Photoionization Models for High-density Gas

Kallman T, Bautista M, Deprince J, Garcia J, Mendoza C, Ogorzalek A, Palmeri P, Quinet P (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Astrophysical Journal American Astronomical Society

Book Volume: 908

Article Number: 94

Journal Issue: 1

DOI: 10.3847/1538-4357/abccd6

Abstract

Relativistically broadened and redshifted 6.4-6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei. The existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to remain partially ionized. Simple estimates indicate that high gas densities are needed to allow for the survival of iron against ionization. These are high enough that rates for many atomic processes are affected by mechanisms related to interactions with nearby ions and electrons. Radiation intensities are high enough that stimulated processes can be important. Most models currently in use for interpreting relativistic lines use atomic rate coefficients designed for use at low densities and neglect stimulated processes. In our work so far we have presented atomic structure calculations with the goal of providing physically appropriate models at densities consistent with line-emitting gas near compact objects. In this paper we apply these rates to photoionization calculations, and produce ionization balance curves and X-ray emissivities and opacities that are appropriate for high densities and high radiation intensities. The final step in our program will be presented in a subsequent paper in which model atmosphere calculations will incorporate these rates into synthetic spectra.

Authors with CRIS profile

Javier Garcia Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut

Involved external institutions

National Aeronautics and Space Administration (NASA) US United States (USA) (US) University of Mons / Université de Mons BE Belgium (BE) Western Michigan University (WMU) US United States (USA) (US)

How to cite

APA:

Kallman, T., Bautista, M., Deprince, J., Garcia, J., Mendoza, C., Ogorzalek, A.,... Quinet, P. (2021). Photoionization Models for High-density Gas. Astrophysical Journal, 908(1). https://dx.doi.org/10.3847/1538-4357/abccd6

MLA:

Kallman, T., et al. "Photoionization Models for High-density Gas." Astrophysical Journal 908.1 (2021).

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