Search Publications
The origin of very massive stars around NGC 3603
Vink, J. S.; de Wit, W. J.; Méndez, R. A. +2 more
The formation mechanism of the most massive stars in the Universe remains an unsolved problem. Are they able to form in relative isolation in a manner similar to the formation of solar-type stars, or do they necessarily require a clustered environment? In order to shed light on this important question, we study the origin of two very massive stars…
Flares of accretion activity of the 20 Myr old UXOR RZ Psc
Grinin, V. P.; Potravnov, I. S.; Serebriakova, N. A.
We discuss a revision of accretion activity and kinematics of the enigmatic isolated UX Ori type star RZ Psc. Previously, RZ Psc was known to possess only spectroscopic signatures of outflow in the low-excitation lines of alkali metals. The archival high-resolution spectra reveal a short-lived episode of magnetospheric accretion in the system obse…
Gaia 8: Discovery of a star cluster containing β Lyrae
Bastian, U.
Aims: The aim here is to try and clarify whether there are stars in the neighbourhood of β Lyrae which are physically connected to the famous prototype eclipsing binary.
Methods: We scrutinised the astrometric and photometric data (from HIPPARCOS and Gaia DR2) of stars in a limited sky field around β Lyrae.
Results: A star cluster o…
The OTELO survey. III. Demography, morphology, IR luminosity and environment of AGN hosts
Gallego, Jesús; Sánchez-Portal, Miguel; Pintos-Castro, Irene +16 more
Aims: We take advantage of the capabilities of the OSIRIS Tunable Emission Line Object (OTELO) survey to select and study the AGN population in the field. In particular, we aim to perform an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of Hα emitters at z ∼ …
Flattened loose particles from numerical simulations compared to particles collected by Rosetta
Lasue, J.; Bentley, M. S.; Merouane, S. +5 more
Context. Cometary dust particles are remnants of the primordial accretion of refractory material that occurred during the initial formation stages of the solar system. Understanding their physical structure can help constrain their accretion process.
Aims: The in situ study of dust particles that were collected at slow speeds by instruments o…
A population of high-velocity absorption-line systems residing in the Local Group
Fechner, C.; Richter, P.; Bouma, S. J. D.
Aims: We investigated the ionisation conditions and distances of Galactic high-velocity clouds (HVCs) in the Galactic halo and beyond in the direction of the Local Group (LG) barycentre and anti-barycentre, by studying spectral data of 29 extragalactic background sources obtained with the Cosmic Origins Spectropgraph (COS) installed on the Hu…
Growth and disruption in the Lyra complex
Brunetti, G.; Rossetti, M.; Molendi, S. +16 more
Context. Nearby clusters of galaxies, z ≲ 0.1, are cosmic structures still under formation. Understanding the thermodynamic properties of merging clusters can provide crucial information on how they grow in the local universe.
Aims: A detailed study of the intra-cluster medium (ICM) properties of un-relaxed systems is essential to understand …
Combining high-contrast imaging and radial velocities to constrain the planetary architectures of nearby stars
Quanz, S. P.; Apai, D.; Ségransan, D. +3 more
Context. Nearby stars are prime targets for exoplanet searches and characterization using a variety of detection techniques. Combining constraints from the complementary detection methods of high-contrast imaging (HCI) and radial velocity (RV) can further constrain the planetary architectures of these systems because these methods place limits at …
Realization of a multifrequency celestial reference frame through a combination of normal equation systems
Nothnagel, A.; Karbon, M.
Context. We present a celestial reference frame (CRF) based on the combination of independent, multifrequency radio source position catalogs using nearly 40 years of very long baseline interferometry observations at the standard geodetic frequencies at SX band and about 15 years of observations at higher frequencies (K and XKa). The final catalog …
Upper limits on the water vapour content of the β Pictoris debris disk
Olofsson, G.; Liseau, R.; Larsson, B. +3 more
Context. The debris disk surrounding β Pictoris has been observed with ALMA to contain a belt of CO gas with a distinct peak at 85 au. This CO clump is thought to be the result of a region of enhanced density of solids that collide and release CO through vaporisation. The parent bodies are thought to be comparable to solar system comets, in which …