N-body simulations of the Cold Dark Matter (CDM) model yield singular halo density profiles in apparent conflict with halo profiles of dark-matter-dominated galaxies derived from observed rotation curves. An analytical model we have derived elsewhere for the postcollapse equilibrium of cosmological halos reproduces many of the average properties of halos in CDM simulations to good accuracy, inc...

We present our investigation on the effect of warps on the extraction of rotation curves in edge-on galaxies. The method to derive the rotation curve from the position-velocity diagram in warped edge-on systems yields underestimated velocities, and the tilted-ring model is not reliable in highly inclined, poorly resolved galaxies. In a warped system the kinematical major axis is different from ...

In the last 20 years, rotation curves derived from H I kinematics obtained on radio synthesis instruments were used to probe the dark matter distribution in spiral and dwarf irregular galaxies. It is shown, with the aid of the Sd galaxy NGC 5585, that high resolution 2–D H II kinematics is necessary to determine accurately the mass distribution of spirals. New CFHT Fabry–Perot Hα observations a...

Abstract Magnetic fields of various astrophysical objects are described using the dynamo mechanism. Corresponding equations in three-dimensional case quite difficult to be solved. So, two-dimensional models can useful for such problems. For galactic and accretion discs, it is convenient use no- z z approximation. The i...