PhD ceremony: A.F. Loenen, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen
Thesis: Star formation and the ISM: interactions in the Milky Way and other galaxies
Promotor(s): prof. M. Spaans, prof. W.A. Baan
Faculty: Mathematics and Natural Sciences
In his thesis Edo Loenen describes his study of the formation and evolution of stars by looking at their ‘birthplace’: the gas spread everywhere in space, called the Inter Stellar Medium (ISM). He studied the properties of the ISM in which stars form and how these properties change throughout the ‘lifetime’ of the stars. Additionally, he investigated if there are differences in these properties between the Milky Way and other galaxies.
Stars are the building blocks of the universe. During their life stars influence their surroundings in all kinds of ways: they heat it with radiation, during their ‘birth’ and ‘death’ they produce strong streams of gas that can cause new stars to form, and stars make the elements that are the base for the formation of planets and ultimately life itself.
To determine the properties of the ISM, Loenen has compiled two large sets of observations of radiation coming from gas molecules in both the Milky Way and other galaxies. He has tried to explain these observations by comparing them to the predictions made by theoretical models.
Loenens analysis showed that the properties of the ISM in the Milky Way are largely the same as in other galaxies. A surprising conclusion of his research is that the mechanical processes of stars (streams of gas formed during the creation and destruction of stars) have a large influence on the temperature of the ISM. The derived temperatures are higher than generally assumed, which can have large consequences for the formation of new stars.
