Search Publications
A deep Hα survey of the Carina tangent arm direction
Zavagno, A.; Elia, D.; Molinari, S. +3 more
Aims: The arm tangent direction provides a unique viewing geometry, with a long path in relatively narrow velocity ranges and lines of view that cross the arm perpendicular to its thickness. The spiral arm tangent regions are therefore the best directions for studying the interstellar medium within spiral density waves in the Milky Way, probi…
Apsidal motion in the α CrB binary system revealed through X-ray and optical eclipse timing
Schmitt, J. H. M. M.; Czesla, S.; Robrade, J. +1 more
The α CrB system is among the brightest known eclipsing binaries in an eccentric orbit. In such systems, the periods between successive primary (Pprim) and secondary minima (Psec) typically differ, and the difference between the two periods provides information on apsidal motion in the system. However, with a binary period of…
BCD spectrophotometry for massive stars in transition phases
Zorec, J.; Borges Fernandes, M.; Kraus, M. +7 more
Context. Stars in transition phases, such as those showing the B[e] phenomenon and luminous blue variables (LBVs), undergo strong, often irregular mass-ejection events. The prediction of these phases in stellar evolution models is therefore extremely difficult, if not impossible. As a result, their effective temperatures, their luminosities, and e…
The nature of the solar wind electron temperature and electron heat flux. II. Case of a spiral interplanetary magnetic field
Salem, Chadi S.; Pulupa, Marc; Hubert, Daniel
Aims: We aim to analyze the solutions of the solar wind electron energy equation in a spherical expansion with a spiral interplanetary magnetic field (IMF), a radial power law of the electron heat flux with a constant index α, and a constant or a smooth increase of the solar wind speed.
Methods: Generic analytical electron temperature pr…
Model-independent periodogram for scanning astrometry
Zucker, S.; Binnenfeld, A.; Shahaf, S.
We present a new periodogram for the periodicity detection in one-dimensional time-series data from scanning astrometry space missions such as HIPPARCOS or Gaia. The periodogram is non-parametric and does not rely on a full or approximate orbital solution. Since no specific properties of the periodic signal are assumed, the method is expected to b…
Search strategies for supermassive stars in young clusters and application to nearby galaxies
Schaerer, D.; Marques-Chaves, R.; Usher, C. +4 more
Context. Supermassive stars (SMSs) with masses M ≳ 103 − 104 M⊙ formed by runaway collisions in young, massive, and dense star clusters have been invoked as a possible solution to the problem of the presence of multiple stellar populations and peculiar abundance patterns observed in globular clusters (GCs). However…
Langmuir waves associated with magnetic holes in the solar wind
André, M.; Maksimovic, M.; Souček, J. +6 more
Context. Langmuir waves (electrostatic waves near the electron plasma frequency) are often observed in the solar wind and may play a role in the energy dissipation of electrons. The largest amplitude Langmuir waves are typically associated with type II and III solar radio bursts and planetary foreshocks. In addition, Langmuir waves not related to …
Sapaki: Galactic O3If* star possibly born in isolation
Roman-Lopes, A.; Sanmartim, D.; Zarricueta Plaza, M. S.
Context. The study of high-mass stars found to be isolated in the field of the Milky Way may help to probe the feasibility of the core-accretion mechanism in the case of massive star formation. The existence of truly isolated stars may efficiently probe the possibility that individual massive stars can be born in isolation.
Aims: We observed …
The active CGCG 077-102 NED02 galaxy within the Abell 2063 galaxy cluster
Adami, C.; Lima Neto, G. B.; Ulmer, M. P. +3 more
Context. Within the framework of investigating the link between the central super massive black holes in the cores of galaxies and the galaxies themselves, we detected a variable X-ray source in the center of CGCG 077-102 NED02, which is a member of the CGCG 077-102 galaxy pair within the Abell 2063 cluster of galaxies.
Aims: Our goal is to c…
A runaway T Tauri star leaving an extended trail
Luque-Escamilla, Pedro L.; Martí, Josep; Sánchez-Ayaso, Estrella
Aims: We address the problem of young stellar objects that are found too far away from possible star formation sites. Different mechanisms have been proposed before to explain this unexpected circumstance. The idea of high-velocity protostars is one of these mechanisms, although observational support is not always easy to obtain. We aim to sh…