Search Publications
Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly
Mignard, François; Thévenin, Frédéric; Kervella, Pierre +1 more
Context. The census of stellar and substellar companions of nearby stars is largely incomplete, in particular toward the low-mass brown dwarf and long-period exoplanets. It is, however, fundamentally important in the understanding of the stellar and planetary formation and evolution mechanisms. Nearby stars are particularly favorable targets for h…
Mass and shape of the Milky Way's dark matter halo with globular clusters from Gaia and Hubble
Helmi, Amina; Posti, Lorenzo
Aims: We estimate the mass of the inner (< 20 kpc) Milky Way and the axis ratio of its inner dark matter halo using globular clusters as tracers. At the same time, we constrain the distribution in phase-space of the globular cluster system around the Galaxy.
Methods: We use the Gaia Data Release 2 catalogue of 75 globular clusters' pr…
ALMA observations of molecular tori around massive black holes
Krips, M.; van der Werf, P.; Combes, F. +12 more
We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of CO(3-2) emission in a sample of seven Seyfert/LINER galaxies at the unprecedented spatial resolution of 0.″1 = 4-8 pc. Our aim is to explore the close environment of active galactic nuclei (AGN), and the dynamical structures leading to their fueling…
A stellar census in globular clusters with MUSE: Binaries in NGC 3201
Brinchmann, Jarle; Weilbacher, Peter M.; Kamann, Sebastian +8 more
We utilise multi-epoch MUSE spectroscopy to study binary stars in the core of the Galactic globular cluster NGC 3201. Our sample consists of 3553 stars with 54 883 spectra in total comprising 3200 main-sequence stars up to 4 magnitudes below the turn-off. Each star in our sample has between 3 and 63 (with a median of 14) reliable radial velocity m…
Tension with the flat ΛCDM model from a high-redshift Hubble diagram of supernovae, quasars, and gamma-ray bursts
Paolillo, M.; Nardini, E.; Amati, L. +4 more
In the current framework, the standard parametrization of our Universe is the so-called Lambda cold dark matter (ΛCDM) model. Recently, a ∼4σ tension with the ΛCDM model was shown to exist via a model-independent parametrization of a Hubble diagram of type Ia supernovae (SNe Ia) from the JLA survey and quasars. Model-independent approaches and ind…
Ubiquitous cold and massive filaments in cool core clusters
Godard, B.; Fabian, A. C.; Combes, F. +19 more
Multi-phase filamentary structures around brightest cluster galaxies (BCG) are likely a key step of AGN-feedback. We observed molecular gas in three cool cluster cores, namely Centaurus, Abell S1101, and RXJ1539.5, and gathered ALMA (Atacama Large Millimeter/submillimeter Array) and MUSE (Multi Unit Spectroscopic Explorer) data for 12 other cluste…
The strong gravitational lens finding challenge
Kneib, J. -P.; Bertin, E.; Jullo, E. +34 more
Large-scale imaging surveys will increase the number of galaxy-scale strong lensing candidates by maybe three orders of magnitudes beyond the number known today. Finding these rare objects will require picking them out of at least tens of millions of images, and deriving scientific results from them will require quantifying the efficiency and bias…
Effect of galaxy mergers on star-formation rates
Wang, L.; van der Tak, F. F. S.; Holwerda, B. W. +8 more
Context. Galaxy mergers and interactions are an integral part of our basic understanding of how galaxies grow and evolve over time. However, the effect that galaxy mergers have on star-formation rates (SFRs) is contested, with observations of galaxy mergers showing reduced, enhanced, and highly enhanced star formation.
Aims: We aim to determi…
The MUSE-Wide Survey: survey description and first data release
Steinmetz, M.; Diener, C.; Enke, H. +17 more
We present the MUSE-Wide survey, a blind, 3D spectroscopic survey in the CANDELS/GOODS-S and CANDELS/COSMOS regions. The final survey will cover 100 × 1 arcmin2 MUSE fields. Each MUSE-Wide pointing has a depth of one hour and hence targets more extreme and more luminous objects over ten times the area of the MUSE-Deep fields. The legacy…
High-resolution confirmation of an extended helium atmosphere around WASP-107b
Aceituno, J.; Ehrenreich, D.; Lovis, C. +7 more
Context. Probing the evaporation of exoplanet atmospheres is key to understanding the formation and evolution of exoplanetary systems. The main tracer of evaporation in the UV is the Lyman-α transition, which can reveal extended exospheres of neutral hydrogen. Recently, the near-infrared (NIR) metastable helium triplet (10 833 Å) revealed extended…