The study of how stars form under various chemical and physical conditions in the Universe is crucial in order to get better insights on how larger structures such as galaxies form and evolve in time.
Stars form in dense condensations of gas. It is thus important to determine as precisely as possible the properties of this gas (e.g. gas temperatures and pressures), and especially how they vary from one galaxy to another.
Galaxies vary in type and characteristics: some experience a burst of star formation activity in their nucleus, some are are quiescent, some are merging (see Figure 1), some host black holes in their central region. All these different environments directly influence the properties of the gas and thus the way stars are forming within it.