Abstract:
In the struggle toward an understanding of the process of star formation it is one of the
most important tasks to study the initial properties of the cold and dense interstellar
medium. Stars are known to form in dense molecular clouds, but it is not yet fully
understood how they from the neutral gas that permeates the Galaxies. Therefore, it
is crucial to fully understand the creation process of molecular clouds. Colliding
ows
are a possible explanation for this process.For the Jeans mass and spiral structure
we use virial theorem is used and this tell as the gravity must stronger than the
kinetic energy ( the energy due to thermal pressure.)in order to the clouds collapse
and forms prostar 3 2 GM R 2 3 2 M m KT .For a spherically symmetric system with a mass
pro le M(r), neglecting pressure forces, we can calculate the time a freely falling
mass shell at a radius R needs to fall to the center. By considering the conservation
total energy the free time is derived (tff = ( 32 3G ) 1 2) By numerical models equations
are governed considering initial and boundary condition of conservation laws for the
mass, momentum, magnetic
ux, and energy is solved in a cubic domain of linear size
L with triply periodic boundary conditions , the log normal distribution of column
densities, the mass-weighted distribution of thermal pressure, and relationship for
molecular clouds.Finally,by considering Gaussian probability function of nding a
particle in a given position spherical boundary condition can be solved the distribution
of molecular clouds in the galaxies.
