Effect of Internal and External Dynamics on Galaxy Properties and Their Evolution

Abstract

The current work is an account of few aspects of galaxy evolution, where the galaxies dy- namic plays a crucial role. The thesis has been split into five chapters, the first of which includes an introduction to the subject matter and a review of the literature, followed by a summary of the thesis’s contents. In the second chapter, we study simple analytic model of nearly Keplerian modes for co-rotating gravitationally coupled gaseous and stellar discs. We present a simple analysis for large-scale, long-wavelength slow modes for m = 1 for co-rotating gravitationally coupled gaseous and stellar discs. We derived the dispersion relation using the Wentzel-Kramers-Brillouin (WKB) approximation and explored the stability of modes. Such modes are useful to address the problem of asym- metric light distribution observed in galaxies like M31. In the third chapter, we analyze stellar orbits at the galaxy’s central region that are disturbed by an asymmetric dark matter halo potential which are observed in observations as well as numerical simulations recently. We used first-order epicyclic theory to solve the orbits and obtained a central region’s azimuthal variation in the effective stellar orbits. We discuss the kinematical lopsidedness of the stellar orbits within a 3 kpc radius of the galaxies. The fourth & fifth chapter discusses the gas-removing mechanism (Ram pressure stripping) when the galaxy passes through the cluster medium. In the fourth chapter, we analyze the effect of spiral arms on the ram pressure in the galaxy; for this, we have considered different types of mass galaxies with different numbers of arms and widths. We analyze how the gravitationally bound force affects the ram pressure on removing gas from the disc, these parameters help us to study this phenomena In the fifth chapter, we analyze the impact of the magnetic field on the ram pressure. The magnetic field is an intrinsic part of the galaxy, and it acts as a restoring force against ram pressure stripping in the galaxies. The resulting in gas retention when a galaxy passes through the cluster medium.