Search Publications
Anisotropies of solar energetic electrons in the MeV range measured with Solar Orbiter/EPD/HET
Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F.; Dresing, N. +4 more
Aims: This study analyses relativistic electron measurements obtained by the High Energy Telescope (HET) aboard Solar Orbiter in the energy range from 200 keV to above 10 MeV. Caveats of these measurements are discussed. The purpose of this study is to analyse anisotropies of relativistic solar energetic electrons utilising the different view…
Optical/X-ray/radio view of Abell 1213: A galaxy cluster with anomalous diffuse radio emission
De Grandi, S.; Riva, G.; Boschin, W. +5 more
Context. Abell 1213, a low-richness galaxy system, is known to host an anomalous radio halo detected in data of the Very Large Array (VLA). It is an outlier with regard to the relation between the radio halo power and the X-ray luminosity of the parent clusters.
Aims: Our aim is to analyze the cluster in the optical, X-ray, and radio bands to…
V4142 Sgr: Double periodic variable with an accretor surrounded by the accretion disk's atmosphere
Mennickent, R. E.; Djurašević, G.; Petrović, J. +4 more
Context. A detailed study of the close interacting binary V4142 Sgr, based on photometric and spectroscopic analyses, indicates that this system belongs to the enigmatic class of Algol-like variables exhibiting a long photometric cycle of an unknown nature.
Aims: By performing photometric data-mining and spectroscopic observations covering th…
Young nearby open clusters and their luminosity functions
Béjar, V. J. S.; Martín, E. L.; Lodieu, N. +3 more
Context. Open clusters are groups of coeval stars sharing properties such as distance and metallicity, and they are key to understanding stellar evolution.
Aims: Our main goal is to study the evolution of open clusters with a special focus on the universality of the luminosity function.
Methods: We applied an upgraded version of the conv…
Particle-in-cell modelling of comet 67P/Churyumov-Gerasimenko. Spatial structures of densities and electric fields
Goetz, Charlotte; Gunell, Herbert
Context. Sufficiently far from the Sun, all comets go through a phase of low activity. Rosetta observations at large heliocentric distances of approximately 3 au showed that the plasma at a low-activity comet is affected by both steady state electric fields and low-frequency waves.
Aims: Our goal is to provide a model for the electric fields …
Dust giant: Extended and clumpy star-formation in a massive dusty galaxy at z = 1.38
Trebitsch, Maxime; Daddi, Emanuele; Liu, Daizhong +8 more
We present NOEMA CO (2-1) line and ALMA 870 µm continuum observations of a main-sequence galaxy at z = 1.38. The galaxy was initially deemed a "gas giant" based on the gas mass derived from sub-mm continuum (log(Mgas/M⊙) = 11.20 ± 0.20), however, the gas mass derived from CO (2−1) luminosity brings the gas mass value down to …
Identifying and characterising the population of hot sub-luminous stars with multi-colour MeerLICHT data
Groot, P. J.; Aerts, C.; Ranaivomanana, P. +9 more
Context. Colour-magnitude diagrams reveal a population of blue (hot) sub-luminous objects with respect to the main sequence. These hot sub-luminous stars are the result of evolutionary processes that require stars to expel their obscuring, hydrogen-rich envelopes to reveal the hot helium core. As such, these objects offer a direct window into the …
High-velocity CP2 stars in the Galactic halo
Paunzen, E.; Prišegen, M.; Faltová, N. +2 more
Context. The second subclass of chemically peculiar stars, the CP2 stars, are early-type stars exhibiting anomalous abundances with variable line strengths possibly also accompanied by photometric variability that typically belong to the Galactic disk. However, a small fraction of these objects were recently found to be located far from the Galact…
TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS
Alonso, R.; Deleuil, M.; Erikson, A. +89 more
Context. TOI-1055 is a Sun-like star known to host a transiting Neptune-sized planet on a 17.5-day orbit (TOI-1055 b). Radial velocity (RV) analyses carried out by two independent groups using nearly the same set of HARPS spectra have provided measurements of planetary masses that differ by ∼2σ.
Aims: Our aim in this work is to solve the inco…
Low NH3/H2O ratio in comet C/2020 F3 (NEOWISE) at 0.7 au from the Sun
McGuire, Brett A.; Drozdovskaya, Maria N.; Opitom, Cyrielle +7 more
Context. A lower-than-solar elemental nitrogen content has been demonstrated for several comets, including 1P/Halley and 67P/Churyumov-Gerasimenko (67P/C-G) with independent in situ measurements of volatile and refractory budgets. The recently discovered semi-refractory ammonium salts in 67P/C-G are thought to be the missing nitrogen reservoir in …