Search Publications
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 …
Broadband X-ray observations of four gamma-ray narrow-line Seyfert 1 galaxies
Piconcelli, E.; Foschini, L.; Pogge, R. W. +4 more
Narrow-line Seyfert 1 galaxies (NLS1s) is one of the few classes of active galactic nuclei harboring powerful relativistic jets and detected in γ-rays. NLS1s are well-known X-ray sources. While in non-jetted sources the origin of this X-ray emission may be a hot corona surrounding the accretion disk, in jetted objects, especially beamed ones, the …
Iron abundance distribution in the hot gas of merging galaxy clusters
Urdampilleta, I.; Simionescu, A.; Kaastra, J. S. +4 more
We present XMM-Newton/EPIC observations of six merging galaxy clusters and study the distributions of their temperature, iron (Fe) abundance and pseudo-entropy along the merging axis. For the first time, we focused simultaneously, and in a comprehensive way, on the chemical and thermodynamic properties of the newly collided intra cluster medium (I…
A massive nebula around the luminous blue variable star RMC 143 revealed by ALMA
Paladini, R.; Umana, G.; Mehner, A. +11 more
The luminous blue variable (LBV) RMC 143 is located in the outskirts of the 30 Doradus complex, a region rich with interstellar material and hot luminous stars. We report the 3σ sub-millimetre detection of its circumstellar nebula with ALMA. The observed morphology in the sub-millimetre is different than previously observed with HST and ATCA in th…
Gaia DR2 white dwarfs in the Hercules stream
Rebassa-Mansergas, Alberto; Althaus, Leandro G.; Torres, Santiago +5 more
Aims: We analyzed the velocity space of the thin- and thick-disk Gaia white dwarf population within 100 pc by searching for signatures of the Hercules stellar stream. We aimed to identify objects belonging to the Hercules stream, and by taking advantage of white dwarf stars as reliable cosmochronometers, to derive a first age distribution.
Accurate stellar parameters and distance to two evolved eclipsing binary systems, OGLE-BLG-ECL-123903 and OGLE-BLG-ECL-296596, towards the Galactic bulge
Soszyński, I.; Smolec, R.; Thompson, I. B. +15 more
Aims: Our aim is to obtain high-accuracy measurements of the physical and orbital parameters of two evolved eclipsing binary systems, and to use these measurements to study their evolutionary status. We also aim to derive the distances to the systems by using a surface brightness-colour relation and compare these distances with the measuremen…
Interferometric observations of SiO thermal emission in the inner wind of M-type AGB stars IK Tauri and IRC+10011
Alcolea, J.; Bujarrabal, V.; Castro-Carrizo, A. +2 more
Context. Asymptotic giant branch (AGB) stars go through a process of strong mass loss that involves pulsations of the atmosphere, which extends to a region in which the conditions are adequate for dust grains to form. Radiation pressure acts on these grains which, coupled to the gas, drive a massive outflow. The details of this process are not cle…