The new generation of spectrometers designed for extreme precision radial velocities enable correspondingly precise stellar spectroscopy. It is now fruitful to...
2D-FIS, a bundle of 125 optical fibres mounted in the focal plane of the WHT, has been used to study two-dimensional stellar kinematics and populations in...
Jormungandr: A Large Substructure Circling the Milky Way Identified from Gaia DR3 Data
We report the discovery of a large substructure in the Milky Way passing through the solar neighborhood, detected in actions calculated from Gaia DR3 data. We...
Milky Way Dark Matter Distribution or MOND Test from Vertical Stellar Kinematics with Gaia DR3
Vertical stellar kinematics+density can be used to trace the dark matter distribution (or the equivalent phantom mass in a Modified Newtonian Dynamics (MOND)...
Multiple Populations in Low-mass Globular Clusters: Palomar 13
Since the discovery of chemically peculiar stars in globular clusters in the last century, the study of multiple populations has become increasingly important...
On the extreme properties of massive galaxies at high redshifts
Massive (≥ 10 11 M⊙) galaxies at high redshift (z ≥ 1.5) remain mysterious objects. Their extremely small sizes (effective radii of 1-2 kpc) make them...
Orbital Torus Imaging: Using Element Abundances to Map Orbits and Mass in the Milky Way
Many approaches to galaxy dynamics assume that the gravitational potential is simple and the distribution function is time invariant. Under these assumptions...
Dwarf galaxies are a complex population. They comprise objects with young and old stellar populations, slow and fast rotation, as well as single- and multi...