Related papers: An extensive numerical survey of the correlation b…
The main aim of this paper is studying the effect of toroidal magnetic field on the structure of Advection-Dominated Accretion Flows (ADAF) in the presence of the turbulence viscosity and diffusivity due to viscosity and magnetic field…
Relativistic jets are launched from black hole (BH) X-ray binaries and active galactic nuclei when the disk accretion rate is below a certain limit (i.e., when the ratio of the accretion rate to the Eddingtion accretion rate, $\dot{m}$, is…
Young low-mass stars are characterized by ejection of collimated outflows and by circumstellar disks which they interact with through accretion of mass. The accretion builds up the star to its final mass and is also believed to power the…
Collimated outflows (jets) are ubiquitous in the universe appearing around sources as diverse as protostars and extragalactic supermassive blackholes. Jets are thought to be magnetically collimated, and launched from a magnetized accretion…
Because the magneto-rotational instability is capable of exponentially amplifying weak preexisting magnetic fields, it might be hoped that the character of the magnetic field in accretion disks is independent of the nature of the seed…
During the main phase of evolution of a protoplanetary disk, accretion regulates the inner-disk properties, such as the temperature and mass distribution, and in turn, the physical conditions associated with planet formation. The driving…
We present an analytical model for describing highly relativistic acceleration of magnetically driven jets, within the framework of ideal MHD for cold, stationary and axisymmetric outflows. Our novel procedure is to treat the wind equation…
Jet systems with two unequal components interact with their parent accretion disks through the asymmetric removal of linear momentum from the star-disk system. We show that as a result of this interaction, the disk's state of least energy…
Accretion discs properties should deviate from standard theory when magnetic pressure exceeds the thermal pressure. To quantify these deviations, we present a systematic study of the dynamical properties of magnetically arrested discs…
We study the coupled disc-jet system around the black hole where the outflow solutions are obtained in terms of the inflow parameters. We observe that an advective accretion disc can eject outflows/jets for wide range of viscosity…
(Abriged) We present a comprehensive set of axisymmetric, time-dependent simulations of jets from Keplerian disks whose mass loading as a function of disk radius is systematically changed. For a reasonable model for the density structure…
Large-scale magnetic field is crucial in launching and collimating the jets/outflows. It is found that the magnetic flux can be efficiently transported inward by the fast moving corona above a thin disk. In this work we investigate the…
Accreting black holes produce collimated outflows, or jets, that traverse many orders of magnitude in distance, accelerate to relativistic velocities, and collimate into tight opening angles. Of these, perhaps the least understood is jet…
The inner regions of protoplanetary disks are the locations where most of planets are thought to form and where processes that influence the global evolution of the disk, such as MHD-winds and photoevaporation, originate. Transition disks…
We discuss the problem of the formation of a large-scale magnetic field in the accretion disks around black holes, taking into account the nonuniform vertical structure of the disk. The high electrical conductivity of the outer layers of…
Planet formation and migration in accretion discs is a very active topic. Among the many aspects related to that question, dead zones are of particular importance as they can influence both the formation and the migration of planetary…
Ultraviolet observations of classical T Tauri Stars (cTTSs) have shown that there is a hot (Te ~ 80,000 K) and dense (ne ~ 1e10 cm-3) component associated with the large scale jet. This hot component is formed very close to the base of the…
Star formation is usually accompanied by outflow phenomena. There is strong evidence that these outflows and jets are launched from the protostellar disk by magneto-rotational processes. Here, we report on our three dimensional, adaptive…
The driving mechanism of protostellar outflows and jets and their effects on the star formation process obtained from recent theoretical and numerical studies are described. Low-velocity outflows are driven by an outer region of the…
The central problem in forming a star is the angular momentum in the circumstellar disk which prevents material from falling into the central stellar core. An attractive solution to the "angular momentum problem" appears to be the…