Search Publications
Structure of sunspot light bridges in the chromosphere and transition region
Rezaei, R.
Context. Light bridges (LBs) are elongated structures with enhanced intensity embedded in sunspot umbra and pores.
Aims: We studied the properties of a sample of 60 LBs observed with the Interface Region Imaging Spectrograph (IRIS).
Methods: Using IRIS near- and far-ultraviolet spectra, we measured the line intensity, width, and Doppler …
Discovery of large scale shock fronts correlated with the radio halo and radio relic in the A2163 galaxy cluster
Thölken, Sophia; Reiprich, Thomas H.; Ota, Naomi +1 more
Context. Galaxy clusters form at the intersections of the filamentary large scale structure in merging events and by the accretion of matter along these filaments. Imprints of these formation processes should be visible in the intracluster medium and can arise in shock fronts, which are detectable via discontinuities in, for example, the gas tempe…
Solving non-LTE problems in rotational transitions using the Gauss-Seidel method and its implementation in the Atmospheric Radiative Transfer Simulator
Hartogh, P.; Yamada, T.; Rezac, L. +3 more
This article presents our implementation of a non-LTE solver in spherical symmetry for molecular rotational transition in static or expanding atmospheres. The new open-source code relies on the Gauss-Seidel Accelerated Lambda Iteration methodology that provides a rapid and accurate convergence of the non-LTE problems, which is now routinely used i…
PACS and SPIRE range spectroscopy of cool, evolved stars
Decin, L.; Lombaert, R.; Groenewegen, M. A. T. +3 more
Context. At the end of their lives AGB stars are prolific producers of dust and gas. The details of this mass-loss process are still not understood very well. Herschel PACS and SPIRE spectra which cover the wavelength range from ∼55 to 670 µm almost continuously, offer a unique way of investigating properties of AGB stars in general and the …
The long-period massive binary HD 54662 revisited
Rauw, G.; Mahy, L.; Mossoux, E.
Context.
Aims: The goal of this study is to improve our knowledge of the orbital and stellar parameters of
THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy
García-Lario, P.; Solano, E.; Sánchez Contreras, C. +3 more
This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 µm) with the Herschel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we …
LBT/ARGOS adaptive optics observations of z ∼ 2 lensed galaxies
Lutz, D.; Grillo, C.; Contursi, A. +24 more
Aims: Gravitationally lensed systems allow a detailed view of galaxies at high redshift. High spatial- and spectral-resolution measurements of arc-like structures can offer unique constraints on the physical and dynamical properties of high-z systems.
Methods: We present near-infrared spectra centred on the gravitational arcs of six know…
Long-term variations in the X-ray activity of HR 1099
Schmitt, J. H. M. M.; Robrade, J.; Schneider, P. C. +6 more
Context. Although timing variations in close binary systems have been studied for a long time, their underlying causes are still unclear. A possible explanation is the so-called Applegate mechanism, where a strong, variable magnetic field can periodically change the gravitational quadrupole moment of a stellar component, thus causing observable pe…
Star formation history of Canis Major OB1. II. A bimodal X-ray population revealed by XMM-Newton
Montmerle, T.; Stelzer, B.; Gregorio-Hetem, J. +2 more
Aims: The Canis Major OB1 Association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. This work is focussed on the young stellar population associated with CMa R1, for which our previous results from ROSAT, op…
The VMC Survey. XXXII. Pre-main-sequence populations in the Large Magellanic Cloud
Sun, Ning-Chen; de Grijs, Richard; Marconi, Marcella +11 more
Context. Detailed studies of intermediate- and low-mass pre-main-sequence (PMS) stars outside the Galaxy have so far been conducted only for small targeted regions harbouring known star formation complexes. The VISTA Survey of the Magellanic Clouds (VMC) provides an opportunity to study PMS populations down to solar masses on a galaxy-wide scale. …