Related papers: Early magnetic B-type stars: X-ray emission and wi…
Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations,…
Most types of massive stars display X-ray emission that is affected by the properties of their stellar winds. Single non-magnetic OB stars have an X-ray luminosity that scales with their bolometric luminosity and their emission is thought…
The X-ray properties of twenty ~1 Myr old O, B, and A stars of the Orion Trapezium are examined with data from the Chandra Orion Ultradeep Project (COUP). On the basis of simple theories for X-ray emission, we define two classes separated…
We investigate the connections between the magnetic fields and the X-ray emission from massive stars. Our study shows that the X-ray properties of known strongly magnetic stars are diverse: while some comply to the predictions of the…
We report on the properties of 11 early B stars observed with gratings on board XMM-Newton and Chandra, thereby doubling the number of B stars analysed at high resolution. The spectra typically appear soft, with temperatures of 0.2--0.6…
Context. The first magnetic fields in O- and B-type stars that do not belong to the Bp-star class, have been discovered. The cyclic UV wind-line variability, which has been observed in a significant fraction of early-type stars, is likely…
Recent spectropolarimetric surveys of bright, hot stars have found that ~10% of OB-type stars contain strong (mostly dipolar) surface magnetic fields (~kG). The prominent paradigm describing the interaction between the stellar winds and the…
Nearly all types of massive stars with radiatively driven stellar winds are X-ray sources that can be observed by the presently operating powerful X-ray telescopes. In this review I briefly address recent advances in our understanding of…
A common explanation for the observed X-ray emission of A-type stars is the presence of a hidden late-type companion. While this hypothesis can be shown to be correct in some cases, there is also evidence suggesting that low-mass companions…
Observations with powerful X-ray telescopes, such as XMM-Newton and Chandra, significantly advance our understanding of massive stars. Nearly all early-type stars are X-ray sources. Studies of their X-ray emission provide important…
High-resolution X-ray spectra of high-mass stars and low-mass T-Tauri stars obtained during the first year of the Chandra mission are providing important clues about the mechanisms which produce X-rays on very young stars. For zeta Puppis…
High resolution X-ray spectra of very young massive stars opened a new chapter in the diagnostics and understanding of the properties of stellar wind plasmas. Observations of several very young early type stars in the Orion Trapezium…
Context: X-ray surveys carried out with the Einstein and ROSAT satellites have resulted in rather unexpected detections of X-ray emission from late B-type and early A-type stars. These stars possess neither winds like early-type stars nor…
Stellar evolutionary models predict that most of the early type subdwarf stars in close binary systems have white dwarf companions. More massive companions, such as neutron stars or black holes, are also expected in some cases. The presence…
Wind-fed high-mass X-ray binaries are powered by accretion of the radiatively driven wind on the compact star. Accretion-generated X-rays alter the ionization state of the wind. Because higher ionization states drive the wind less…
Context. For stellar evolution models we rely on mass-loss rate prescriptions that show features that lack empirical confirmation, such as the bi-stability jump. This jump is an increase in mass loss in the decreasing temperature regime…
Young O stars are strong, hard, and variable X-ray sources, properties which strongly affect their circumstellar and galactic environments. After ~1 Myr, these stars settle down to become steady sources of soft X-rays. I use high-resolution…
X-rays give direct evidence of instabilities, time-variable structure, and shock heating in the winds of O stars. The observed broad X-ray emission lines provide information about the kinematics of shock-heated wind plasma, enabling us to…
Chandra high energy resolution observations have now been obtained from numerous non-peculiar O and early B stars. The observed X-ray emission line properties differ from pre-launch predictions, and the interpretations are still…
Binaries with hot massive components are strong X-ray sources. Besides the intrinsic X-ray emission of individual binary members originating in their winds, X-ray emission stems from the accretion on the compact companion or from wind…