The SS433 jet from subparsec to parsec scales

Abstract

Context. Relativistic jets associated with compact objects, as in the X-ray binary SS433, are known to be multiscale because they spawn over many orders of magnitude in distance. Here we model the precessing SS433 jet and study its dynamics from O(0.01) to O(1) parsec scales. Aims. We aim to solve the discrepancy between the observations on a 0.1 pc scale of SS433, where the jet is clearly precessing with an angle of 20• , and the larger scale observations where the jet of SS433 interacts with the associated supernova remnant W50, requiring a precessing angle of 10• . Methods. We use 3D special relativistic hydrodynamical simulations on a domain of a scale of 1 pc. We use the finite volume code MPI-AMRVAC, solving the relativistic variant of the Euler equations. To cover lengthscale variations from O(0.001) pc as the jet beam width up to the domain size, we take full advantage of code parallelization and its adaptive mesh refinement scheme. Results. We found that by means of a simple hydrodynamical process, the jet of SS433 can transit from a precessing jet with an angle of 20• , to a continuous hollow non-precessing jet with a smaller opening angle of about 10• . Successive windings of the precessing jet helix undergo gradual deceleration by ISM interaction, to ultimately merge in a hollow straight jet at distances where the ram pressure of individual jet elements match the ISM pressure at about 0.068 pc from the source. Conclusions. We solve the discrepancy with an elegant and simple model that does not require the jet of SS433 to undergo any temporal changes in jet injection dynamics, but does so as a consequence of a hydrodynamically enforced spatial recollimation. Our simulation thus serves to validate simpler model prescriptions for SS433 on large scales, where a continuous jet profile suffices.

The Large-scale Interstellar Medium of SS 433/W50 Revisited

“…In Figure 13, the opening angle from CO data is about ±10 • , which is comparable to the results from the radio and X-ray studies of W50 at large distances (e.g., jet-ISM encounters at ∼35-80 arcmin from SS 433, Brinkmann et al 1996;Dubner et al 1998;Brinkmann et al 2007), but much smaller than the ±20 • of the current precession cone of the SS 433 jets at the inner region (e.g., < ∼ 6 arcsec from the compact source, Hjellming & Johnston 1981;Stirling et al 2002). The discrepancy of the two opening angles with respect to SS 433 is possibly due to the changing state of the jet precession with time (e.g., Kochanek & Hawley 1990;Zavala et al 2008;Goodall et al 2011a) and/or some hydrodynamical recollimated mechanisms for a precessing jet (e.g., Eichler 1983;Peter & Eichler 1993;Monceau-Baroux et al 2015).…”

How is the Jovian main auroral emission affected by the solar wind?

“…The MHD equations are solved in conservative form, and the magnetic field splitting method developed by Tanaka [] is used. Various problems have already been studied successfully with VAC or MPI‐AMRVAC, for instance, the solar wind and coronal mass ejections [ van der Holst et al , ; Chané et al , ], solar prominences [ Keppens et al , ], relativistic jets [ Monceau‐Baroux et al , ], or even dust dynamics in nebulae [ Hendrix et al , ].…”

Long-term Simulation of MHD Jet Launching in an Orbiting Star–Disk System

“…VLBA observations of SS433 at 10 −4 pc scale covering 40 days of data show the dynamics and the precession of the jet close to its launching area (Mioduszewski et al 2004). Monceau-Baroux et al (2015) studied the SS433 structure at different scales by 3D hydrodynamic simulations and subsequent radiation transfer to investigate the discrepancy between the larger scales of the jet of SS433 and its inner region.…”