Search Publications
Evidence for two early accretion events that built the Milky Way stellar halo
Myeong, G. C.; Evans, N. W.; Belokurov, V. +2 more
The Gaia Sausage is the major accretion event that built the stellar halo of the Milky Way galaxy. Here, we provide dynamical and chemical evidence for a second substantial accretion episode, distinct from the Gaia Sausage. The Sequoia Event provided the bulk of the high-energy retrograde stars in the stellar halo, as well as the recently discover…
Mean proper motions, space orbits, and velocity dispersion profiles of Galactic globular clusters derived from Gaia DR2 data
Hilker, M.; Bellini, A.; Baumgardt, H. +1 more
We have derived the mean proper motions and space velocities of 154 Galactic globular clusters and the velocity dispersion profiles of 141 globular clusters based on a combination of Gaia DR2 proper motions with ground-based line-of-sight velocities. Combining the velocity dispersion profiles derived here with new measurements of the internal mass…
A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS
Toonen, Silvia; Hollands, Mark; Raddi, Roberto +11 more
We present a catalogue of white dwarf candidates selected from the second data release of Gaia (DR2). We used a sample of spectroscopically confirmed white dwarfs from the Sloan Digital Sky Survey (SDSS) to map the entire space spanned by these objects in the Gaia Hertzsprung-Russell diagram. We then defined a set of cuts in absolute magnitude, co…
The formation and assembly history of the Milky Way revealed by its globular cluster population
Kruijssen, J. M. Diederik; Crain, Robert A.; Bastian, Nate +2 more
We use the age-metallicity distribution of 96 Galactic globular clusters (GCs) to infer the formation and assembly history of the Milky Way (MW), culminating in the reconstruction of its merger tree. Based on a quantitative comparison of the Galactic GC population to the 25 cosmological zoom-in simulations of MW-mass galaxies in the E-MOSAICS proj…
Vertical waves in the solar neighbourhood in Gaia DR2
Bovy, Jo; Bennett, Morgan
The vertical structure and dynamics of stars in our local Galactic neighbourhood contains much information about the local distribution of visible and dark matter and of perturbations to the Milky Way disc. We use data on the positions and velocities of stars in the solar neighbourhood from Gaia Data Release 2 (DR2) and large spectroscopic surveys…
The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
Li, T. S.; Evans, N. W.; Belokurov, V. +14 more
In a companion paper by Koposov et al., RR Lyrae from Gaia Data Release 2 are used to demonstrate that stars in the Orphan stream have velocity vectors significantly misaligned with the stream track, suggesting that it has received a large gravitational perturbation from a satellite of the Milky Way. We argue that such a mismatch cannot arise due …
The origin of accreted stellar halo populations in the Milky Way using APOGEE, Gaia, and the EAGLE simulations
Bovy, Jo; Majewski, Steven R.; Holtzman, Jon +12 more
Recent work indicates that the nearby Galactic halo is dominated by the debris from a major accretion event. We confirm that result from an analysis of APOGEE-DR14 element abundances and Gaia-DR2 kinematics of halo stars. We show that ∼2/3 of nearby halo stars have high orbital eccentricities (e ≳ 0.8), and abundance patterns typical of massive Mi…
juliet: a versatile modelling tool for transiting and non-transiting exoplanetary systems
Espinoza, Néstor; Kossakowski, Diana; Brahm, Rafael
Here we present juliet, a versatile tool for the analysis of transits, radial velocities, or both. juliet is built over many available tools for the modelling of transits, radial velocities, and stochastic processes (here modelled as Gaussian Processes; GPs) in order to deliver a tool/wrapper which can be used for the analysis of transit photometr…
Proper motions and dynamics of the Milky Way globular cluster system from Gaia DR2
Vasiliev, Eugene
We use Gaia Data Release 2 to determine the mean proper motions for 150 Milky Way globular clusters (almost the entire known population), with a typical uncertainty of 0.05 mas yr-1 limited mainly by systematic errors. Combining them with distance and line-of-sight velocity measurements from the literature, we analyse the distribution o…
The ASAS-SN catalogue of variable stars - II. Uniform classification of 412 000 known variables
Kochanek, C. S.; Stanek, K. Z.; Dong, Subo +12 more
The variable stars in the VSX catalogue are derived from a multitude of inhomogeneous data sources and classification tools. This inhomogeneity complicates our understanding of variable star types, statistics, and properties, and it directly affects attempts to build training sets for current (and next) generation all-sky, time-domain surveys. We …