Search Publications
HD 45314: a new γ Cassiopeiae analog among Oe stars
Morel, T.; Nazé, Y.; Rauw, G. +2 more
Context. Oe stars possibly form an extension to higher temperatures of the Be phenomenon, but it is still unclear whether these stars have disks.
Aims: X-ray spectra could provide hints for interactions of the star with a putative surrounding disk.
Methods: We obtained XMM-Newton observations of two Oe stars, HD 45314 and HD 60848. Spect…
X-ray emission regimes and rotation sequences in M 35 . An updated model of stellar activity evolution on the main sequence
Gondoin, P.
Context. Late-type stars in young open clusters show two kinds of dependence of their X-ray emission on rotation. They also tend to group into two main sub-populations that lie on narrow sequences in diagrams where their rotation periods are plotted against their (B - V) colour indices. A correlation between these two regimes of X-ray emission and…
X-ray properties of the young open clusters HM1 and IC 2944/2948
Corcoran, M. F.; Nazé, Y.; Rauw, G. +1 more
Using XMM-Newton data, we study for the first time the X-ray emission of HM1 and IC 2944/2948. Low-mass, pre-main-sequence objects with an age of a few Myr are detected, as well as a few background or foreground objects. Most massive stars in both clusters display the usual high-energy properties of that type of objects, though with log [LX
Transiting exoplanets from the CoRoT space mission. XXIV. CoRoT-25b and CoRoT-26b: two low-density giant planets
Mazeh, T.; Aigrain, S.; Alonso, R. +47 more
We report the discovery of two transiting exoplanets, CoRoT-25b and CoRoT-26b, both of low density, one of which is in the Saturn mass-regime. For each star, ground-based complementary observations through optical photometry and radial velocity measurements secured the planetary nature of the transiting body and allowed us to fully characterize th…
Proper motions of young stars in Chamaeleon. II. New kinematical candidate members of Chamaeleon I and II
Bouy, Hervé; Barrado, David; Bayo, Amelia +4 more
Context. The Chamaeleon star-forming region has been extensively studied in the last decades. However, most studies have been confined to the densest parts of the clouds. In a previous paper, we analysed the kinematical properties of the spectroscopically confirmed population of the Chamaeleon I and II clouds.
Aims: We want to search for new …
Nature of the gas and dust around 51 Ophiuchi. Modelling continuum and Herschel line observations
Pinte, C.; Ménard, F.; Woitke, P. +11 more
Context. Circumstellar disc evolution is paramount for the understanding of planet formation. The gas in protoplanetary discs large program (GASPS) aims at determining the circumstellar gas and solid mass around ~250 pre-main-sequence Herbig Ae and T Tauri stars.
Aims: We aim to understand the origin and nature of the circumstellar matter orb…
Can spicules be detected at disc centre in broad-band Ca ii H filter imaging data?
Rezaei, R.; Puschmann, K. G.; Beck, C.
Context. Recently, a possible identification of type II spicules in broad-band (full-width at half-maximum (FWHM) of ~0.3 nm) filter imaging data in Ca ii H on the solar disc was reported.
Aims: We estimate the formation height range contributing to broad-band and narrow-band filter imaging data in Ca ii H to investigate whether spicules can …
Neutral gas in Lyman-alpha emitting galaxies Haro 11 and ESO 338-IG04 measured through sodium absorption
Schaerer, D.; Östlin, G.; Hayes, M. +4 more
Context. The Lyman alpha emission line of neutral hydrogen is an important tool for finding galaxies at high redshift, thus for probing the structure of the early universe. However, the resonance nature of the line and its sensitivity to dust and neutral gas is still not fully understood.
Aims: We present measurements of the velocity, coverin…
P/2010 A2 LINEAR. II. Dynamical dust modelling
Meech, K. J.; Hainaut, O. R.; Kleyna, J.
Astronomical image denoising using dictionary learning
Starck, J. L.; Beckouche, S.; Fadili, J.
Astronomical images suffer a constant presence of multiple defects that are consequences of the atmospheric conditions and of the intrinsic properties of the acquisition equipment. One of the most frequent defects in astronomical imaging is the presence of additive noise which makes a denoising step mandatory before processing data. During the las…