Related papers: Modeling Nonaxisymmetric Bow Shocks: Solution Meth…
High-resolution IRAS maps are used to search for the presence of stellar-wind bow-shocks around high-mass X-ray binaries (HMXBs). Their high space velocities, recently confirmed with Hipparcos observations, combined with their strong…
Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiation, the molecular cloud clump that spawned it. On one side…
The late stellar evolutionary phases of low and intermediate-mass stars are strongly constrained by their mass-loss rates. The wind surrounding cool evolved stars frequently shows non-spherical features, thought to be due to an unseen…
Boson stars are gravitationally bound objects that arise in ultralight dark matter models and form in the centers of galactic halos or axion miniclusters. We systematically study the excitations of a boson star, taking into account the…
Shocks form the basis of our understanding for the density and velocity statistics of supersonic turbulent flows, such as those found in the cool interstellar medium (ISM). The variance of the density field, $\sigma^2_{\rho/\rho_0}$, is of…
We present hydrodynamical simulations, using a 2-D two component model (ambient medium and pul sar wind have different specific heat ratios), of bow shocks in a representative regime for pu lsar wind driven bow-shock nebulae. We also…
Bow-shock pulsar wind nebulae are a subset of pulsar wind nebulae that form when the pulsar has high velocity due to the natal kick during the supernova explosion. The interaction between the relativistic wind from the fast-moving pulsar…
The theory of radiation-driven winds succeeded in describing terminal velocities and mass loss rates of massive stars. However, for A-type supergiants the standard m-CAK solution predicts values of mass loss and terminal velocity higher…
We assess the multi-wavelength observable properties of the bow shock around a runaway early type star using a combination of hydrodynamical modelling, radiative transfer calculations and synthetic imaging. Instabilities associated with the…
We present a mathematical model for the propagation of the shock waves that occur during planetary collisions. Such collisions are thought to occur during the formation of terrestrial planets, and they have the potential to erode the…
Bow shocks around cataclysmic variables (CVs) have traditionally been identified with a single bright optical arc. This feature has been interpreted as the bow shock formed by the interaction between a sustained outflow and the interstellar…
Non-radiative shocks accelerate particles and heat astrophysical plasmas. While supernova remnants are the most well-studied example, neutron star (NS) bow shocks are also non-radiative and Balmer-dominated. NS bow shocks are likely…
Runaway O- and early B-type stars passing throughout the interstellar medium at supersonic velocities and characterized by strong stellar winds may produce bow shocks that can serve as particle acceleration sites. Previous theoretical…
Stationary solutions to the equations of non-linear diffusive shock acceleration play a fundamental role in the theory of cosmic-ray acceleration. Their existence usually requires that a fraction of the accelerated particles be allowed to…
The adiabatic shock produced by a compact object moving supersonically relative to a gas with uniform entropy and no vorticity is a source of entropy gradients and vorticity. We investigate these analytically. The non-axisymmetric…
The problem of accelerating cosmic rays is one of fundamental importance, particularly given the uncertainty in the conditions inside the acceleration sites. Here we examine Diffusive Shock Acceleration in arbitrary turbulent magnetic…
Pulsars have mean space velocities >~500 km/s. The consequent ram pressure results in tight confinement of the star's energetic wind, driving a bow shock into the surrounding medium. Pulsar bow shocks have long been regarded as a curiosity,…
The magnetic field outside the earth is in good approximation a harmonic vector field determined by its values at the earth's surface. The direction problem seeks to determine harmonic vector fields vanishing at infinity and with prescribed…
Recently it has been discussed whether a bow shock ahead of the heliospheric stagnation region does exist or not. This discussion was triggered by measurements indicating that the Alfv\'en speed and that of fast magnetosonic waves are…
Bow Shock Pulsar Wind Nebulae are a class of non-thermal sources, that form when the wind of a pulsar moving at supersonic speed interacts with the ambient medium, either the ISM or in a few cases the cold ejecta of the parent supernova.…