Search Publications
Properties of dark subhaloes from gaps in tidal streams
Erkal, Denis; Belokurov, Vasily
Cold or warm, the dark matter substructure spectrum must extend to objects with masses as low as 107 M⊙, according to the most recent Lyman α measurements. Around a Milky Way-like galaxy, more than a thousand of these subhaloes will not be able to form stars but are dense enough to survive even deep down in the potential well…
Detecting dark matter substructures around the Milky Way with Gaia
Feldmann, Robert; Spolyar, Douglas
Cold dark matter (CDM) theory, a pillar of modern cosmology and astrophysics, predicts the existence of a large number of starless dark matter haloes surrounding the Milky Way (MW). However, clear observational evidence of these `dark' substructures remains elusive. Here, we present a detection method based on the small, but detectable, velocity c…
Biases in the determination of dynamical parameters of star clusters: today and in the Gaia era
Balbinot, E.; Hénault-Brunet, V.; Gieles, M. +4 more
The structural and dynamical properties of star clusters are generally derived by means of the comparison between steady-state analytic models and the available observables. With the aim of studying the biases of this approach, we fitted different analytic models to simulated observations obtained from a suite of direct N-body simulations of star …
Gaia's potential for the discovery of circumbinary planets
Sahlmann, J.; Martin, D. V.; Triaud, A. H. M. J.
The abundance and properties of planets orbiting binary stars - circumbinary planets - are largely unknown because they are difficult to detect with currently available techniques. Results from the Kepler satellite and other studies indicate a minimum occurrence rate of circumbinary giant planets of ∼10 per cent, yet only a handful are presently k…
Total eclipse of the heart: the AM CVn Gaia14aae/ASSASN-14cn
Prusti, T.; Gilmore, G.; Drake, A. J. +82 more
We report the discovery and characterization of a deeply eclipsing AM CVn-system, Gaia14aae (=ASSASN-14cn). Gaia14aae was identified independently by the All-Sky Automated Survey for Supernovae (ASAS-SN; Shappee et al.) and by the Gaia Science Alerts project, during two separate outbursts. A third outburst is seen in archival Pan-STARRS-1 (PS1; Sc…
The analysis of realistic stellar Gaia mock catalogues - I. Red clump stars as tracers of the central bar
Figueras, F.; Antoja, T.; Romero-Gómez, M. +2 more
In this first paper, we simulate the population of disc red clump stars to be observed by Gaia. We generate a set of test particles and we evolve it in a 3D barred Milky Way like galactic potential. We assign physical properties of the red clump trace population and a realistic 3D interstellar extinction model. We add Gaia observational constraint…
The stellar kinematics of corotating spiral arms in Gaia mock observations
Cropper, Mark; Grand, Robert J. J.; Minchev, Ivan +3 more
We have observed an N-body/smoothed particle hydrodynamics simulation of a Milky Way-like barred spiral galaxy. We present a simple method that samples N-body model particles into mock Gaia stellar observations and takes into account stellar populations, dust extinction and Gaia's science performance estimates. We examine the kinematics of stars w…
Testing the inversion of asteroids' Gaia photometry combined with ground-based observations
Tanga, P.; Cellino, A.; Bartczak, P. +2 more
We investigated the reliability of the genetic algorithm which will be used to invert the photometric measurements of asteroids collected by the European Space Agency Gaia mission. To do that, we performed several sets of simulations for 10 000 asteroids having different spin axis orientations, rotational periods and shapes. The observational epoc…
A comparative study of four significance measures for periodicity detection in astronomical surveys
Holl, Berry; Rimoldini, Lorenzo; Mowlavi, Nami +8 more
We study the problem of periodicity detection in massive data sets of photometric or radial velocity time series, as presented by ESA's Gaia mission. Periodicity detection hinges on the estimation of the false alarm probability of the extremum of the periodogram of the time series. We consider the problem of its estimation with two main issues in …
Detection of satellite remnants in the Galactic halo with Gaia- III. Detection limits for ultrafaint dwarf galaxies
Figueras, F.; Brown, A. G. A.; Antoja, T. +8 more
We present a method to identify ultrafaint dwarf galaxies (UFDGs) candidates in the halo of the Milky Way using the future Gaia catalogue and we explore its detection limits and completeness. The method is based on the Wavelet Transform and searches for overdensities in the combined space of sky coordinates and proper motions, using kinematics in …