Search Publications
Solar wind charge exchange in cometary atmospheres. III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko
Alho, Markku; Simon Wedlund, Cyril; Nilsson, Hans +12 more
Context. Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet. The ESA/Rosetta mission to comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in situ.
Aims: To understand the role of these reactions in the evolution of the sola…
Precise radial velocities of giant stars. XII. Evidence against the proposed planet Aldebaran b
Trifonov, Trifon; Stock, Stephan; Reffert, Sabine +2 more
Context. Radial-velocity variations of the K giant star Aldebaran (α Tau) were first reported in the early 1990s. After subsequent analyses, the radial-velocity variability with a period of ∼629 d has recently been interpreted as caused by a planet of several Jovian masses.
Aims: We want to further investigate the hypothesis of an extrasolar …
Properties of central stars of planetary nebulae with distances in Gaia DR2
Dafonte, C.; González-Santamaría, I.; Manteiga, M. +2 more
Context. We have compiled a catalogue of central stars of planetary nebulae (CSPN) with reliable distances and positions obtained from Gaia Data Release 2 (DR2) astrometry. Distances derived from parallaxes allow us to analyse the galactic distribution and estimate other parameters such as sizes, kinematical ages, bolometric magnitudes, and lumino…
Revisiting Kepler-444. I. Seismic modeling and inversions of stellar structure
Buldgen, G.; Farnir, M.; Khan, S. +10 more
Context. The CoRoT and Kepler missions have paved the way for synergies between exoplanetology and asteroseismology. The use of seismic data helps providing stringent constraints on the stellar properties which directly impact the results of planetary studies. Amongst the most interesting planetary systems discovered by Kepler, Kepler-444 is uniqu…
Deriving the Hubble constant using Planck and XMM-Newton observations of galaxy clusters
Mazzotta, Pasquale; Sereno, Mauro; Rasia, Elena +2 more
The possibility of determining the value of the Hubble constant using observations of galaxy clusters in X-ray and microwave wavelengths through the Sunyaev Zel'dovich (SZ) effect has long been known. Previous measurements have been plagued by relatively large errors in the observational data and severe biases induced, for example, by cluster tria…
H/C elemental ratio of the refractory organic matter in cometary particles of 67P/Churyumov-Gerasimenko
Alexander, C.; Hilchenbach, M.; Engrand, C. +11 more
Context. Because comets are part of the most primitive bodies of our solar system, establishing their chemical composition and comparing them to other astrophysical bodies gives new constraints on the formation and evolution of organic matter throughout the solar system. For two years, the time-of-flight secondary ion mass spectrometer COmetary Se…
Possible depletion of metals into dust grains in the core of the Centaurus cluster of galaxies
Mernier, F.; Werner, N.; Lakhchaura, K.
We present azimuthally averaged metal abundance profiles from a full, comprehensive, and conservative re-analysis of the deep (∼800 ks total net exposure) Chandra/ACIS-S observation of the Centaurus cluster core (NGC 4696). After carefully checking various sources of systematic uncertainties, including the choice of the spectral deprojection metho…
Spectroscopic orbits of nearby stars
Tokovinin, A.; Sperauskas, J.; Deveikis, V.
Aims: We observed stars with variable radial velocities to determine their spectroscopic orbits.
Methods: Velocities are presented of 132 targets taken over a time span reaching 30 years. These were measured with the correlation radial velocity spectrometers (1917 velocities) and the new VUES echelle spectrograph (627 velocities), with a…
The MURALES survey. II. Presentation of MUSE observations of 20 3C low-z radio galaxies and first results
Marconi, A.; Capetti, A.; Gilli, R. +12 more
We present observations of a complete sub-sample of 20 radio galaxies from the Third Cambridge Catalog (3C) with redshift < 0.3 obtained from VLT/MUSE optical integral field spectrograph. These data have been obtained as part of the survey MURALES (a MUse RAdio Loud Emission line Snapshot survey) with the main goal of exploring the active galac…
Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. II. 30 Doradus
Lebouteiller, V.; Madden, S. C.; Galliano, F. +6 more
With an aim of probing the physical conditions and excitation mechanisms of warm molecular gas in individual star-forming regions, we performed Herschel SPIRE Fourier Transform Spectrometer (FTS) observations of 30 Doradus in the Large Magellanic Cloud. In our FTS observations, important far-infrared (FIR) cooling lines in the interstellar medium,…