Search Publications
Origin of Lyα absorption in nearby starbursts and implications for other galaxies
Schaerer, D.; Kunth, D.; Atek, H.
Context: Despite the privileged position that Lyman-α (Lyα) emission line holds in the exploration of the distant universe and modern observational cosmology, the origin of the observed diversity of Lyα profiles still needs to be thoroughly explained. Observations of nearby star forming galaxies bring their batch of apparent contradictions between…
On the metal abundances inside mixed-morphology supernova remnants: the case of IC 443 and G166.0+4.3
Troja, E.; Miceli, M.; Bocchino, F.
Context: Recent developments in the study of mixed morphology supernova remnants (MMSNRs) have revealed the presence of metal-rich X-ray emitting plasma inside a fraction of these remnants, a feature not properly addressed by traditional models for these objects.
Aims: Radial profiles of thermodynamical and chemical parameters are needed for a…
X-ray optical depth diagnostics of T Tauri accretion shocks
Peres, G.; Sciortino, S.; Drake, J. J. +4 more
Context: In classical T Tauri stars, X-rays are produced by two plasma components: a hot low-density plasma, with frequent flaring activity, and a high-density lower temperature plasma. The former is coronal plasma related to the stellar magnetic activity. The latter component, never observed in non-accreting stars, could be plasma heated by the s…
Spectroscopic binaries among Hipparcos M giants. III. The eccentricity - period diagram and mass-transfer signatures
Jorissen, A.; Famaey, B.; Frankowski, A. +1 more
Context: This paper is the third one in a series devoted to studying the properties of binaries involving M giants.
Aims: We use a new set of orbits to construct the first (e - log P) diagram of an extensive sample of M giant binaries, to obtain their mass-function distribution, and to derive evolutionary constraints for this class of binaries…
51 Pegasi - a planet-bearing Maunder minimum candidate
Schmitt, J. H. M. M.; Robrade, J.; Poppenhäger, K. +1 more
We observed 51 Peg, the first detected planet-bearing star, in a 55 ks XMM-Newton pointing and in 5 ks pointings each with Chandra HRC-I and ACIS-S. The star has a very low count rate in the XMM observation, but is clearly visible in the Chandra images due to the detectors' different sensitivity at low X-ray energies. This allows a temperature est…
Asteroseismology and interferometry of the red giant star ɛ Ophiuchi
Goupil, M. -J.; Baudin, F.; Kervella, P. +16 more
The GIII red giant star ɛ Oph has been found to exhibit several modes of oscillation by the MOST mission. We interpret the observed frequencies of oscillation in terms of theoretical radial p-mode frequencies of stellar models. Evolutionary models of this star, in both shell H-burning and core He-burning phases of evolution, are constructed using …
INTEGRAL observation of hard X-ray variability of the TeV binary LS 5039/RX J1826.2-1450
Klochkov, D.; Santangelo, A.; Segreto, A. +4 more
Context: LS 5039 / RX J1826.2-1450 is one of the few High Mass X-ray binary systems from which radio and high energy TeV emission has been observed. Moreover, variability of the TeV emission with orbital period was detected.
Aims: We investigate the hard X-ray (25{-}200 keV) spectral and timing properties of the source with the monitoring IBIS…
Non-Maxwellian electron distributions in clusters of galaxies
Kaastra, J. S.; Werner, N.; Bykov, A. M.
Context: Thermal X-ray spectra of clusters of galaxies and other sources are commonly calculated assuming Maxwellian electron distributions. There are situations where this approximation is not valid, for instance near interfaces of hot and cold gas and near shocks.
Aims: The presence of non-thermal electrons affects the X-ray spectrum. To stu…
Long-term chromospheric activity of non-eclipsing RS CVn-type stars
Buccino, A. P.; Mauas, P. J. D.
Context: The IUE database provides several UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE.
Aims: Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22 4…
Removing systematics from the CoRoT light curves. I. Magnitude-dependent zero point
Mazeh, T.; Guterman, P.; Aigrain, S. +31 more
This paper presents an analysis that searched for systematic effects within the CoRoT exoplanet field light curves. The analysis identified a systematic effect that modified the zero point of most CoRoT exposures as a function of stellar magnitude. We could find this effect only after preparing a set of learning light curves that were relatively f…