Search Publications
The influence of binarity on dust obscuration events in the planetary nebula M 2-29 and its analogues
Rauch, T.; Udalski, A.; Cohen, M. +8 more
The central star of the planetary nebula (CSPN) M 2-29 shows an extraordinary R Coronae Borealis-like fading event in its optical lightcurve. The only other CSPN to show these events are CPD-56°8032 (Hen 3-1333) and V651 Mon (NGC 2346). Dust cloud formation in the line of sight appears responsible but the exact triggering mechanism is not well und…
Using the Sun to estimate Earth-like planets detection capabilities . III. Impact of spots and plages on astrometric detection
Meunier, N.; Lagrange, A. -M.; Desort, M. +1 more
Aims: Stellar activity is a potentially important limitation to the detection of low-mass extrasolar planets with indirect methods (radial velocity, photometry, astrometry). In previous papers, using the Sun as a proxy, we investigated the impact of stellar activity (spots, plages, convection) on the detectability of an Earth-mass planet in t…
Galactic distributions of carbon- and oxygen-rich AGB stars revealed by the AKARI mid-infrared all-sky survey
Matsunaga, N.; Onaka, T.; Kaneda, H. +3 more
Context. The environmental conditions for asympotic giant branch (AGB) stars to reach the carbon-rich (C-rich) phase are important to understand the evolutionary process of AGB stars. The difference between the spatial distributions of C-rich and oxygen-rich (O-rich) AGB stars is essential for the study of the Galactic structure and the chemical e…
X-ray spectral properties of Seyfert galaxies and the unification scheme
Singh, V.; Risaliti, G.; Shastri, P.
Context. The unification scheme of Seyfert galaxies predicts that the observed differences between types 1 and 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN. The observed X-ray spectra of Seyfert type 2s compared to type 1s are expected to be affected by higher absorbing column…
Hinode extreme-ultraviolet imaging spectrometer observations of a limb active region
Young, P. R.; Mason, H. E.; Del Zanna, G. +3 more
Aims: We investigate the electron density and temperature structure of a limb active region.
Methods: We have carried out a study of an active region close to the solar limb using observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) and the X-ray telescope (XRT) on board Hinode. The electron density and temperature distri…
COSMOS weak-lensing constraints on modified gravity
Schrabback, T.; Tereno, I.; Semboloni, E.
The observed acceleration of the universe, explained through dark energy, could alternatively be explained through a modification of gravity that would also induce modifications in the evolution of cosmological perturbations. We use new weak lensing data from the COSMOS survey to test for deviations from general relativity (GR). The departure from…
Merging history of three bimodal clusters
Bourdin, H.; Mars, G.; Benoist, C. +5 more
We present a combined X-ray and optical analysis of three bimodal galaxy clusters selected as merging candidates at z ~ 0.1. These targets are part of MUSIC (MUlti-Wavelength Sample of Interacting Clusters), which is a general project designed to study the physics of merging clusters by means of multi-wavelength observations. Observations include …
Evidence for a current sheet forming in the wake of a coronal mass ejection from multi-viewpoint coronagraph observations
Patsourakos, S.; Vourlidas, A.
Context. Ray-like features observed by coronagraphs in the wake of coronal mass ejections (CMEs) are sometimes interpreted as the white light counterparts of current sheets (CSs) produced by the eruption. The 3D geometry of these ray-like features is largely unknown and its knowledge should clarify their association to the CS and place constraints…
Azimuthal variations of magnetic field strength and inclination on penumbral boundaries
Jurčák, J.
Aims: I try to determine the properties of the magnetic field on the inner and outer penumbral boundaries and find out if either magnetic field strength or inclination are constant there and if these plasma parameters depend on the sunspot area.
Methods: The spectropolarimetric data obtained with the Hinode satellite were analysed. Activ…
Multi-wavelength observations of the young binary system Haro 6-10: The case of misaligned discs
Wolf, S.; Henning, T.; Roccatagliata, V. +3 more
Context. We present a multi-wavelength, high-resolution observational survey of the young binary system Haro 6-10 (GV Tau, IRAS 04263+2426), which harbours one of the few known infrared companions.
Aims: The primary goal of this project is to determine the physical and geometrical properties of the circumstellar and circumbinary material in t…