Search Publications
The first high-resolution X-ray spectrum of a Herbig star: AB Aurigae
Audard, M.; Güdel, M.; Briggs, K. R. +3 more
Context: The X-ray emission from Herbig Ae/Be stars remains to be explained. In later-type T Tauri stars, X-rays are thought to be produced by magnetically trapped coronal plasma, although accretion-shock induced X-rays have also been suggested. In earlier-type (OB) stars, shocks in unstable winds are thought to produce X-rays.
Aims: We presen…
Physical parameters and multiplicity of five southern close eclipsing binaries
Mészáros, Sz.; Csizmadia, Sz.; Kiss, L. L. +2 more
Aims:We detected tertiary components of close binaries from spectroscopy and light curve modelling, investigated the light-travel time effect and the possibility of magnetic activity cycles, measured mass ratios for unstudied systems, and derived absolute parameters.
Methods: We carried out new photometric and spectroscopic observations of fiv…
X-rays from RU Lupi: accretion and winds in classical T Tauri stars
Schmitt, J. H. M. M.; Robrade, J.
Context: Low-mass stars are known to exhibit strong X-ray emission during their early evolutionary stages. This also applies to classical T Tauri stars (CTTS), whose X-ray emission differs from that of main-sequence stars in a number of aspects.
Aims: We study the specific case of RU Lup, a well known accreting and wind-driving CTTS. In compar…
Origin of the early-type R stars: a binary-merger solution to a century-old problem?
Jeffery, C. S.; Izzard, R. G.; Lattanzio, J.
The early-R stars are carbon-rich K-type giants. They are enhanced in 12C, 13C and 14N, have approximately solar oxygen, magnesium isotopes, s-process and iron abundances, have the luminosity of core-helium burning stars, are not rapid rotators, are members of the Galactic thick disk and, most peculiarly of all, ar…
XMM-Newton observations of HESS J1813-178 reveal a composite Supernova remnant
Funk, S.; Reimer, O.; Vink, J. +10 more
Aims:We present X-ray and 12CO(J=1-0) observations of the very-high-energy (VHE) γ-ray source
Methods: High-angular resolution X-ray studies of the VHE γ-ray emission region are performed using 18.6 ks of XMM-Newton data, taken on HESS …
On the stratified dust distribution of the GG Tauri circumbinary ring
Pinte, C.; Ménard, F.; Duchêne, G. +2 more
Aims:Our objective is to study the vertical dust distribution in the circumbinary ring of the binary system
Methods: We present a simultaneous analysis of four scattered light images spanning a range of wave…
Stationary parts of an EIT and Moreton wave: a topological model
Aulanier, G.; Hochedez, J. -F.; Delannée, C.
Context: EIT and Moreton waves came into focus in 1997, when a propagating disturbance on a large area of the solar disc was discovered. The process generating the EIT and Moreton waves has been frequently discussed.
Aims: On May 2, 1998, a halo CME was observed related to an EIT wave, a Moreton wave, a X1 flare, radio emission sources, and di…
An accurate determination of the distance to the Pipe nebula
Franco, G. A. P.; Alves, F. O.
Aims:We seek an accurate distance to the Pipe nebula.
Methods: The B-band linear polarimetry collected for stars from the Hipparcos catalogue is used to investigate the dependence of the measured interstellar polarization as a function of the star's trigonometric parallax.
Results: The linear polarization obtained for 82 Hipparcos stars in…
Gamma-ray emission from massive young stellar objects
Paredes, J. M.; Romero, G. E.; Bosch-Ramon, V. +1 more
Context: Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring at some point of the evolution of the protostar. This picture seems to be suppor…
Unveiling the oldest and most massive galaxies at very high redshift
Cimatti, A.; Rodighiero, G.; Bolzonella, M. +3 more
Context: The identification and characterisation of massive galaxies over a wide redshift range allow us to place stringent constraints on the cosmic history of galaxy mass assembly and on current models of galaxy formation and evolution.
Aims: This work explores the existence of high-redshift massive galaxies unveiled with Spitzer+IRAC, but m…