Related papers: Atomic T Tauri disk winds heated by ambipolar diff…
We study the two-dimensional, time-dependent MHD of radiation-driven winds from luminous accretion disks initially threaded by a purely axial magnetic field. The radiation force is mediated primarily by spectral lines. We use ideal MHD to…
The chromosphere is a partially ionized layer of the solar atmosphere, the transition between the photosphere where the gas motion is determined by the gas pressure and the corona dominated by the magnetic field. We study the effect of…
To properly describe heating in weakly collisional turbulent plasmas such as the solar wind, inter-particle collisions should be taken into account. Collisions can convert ordered energy into heat by means of irreversible relaxation towards…
The disk-outflow connection plays a key role in extracting excess angular momentum from a forming protostar. We have previously reported the discovery of a small molecular outflow from the edge-on T Tauri star in the Bok globule CB26 that…
We investigate the formation of hot coronae and vertical outflows in accretion disks by magneto-rotational turbulence. We perform local three-dimensional (3D) MHD simulations with the vertical stratification by explicitly solving an energy…
The HeII (1640 A) line and the resonance doublet of NV (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (Te>40,000K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data…
The frictional heating by ion-neutral drift is calculated and its effect on isobaric thermal instability is carried out. Ambipolar drift heating of one-dimensional self-gravitating magnetized molecular slab is used under the assumptions of…
Strong magnetization makes the disks surrounding young stellar objects rotate at rates that are too sub-Keplerian to enable the thermal launching of disk winds from their surfaces unless the rate of gas diffusion across field lines is…
We present the first high angular resolution 1.4mm and 2.7mm continuum maps of the T Tauri binary system HK Tau obtained with the Plateau de Bure Interferometer. The contributions of both components are well disentangled at 1.4mm and the…
We describe an implicit prediction of the accretion disk models constructed by Wardle and Konigl (1990) for the circumnuclear disk (CND) of gas and dust near the Galactic center: supersonic ambipolar diffusion, an essential dynamical…
Protoplanetary disks can exhibit asymmetric temperature variations due to phenomena such as shadows cast by the inner disk or localized heating by young planets. We investigate the disk features induced by these asymmetric temperature…
We simulate the dynamics of slender magnetic flux tubes (MFTs) in the accretion disks of T Tauri stars. The dynamical equations of our model take into account the aerodynamic and turbulent drag forces, and the radiative heat exchange…
The high opacity of He I 10830 makes it an exceptionally sensitive probe of the inner wind geometry of accreting T Tauri stars. In this line blueshifted absorption below the continuum results from simple scattering of stellar photons, a…
It is argued that the specific heat of amorphous solids at low temperatures can be understood to arise from a single branch of collective modes. The idea is illustrated in a model of a correlated spin glass for which magnetic anisotropies…
We explore the poloidal structure of two-dimensional (2D) MHD winds in relation to their potential association with the X-ray warm absorbers (WAs) and the highly-ionized ultra-fast outflows (UFOs) in AGN, in a single unifying approach. We…
Analogous to the HR diagram for stars, the thermal equilibrium curve encodes the thermodynamics of accretion disks by expressing the local balance between heating -- primarily via viscous dissipation -- and cooling -- typically through…
We present the emission line profile models of hydrogen and helium based on the results from axisymmetric magnetohydrodynamics (MHD) simulations of the wind formed near the disk-magnetosphere boundary of classical T Tauri stars (CTTSs). We…
We present a 3-D NLTE Monte Carlo radiative transfer code that we use to study the temperature and ionization structure of Keplerian disks around Classical Be stars. The method we employ is largely similiar to the Monte Carlo transition…
Most numerical investigations on the role of magnetic fields in turbulent molecular clouds (MCs) are based on ideal magneto-hydrodynamics (MHD). However, MCs are weakly ionized, so that the time scale required for the magnetic field to…
We examine the effects of a hydrodynamical wind on advection dominated accretion flows with thermal conduction in the presence of a toroidal magnetic field under a self-similar treatment. The disk gas is assumed to be isothermal. For a…