Relativistic Radiative Hydrodynamics Calculation of Accretion Flow into Supermassive Black Hole

Leung, Po Kin

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https://hdl.handle.net/2142/18532 Copy

Description

Title

Relativistic Radiative Hydrodynamics Calculation of Accretion Flow into Supermassive Black Hole

Author(s)

Leung, Po Kin

Issue Date

2011-01-21T22:44:59Z

Director of Research (if dissertation) or Advisor (if thesis)

Gammie, Charles F.

Doctoral Committee Chair(s)

Gammie, Charles F.

Committee Member(s)

• Webbink, Ronald F.
• Ricker, Paul M.
• Kemball, Athol J.

Department of Study

Astronomy

Discipline

Astronomy

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Accretion
• Black hole
• Supermassive black hole
• Synchrotron emission
• Sagittarius A*
• Radiative transfer

Abstract

The compact radio source Sagittarius A* (Sgr A*) is the nearest and most-intensively-studied supermassive black hole candidate. With a broadband spectrum which likely requires several emission mechanisms for explanation, and structure of innermost accretion flow not yet well constrained, the understanding of accretion into Sgr A* demands advances in both theories and computational calculation. To increase the understanding of Sgr A* in particular, and low-luminosity active galactic nuclei in general, we perform relativistic radiative transfer (RT) calculation with general relativistic magnetohydrodynamic (GRMHD) simulation of accretion flow simulation. We are able to use the models to constrain observational parameters of Sgr A*. We also compute the synchrotron emissivity and absorptivity from first principles, in order to verify improved approximate equations for the RT calculation. The code can handle a wide range of electron distributions, therefore the application is not limited to accretion disk simulation. In order to explain a feature in the observed flaring spectrum, we add nonthermal component to the electron distribution. We then perform relativistic Monte Carlo RT calculation of the disk model, and show that a small amount of power-law electron is enough to modify the spectral slope. Finally, we describe a recipe for performing relativistic polarized RT, which would allow a further study to constrain model parameters with polarization observations from Sgr A*.

Graduation Semester

2010-12

Permalink

http://hdl.handle.net/2142/18532

Copyright and License Information

2010 by Po Kin Leung. All rights reserved.

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