Search Publications
Gaia DR2 reveals a star formation burst in the disc 2-3 Gyr ago
Luri, X.; Figueras, F.; Mor, R. +2 more
We use Gaia data release 2 (DR2) magnitudes, colours, and parallaxes for stars with G < 12 to explore a parameter space with 15 dimensions that simultaneously includes the initial mass function (IMF) and a non-parametric star formation history (SFH) for the Galactic disc. This inference is performed by combining the Besançon Galaxy Model fast a…
Gaia DR2 unravels incompleteness of nearby cluster population: new open clusters in the direction of Perseus
Castro-Ginard, A.; Jordi, C.; Cantat-Gaudin, T. +13 more
Context. Open clusters (OCs) are popular tracers of the structure and evolutionary history of the Galactic disc. The OC population is often considered to be complete within 1.8 kpc of the Sun. The recent Gaia Data Release 2 (DR2) allows the latter claim to be challenged.
Aims: We perform a systematic search for new OCs in the direction of Per…
The echo of the bar buckling: Phase-space spirals in Gaia Data Release 2
Gerhard, Ortwin; Khoperskov, Sergey; Di Matteo, Paola +5 more
We present a high-resolution numerical study of the phase-space diversity in an isolated Milky Way-type galaxy. Using a single N-body simulation (N ≈ 0.14 × 109) we explore the formation, evolution, and spatial variation of the phase-space spirals similar to those recently discovered by Antoja et al. in the Milky Way disk with Gaia Data…
KiDS+VIKING-450: A new combined optical and near-infrared dataset for cosmology and astrophysics
Sifón, Cristóbal; Heymans, Catherine; Kuijken, Konrad +22 more
We present the curation and verification of a new combined optical and near infrared dataset for cosmology and astrophysics, derived by combining ugri-band imaging from the Kilo-Degree Survey (KiDS) and ZYJHKs-band imaging from the VISTA Kilo degree Infrared Galaxy (VIKING) survey. This dataset is unrivaled in cosmological imaging surve…
The population of hot subdwarf stars studied with Gaia. II. The Gaia DR2 catalogue of hot subluminous stars
Geier, S.; Marsh, T. R.; Raddi, R. +1 more
Based on data from the ESA Gaia Data Release 2 (DR2) and several ground-based, multi-band photometry surveys we have compiled an all-sky catalogue of 39 800 hot subluminous star candidates selected in Gaia DR2 by means of colour, absolute magnitude, and reduced proper motion cuts. We expect the majority of the candidates to be hot subdwarf stars o…
VLT/FLAMES high-resolution chemical abundances in Sculptor: a textbook dwarf spheroidal galaxy
Spite, M.; Skúladóttir, Á.; Jablonka, P. +12 more
We present detailed chemical abundances for 99 red-giant branch stars in the centre of the Sculptor dwarf spheroidal galaxy, which have been obtained from high-resolution VLT/FLAMES spectroscopy. The abundances of Li, Na, α-elements (O, Mg, Si, Ca Ti), iron-peak elements (Sc, Cr, Fe, Co, Ni, Zn), and r- and s-process elements (Ba, La, Nd, Eu) were…
Luminous red novae: Stellar mergers or giant eruptions?
Drake, A. J.; Sollerman, J.; Djorgovski, S. G. +36 more
We present extensive datasets for a class of intermediate-luminosity optical transients known as luminous red novae. They show double-peaked light curves, with an initial rapid luminosity rise to a blue peak (at -13 to -15 mag), which is followed by a longer-duration red peak that sometimes is attenuated, resembling a plateau. The progenitors of t…
Transient processing and analysis using AMPEL: alert management, photometry, and evaluation of light curves
Sollerman, J.; Gal-Yam, A.; Kowalski, M. +18 more
Context. Both multi-messenger astronomy and new high-throughput wide-field surveys require flexible tools for the selection and analysis of astrophysical transients.
Aims: Here we introduce the alert management, photometry, and evaluation of light curves (AMPEL) system, an analysis framework designed for high-throughput surveys and suited for…
Towards emulating cosmic shear data: revisiting the calibration of the shear measurements for the Kilo-Degree Survey
Hoekstra, Henk; Heymans, Catherine; Kuijken, Konrad +9 more
Exploiting the full statistical power of future cosmic shear surveys will necessitate improvements to the accuracy with which the gravitational lensing signal is measured. We present a framework for calibrating shear with image simulations that demonstrates the importance of including realistic correlations between galaxy morphology, size, and mor…
Observation-based modelling of magnetised coronal mass ejections with EUHFORIA
Mierla, M.; Rodriguez, L.; Poedts, S. +2 more
Context. Coronal mass ejections (CMEs) are the primary source of strong space weather disturbances at Earth. Their geo-effectiveness is largely determined by their dynamic pressure and internal magnetic fields, for which reliable predictions at Earth are not possible with traditional cone CME models.
Aims: We study two well-observed Earth-dir…