Search Publications
Particle acceleration in a nearby galaxy cluster pair: the role of cluster dynamics
Brunetti, G.; Rossetti, M.; Shimwell, T. W. +17 more
Context. Diffuse radio emission associated with the intracluster medium (ICM) is observed in a number of merging galaxy clusters. It is currently believed that a fraction of the kinetic energy in mergers is channeled into nonthermal components, such as turbulence, cosmic rays, and magnetic fields, which may lead to the formation of giant synchrotr…
VLTI/PIONIER survey of disks around post-AGB binaries. Dust sublimation physics rules
Min, M.; Van Winckel, H.; Kamath, D. +4 more
Context. Post-asymptotic giant branch (AGB) binaries are surrounded by circumbinary disks of gas and dust that are similar to protoplanetary disks found around young stars.
Aims: We aim to understand the structure of these disks and identify the physical phenomena at play in their very inner regions. We want to understand the disk-binary inte…
Discovery of a 21 Myr old stellar population in the Orion complex⋆
Lewis, Geraint F.; Buder, Sven; Ness, Melissa K. +12 more
Context. The Orion complex is arguably the most studied star-forming region in the Galaxy. While stars are still being born in the Orion nebula, the oldest part was believed to be no more than 13 Myr old.
Aims: In order to study the full hierarchy of star formation across the Orion complex, we perform a clustering analysis of the Ori OB1a reg…
Properties of small meteoroids studied by meteor video observations
Vojáček, V.; Borovička, J.; Koten, P. +2 more
Aims: The complex study of millimetre-sized meteoroids can reveal more about the structure and origin of population of these meteoroids.
Methods: Double-station video observations, paired with spectroscopic video observations, were used to study small meteoroids. In total 152 sporadic and shower meteors of maximum brightness between magn…
Consistent accretion-induced heating of the neutron-star crust in MXB 1659-29 during two different outbursts
Degenaar, N.; Wijnands, R.; Homan, J. +10 more
Monitoring the cooling of neutron-star crusts heated during accretion outbursts allows us to infer the physics of the dense matter present in the crust. We examine the crust cooling evolution of the low-mass X-ray binary MXB 1659-29 up to ∼505 days after the end of its 2015 outburst (hereafter outburst II) and compare it with what we observed afte…
Radial abundance gradients in the outer Galactic disk as traced by main-sequence OB stars
McMillan, P. J.; Oey, M. S.; Borges Fernandes, M. +8 more
Context. Elemental abundance gradients in galactic disks are important constraints for models of how spiral galaxies form and evolve. However, the abundance structure of the outer disk region of the Milky Way is poorly known, which hampers our understanding of the spiral galaxy that is closest to us and that can be studied in greatest detail. Youn…
Background modelling for γ-ray spectroscopy with INTEGRAL/SPI
Diehl, Roland; Greiner, Jochen; Siegert, Thomas +3 more
Context. The coded-mask spectrometer-telescope SPI on board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) records photons in the energy range between 20 and 8000 keV. A robust and versatile method for modelling the dominating instrumental background radiation is difficult to establish for such a telescope in the rapidly changing s…
Hot UV-bright stars of galactic globular clusters
Lanz, T.; Miller Bertolami, M. M.; Landsman, W. B. +1 more
Context. We have performed a census of the UV-bright population in 78 globular clusters using wide-field UV telescopes. This population includes a variety of phases of post-horizontal branch (HB) evolution, including hot post-asymptotic giant branch (AGB) stars, and post-early AGB stars. There are indications that old stellar systems like globular…
ALMA observations of PKS 1549-79: a case of feeding and feedback in a young radio quasar
Morganti, Raffaella; Oosterloo, Tom; Tadhunter, Clive +4 more
We present CO(1-0) and CO(3-2) Atacama Large Millimeter/submillimeter Array observations of the molecular gas in PKS 1549-79, as well as mm and very long baseline interferometry 2.3-GHz continuum observations of its radio jet. PKS 1549-79 is one of the closest young, radio-loud quasars caught in an on-going merger in which the active galactic nucl…
Heavy metals in intermediate He-rich hot subdwarfs: the chemical composition of HZ 44 and HD 127493
Heber, U.; Latour, M.; Dorsch, M.
Context. Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid of hydrogen, whereas a small group of hot subdwarf stars of mixed H/He composition exists, showing ex…