Related papers: X-ray line emission from a fragmented stellar wind
We study the formation of photospheric emission lines in O stars and show that the rectangular profiles, sometimes double peaked, that are observed for some stars are a direct consequence of rotation, and it is unnecessary to invoke an…
The flow generated by low-density radiatively driven winds which decouple their gas and radiation fields is discussed. In particular we concentrate on flow which is still bound to the star and can therefore reaccrete. The wind decelerates…
Archival Chandra observations are used to study the X-ray emission associated with star formation in the central region of the nearby SAB(s)cd galaxy NGC 2403. The distribution of X-ray emission is compared to the morphology visible at…
Significant gravitational wave emission is expected from gamma-ray bursts arising from compact stellar mergers, and possibly also from bursts associated with fast-rotating massive stellar core collapses. These models have in common a high…
The optical emission line spectra of X-ray binaries (XRBs) are thought to be produced in an irradiated atmosphere, possibly the base of a wind, located above the outer accretion disc. However, the physical nature of - and physical…
One of the main properties of Wolf-Rayet (WR) stars is a very intense outflow of gas. No less than 40\% \ of WR stars belong to binary systems. Young massive O and B stars are the secondary components of such systems. OB stars also have an…
Recombination line profile shapes are derived for ionized spherical stellar winds at radio wavelengths. It is assumed that the wind is optically thick owing to free-free opacity. Emission lines of arbitrary optical depth are obtained…
A mysterious X-ray-emitting object has been detected moving away from the high-mass gamma-ray binary PSR B1259-63, which contains a non-accreting pulsar and a Be star whose winds collide forming a complex interaction structure. Given the…
In the era of Chandra and XMM-Newton, the detection (or nondetection) of diffuse and/or point-like X-ray sources within planetary nebulae (PNe) yields important, unique insight into PN shaping processes. Diffuse X-ray sources, whether due…
We present results from Hubble Space Telescope UV spectroscopy of the massive X-ray binary system, HD226868 = Cyg X-1. The spectra were obtained at both orbital conjunction phases in two separate runs in 2002 and 2003 when the system was in…
High spectral resolution and long exposure times are providing unprecedented levels of data quality of massive stars at X-ray wavelengths. A key diagnostic of the X-ray emitting plasma are the fir lines for He-like triplets. In particular,…
X-ray and UV line emission in X-ray binaries can be accounted for by a hot corona. Such a corona forms through irradiation of the outer disk by radiation produced in the inner accretion flow. The same irradiation can produce a strong…
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…
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…
Gamma-ray binaries are systems containing a massive star and a compact object that have been detected up to TeV energies. The high energy emission could result from particle acceleration in the region where the stellar wind from the massive…
We present a general procedure for deriving a line profile model for massive star X-ray spectra that captures the dynamics of the wind more directly. The basis of the model is the analytic solution to the problem of variable jets in…
This chapter is intended to provide a general presentation of the atomic and nuclear processes responsible for X-ray line and gamma-ray line emission in various astrophysical environments. I consider line production from hot plasmas, from…
We fit a new line shape model to \textit{Chandra} X-ray spectra of the O supergiant $\zeta$ Puppis to test the robustness of mass-loss rates derived from X-ray wind line profiles against different assumed heating models. Our goal is to…
We have developed a clumpy stellar wind model for OB supergiants in order to compare predictions of this model with the X-ray behaviour of both classes of persistent and transient High Mass X-ray Binaries (HMXBs).
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…