Multi-phase gas nature in the sub-pc region of the active galactic nuclei I: Dynamical structures of dusty and dust-free outflow [GA]

http://arxiv.org/abs/2304.05950


We investigated dusty and dust-free gas dynamics for a radiation-driven sub-pc scale outflow in an active galactic nucleus (AGN) associated with a supermassive black hole $10^7 M_\odot$ and bolometric luminosity $10^{44}$ erg s$^{-1}$ based on the two-dimensional radiation-hydrodynamic simulations. A radiation-driven lotus-like'' multi-shell outflow is launched from the inner part ($r \lesssim 0.04$ pc) of the geometrically thin disk, and it repeatedly and steadily produces shocks as mass accretion continues through the disk to the center. The shape of the dust sublimation radius is not spherical and depends on the angle ($\theta$) from the disk plane, reflecting the non-spherical radiation field and non-uniform dust-free gas. Moreover, we found that the sublimation radius of $\theta \sim 20$-$60$ deg varies on a timescale of several years. Theinflow-induced outflow” contributes the obscuration of the nucleus in the sub-pc region. The column density of the dust-free gas is $N_{\rm H} \gtrsim 10^{22}$ cm$^{-2}$ for $r \lesssim 0.04$ pc. Gases near the disk plane ($\theta \lesssim 30$ degree) can be the origin of the Compton-thick component, which was suggested by the recent X-ray observations of AGNs. The dusty outflow from the sub-pc region can be also a source of material for the radiation-driven fountain for a larger scale.

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Y. Kudoh, K. Wada, N. Kawakatu, et. al.
Thu, 13 Apr 23
16/59

Comments: 13 pages, 9 figures, accepted for publication in ApJ