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Practical matters How to find us prof. dr. A. (Amina) Helmi

Research interests

 My main research interests are in galaxy evolution and dynamics, with emphasis on what can be learned from the nearby Universe, and in particular from our own Galaxy. The assembly process of a galaxy leaves imprints in the present-day spatial distribution, motions, ages and chemical abundances of its stars. The Milky Way is the only system (for now) for which we have direct access to this information, because only in our Galaxy and its nearby satellites can we measure the properties of millions of individual stars. One of the main goals of my research has been to characterize these fossil signatures from a theoretical point of view, and to use observational data to recover those fossils and thereby reconstruct the formation history of our Galaxy.   

The recently launched European Space Agency’s satellite, Gaia, is currently measuring accurately the spatial distribution, kinematics and properties of a billion stars in the Milky Way. This unparalleled new dataset is allowing us to address the most fundamental questions about our Galaxy’s history and dynamics. With the revolutionary new understanding of a typical galaxy like ours that Gaia is already delivering, we are obtaining unique insights on the process of galaxy formation and on the nature and role of dark matter, two of the most urgent open questions in modern Astrophysics. 

My group’s research presently covers three areas: the merger history of the Galaxy (combining kinematics and chemistry); the dynamics of the different Galactic components, including the halo and the disk with the aim of constraining the spatial distribution and granularity of dark matter, and the kinematics and dynamics of globular clusters and dwarf galaxies. We are currently also strongly involved in Gaia’s data validation work, and in two new multi-object spectrographs: WEAVE on the WHT (La Palma) and 4most on VISTA (ESO, Chile).

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Publications

The merger that led to the formation of the Milky Way’s inner stellar halo and thick disk

Three-dimensional motions in the Sculptor dwarf galaxy as a glimpse of a new era

The vertical force in the solar neighbourhood using red clump stars in TGAS and RAVE: Constraints on the local dark matter density

The time evolution of gaps in tidal streams in axisymmetric potentials

Substructures, resonances, and debris streams: A new constraint on the inner shape of the Galactic dark halo

Corrigendum: Gaia Early Data Release 3. Summary of the contents and survey properties

Determination of the escape velocity of the Milky Way using a halo sample selected based on proper motion

Frequencies, chaos, and resonances: A study of orbital parameters of nearby thick-disc and halo stars

Gaia Early Data Release 3. Acceleration of the Solar System from Gaia astrometry

Gaia Early Data Release 3. Catalogue validation

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Press/media

Klein sterrenstelsel maakte 'slakkenhuis' in onze hoek van Melkweg

Satelliet Gaia ontdekt ‘rommelige’ banen van dwergsterrenstelsels en sterren

Spinoza Prize 2019 for astronomer Amina Helmi

Jonge Melkweg slokt Gigant op

Milky Way archaeology and the dynamical signatures of mergers

New GAIA data reveals mergers in Milky Way

Nieuwe dataset Gaia-telescoop toont fusies van de Melkweg

We zijn stelsels rond de Melkweg kwijt.

Kunstmaan Gaia brengt 1.692.919.135 sterren in kaart

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