Related papers: Simulating three-dimensional nonthermal high-energ…
Galactic black hole (BH) X-ray binaries are known to exhibit episodic outbursts, during which accretion and spectral mode distinctively transition between low/hard and high/soft state. X-ray observations during high/soft state occasionally…
Strong wind-wind collisions in massive binaries generate a very hot plasma that frequently produces a moderately strong iron line. The morphology of this line depends upon the properties of the wind interaction zone and its orientation with…
Stars and their winds can contribute to the non-thermal (NT) emission in extragalactic jets. Given the complexity of jet-star interactions, the properties of the resulting emission are strongly linked to those of the emitting flows. We…
Hard X- and $\gamma$-ray spectra and light curves resulting from radioactive decays are computed for aspherical (jet-like) and energetic supernova models (representing a prototypical hypernova SN 1998bw), using a 3D energy- and…
Recent observations of X-ray pulsars at low luminosities allow, for the first time, to compare theoretical models for the emission from highly magnetized neutron star atmospheres at low mass accretion rates ($\dot{M} \lesssim 10^{15}$ g…
We perform global particle-in-cell simulations of pulsar magnetospheres including pair production, ion extraction from the surface, frame dragging corrections, and high energy photon emission and propagation. In the case of oblique…
Binary systems containing a massive star and a non-accreting pulsar present strong interaction between the stellar and the pulsar winds. The properties of this interaction, which largely determine the non-thermal radiation in these systems,…
Unlike high-mass gamma-ray binaries, low-mass microquasars lack external sources of radiation and matter that could produce high-energy emission through interactions with relativistic particles. In this work we consider the synchrotron…
We use radiation-hydrodynamical simulations to investigate the formation and synthetic X-ray emission of hot bubbles within planetary nebulae (PNe) driven by the powerful winds of H-deficient, [Wolf-Rayet]([WR])-type stars. Our models,…
Spectral properties of super-Eddington accretion flows are investigated by means of a parallel line-of-sight calculation. The subjacent model, taken from two-dimensional radiation hydrodynamic simulations by Ohsuga et al. (2005), consists…
Context: Massive colliding-wind binaries (CWBs) can be non-thermal sources. The emission produced in their wind-collision region (WCR) encodes information of both the shocks properties and the relativistic electrons accelerated in them. The…
We present results of a 20 ksec X-ray observation of the Wolf-Rayet (WR) binary system WR 147 obtained with XMM-Newton. Previous studies have shown that this system consists of a nitrogen-type WN8 star plus an OB companion whose winds are…
Massive colliding wind binary stars serve as laboratories for the study of strong-shock physics. In these systems fundamental flow parameters (velocities, densities, directions) are often well known, and photon fields important for Compton…
Gamma-ray binaries are composed of a massive star and a rotation-powered pulsar with a highly relativistic wind. The collision between the winds from both objects creates a shock structure where particles are accelerated, resulting in the…
The beaming pattern of radiation emitted by a relativistically moving source like jets in microquasars, AGN and GRBs, is a key issue for understanding of acceleration and radiation processes in these objects. In this paper we introduce a…
After having reported the detection of X-rays emitted by the peculiar system HD5980, we assess here the origin of this high-energy emission from additional X-ray observations obtained with XMM-Newton. This research provides the first…
We derived simple analytical parametrizations for energy distributions of photons, electrons, and neutrinos produced in interactions of relativistic protons with an isotropic monochromatic radiation field. The results on photomeson…
The interaction between the strong winds in stellar colliding-wind binary (CWB) systems produces two shock fronts, delimiting the wind collision region (WCR). There, particles are expected to be accelerated mainly via diffusive shock…
We study collective wind configurations produced by a number of massive stars, and obtain densities and expansion velocities of the stellar wind gas that is to be target, in this model, of hadronic interactions. We study the expected…
A gamma-ray line production calculation in astrophysics depends on i) the composition and energy source spectrum of the energetic particles, ii) the propagation model, and iii) the nuclear cross sections. The main difficulty for model…