Poynting-Robertson effect on black-hole-driven winds
arXiv:2301.02681 · doi:10.1051/0004-6361/202244614
Abstract
Layers of ionized plasma, in the form of winds ejected from the accretion disk of Supermassive Black Holes (SMBHs) are frequently observed in Active Galactic Nuclei (AGNs). Winds with a velocity often exceeding are called Ultra-Fast-Outflows (UFOs) and thanks to their high power they can play a key role in the co-evolution between the SMBH and the host galaxy. In order to construct a proper model of the properties of these winds, it is necessary to consider special relativistic corrections due to their very high velocities. We present a derivation of the Poynting-Robertson effect (P-R effect) and apply it to the description of the dynamics of UFOs. The P-R effect is a special relativistic correction which breaks the isotropy of the radiation emitted by a moving particle funneling the radiation in the direction of motion. As a result of the conservation of the four-momentum, the emitting particles are subjected to a drag force and decelerate. We provide a derivation of the drag force caused by the P-R effect starting from general Lorentz transformations and assuming isotropic emission in the gas reference frame. Then, we derive the equations to easily implement this drag force in future simulations. Finally, we apply them in a toy model in which the gas particles move radially under the influence of the gravitation force, the radiation pressure and the drag due to the P-R effect. P-R effect plays an important role in determining the velocity profile of the wind. For a wind launched from (where stands for the Schwarzschild radius), the asymptotic velocity reached by the wind is between % and % smaller than the one it would possess if we neglect the effect. This shows that the P-R effect should be taken into account when studying the dynamics of high-velocity, photoionized outflows in general.
arXiv commentAccepted for publication on Astronomy & Astrophysics. 7 pages, 4 figures
References in corpus (18)
- Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
- Evidence for ultra-fast outflows in radio-quiet AGNs: I - detection and statistical incidence of Fe K-shell absorption lines
- AGN wind scaling relations and the co-evolution of black holes and galaxies
- A high velocity ionised outflow and XUV photosphere in the narrow emission line quasar PG1211+143
- The Suzaku view of highly-ionised outflows in AGN: I - Statistical detection and global absorber properties
- MHD Accretion-Disk Winds as X-ray Absorbers in AGNs
- Magnetically-Driven Accretion-Disk Winds and Ultra-Fast Outflows in PG1211+143
- X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk509
- Radiation Hydrodynamic Simulations of Line-Driven Disk Winds for Ultra Fast Outflows
- UV line driven disc wind as the origin of ultrafast outflows in AGN
- On the importance of special relativistic effects in modelling ultra-fast outflows
- Radiation Drag Effects in Black Hole Outflows from Super-critical Accretion Disks via Special Relativistic Radiation Magnetohydrodynamics Simulations
- A deep X-ray view of the bare AGN Ark 120. II. Evidence for Fe K emission transients
- Radiatively driven rotating pair-plasma jets from two component accretion flows
- Synthetic X-ray spectra for simulations of the dynamics of an accretion flow irradiated by a quasar
- Speed limits for radiation driven SMBH winds
- Magnetohydrodynamic winds driven by line force from the standard thin disk around supermassive black holes: II. a possible model for ultra-fast outflows in radio-loud AGNs
- Simulations of radiation driven winds from Keplerian discs