Related papers: Ionisation Structure in Accretion Shocks with a Co…
Metal-polluted white dwarfs (DZ stars) are characterized by a helium-rich atmosphere contaminated by heavy elements traces originating from accreted rocky planetesimals. As a detailed spectroscopic analysis of those objects can reveal the…
We model the post-shock accretion column (PSAC) for intermediate polars (IPs), with parameterizing specific accretion rate between 0.0001 and 100 g cm-2 s-1 and metal abundance between 0.1 and 2 times of solar abundance, and taking into…
We study the radial ionization structure at the surface of an X-ray illuminated accretion disk. We plot the expected iron K$\alpha$ line energy as a function of the Eddington ratio and of the distance of the emitting matter from the central…
X-ray flux from the inner hot region around central compact object in a binary system illuminates the upper surface of an accretion disc and it behaves like a corona. This region can be photoionised by the illuminating radiation, thus can…
We investigate the iron K$\alpha$ fluorescent line produced by hard X-ray photons from magnetic reconnection-heated corona. The hot corona with temperature being about $10^9$K can irradiate the underlying disk with a continuum X-ray…
Observations of AGNs and microquasars by ASCA, RXTE, Chandra and XMM-Newton indicate the existence of broad X-ray emission lines of ionized heavy elements in their spectra. Such spectral lines were discovered also in X-ray spectra of…
Low Mach number collisionless shocks are routinely observed in the solar wind and upstream of planetary bodies. However, most in situ observations have lacked the necessary temporal resolution to directly study the kinetic behavior of ions…
Using Chandra HETG data we present light curves for individual spectral lines of Mg XI and Mg XII for EX Hydrae, an intermediate-polar type cataclysmic variable. The Mg XI light curve, folded on the white dwarf spin period, shows two spikes…
A merger of clusters naturally drives shocks with Mach number $\mathscr{M}\lesssim 3$ in the intra-cluster medium (ICM). This process creates several distinct signatures, including sharp surface brightness "edges", temperature, and gas…
Accretion flows having positive specific energy are known to produce outflows and winds which escape to a large distance. According to Two Component Advective Flow (TCAF) model, centrifugal pressure dominated region of the flow just outside…
We investigate a non-equilibrium ionization state and two-temperature structure of the intracluster medium in the linked region of Abell 399/401, using a series of N-body + SPH simulations, and find that there exist significant shock layers…
We calculate the temperature and ionization balance in an outflow from an accreting black hole under illumination by hard radiation from the central object. Electron scattering of the Fe K_alpha photons within the highly ionized expanding…
The HH54 shock is a Herbig-Haro object, located in the nearby Chamaeleon II cloud. Observed CO line profiles are due to a complex distribution in density, temperature, velocity, and geometry. Resolving the HH54 shock wave in the…
The analysis of the third INTEGRAL/IBIS survey has revealed several new cataclysmic variables, most of which turned out to be intermediate polars, thus confirming that these objects are strong emitters in hard X-rays. Here we present high…
We address the ability of broad iron emission lines from black hole accretion disks to diagnose the spin of the black hole. Using a high-resolution 3-dimensional MHD simulation of a geometrically-thin accretion disk in a Pseudo-Newtonian…
I present computations of the integrated column densities produced in the post-shock cooling layers and in the radiative precursors of partially-cooled fast shocks as a function of the shock age. The results are applicable to the…
Low angular momentum accretion flows can have standing and oscillating shock waves. We study the region of the parameter space in which multiple sonic points occur in viscous flows in presence of various cooling effects such as…
We present angle-dependent, broad-band intensity spectra from accretion disks around black holes of 10 M$_\odot$. In our computations disks are assumed to be slim, which means that the radial advection is taken into account while computing…
We have studied shock in magnetized accretion flow/funnel flow in case of neutron star with bremsstrahlung cooling and cyclotron cooling. All accretion solutions terminate with a shock close to the neutron star surface, but at some region…
We present new optical and near-infrared spectra of WD0137-349; a close white dwarf - brown dwarf non-interacting binary system with a period of $\approx$114 minutes. We have confirmed the presence of H$\alpha$ emission and discovered He,…