Abstract:
Oscillations in galaxies have been investigated by numerical simulations. The various models used have density distributions corresponding to that of polytrope of index n in the range 0 ≤ n ≤ 4 and their evolution has been followed for more than 70 crossing times. The kinetic energy shows regular and smooth oscillations for models with n = 0, 1 and 2 whereas in other models it shows noisy oscillation. The oscillation in kinetic energy is observed to have a period of 3 crossing time irrespective of the density and size of the galaxy. The amplitude of oscillation is seen to decrease as the central density of the galaxy increases.
