Search Publications
Astrometric Exoplanet Detection with Gaia
Bakos, Gáspár Á.; Lindegren, Lennart; Hartman, Joel +1 more
We provide a revised assessment of the number of exoplanets that should be discovered by Gaia astrometry, extending previous studies to a broader range of spectral types, distances, and magnitudes. Our assessment is based on a large representative sample of host stars from the TRILEGAL Galaxy population synthesis model, recent estimates of the exo…
Gaia FGK benchmark stars: Metallicity
Montes, D.; de Laverny, P.; Cantat-Gaudin, T. +22 more
Context. To calibrate automatic pipelines that determine atmospheric parameters of stars, one needs a sample of stars, or "benchmark stars", with well-defined parameters to be used as a reference.
Aims: We provide detailed documentation of the iron abundance determination of the 34 FGK-type benchmark stars that are selected to be the pillars …
The Besançon Galaxy model renewed. I. Constraints on the local star formation history from Tycho data
Luri, X.; Figueras, F.; Haywood, M. +2 more
Context. The understanding of Galaxy evolution can be facilitated by the use of population synthesis models, which allows us to test hypotheses on the star formation history, star evolution, and chemical and dynamical evolution of the Galaxy.
Aims: The new version of the Besançon Galaxy model (BGM) aims to provide a more flexible and powerful…
The Gaia FGK benchmark stars. High resolution spectral library
Soubiran, C.; Heiter, U.; Blanco-Cuaresma, S. +1 more
Context. An increasing number of high-resolution stellar spectra is available today thanks to many past and ongoing spectroscopic surveys. Consequently, numerous methods have been developed to perform an automatic spectral analysis on a massive amount of data. When reviewing published results, biases arise and they need to be addressed and minimiz…
Astrometric detection of giant planets around nearby M dwarfs: the Gaia potential
Sozzetti, A.; Giacobbe, P.; Lattanzi, M. G. +3 more
Cool M dwarfs within a few tens of parsecs from the Sun are becoming the focus of dedicated observational programs in the realm of exoplanet astrophysics. Gaia, in its all-sky survey of >109 objects, will deliver precision astrometry for a magnitude-limited (V = 20) sample of M dwarfs. We investigate some aspects of the synergy betwe…
Reproducing properties of MW dSphs as descendants of DM-free TDGs
Kroupa, Pavel; Hammer, François; Puech, Mathieu +4 more
The Milky Way (MW) dwarf spheroidal (dSph) satellites are known to be the most dark-matter (DM) dominated galaxies with estimates of dark-to-baryonic matter reaching even above 100. It comes from the assumption that dwarfs are dynamically supported by their observed velocity dispersions. However, their spatial distributions around the MW are not a…
Predicted Space Motions for Hypervelocity and Runaway Stars: Proper Motions and Radial Velocities for the Gaia Era
Geller, Margaret J.; Brown, Warren R.; Kenyon, Scott J. +1 more
We predict the distinctive three-dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10 kpc, unbound stars are rare; proper motions alone rarely isolate bound HVSs and runaways from indigenous halo stars. At large distances of 20-100 kpc, unbo…
Gaia photometry for white dwarfs
Jordi, C.; Luri, X.; Carrasco, J. M. +5 more
Context. White dwarfs can be used to study the structure and evolution of the Galaxy by analysing their luminosity function and initial mass function. Among them, the very cool white dwarfs provide the information for the early ages of each population. Because white dwarfs are intrinsically faint only the nearby (~ 20 pc) sample is reasonably comp…
Joint astrometric solution of HIPPARCOS and Gaia. A recipe for the Hundred Thousand Proper Motions project
Michalik, Daniel; Lindegren, Lennart; Hobbs, David +1 more
Context. The first release of astrometric data from Gaia is expected in 2016. It will contain the mean stellar positions and magnitudes from the first year of observations. For more than 100 000 stars in common with the Hipparcos Catalogue it will be possible to compute very accurate proper motions due to the time difference of about 24 years betw…
Overview and stellar statistics of the expected Gaia Catalogue using the Gaia Object Generator
Jordi, C.; Luri, X.; Arenou, F. +13 more
Aims: An effort has been made to simulate the expected Gaia Catalogue, including the effect of observational errors. We statistically analyse this simulated Gaia data to better understand what can be obtained from the Gaia astrometric mission. This catalogue is used to investigate the potential yield in astrometric, photometric, and spectrosc…