We present an edge-on Keplerian disc model to explain the main component of the 12.2 and 6.7GHz methanol maser emission detected toward NGC7538IRS1N . The brightness distribution and spectrum of the line of bright masers are successfully modeled with high amplification of background radio continuum emission along velocity coherent paths through a maser disc. The bend seen in the position-veloci...

Numerical simulations of turbulent, magnetized, differentially rotating flows driven by the magnetorotational instability are often used to calculate the effective values of alpha viscosity that is invoked in analytical models of accretion discs. In this paper we use various dynamical models of turbulent magnetohydrodynamic stresses, as well as numerical simulations of shearing boxes, to show t...

Sequences of infinitesimally thin, uniformly rotating, self-gravitating relativistic discs with internal two-dimensional pressure have been constructed. It is shown that in weaker relativistic configurations the sequences undergo a continuous bifurcation from a disc to a ring structure, while in stronger relativistic cases the sequences terminate at the mass-shed limit where gravitational force...

The present study deals with stress analysis on orthotropic graded rotating annular discs subjected to temperature distributions parabolically decreasing with radius. I have used infinitesimal deformation theory of elasticity and for graded parameters power law functions in the solution procedure. With the increasing temperature, the tangential stress component decreased at the inner surface wh...

The accretion disc around a rotating magnetic star (neutron star, white dwarf or T Tauri star) is subjected to periodic vertical magnetic forces from the star, with the forcing frequency equal to the stellar spin frequency or twice the spin frequency. This gives rise bending waves in the disc that may influence the variabilities of the system. We study the excitation, propagation and dissipatio...