Related papers: Diffuse X-ray emission in the Cygnus OB2 associati…
The aim of this work is to identify the so far unknown low mass stellar population of the ~2Myr old Cygnus OB2 region, and to investigate the X-ray and near-IR stellar properties of its members. We analyzed a 97.7 ksec Chandra ACIS-I…
Context. The Cygnus OB2 association, the central engine of the Cygnus X star-forming region, is the subject of an extensive INTEGRAL Key Project that will accumulate 6Ms of observations. Analysis of 2Ms of observations by De Becker and…
High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations…
We study the properties of the diffuse X-ray background by using the results of a cosmological hydrodynamical simulation of the concordance LambdaCDM model. The simulation follows gravitational and gas dynamics and includes a treatment of…
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…
The Cygnus region is a vast star-forming complex harbouring a population of powerful objects, including massive star clusters and associations, Wolf-Rayet stars, pulsars, and supernova remnants. The multi-wavelength picture is far from…
We report on a Chandra line spectrum observation of the O supergiant, Zeta Orionis (O9.7 Ib). A 73.4 ks HETGS observation shows a wide range of ionization stages and line strengths over the wavelength range of 5 to 26 A. The observed…
The COMPTEL observations of the diffuse galactic 1.809 MeV emission attributed to the radioactive decay of 26Al have confirmed the diffuse nature of this interstellar emission line. One of the most significant features of the reconstructed…
We present a detailed case study of the diffuse X-ray and H-alpha emission in the halo of NGC 253, a nearby edge-on starburst galaxy driving a galactic superwind. The arcsecond spatial resolution of the Chandra ACIS instrument allows us to…
The Cygnus\,OB2 region, $\sim 3.5-5~\text{Myr}$ old, contains one of the most significant populations of massive stars of the Milky Way. Such stars substantially contribute to producing large scale soft ($<2~\text{keV}$) diffuse X-ray…
We present a high-precision proper motion study of 873 X-ray and spectroscopically selected stars in the massive OB association Cygnus OB2 as part of the DANCe project. These were calculated from images spanning a 15 year baseline and have…
We report results of one-day simultaneous multiwavelength observations of Cygnus X-2 using XMM, Chandra, the European VLBI Network and the XMM Optical Monitor. During the observations, the source did not exhibit Z-track movement, but…
Chandra ACIS-I data of the molecular cloud and HII region complex NGC 6334 were analyzed. The hard X-ray clumps detected with ASCA (Sekimoto et al. 2000) were resolved into 792 point sources. After removing the point sources, an extended…
We compare the soft diffuse X-ray emission from Chandra images of 12 nearby intermediate inclination spiral galaxies to the morphology seen in Halpha, molecular gas, and mid-infrared emission. We find that diffuse X-ray emission is often…
Using the Chandra ACIS-I instruments, we have carried out a deep X-ray observation on the Galactic plane region at (l,b) ~ (28.5, 0.0), where no discrete X-ray sources have been known previously. We have detected, as well as strong diffuse…
We investigated the kinematics of ionized gas in an extended (20 degrees by 15 degrees) region containing the X-ray Superbubble in Cygnus with the aim of finding the shell swept up by a strong wind from Cyg OB2. H-alpha observations were…
The interstellar medium of galaxies, with temperatures reaching several million degrees, provides a pivotal perspective for understanding the physical and chemical properties of star formation, galactic evolution, and their associated…
A deep 75 ks {\it Chandra} ACIS--I data of NGC 2024 was analyzed, aiming at a search for diffuse X-ray emission in this one of the most nearby (415 pc) massive star-forming regions. After removing point sources, an extended emission was…
We present Chandra/ACIS images of several high-mass star-forming regions. The massive stellar clusters powering these HII regions are resolved at the arcsecond level into hundreds of stellar sources, similar to those seen in closer young…
Context: Cygnus X-1 is a black hole X-ray binary system in which the black hole captures and accretes gas from the strong stellar wind emitted by its supergiant O9.7 companion star. The irradiation of the supergiant star essentially…