Related papers: X-rays, clumping and stellar wind structures
We calculate the X-ray emission from the shocked fast wind blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric self similar solutions, we calculate the flow structure and X-ray…
(abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy…
XMM-Newton has deeply changed our picture of X-ray emission of hot, massive stars. High-resolution X-ray spectroscopy as well as monitoring of these objects helped us gain a deeper insight into the physics of single massive stars with or…
Massive stars lose mass in the form of stellar winds and outbursts. This material accumulates around the star. When the star explodes as a supernova (SN) the resulting shock wave expands within this circumstellar medium. The X-ray emission…
Chandra gratings spectra of a sample of 15 massive OB stars were analyzed under the basic assumption that the X-ray emission is produced in an ensemble of shocks formed in the winds driven by these objects. Shocks develop either as a result…
Here, I review some recent works on magnetism of cool, main-sequence stars, their winds and potential impact on surrounding exoplanets. The winds of these stars are very tenuous and persist during their lifetime. Although carrying just a…
This brief review describes radio observations of colliding winds in massive stars starting with the first direct observational support for the colliding-wind model advanced in the early 1990's to explain non-thermal radio and thermal X-ray…
We investigate the structure and X-ray emission from the colliding stellar winds in massive star binaries. We find that the opening angle of the contact discontinuity (CD) is overestimated by several formulae in the literature at very small…
Motivated by recent detections by the XMM and Chandra satellites of X-ray line emission from hot, luminous stars, we present synthetic line profiles for X-rays emitted within parameterized models of a hot-star wind. The X-ray line emission…
We discuss recent evidence that currently accepted mass-loss rates may need to be revised downwards, as a consequence of previously neglected ``clumping'' of the wind. New results on the radial stratification of the corresponding clumping…
The X-ray emission from the wind-wind collision in short-period massive O+O-star binaries is investigated. The emission is calculated from three-dimensional hydrodynamical models which incorporate gravity, the driving of the winds, orbital…
\mu\ Columbae is a prototypical weak-wind O-star for which we have obtained a high-resolution X-ray spectrum with the Chandra LETG/ACIS-S instrument and a low resolution spectrum with Suzaku. This allows us, for the first time, to…
Several gamma-ray binaries show extended X-ray emission that may be associated to interactions of an outflow with the medium. Some of these systems are, or may be, high-mass binaries harboring young nonaccreting pulsars, in which the…
The role of X-ray observations for cosmological studies and conclusions is briefly explored. X-rays currently yield cosmologically interesting results on the abundances, evolution and gas content of clusters of galaxies, on the clustering…
Magnetic massive stars -- which are being discovered with increasing frequency -- represent a new category of wind-shaping mechanism for O and B stars. Magnetic channeling of these stars' radiation-driven winds, the Magnetically Confined…
The Chandra X-ray Observatory grating spectrometers allow study of stellar spectra at resolutions on the order of 1000. Prior x-ray observatories' low resolution data have shown that nearly all classes of stars emit x-rays. Chandra reveals…
The stellar wind around the compact object in luminous wind-accreting high mass X-ray binaries is expected to be strongly ionized with the X-rays coming from the compact object. The stellar wind of hot stars is mostly driven by light…
Massive stars lose a large fraction of their original mass over the course of their evolution. These stellar winds shape the surrounding medium according to parameters that are the result of the characteristics of the stars, varying over…
Stars interact with their planets through gravitation, radiation, and magnetic fields. Although magnetic activity decreases with time, reducing associated high-energy (e.g., coronal XUV emission, flares), stellar winds persist throughout…
We have performed an extensive hydrodynamical parameter study of starburst-driven galactic winds, motivated by the latest observation data on the best-studied starburst galaxy M82. We study how the wind dynamics, morphology and X-ray…