Open positions

Jobs at CTAC

The Graduate and Postgraduate Program at the Center for Theoretical Astrophysics and Cosmology aims to attract to Zurich the most promising young scientists from across the world. Our programs offer a comprehensive and challenging research education that allows our students and postdoctoral fellows to develop into tomorrow's leaders.

Open PhD position in theoretical astrophysics: Planet formation via gravitational instability

When a star forms, not all infalling gas can directly fall onto the star because of angular momentum conservation. Instead it first falls onto a protoplanetary disk. During the main infall phase that forms the star, the mass of this disk can become so high that it becomes unstable to its own gravity. The disk then fragments into bound clumps of gas, a process that is known as planet formation via gravitational instability. In this PhD thesis we investigate under which physical conditions such bound clumps form and whether they are the progenitors of gaseous giant planets. We study this by first simulating the formation and evolution of a disk with a numerical model. We then check when and where the simulated disk becomes unstable and forms a bound object. In the second step, we follow the evolution of this newly formed planet, considering its mass accretion and orbital evolution as well as the evolution of its interior. Finally, we statistically compare the population of resulting planets with the observed extrasolar planets, in particular those at large orbital distances that were found in the last few years like HR8799bcde or 51 Eri b.

This four-year PhD position is founded by the National Centre of Competence in Research PlanetS and shared between the University of Bern and the University of Zürich. The first two years of work will mainly take place in Bern, the remaining two in Zürich. The position is available immediately (1.8/2016) and a rapid start by the student is appreciated. The competitive salary follows the regulations of the Swiss National Science Foundation. 

Prof. R. Helled, University of Zürich,
Prof. C. Mordasini, University of Bern,