Aims. We analyze the high-resolution X-ray spectrum of the supergiant O-star δ Orionis (O9.5II) with line ratios of He-like ions and a thermal plasma model, and we examine its variability. Methods. The O-supergiant δ Ori was observed in the wavelength range 5-175 Å by the X-ray detector HRC-S in combination with the grating LETG aboard Chandra. We studied the He-like ions in combination with the UV-radiation field to determine local plasma temperatures and to establish the distance of the X-ray emitting ions to the stellar surface. We measured individual lines by means of Gaussian profiles, folded through the response matrix, to obtain wavelengths, line fluxes, half widths at half maximum (HWHM) and line shifts to characterize the plasma. W...
We present results of a 90 ks Chandra X-ray observation of the young Orionis cluster (age 3Myr) ob...
The stellar winds of hot stars have an important impact on both stellar and galactic evolution, yet ...
XMM-Newton observations of the O supergiant ζ Orionis (O9.7 Ib) extend knowledge of its high-resolu...
We present results of the analysis of the X‐ray spectrum of the giant O‐star δ Orionis (O9.5II), obs...
We report on a Chandra line spectrum observation of the O supergiant, Zeta Orionis (O9.7 Ib). A 73.4...
We investigate X-ray emission properties of the peculiar X-ray source θ[superscript 2] Ori A in the ...
We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. D...
Context. ζ Pup is the X-ray brightest O-type star of the sky. This object was regularly ob...
We investigate X-ray emission properties of the peculiar X-ray source θ² Ori A in the Orion Trapeziu...
Aims. We analyze the high-resolution X-ray spectrum of the supergiant O-star δ Orioni
The Orion Trapezium is one of the youngest and closest star-forming regions within our Galaxy. With ...
We present XMM-Newton observations of the O supergiant zeta Orionis (O9.7 Ib). The spectra are rich ...
XMM-Newton observations of the O supergiant zeta Orionis (O9.7 Ib) extend knowledge of its high-reso...
We analyzed high resolution X-ray spectra in the wavelength range of 1.5 -- 25 A of three of its X-r...
X-ray line pro¯le analysis has proved to be the most direct diagnostic of the kine-matics and spatia...
We present results of a 90 ks Chandra X-ray observation of the young Orionis cluster (age 3Myr) ob...
The stellar winds of hot stars have an important impact on both stellar and galactic evolution, yet ...
XMM-Newton observations of the O supergiant ζ Orionis (O9.7 Ib) extend knowledge of its high-resolu...
We present results of the analysis of the X‐ray spectrum of the giant O‐star δ Orionis (O9.5II), obs...
We report on a Chandra line spectrum observation of the O supergiant, Zeta Orionis (O9.7 Ib). A 73.4...
We investigate X-ray emission properties of the peculiar X-ray source θ[superscript 2] Ori A in the ...
We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. D...
Context. ζ Pup is the X-ray brightest O-type star of the sky. This object was regularly ob...
We investigate X-ray emission properties of the peculiar X-ray source θ² Ori A in the Orion Trapeziu...
Aims. We analyze the high-resolution X-ray spectrum of the supergiant O-star δ Orioni
The Orion Trapezium is one of the youngest and closest star-forming regions within our Galaxy. With ...
We present XMM-Newton observations of the O supergiant zeta Orionis (O9.7 Ib). The spectra are rich ...
XMM-Newton observations of the O supergiant zeta Orionis (O9.7 Ib) extend knowledge of its high-reso...
We analyzed high resolution X-ray spectra in the wavelength range of 1.5 -- 25 A of three of its X-r...
X-ray line pro¯le analysis has proved to be the most direct diagnostic of the kine-matics and spatia...
We present results of a 90 ks Chandra X-ray observation of the young Orionis cluster (age 3Myr) ob...
The stellar winds of hot stars have an important impact on both stellar and galactic evolution, yet ...
XMM-Newton observations of the O supergiant ζ Orionis (O9.7 Ib) extend knowledge of its high-resolu...