Case Studies in Star Formation offers an overview of our current observational and theoretical understanding in the molecular astronomy of star formation. The book is divided into six sections: the first introduces an overview of star formation and the essential language, concepts and tools specific to molecular astronomy studies. Each subsequent section focuses on individual sources, beginning with a description of large-scale surveys. The volume covers low- and high mass star formation, ionization and photodissociation regions, and concludes with the extragalactic perspective. Conventional textbooks begin with principles, ending with a few convenient examples. Through copious examples, Case Studies reflects the reality of research, which requires the creative matching of ongoing observations to theory and vice-versa, often raising as many questions as answers. This supplementary study guide enables graduate students and early researchers to bridge the gap between textbooks and the wealth of research literature.

Stars form from molecular cloud cores by gravoturbulent fragmentation. Understanding the angular momentum and the thermal evolution of cloud cores thus plays a fundamental role in completing the theoretical picture of star formation. This is true not only for current star formation as observed in regions like the Orion nebula or the -Ophiuchi molecular cloud but also for the formation of stars of the first or second generation in the universe. In this thesis we show how the angular momentum of prestellar and protostellar cores evolves and compare our results from hydrodynamical simulations with observed quantities. We find that collapse induced by gravoturbulent fragmentation is accompanied by a substantial loss of specific angular momentum. This eases the "angular momentum problem" in star formation. The distribution of stellar masses at birth (the initial mass function, IMF) is another aspect that any theory of star formation must explain. Our investigation generally supports the idea that the distribution of stellar masses depends mainly on the thermodynamic state of the gas.