Jeroen Stil

Radio Astronomy
Radio Astronomy reveals events in the cosmos that cannot be observed by other means. We use the largest radio telescopes in the world to observe the motions of gas in galaxies, and elusive magnetic fields that thread through galaxies and affect the flow of gas. Some galaxies contain super-massive black holes that consume the surrounding gas and in the process eject fast beams of matter (jets) that can travel at nearly the speed of light for up to a few million years before finally running into something. These process define the course of evolution of galaxies, the distribution of chemical elements through space, and the locations where the next generation of stars will form. We make images with radio telescopes and apply advanced image analysis and statistics tools to build astrophysical models of galaxy evolution. To this end, we often use data from conventional telescopes and space missions to obtain a complete picture of the galaxies that we study.

Radio Astronomical Surveys
Statistical analysis is one of the most powerful analysis tools in astrophysics, and one that requires skills that can be applied in many other situations outside astrophysics. These include advanced imaging techniques, the design of algorithms for extracting information from large multi-dimensional survey images, simulations, and statistical analysis of the acquired information. The design, execution, and analysis of large surveys of the sky with radio telescopes creates multi-disciplinary research opportunities on the boundary of astrophysics, computer science, and statistics. Current research in astronomical surveys includes a survey of part of the Milky Way with the Jansky Very Large Array, a survey of magnetic fields in the nearby interstellar medium with the 300-m Arecibo Radio Telescope, and measuring polarization of millions of sources in images from a starting survey with the Australian Square Kilometre Array Pathfinder (ASKAP).