Search Publications
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…
Abundance to age ratios in the HARPS-GTO sample with Gaia DR2. Chemical clocks for a range of [Fe/H]
Chaplin, W. J.; Moya, A.; Davies, G. R. +8 more
Aims: The purpose of this work is to evaluate how several elements produced by different nucleosynthesis processes behave with stellar age and provide empirical relations to derive stellar ages from chemical abundances.
Methods: We derived different sets of ages using Padova and Yonsei-Yale isochrones and HIPPARCOS and Gaia parallaxes fo…
Synthesis of the morphological description of cometary dust at comet 67P/Churyumov-Gerasimenko
Lasue, J.; Langevin, Y.; Krüger, H. +28 more
Before Rosetta, the space missions Giotto and Stardust shaped our view on cometary dust, supported by plentiful data from Earth based observations and interplanetary dust particles collected in the Earth's atmosphere. The Rosetta mission at comet 67P/Churyumov-Gerasimenko was equipped with a multitude of instruments designed to study cometary dust…
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…
Characterization and history of the Helmi streams with Gaia DR2
Helmi, Amina; Koppelman, Helmer H.; Massari, Davide +2 more
Context. The halo of the Milky Way has long been hypothesized to harbour significant amounts of merger debris. For more than a decade this view has been supported by wide-field photometric surveys which have revealed the outer halo to be lumpy.
Aims: The recent release of Gaia DR2 is allowing us to establish that mergers also have been import…
Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
Tamura, M.; Nagel, E.; Amado, P. J. +73 more
We report the detection of a transiting Earth-size planet around GJ 357, a nearby M2.5 V star, using data from the Transiting Exoplanet Survey Satellite (TESS). GJ 357 b (TOI-562.01) is a transiting, hot, Earth-sized planet (Teq = 525 ± 11 K) with a radius of Rb = 1.217 ± 0.084 R⊕ and an orbital period of Pb
Carbon, oxygen, and iron abundances in disk and halo stars. Implications of 3D non-LTE spectral line formation
Skúladóttir, Á.; Amarsi, A. M.; Nissen, P. E.
The abundances of carbon, oxygen, and iron in late-type stars are important parameters in exoplanetary and stellar physics, as well as key tracers of stellar populations and Galactic chemical evolution. However, standard spectroscopic abundance analyses can be prone to severe systematic errors, based on the assumption that the stellar atmosphere i…
Hyades tidal tails revealed by Gaia DR2
Goldman, Bertrand; Röser, Siegfried; Schilbach, Elena
Aims: Within a 200 pc sphere around the Sun, we search for the Hyades tidal tails in the Gaia DR2 dataset.
Methods: We used a modified convergent-point method to search for stars with space velocities close to the space velocity of the Hyades cluster.
Results: We find a clear indication for the existence of the Hyades tidal tails, a…
The GALAH survey: An abundance, age, and kinematic inventory of the solar neighbourhood made with TGAS
Freeman, K. C.; Skúladóttir, Á.; Rix, H. -W. +32 more
The overlap between the spectroscopic Galactic Archaeology with HERMES (GALAH) survey and Gaia provides a high-dimensional chemodynamical space of unprecedented size. We present a first analysis of a subset of this overlap, of 7066 dwarf, turn-off, and sub-giant stars. These stars have spectra from the GALAH survey and high parallax precision from…