The Picture of BLR in 2.5D FRADO: Dynamics and Geometry
- 1 October 2021
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 920 (1), 30
- https://doi.org/10.3847/1538-4357/ac139d
Abstract
The dynamics of the broad line region (BLR) in active galaxies is an open question; direct observational constraints suggest a predominantly Keplerian motion, with possible traces of inflow or outflow. In this paper we study in detail the physically motivated BLR model of Czerny & Hryniewicz based on the radiation pressure acting on dust at the surface layers of the accretion disk (AD). We consider here a nonhydrodynamical approach to the dynamics of the dusty cloud under the influence of radiation coming from the entire AD. We use here a realistic description of the dust opacity, and we introduce two simple geometrical models of the local shielding of the dusty cloud. We show that the radiation pressure acting on dusty clouds is strong enough to lead to dynamical outflow from the AD surface, so the BLR has a dynamical character of a (mostly failed) outflow. The dynamics strongly depends on the Eddington ratio of the source. Large Eddington ratio sources show a complex velocity field and large vertical velocities with respect to the AD surface, while for lower Eddington ratio sources vertical velocities are small and most of the emission originates close to the AD surface. Cloud dynamics thus determines the 3D geometry of the BLR.Keywords
Funding Information
- Polish funding agency national science center (2017/26/A/ST9/00756)
- Ministerstwo Nauki i Szkolnictwa Wyższego (DIR/WK/2018/12)
This publication has 188 references indexed in Scilit:
- THE STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. I. RECONSTRUCTED VELOCITY-DELAY MAPSThe Astrophysical Journal, 2013
- ION-BY-ION COOLING EFFICIENCIESThe Astrophysical Journal Supplement Series, 2012
- AGN OBSCURATION THROUGH DUSTY, INFRARED-DOMINATED FLOWS. II. MULTIDIMENSIONAL, RADIATION-HYDRODYNAMICS MODELINGThe Astrophysical Journal, 2012
- The origin of the broad line region in active galactic nucleiAstronomy & Astrophysics, 2010
- What broad emission lines tell us about how active galactic nuclei workNew Astronomy Reviews, 2009
- A Systematic Analysis of FeiiEmission in Quasars: Evidence for Inflow to the Central Black HoleThe Astrophysical Journal, 2008
- The Magnetohydrodynamics of Shock‐Cloud Interaction in Three DimensionsThe Astrophysical Journal, 2008
- The Origin of FeiiEmission in Active Galactic NucleiThe Astrophysical Journal, 2004
- Radiation-driven winds from luminous accretion discsMonthly Notices of the Royal Astronomical Society, 1998
- Nuclear Emission in Spiral Nebulae.The Astrophysical Journal, 1943