Related papers: Magnetohydrodynamic DiscWinds and LineWidth Distri…

We use numerical hydrodynamics simulations to study line driven winds launched from an accreting alpha-disc. Building on previous work where the driving radiation field is static, we compute a time-dependent radiation flux from the local,…

An integral part of the Unified Model for Active Galactic Nuclei (AGNs) is an axisymmetric obscuring medium, which is commonly depicted as a torus of gas and dust surrounding the central engine. However, a robust, dynamical model of the…

Aims: We consider cold self-similar magnetohydrodynamic (MHD) disc wind solutions to describe jets that are launched from the circumcompanion accretion discs in post-AGB binaries. Resulting predictions are matched to observations for five…

We present the first theoretical study on center-to-limb variation (CLV) properties and relative radius interpretation for narrow and broad-band filters, on the basis of a set of dynamic model atmospheres of C-rich AGB stars. We computed…

AGNs exhibit a wide range of black hole masses and inflow/outflow properties. It is now possible to probe regions close to the event horizons of nearby SMBHs using VLBI with earth-sized baselines, as performed by the EHT. This study…

Understanding the origin of AGN absorption line profiles and their diversity could help to explain the physical structure of the accretion flow, and also to assess the impact of accretion on the evolution of the AGN host galaxies. Here we…

We perform local, vertically stratified shearing-box MHD simulations of protoplanetary disks (PPDs) at a fiducial radius of 1 AU that take into account the effects of both Ohmic resistivity and ambipolar diffusion (AD). The magnetic…

Accretion disk winds are thought to produce many of the characteristic features seen in the spectra of active galactic nuclei (AGN) and quasi-stellar objects (QSOs). These outflows also represent a natural form of feedback between the…

AGN SEDs generally show a turnover at lambda 1000A, implying a maximal accretion disc (AD) temperature of T_max~50,000K. Massive O stars display a similar T_max, associated with a sharp rise in a line driven mass loss Mdot_wind with…

The hydrodynamics of a variant of classical Bondi-Hoyle-Lyttleton accretion is investigated: a totally absorbing sphere moves at various Mach numbers (3 and 10) relative to a medium, which is taken to be an ideal gas having a density…

X-ray obscuration of active galactic nuclei (AGNs) is considered in the context of ionized winds of stratified structure launched from accretion disks. We argue that a Compton-thick layer of a large-scale disk wind can obscure continuum…

Our current understanding has crystallised around two possible evolution scenarios for protoplanetary discs (turbulent viscosity and magnetohydrodynamic (MHD) wind-driven) - but which dominates remains uncertain. Our aims are twofold:…

(abridged) The accretion disk in AGN is expected to produce strong outflows, in particular a UV-line driven wind. Despite providing a good fit to the data, current spectral models of the X-ray spectrum of AGN observed through an accretion…

We present a magnetic stripping model for AM Her type objects. Our model is based on an equilibrium condition between ram pressure and magnetic pressure in a stiff dipolar magnetic field. We investigate the detailed geometry of the…

We present results of axisymmetric magnetohydrodynamic (MHD) simulations investigating the launching of jets and outflows from a magnetically diffusive accretion disk. The time evolution of the disk structure is self-consistently taken into…

We study mass outflows driven from accretion discs by radiation pressure due to spectral lines. To investigate non-axisymmetric effects, we use the Athena++ code and develop a new module to account for radiation pressure driving. In 2D, our…

We present the first-ever simulations of non-ideal magnetohydrodynamical (MHD) stellar magnetospheric winds coupled with disc-driven jets where the resistive and viscous accretion disc is self-consistently described. These innovative MHD…

We present an analytic, quasi-local model for accretion discs threaded by net, vertical magnetic flux. In a simple slab geometry and ignoring stochastic mean-field dynamo effects, we calculate the large-scale field resulting from the…

We report on the second phase of our study of slightly rotating accretion flows onto black holes. We consider magnetohydrodynamical (MHD) accretion flows with a spherically symmetric density distribution at the outer boundary, but with…

Winds from black hole accretion disks are essential ingredients in understanding the coevolution between the supermassive black hole and its host galaxy. The great difference of dynamical ranges from small-scale accretion disk simulations…