Related papers: A Re-interpretation of the STEREO/STE Observations…
We report an observation of X-ray emission from the exciting region of Cepheus A with the Chandra/ACIS instrument. What had been an unresolved X-ray source comprising the putative power sources is now resolved into at least 3 point-like…
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) instrument onboard the Russian-German `Spectrum-Roentgen-Gamma' (SRG) mission observed the Her X-1/HZ Her binary system in multiple scans over the source during the first…
We present case studies of two impulsive solar energetic electron (SEE) events during which particles at energies from 1-600 keV were detected by THEMIS-ARTEMIS orbiting the Moon, Wind at Earth's first Lagrange point, and (for one event)…
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…
Context. NRAO 150 is one of the brightest radio and mm AGN sources on the northern sky. It has been revealed as an interesting source where to study extreme relativistic jet phenomena. However, its cosmological distance has not been…
We present results from two observations of the wind-accreting X-ray pulsar 4U 1907+09 using the Suzaku observatory. The broadband time-averaged spectrum allows us to examine the continuum emission of the source and the cyclotron resonance…
Despite the significant progress achieved in recent years, the physical mechanisms underlying the origin of solar energetic particles (SEPs) are still a matter of debate. The complex nature of both particle acceleration and transport poses…
We report on the detection of X-ray emission from the unusual Galactic radio source G357.7-0.1 (the "Tornado"). Observations made with the Chandra X-ray Observatory demonstrate the presence of up to three sources of X-ray emission from the…
X-ray emission is ubiquitous among massive stars. In the last decade, X-ray observations revolutionized our perception of stellar winds but opened a Pandora's box of urgent problems. X-rays penetrating stellar winds suffer mainly continuum…
Experimental and theoretical state-selective X-ray spectra resulting from single-electron capture in charge exchange (CX) collisions of Ne^10+ with He, Ne, and Ar are presented for a collision velocity of 933 km s^-1 (4.54 keV nucleon^-1),…
We report results of two BeppoSAX observations of the transient X-ray source XTE J0421+560 during the outburst that started in March 1998. The source exhibits radio jets and coincides with the binary system CI Cam. The 0.1--50 keV spectrum…
We present further evidence of the presence of acoustic oscillations on the slowly-rotating, over-active G8 sub-giant EK Eri. This star was observed with the 1-m Hertzsprung SONG telescope, at the Observatorio del Teide for two different…
We report the discovery of an unusual source of extended X-ray emission CXOU J184846.3-013040 (`The Stem') located on the outskirts of the globular cluster GLIMPSE-C01. No point-like source falls within the extended emission which has an…
Stochastic acceleration of particles under a pressure balance condition can accommodate the universal $p^{-5}$ spectra observed under many different conditions in the inner heliosphere. In this model, in order to avoid an infinite build up…
Winds of massive stars are suspected to be inhomogeneous (or clumpy), which biases the measures of their mass loss rates. In High Mass X-ray Binaries (HMXBs), the compact object can be used as an orbiting X-ray point source to probe the…
Aims: Investigate/Study de-charging of solar wind C, N, O, Mg, Si and S ions and assess fluxes of resulting ENA in the heliosphere. Methods: The model treats the heavy ions as test particles convected by (and in a particular case also…
We present some of the salient aspects of the scientific motivation for high resolution soft X-ray spectroscopy of early-type stars with the Line Emission Mapper X-ray Probe. The major strength of {\it LEM} for hot star physics is its large…
We present the results of the first {\it XMM-Newton} observation of the interacting type IIn supernova 1995N, performed in July 2003. We find that the 0.2--10.0 keV unabsorbed flux dropped at a value of $\simeq 1.8 \times 10^{-13}$ erg…
We report for several solar energetic particle events intensity and anisotropy measurements of energetic electrons in the energy range ~ 27 to ~ 500 keV as observed with the Wind and ACE spacecraft in June 2000. The observations onboard…
Context. A solar eruption on 17 April 2021 produced a widespread Solar Energetic Particle (SEP) event that was observed by five longitudinally well-separated observers in the inner heliosphere at heliocentric distances of 0.42 to 1 au:…