92 citations · 498 across the 30 of their papers we have counts for
21 papers · 1 filter
Flux-Averaged Force Multipliers
Sergei Dyda, Randall C. Dannen, Shane W. Davis +2
We apply novel developments in photoionization modeling and multi-frequency radiation hydrodynamics to the study of line driven AGN disc winds. We use a flux-averaged force multipl…
Time-Dependent AGN Disc Winds II -- Effects of Photoionization
Sergei Dyda, Randall C. Dannen, Timothy R. Kallman +2
We use a combination of radiation hydrodynamics (rad-HD) and photoionization modeling to study line-driven disc winds for a range of black hole masses. We refined previous models b…
Blackbodies Matter
Sergei Dyda
We study line driven stellar winds using multifrequency, time-dependent radiation hydrodynamics. We compute the radiation force due to lines, the so called force multiplier, using…
Time-Dependent AGN Disc Winds I -- X-ray Irradiation
Sergei Dyda, Shane W. Davis, Daniel Proga
We study AGN line driven disc winds using time-dependent radiation hydrodynamics. The key criterion for determining wind launching is the coupling strength of the UV radiation fiel…
Vertical wind structure in an X-ray binary revealed by a precessing accretion disk
P. Kosec, E. Kara, A. C. Fabian +11
The accretion of matter onto black holes and neutron stars often leads to the launching of outflows that can greatly affect the environments surrounding the compact object. In supe…
Line Driven Winds from Variable Accretion Discs
Anthony Kirilov, Sergei Dyda, Christopher S. Reynolds
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,…
The long stare at Hercules X-1 -- I. Emission lines from the outer disk, the magnetosphere boundary and the accretion curtain
P. Kosec, E. Kara, A. C. Fabian +11
Hercules X-1 is a nearly edge-on accreting X-ray pulsar with a warped accretion disk, precessing with a period of about 35 days. The disk precession allows for unique and changing…
Thermal instability in radiation hydrodynamics: instability mechanisms, position-dependent S-curves, and attenuation curves
Daniel Proga, Tim Waters, Sergei Dyda +1
Local thermal instability can plausibly explain the formation of multiphase gas in many different astrophysical environments, but the theory is only well understood in the opticall…
Lense-Thirring Precession of Misaligned Discs I
Sergei Dyda, Christopher S. Reynolds
We study Lense-Thirring precession of inviscid and viscous misaligned discs around a black hole using a gravitomagnetic term in the momentum equation. For weak misalignments, $…
The Soft State of the Black Hole Transient Source MAXI J1820+070: Emission from the Edge of the Plunge Region?
A. C. Fabian, D. J Buisson, P. Kosec +18
The Galactic black hole X-ray binary MAXI J1820+070 had a bright outburst in 2018 when it became the second brightest X-ray source in the Sky. It was too bright for X-ray CCD instr…
Effects of Opacity Temperature Dependence on Radiatively Accelerated Clouds
Sergei Dyda, Daniel Proga, Christopher S Reynolds
We study how different opacity-temperature scalings affect the dynamical evolution of irradiated gas clouds using time-dependent, radiation-hydrodynamics (rad-HD) simulations. When…
Line Driven Acceleration using Multi-Frequency Radiation Hydrodynamics
Sergei Dyda, Christopher S. Reynolds, Yan-Fei Jiang
We use multi-frequency radiation hydrodynamics (rad-HD) to simulate radiative acceleration of a spherically symmetric stellar wind. We demonstrate the rad-HD capabilities of Athena…
An ionised accretion disc wind in Hercules X-1
P. Kosec, A. C. Fabian, C. Pinto +3
Hercules X-1 is one of the best studied highly magnetised neutron star X-ray binaries with a wealth of archival data. We present the discovery of an ionised wind in its X-ray spect…
Effects of Radiation Field Geometry on Line Driven Disc Winds
Sergei Dyda, Daniel Proga
We study line driven winds for models with different radial intensity profiles: standard Shakura-Sunyaev radiating thin discs, uniform intensity discs and truncated discs where dri…
Time Dependent Radiation Driven Winds
Sergei Dyda, Daniel Proga
We study temporal variability of radiation driven winds using one dimensional, time dependent simulations and an extension of the classic theory of line driven winds developed by C…
Non-Axisymmetric Line Driven Disc Winds II - Full Velocity Gradient
Sergei Dyda, Daniel Proga
We study non-axisymetric features of 3D line driven winds in the Sobolev approximation, where the optical depth is calculated using the full velocity gradient. We find that non-axi…
Non-Axisymmetric Line Driven Disc Winds I - Disc Perturbations
Sergei Dyda, Daniel Proga
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…
Irradiation of Astrophysical Objects - SED and Flux Effects on Thermally Driven Winds
Sergei Dyda, Randall Dannen, Tim Waters +1
We develop a general method for the self consistent calculation of the hydrodynamics of an astrophysical object irradiated by a radiation field with an arbitrary strength and spect…
Magnetic Field Amplification via Protostellar Disc Dynamos
Sergei Dyda, Richard V. E. Lovelace, Galina V. Ustyugova +2
We numerically investigate the generation of a magnetic field in a protostellar disc via an -dynamo and the resulting magnetohydrodynamic (MHD) driven outflows. We find that fo…
Asymmetric MHD Outflows/Jets from Accreting T Tauri Stars
Sergei Dyda, Richard V. E. Lovelace, Galina V. Ustyugova +3
Observations of jets from young stellar objects reveal the asymmetric outflows from some sources. A large set of D MHD simulations has been carried out for axisymmetric viscou…
Relativistic Poynting-Flux Jets as Transmission Lines
R. V. E. Lovelace, S. Dyda, P. P. Kronberg
Recent radio emission, polarization, and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet has a {\it galactic}-scale electric curren…