Search Publications
Prospects for detection of detached double white dwarf binaries with Gaia, LSST and LISA
Toonen, Silvia; Brown, Anthony G. A.; Nelemans, Gijs +3 more
Double white dwarf (DWD) binaries are expected to be very common in the Milky Way, but their intrinsic faintness challenges the detection of these systems. Currently, only a few tens of detached DWDs are know. Such systems offer the best chance of extracting the physical properties that would allow us to address a wealth of outstanding questions r…
The GALAH survey: observational overview and Gaia DR1 companion
Freeman, K. C.; Marshall, J. P.; Da Costa, G. S. +31 more
The Galactic Archaeology with HERMES (GALAH) survey is a massive observational project to trace the Milky Way's history of star formation, chemical enrichment, stellar migration and minor mergers. Using high-resolution (R ≃ 28 000) spectra, taken with the High Efficiency and Resolution Multi-Element Spectrograph (HERMES) instrument at the Anglo-Au…
Clouds, Streams and Bridges. Redrawing the blueprint of the Magellanic System with Gaia DR1
Erkal, Denis; Belokurov, Vasily; Mackey, Dougal +5 more
We present the discovery of stellar tidal tails around the Large and the Small Magellanic Clouds (LMC and SMC, respectively) in the Gaia DR1 data. In between the Clouds, their tidal arms are stretched towards each other to form an almost continuous stellar bridge. Our analysis relies on the exquisite quality of the Gaia's photometric catalogue to …
Stellar inventory of the solar neighbourhood using Gaia DR1
Bovy, Jo
The absolute number and the density profiles of different types of stars in the solar neighbourhood are a fundamental anchor for studies of the initial mass function, stellar evolution, and Galactic structure. Using data from Gaia DR1, we reconstruct Gaia's selection function and determine Gaia's volume completeness, the local number density, and …
Galactic rotation in Gaia DR1
Bovy, Jo
The spatial variations of the velocity field of local stars provide direct evidence of Galactic differential rotation. The local divergence, shear and vorticity of the velocity field - the traditional Oort constants - can be measured based purely on astrometric measurements and in particular depend linearly on proper motion and parallax. I use dat…
The VMC survey - XXV. The 3D structure of the Small Magellanic Cloud from Classical Cepheids
Piatti, Andrés E.; de Grijs, Richard; Marconi, Marcella +13 more
The VISTA near-infrared YJKs survey of the Magellanic System (VMC) is collecting deep Ks-band time-series photometry of pulsating stars hosted by the two Magellanic Clouds and their connecting bridge. Here, we present Y, J, Ks light curves for a sample of 717 Small Magellanic Cloud (SMC) Classical Cepheids (CCs). T…
Fundamental parameters and infrared excesses of Tycho-Gaia stars
Zijlstra, A. A.; McDonald, I.; Watson, R. A.
Effective temperatures and luminosities are calculated for 1475 921 Tycho-2 and 107 145 Hipparcos stars, based on distances from Gaia Data Release 1. Parameters are derived by comparing multi-wavelength archival photometry to bt-settl model atmospheres. The 1σ uncertainties for the Tycho-2 and Hipparcos stars are ±137 and ±125 K in temperature and…
The AMBRE project: chemical evolution models for the Milky Way thick and thin discs
Recio-Blanco, A.; de Laverny, P.; Hayden, M. +5 more
We study the chemical evolution of the thick and thin discs of the Galaxy by comparing detailed chemical evolution models with recent data from the Archéologie avec Matisse Basée sur les aRchives de l'ESO project. The data suggest that the stars in the thick and thin discs form two distinct sequences with the thick disc stars showing higher [α/Fe]…
Wide binaries in Tycho-Gaia: search method and the distribution of orbital separations
Agüeros, Marcel A.; Andrews, Jeff J.; Chanamé, Julio
We mine the Tycho-Gaia astrometric solution (TGAS) catalogue for wide stellar binaries by matching positions, proper motions and astrometric parallaxes. We separate genuine binaries from unassociated stellar pairs through a Bayesian formulation that includes correlated uncertainties in the proper motions and parallaxes. Rather than relying on assu…
The slight spin of the old stellar halo
Gómez, Facundo A.; Marinacci, Federico; Pakmor, Rüdiger +4 more
We combine Gaia data release 1 astrometry with Sloan Digital Sky Survey (SDSS) images taken some ∼10-15 years earlier, to measure proper motions of stars in the halo of our Galaxy. The SDSS-Gaia proper motions have typical statistical errors of 2 mas yr-1 down to r ∼ 20 mag, and are robust to variations with magnitude and colour. Armed …