My group's research focuses on understanding how galaxies in the early (z>1) universe formed and evolved. In particular, much of our recent work aims to reveal and study the dust-obscured star formation and cold gaseous reservoirs of distant galaxies that have until recently been out-of-reach (see my recent invited review article on the advances made with the Atacama Large Millimeter Array, in particular). Some media coverage of our discoveries and a few selected topics are highlighted below.
A significant fraction of the Universe's star formation occurred shrouded in cosmic dust. With its near- and mid-infrared wavelength coverage and exquisite sensitivity, the recently launched James Webb Space Telescope will pierce through this cosmic dust and provide an unprecedented look at early (z>1) galaxy evolution. My group is using JWST to reveal these previously hidden galaxies, beginning with a Cycle 1 GO program I am leading. (Image: JWST, NASA/JPL-Caltech)
Due to the dust often accompanying star formation, the total star formation history of the universe at the highest redshifts is still debated. Radio observations provide a unique and complementary tracer of the total (dust-unbiased) star formation in distant galaxies, provided the observations are deep enough. My group uses radio emission to trace this distant star formation, including a new ultra-deep, multi-band survey with the Karl G. Jansky Very Large Array called COSMOS-XS. (Image: VLA)
Prior to the advent of the Atacama Large Millimeter Array (ALMA), the limitations of most earlier-generation telescopes meant that the most prolifically star-forming galaxies in the Universe could not even be reliably located. ALMA's incredible sensitivity and angular resolution has now transformed our understanding of these galaxies. My group has been at the forefront of these efforts, including discovering evidence for striking sub-structure in the current star formation. (Image from press release.)
Understanding how nascent stars formed out of the surrounding interstellar medium is one of the most fundamental questions in astronomy. We know that cold molecular gas is the primary fuel of this star formation, but observations of molecular gas in distant (z>1) galaxies are still challenging. My group's work strives to push the boundaries of our knowledge, with the ultimate aim of understanding how and why star formation at early cosmic times was different than in today's universe. (Image of the gas and dusty star formation in a z~3 galaxy from Rybak et al. 2020)