Extragalactic Group
How did the first galaxies and black holes form, and how did they grow into the Universe we see around us today?
The James Webb Space Telescope has recently opened the window into studying the earliest phases of galaxy formation. JWST has revealed distant galaxies that are surprisingly massive and unexpectedly mature given the very young age of the Universe. An entirely new class of compact red sources known as “little red dots” has unveiled a previously unknown phase of black hole formation. These discoveries with JWST are rewriting the early chapters of cosmic history faster than our models can keep up.
To understand how these early galaxies and black holes formed and grew so quickly, we need to study large, carefully selected samples with deep imaging and spectroscopy. Spectra provide the redshifts, stellar masses, ages, kinematics and chemical enrichment of galaxies in the early Universe, and reveal accreting black holes that images alone cannot identify. By placing rare and unexpected objects in the context of the full galaxy population, and comparing them with later epochs and with simulations, we can trace galaxy evolution across more than thirteen billion years. This allows us to ask when galaxies like our own Milky Way first appeared, and how they evolve with cosmic time.
Our group leads several spectroscopic programs on JWST (e.g. RUBIES) and is involved in a range of large spectroscopic and photometric surveys with state-of-the-art instruments (Euclid, Roman, 4MOST). With these data we study the detailed physics of how massive galaxies could form so early, when disky galaxies like the Milky Way first emerged, and what role little red dots play in the growth of supermassive black holes. We complement our observations with galaxy formation simulations and legacy data of the late-time Universe to determine the evolution of galaxies early Universe into the present-day galaxy population.
Our research group is funded through the Lise Meitner Excellence Program and the ERC Starting Grant FIRST-GIANTS.