Time-Dependent AGN Disc Winds II -- Effects of Photoionization
Abstract
We use a combination of radiation hydrodynamics (rad-HD) and photoionization modeling to study line-driven disc winds for a range of black hole masses. We refined previous models by incorporating heating, cooling, and radiation forces from spectral lines calculated using a photoionization code, assuming that composite AGN spectra irradiate the gas. For black holes with masses , the mass loss rate, increases proportionally with the disk Eddington fraction, . The insensitivity of to the hardness of the spectral energy distribution (SED) arises because the central region is dominated by radiation in the frequency range with ample spectral lines for the range of considered here. Disc winds are suppressed or fail outside the above mass range because of a dearth of line-driving photons. We find \emph{stronger} winds, both in terms of and wind velocity compared to previous disc wind models. Our winds are stronger because of an enhanced line force from including many spectral lines in the X-ray band. These lines were unavailable and, hence, unaccounted for in previous photoionization studies and their subsequent application to AGN wind models. For , is higher than the assumed disc accretion rate, implying that the wind feeds back strongly. Our findings indicate the necessity of utilizing comprehensive and current atomic data along with a more thorough approach to radiation transfer - both spatially and temporally - to accurately calculate the line force.
Cite
@article{arxiv.2504.00117,
title = {Time-Dependent AGN Disc Winds II -- Effects of Photoionization},
author = {Sergei Dyda and Randall C. Dannen and Timothy R. Kallman and Shane W. Davis and Daniel Proga},
journal= {arXiv preprint arXiv:2504.00117},
year = {2025}
}
Comments
12 pages, 11 figures