Stellar birth: How do stars get their mass? (Astronomy and astrophysics)

A debate is raging in star formation: are the masses of stars set by the turbulent fragmentation of the clouds in which they form, or are they set by the fight between gravity and radiative feedback processes? Both appear to be possible, and perhaps dominate in different star-forming environments, but how and when they dominate is poorly understood. This is a long standing problem in astronomy, as the the shape of the mass distribution of stars — the initial mass function, or “IMF” — is central nearly all fields or modern astrophysics, including observational cosmology and planet formation. In this PhD, the student will use high-resolution computer simulations to investigate how stars are born in very different environments, such as those found that are found at the centre of the Milky Way (violent) and those found in the outskirts of the Galaxy (quiescent). By exploring different physical processes, such as cloud turbulence, magnetic fields, chemical enrichment of the gas and radiative heating from stars, they will determine how the mass distribution of stars is shaped by the physics of the interstellar medium (ISM). The student will be using a state-of-the art astrophysics fluid code, Arepo, which they will run at dedicated supercomputing centres (including those at Cardiff and national facilities). Arepo is the most advanced code in the world for studying star formation, and our group at Cardiff are active developers of the code, adding new capabilities that allow us to study a wide range of astrophysical phenomena. This project will introduce the student to a wide variety of marketable skills, including high-performance computing, code development, and fluid dynamics. The project will also introduce the student to a thriving international research community, in one of the most active subjects in astrophysics. A good grasp of basic coding is recommended (in any language, e.g. Fortran, C/C++/ Python).