The spiral pattern is the most recognizable feature of the majority of disc galaxies. Despite significant efforts in investigating the spiral arm phenomenon, as well as the fact this it is routinely reproduced in computer simulations, the principle of spiral pattern formation is still poorly understood.
Currently, the most elaborate theory of spiral arms origin is the so-called theory of density waves which predicts long-lived and well defined spiral patterns in galaxies. However, during the last decade or so it was found that this theory reveals certain inconsistencies with the results of numerical simulations employing high-resolution galaxy models: in these models spiral arms are observed as short-lived by repeatedly emerging, vaguely-shaped structures. The existing alternative theories, such as swing amplification theory, material arms theory, and force wake theory also display some contradictions if compared with computer simulations and, thus, also do not provide a comprehensive explanation of the spiral pattern origin. In this project we aim at performing a series of controlled numerical experiments on the formation and evolution of spiral arms at a fundamentally new level. We note two of our major advantages over preceding research in this field. First, we possess an original newly developed computational tool to generate high-quality equilibrium disc galaxy models – the GALIC-3D computer code. When studying phenomena like spiral arms it is very important to keep digital noise and other possible artificial perturbations as minimized as possible, and the GALIC-3D allows to achieve these conditions. Second, we are going to apply an original approach, based on transferring into non-inertial reference frame co-rotating with the galaxy, and analyzing the balance of all resulting forces – including inertial ones.
