We present investigations of the interaction between the relativistic, precessing jets of the microquasar SS 433 and the surrounding, expanding supernova remnant (SNR) shell, W 50, and the consequent evolution in the inhomogeneous interstellar medium (ISM). We model their evolution using the hydrodynamic FLASH code, which uses adaptive mesh refinement. We show that the peculiar morphology of the entire nebula can be reproduced to a good approximation, due to the combined effects of (i) the evolution of the SNR shell from the free-expansion phase through the Sedov blast wave in an exponential density profile from the Milky Way disc, and (ii) the subsequent interaction of the relativistic, precessing jets of SS 433. Our simulations reveal: (1) Independent measurement of the Galaxy scaleheight and density local to SS 433 (as n 0 = 0.2 cm −3 , Z d = 40 pc), with this scaleheight being in excellent agreement with the work of Dehnen & Binney.(2) A new mechanism for hydrodynamic refocusing of conical jets.(3) The current jet precession characteristics do not simply extrapolate back to produce the lobes of W 50, but a history of episodic jet activity having at least three different outbursts with different precession characteristics would be sufficient to produce the W 50 nebula. A history of intermittent episodes of jet activity from SS 433 is also suggested in a kinematic study of W 50 detailed in a companion paper. (4) An estimate of the age of W 50, and equivalently the age of SS 433's black hole created during the supernova explosion, in the range of 17 000-21 000 yr.

We present a new 3d self-consistent two-component (plasma and neutral hydrogen) model of the solar wind interaction with the local interstellar medium (LISM). This model (K-MHD) combines the MHD treatment of the solar wind and the ionized LISM component, with a kinetic model of neutral interstellar hydrogen (LISH). The local interstellar magnetic field (B LISM ) intensity and orientation are chosen based on an early analysis of the heliosheath flows (Opher et al. 2009). The properties of the plasma and neutrals obtained using the (K-MHD) model are compared to previous multi-fluid (Opher et al. 2009) and kinetic models (Izmodenov et al. 2005). The new treatment of LISH revealed important changes in the heliospheric properties not captures by the multi-fluid model. These include a decrease in the heliocentric distance to the termination shock (TS), a thinner heliosheath and a reduced deflection angle (θ) of the heliosheath flows. The asymmetry of the termination shock, however, seems to be unchanged by the kinetic aspect of the LISH.

In August of 2012 the Voyager 1 space probe entered a distinctly new region of space characterized by a virtual absence of heliospheric energetic charged particles and magnetic fluctuations, dubbed a "magnetic highway". Prior to their disappearance, the particle distributions strongly peaked at a 90 • pitch angle implying a faster particle escape along the magnetic field lines. We investigate the process of particle crossing from the heliosheath region into the "magnetic highway" region using a kinetic approach resolving scales of the particle's cyclotron radius and smaller. We show that a "loss-cone" type distribution naturally arises as the orbiting particles enter a region of space with an extremely low pitch-angle scattering rate.

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