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Paper: Warm Absorbers as MHD Accretion-Disk Winds for AGNs/Quasars
Volume: 427, Accretion and Ejection in AGN: a Global View
Page: 106
Authors: Fukumura, K.; Kazanas, D.; Contopoulos, I.; Behar, E.
Abstract: We present a two-dimensional (2D) model for X-ray absorbing plasma based on well-defined magnetohydrodynamic (MHD) accretion disk winds. These winds are primarily characterized by only two parameters, accretion-rate m(dot) and line of sight (LOS) angle θ, for a given magnetic field geometry specified by a free-parameter q. This model naturally produces density profiles n(r,θ) ∝ f(θ)/r (with q=1) where r is the LOS distance, and f(θ) is its angular dependence. This implies equal column density per log(r) and normalization proportional to m(dot). Our 2D MHD wind geometry is then coupled to XSTAR photoionization code to compute a global 2D ionization structure of this wind and the columns of observable ionic species (e.g. Fe XVII and Fe XXV). The specific radial-dependence of the wind ionization parameter, ξ ∝ 1/[rf(θ)], leads naturally to a constant-value of dNH / dlog(ξ), also known as absorption measure distribution (AMD), in excellent agreement with some AGNs/quasars observations; e.g. IRAS 13349+2438, MCG-6-30-15, NGC 5548, NGC 7469 and NGC 3783.
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