Related papers: Suppression of X-rays from radiative shocks by the…
We perform 2D and 3D kinetic simulations of reconnection-mediated turbulent flares in a magnetized electron-positron plasma, with weak and strong radiative cooling. Such flares can be generated around neutron stars and accreting black…
We present a simple analysis of X-ray emission and absorption for hot-star winds, designed to explore the natural scalings of the observed X-ray luminosity with wind and sstellar properties. We show that an exospheric approximation, in…
Non-thermal photo-ionized plasmas are now established in the laboratory, and require models that treat the atomic processes and electron distribution self-consistently. We investigate the effects of inelastic thermalization in iron under…
In this paper we study the relation of radio emission to X-ray spectral and variability properties for a large sample of black hole X-ray binary systems. This is done to test, refine and extend -- notably into the timing properties -- the…
We study the effects of mass and energy injection due to OB associations spread across the rotating disc of a Milky Way-type galaxy, with the help of 3D hydrodynamic simulations. We compare the resulting X-ray emission with that produced…
The X-ray emission properties from the hot thermalized plasma that results from the collisions of individual stellar winds and supernovae ejecta within rich and compact star clusters are discussed. We propose a simple analytical way of…
We investigate apparent internal structure of kiloparsec scale jets of AGNs arising from the energy dependent cooling of accelerated electrons and light travel time effect for relativistically moving sources. Using a simple cylindrical…
Young supernova remnants (SNRs) strongly modify surrounding magnetic fields, which in turn play an essential role in accelerating cosmic rays (CRs). X-ray polarization measurements probe magnetic field morphology and turbulence at the…
Extended emission is a mystery in short gamma-ray bursts (SGRBs). By making time resolved spectral analyses of brightest nine events observed by ${\it Swift}$ XRT, we obviously classify the early X-ray emission of SGRBs into two types. One…
Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations,…
Collisional self-interactions occurring in protostellar jets give rise to strong shocks, the structure of which can be affected by radiative cooling within the flow. To study such colliding flows, we use the AstroBEAR AMR code to conduct…
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…
We investigate the properties of X-ray emission from shock breakout of a supernova in a stellar wind. We consider a simple model describing aspherical explosions, in which the shock front with an ellipsoidal shape propagates into the dense…
An explosively generated shockwave with time-dependent radius $R(t)$ is characterized by a phase in which the shocked gas becomes radiative with an effective adiabatic index $\gamma \simeq 1$. Using the result that the post-shock gas is…
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…
X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from…
X-ray flares, lasting for $\sim 100 - 1000$ s in the X-ray band, are often observed following gamma-ray bursts (GRBs). The physical origin of X-ray flares is still unknown merely with the temporal/spectral information. On the other hand,…
Thermonuclear (type-I) X-ray bursts, observed from neutron star (NS) low-mass X-ray binaries (LMXB), provide constraints on NS masses and radii and consequently the equation of state of NS cores. In such analyses various assumptions are…
The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the…
Thermal electrons cannot directly participate in the process of diffusive acceleration at electron-ion shocks because their Larmor radii are smaller than the shock transition width: this is the well-known electron injection problem of…