The effect of environment on the evolution of nearby gas-rich spiral galaxies

The distribution of galaxies in the Universe is not uniform - galaxies are located in filamentary structures, groups and clusters. Due to the small separation between galaxies in high density regions, galaxy-galaxy interactions may occur, which can transform the properties of the galaxies. In my thesis, I classify the Ursa Major region and look for evidence of galaxy transformation. This study utilizes observations of neutral hydrogen, which is a sensitive tracer of environmental effects. I find that the Ursa Major region is a `supergroup', i.e. several galaxy groups in the process of merging, whose members show signs of transformation.