DDA’s annual Dirk Brouwer Career Award (https://dda.aas.org/awards/br
Prof. Helmi (http://www.astro.rug.nl/~ahel
Professor Helmi’s work provided direct evidence that a fair fraction of the Milky Way’s globular clusters originated from accreted satellite dwarf galaxies. She also discovered that the inner halo of our galaxy is dominated by debris from a much larger accreted system, which she named Gaia-Enceladus. She demonstrated that its accretion must have led to substantial dynamical heating and was a key contributor to the formation of the so-called thick disk starting about 10 billion years ago. This major event is likely the defining moment in the formation history of the Milky Way and is consistent with our theoretical expectations from cosmological simulations.
In addition to her own research and impressive publication record, Prof. Helmi has also mentored many students and postdoctoral researchers who have moved on to begin outstanding careers of their own.
Prof. Helmi earned her PhD in astronomy at Leiden University in 2000 under the supervision of Tim de Zeeuw and Simon White. Following postdoctoral fellowships at the University of La Plata, the Max Planck Institute for Astrophysics, and the University of Utrecht, she became a professor at the University of Groningen in 2003.
2021 Vera Rubin Early Career Prize to Prof. Ann-Marie Madigan
DDA’s annual Vera Rubin Early Career Prize (https://dda.aas.org/awards/ru
Prof. Madigan (https://www.colorado.edu/aps/
Interactions between stars and their remnants with supermassive black holes produce exotic astrophysical events including tidal disruptions of stars, ejections of hypervelocity stars into a galaxy’s halo, and gravitational-wave-driven inspirals of compact objects into the central black hole. Prof. Madigan has advanced our understanding of the statistical properties of the orbits of stars around these supermassive black holes, the interactions of intermediate black holes with supermassive ones, and the stability of stellar disks in active galactic nuclei. She also has probed the formation history of stars near galactic nuclei, the evolution of their orbits, and the mechanism by which they can be disrupted and ultimately captured by the central black hole.
Prof. Madigan has further applied her knowledge of near-Keplerian systems to other scales. For example, she has suggested a possible mechanism by which the observed alignments of the orbits of long-period Kuiper belt objects could arise, and she has proposed that the mutual gravity of comets could cause a periodic influx of comets into the inner solar system.
Prof. Helmi and Prof. Madigan both will be invited to present lectures at the 53rd annual DDA meeting in the spring of 2022.