Hydrodynamic Simulations of the SS433-W50 Complex

Abstract

The compelling evidence for a connection between SS 433 and W50 has provoked much imagination for decades. There are still many unanswered questions: What was the nature of the progenitor of the compact object in SS 433? What causes the evident re-collimation in SS 433's jets? How recent is SS 433's current precession state? What mass and energy contributions from a possible supernova explosion are required to produce W50? Here we comment on two of our 53 models: (i) featuring the SNR evolution alone, and (ii) the SNR combined with a simple jet model.

Probing the history of SS 433’s jet kinematics via decade-resolution radio observations of W 50

“…A velocity map (Fig. 3) taken from high‐resolution hydrodynamic simulations of the SS 433–W 50 interaction (detailed in Goodall et al 2011) shows no signs of the required deceleration along the jet axis and therefore supports the second possibility.…”

“…These data would imply a lower limit of ∼85 per cent kinetic energy loss in the jets, and this energy would have been transferred to the ISM of the lobes. However, high‐resolution hydrodynamic simulations of the jets in SS 433 (Goodall et al 2011) reveal that, for any reasonable combination of the jet mass‐loss rate in the range 10 −5 –10 −4 M ⊙ yr −1 and ISM density in the range 0.1–1 particles cm −3 , a persistently active jet of speed v jet = 0.26 c does not suffer such extreme deceleration (see Fig. 3).…”

“…This has led to suggestions that SS 433’s jets are being refocused back towards the mean jet axis (Peter & Eichler 1993) or that the X‐ray emission arises due to reflective hydrodynamic shocks propagating along the symmetry axis because of the SNR–jet interaction (Velázquez & Raga 2000). However, more recent hydrodynamic simulations of the SS 433–W 50 interaction show a new mechanism for hydrodynamic refocusing of conical jets (Goodall, Alouani‐Bibi & Blundell 2011), where W 50’s nebular morphology and SS 433’s refocused jets are both reproduced to a good approximation. X‐rays have been detected from SS 433 itself by the Chandra satellite; on the basis of some of these observations, Migliari, Fender & Méndez (2002) suggest in situ reheating of the baryonic components, while Migliari et al (2005) interpret the variability of the arcsec‐scale X‐ray jets as evidence of a second, faster outflow connected with the jets.…”

“… We present a velocity map from high‐resolution hydrodynamic simulations of the SNR–jet interaction in SS 433 (see Goodall et al 2011 for a detailed account of these simulations). A contour map of the Dubner‐96 observation (white dashed line) has been overlaid upon the image to trace out the outline of the W 50 nebula.…”

“…The SS 433–W 50 system is amenable to numerical simulations, and the results of a wide range of hydrodynamic models are presented in a companion paper (Goodall et al 2011). In this paper, we present a detailed examination of three Very Large Array (VLA) radio images of W 50 spanning 12 yr. We aim to ascertain whether meaningful constraints can be placed on the proper motion of the persistent radio features (the filamentary structure in W 50) where the jets have impinged and penetrated through the SNR shell.…”