Related papers: Flux-Averaged Force Multipliers
We propose a system to optimize parametric designs subject to radiation pressure, \ie the effect of light on the motion of objects. This is most relevant in the design of spacecraft, where radiation pressure presents the dominant…
Ablation with mixed $2\omega$--$3\omega$ lasers is investigated as a possible drive strategy for balancing drive efficiency and ablative stabilization in direct-drive inertial confinement fusion. One-dimensional radiation-hydrodynamic…
We have developed a new dynamical model of the torus region in active galactic nucleus (AGN), using a three-dimensional radiation hydrodynamics algorithm. These new simulations have the specific aim to explore the role of radiatively-driven…
We present a new method for using measured X-ray emission line fluxes from O stars to determine the shock-heating rate due to instabilities in their radiation-driven winds. The high densities of these winds means that their embedded shocks…
Infrared interferometry of local AGN has revealed a warm (~300K-400K) polar dust structure that cannot be trivially explained by the putative dust torus of the unified model. This led to the development of the disk+wind scenario which…
Many high-state non-magnetic cataclysmic variables (CVs) exhibit blue-shifted absorption or P-Cygni profiles associated with ultraviolet (UV) resonance lines. These features imply the existence of powerful accretion disk winds in CVs. Here,…
We present a systematic study of ionized gas outflows based on the velocity shift and dispersion of the [O III] {\lambda}5007 $\AA$ emission line, using a sample of ~ 5000 Type 1 AGNs at z < 0.3 selected from Sloan Digital Sky Survey. This…
We provide a brief review of the physical processes behind the radiative driving of the winds of OB stars and the Bondi-Hoyle-Lyttleton capture and accretion of a fraction of the stellar wind by a compact object, typically a neutron star,…
A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer…
Ultra-fast outflows (UFOs) are highly ionized, mildly relativistic winds seen in the X-ray spectra of active galactic nuclei (AGN) and are thought to contribute to AGN feedback and galaxy evolution. We investigate UFO signatures by…
We introduce a new Rigid-Field Hydrodynamics approach to modeling the magnetospheres of massive stars in the limit of very-strong magnetic fields. Treating the field lines as effectively rigid, we develop hydrodynamical equations describing…
Streamwise acceleration of the background flow field is one of various effects occurring when wind turbines operate under non-idealized conditions, such as in complex terrain or in dense wind farms. Thus, studying this effect is essential…
We present results from a study of high- and low-ionization emission line ratios as a function of projected velocity for a sample of eight active galactic nuclei (AGNs). Our results are based on analysis of high signal-to-noise optical and…
Hot stars emit large amounts of X-rays, which are assumed to originate in the supersonic stellar wind. Part of the emitted X-rays is subsequently absorbed in the wind and influences its ionization state. Because hot star winds are driven…
X-ray signatures of outflowing gas have been detected in several accreting black-hole binaries, always in the soft state. A key question raised by these observations is whether these winds might also exist in the hard state. Here, we carry…
The origin, geometry and kinematics of the broad line region (BLR) gas in quasars and active galactic nuclei (AGN) are uncertain. We demonstrate that clumpy biconical disc winds illuminated by an AGN continuum can produce BLR-like spectra.…
We use a wide-field (0.9 square degree) X-ray sample with optical and GALEX ultraviolet observations to measure the contribution of Active Galactic Nuclei (AGNs) to the ionizing flux as a function of redshift. Our analysis shows that the…
We investigate the momentum fluxes between a turbulent air boundary layer and a growing-breaking wave field by solving the air-water two-phase Navier-Stokes equations through direct numerical simulations (DNS). A fully-developed turbulent…
We construct a radiation-hydrodynamics model for the obscuring toroidal structure in active galactic nuclei. In this model the obscuration is produced at parsec scale by a dense, dusty wind which is supported by infrared radiation pressure…
We perform two-dimensional hydrodynamical simulations of slowly rotating accretion flows in the region of $ 0.01-7\, \mathrm{pc} $ around a supermassive black holes with $ M_\mathrm{BH} = 10^{8} M_{\odot} $. The accretion flow is irradiated…