Search Publications
Co-formation of the disc and the stellar halo
Evans, N. W.; Belokurov, V.; Koposov, S. E. +2 more
Using a large sample of main sequence stars with 7D measurements supplied by Gaia and SDSS, we study the kinematic properties of the local (within ∼10 kpc from the Sun) stellar halo. We demonstrate that the halo's velocity ellipsoid evolves strongly with metallicity. At the low-[Fe/H] end, the orbital anisotropy (the amount of motion in the radial…
The GALAH Survey: second data release
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +41 more
The Galactic Archaeology with HERMES (GALAH) survey is a large-scale stellar spectroscopic survey of the Milky Way, designed to deliver complementary chemical information to a large number of stars covered by the Gaia mission. We present the GALAH second public data release (GALAH DR2) containing 342 682 stars. For these stars, the GALAH collabora…
On the use of Gaia magnitudes and new tables of bolometric corrections
Casagrande, L.; VandenBerg, Don A.
The availability of reliable bolometric corrections and reddening estimates, rather than the quality of parallaxes, will be one of the main limiting factors in determining the luminosities of a large fraction of Gaia stars. With this goal in mind, we provide GaiaGBP, G, and GRP synthetic photometry for the entire MARCS grid a…
The Next Generation Transit Survey (NGTS)
Jordán, Andrés; Wheatley, Peter J.; Bayliss, Daniel +43 more
We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars. NGTS builds on the legacy of previous surveys, most notably WASP, and is designed to achieve higher photometric precision and hence find smaller planets than have previously been detected from the ground…
Confirming chemical clocks: asteroseismic age dissection of the Milky Way disc(s)
Serenelli, A. M.; Johnson, J. A.; Lund, M. N. +22 more
Investigations of the origin and evolution of the Milky Way disc have long relied on chemical and kinematic identifications of its components to reconstruct our Galactic past. Difficulties in determining precise stellar ages have restricted most studies to small samples, normally confined to the solar neighbourhood. Here, we break this impasse wit…
StarHorse: a Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars
da Costa, L. N.; Maia, M. A. G.; Anders, F. +12 more
Understanding the formation and evolution of our Galaxy requires accurate distances, ages, and chemistry for large populations of field stars. Here, we present several updates to our spectrophotometric distance code, which can now also be used to estimate ages, masses, and extinctions for individual stars. Given a set of measured spectrophotometri…
LISA verification binaries with updated distances from Gaia Data Release 2
Rossi, E. M.; Groot, P. J.; Marsh, T. R. +6 more
Ultracompact binaries with orbital periods less than a few hours will dominate the gravitational wave signal in the mHz regime. Until recently, 10 systems were expected to have a predicted gravitational wave signal strong enough to be detectable by the Laser Interferometer Space Antenna (LISA), the so-called `verification binaries'. System paramet…
Ghostly tributaries to the Milky Way: charting the halo's stellar streams with the Gaia DR2 catalogue
Malhan, Khyati; Ibata, Rodrigo A.; Martin, Nicolas F.
We present a panoramic map of the stellar streams of the Milky Way based upon astrometric and photometric measurements from the Gaia DR2 catalogue. In this first contribution, we concentrate on the halo at heliocentric distances beyond 5{ kpc}, and at Galactic latitudes |b| > 30°, using the STREAMFINDER algorithm to detect structures along plau…
Estimating stellar birth radii and the time evolution of Milky Way's ISM metallicity gradient
Recio-Blanco, A.; de Laverny, P.; Hayden, M. +14 more
We present a semi-empirical, largely model-independent approach for estimating Galactic birth radii, rbirth, for Milky Way disc stars. The technique relies on the justifiable assumption that a negative radial metallicity gradient in the interstellar medium (ISM) existed for most of the disc lifetime. Stars are projected back to their bi…
Circumbinary, not transitional: on the spiral arms, cavity, shadows, fast radial flows, streamers, and horseshoe in the HD 142527 disc
Pinte, Christophe; Lodato, Giuseppe; Casassus, Simon +13 more
We present 3D hydrodynamical models of the HD 142527 protoplanetary disc, a bright and well-studied disc that shows spirals and shadows in scattered light around a 100 au gas cavity, a large horseshoe dust structure in mm continuum emission, together with mysterious fast radial flows and streamers seen in gas kinematics. By considering several pos…