorption Measure Distribution Intermediate Line Emission Density Diagnostic Active Galactic Nuclei

Authors and affiliations

  • Tek Prasad Adhikari
    • 1
  1. 1.Nicolaus Copernicus Astronomical Center Polish Academy of Sciences(NCAC PAS)WarsawPoland

Bibliographic information