• Large-scale Dynamics of Line-driven Winds with the Re-radiation Effect

    分类: 物理学 >> 地球物理学、天文学和天体物理学 提交时间: 2024-01-09 合作期刊: 《Research in Astronomy and Astrophysics》

    摘要: Previous simulations studying winds only focus on the line force due to photons from central active galactic nuclei. What properties of the winds will be when including the re-radiation force due to the scattered and reprocessed photons (i.e., the re-radiation effect)? We perform simulations to study the large-scale dynamics of accretion disk winds driven by radiation line force and re-radiation force. For the fiducial run, we find that the re-radiation force drives stronger outflows during the early stages. When the flows get into the steadiness, the UV radiation due to spectral lines dominates total radiation and the re-radiation effect could be negligible. The opening angle of winds narrows as the initial gas density increases. The larger the gas density is, the stronger the re-radiation effect will be. For MBH = 106M⊙, ε = 0.3, the outflows do become much stronger with the re-radiation effect and the winds still cannot escape from gravitational potential. We find that the detection probability of ultra-fast outflows and the properties of the winds are both consistent with the observations.

  • Large-scale Dynamics of Winds Driven by Line Force from a Thin Accretion Disk

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Winds play a significant role in active galactic nuclei feedback process. Previous simulations studying winds only focus on a small dynamical range. Therefore, it is unknown how far the winds can go and what the properties of the winds will be if they can move to large radii. We perform simulations to study the large scale dynamics of winds driven by line force. We find that the properties of the winds depend on both black hole mass ($M_{BH}$) and accretion disk luminosity. When the accretion disk luminosity is $0.6L_{edd}$ ($L_{edd}$ being Eddington luminosity), independent of $M_{BH}$, the winds have kinetic energy flux exceeding $1\% L_{edd}$ and can escape from the black hole potential. For the case with the accretion disk luminosity equaling 0.3$L_{edd}$, the strength of the winds decreases with the decrease of $M_{BH}$. If $M_{BH}$ decreases from $10^9$ to $10^6$ solar mass ($M_\odot$), the winds kinetic energy flux decreases from $\sim 0.01 L_{edd}$ to $ \sim 10^{-6} L_{edd}$. In case of $M_{BH}\geq 10^7 M_\odot$, winds can escape from black hole potential. In the case of $M_{BH}=10^6 M_\odot$, the winds can not escape. We find that for the ultra-fast winds observed in hard X-ray bands (\citealt{Gofford et al. 2015}), the observed dependence of the mass flux and the kinetic energy flux on accretion disk luminosity can be well produced by line force driven winds model. We also find that the properties of the ultra-fast winds observed in soft X-ray bands can be explained by the line force driven winds model.