Simulation of kinematics of SS 433 radio jets that interact with the ambient medium

Abstract

Context. The mildly relativistic jets of SS 433 are believed to inflate the surrounding supernova remnant W 50, possibly depositing more than 99% of their kinetic energy in the remnant expansion. Where and how this transformation of the energy occurs is as yet unknown. We can learn from this that the jets decelerate and that this deceleration is non-dissipative. Aims. We uncover the deviation of the arcsecond-scale precessing radio jets of SS 433 from the ballistic locus described by the kinematic model as a signature of the dynamics issuing from the interaction of the jets with the ambient medium. Methods. To do this, we simulated the kinematics of these jets, taking into account the ram pressure on the jets, which we estimated from the profile of brightness of synchrotron radiation along the radio jets, assuming pressure balance in the jets. Results. We found that to fit an observable locus in all scales the radio jets need to be decelerated and twisted in addition to the precession torsion, mostly within the first one-fifth of the precession period, and subsequently they extend in a way that imitates ballistic jets. This jet kinematics implies a smaller distance to SS 433 than the currently accepted 5.5 kpc. The physical parameters of the jet model, which links jets dynamics with radiation, are physically reliable and characteristic for the SS 433 jets. The model proposes that beyond the radio-brightening zone, the jet clouds expand because they are in pressure balance with the intercloud medium, and heat up with distance according to the law T = 2 × 10 4 (r/10 15 cm) 1.5 K. Conclusions. This model naturally explains and agrees with, the observed properties of the radio jets: a) the shock-pressed morphology; b) the brightness profile; c) the ∼10% deflections of the jet kinematics from the standard kinematic model -a magnitude of the jet speed decrement in our simulation; d) the precession-phase deviations from the standard kinematic model predictions; e) the dichotomy of the distances to the object, 4.8 kpc vs. 5.5 kpc, which are determined on the basis of the jet kinematics on scales of sub-arcsecond and several arcseconds, respectively; and f) the reheating on arcsecond scales.

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

“…The LSR velocity of the associated gas from radio observations is consistent with those from optical observations. Accordingly, the near kinematic distance of the system is 4.9±0.4 kpc, which agrees well with the results from the kinematic model of the proper motions of the SS 433 jets within the error (e.g., see views in Panferov 2014). The far distance of the system can be excluded due to lacking the H i absorption near the tangent point, e.g., V LSR ∼85 km s −1 .…”

Identification of X-ray lines in the spectrum of the arcsec-scale precessing jets of SS 433

“…Marshall et al (2013)) to a few arcseconds, where it forms a remarkable 'corkscrew' pattern generally consistent with the prediction of the kinematic model (e.g. (MillerJones et al, 2008)), albeit with slight deflections that might be caused by the interaction of the jets with the surrounding medium (Panferov, 2014). Further away, however, the jets stay invisible up to ∼ 10 arcminute scales, where extended X-ray emission, which probably has relation to their propagation through the interstellar medium (ISM), is observed (Brinkmann, * E-mail: khabibullin@iki.rssi.ru Kotani, & Kawai, 2005), and then they appear to be terminated at the boundary of the surrounding radio nebula W50 (Dubner et al, 1998), giving rise to its severe deformation (Goodall, Alouani-Bibi, & Blundell, 2011) and bright X-ray emission from the supposed termination region (Brinkmann, Aschenbach, & Kawai, 1996).…”

Jets of SS 433 on scales of dozens of parsecs

“…2 of Roberts et al 2010), except may be the predicted 10% deceleration and twist (the shift of the precession phase by ∼ −0.1) in the innermost ∼ 0. 5 (Panferov 2014; see also Stirling et al 2004). At larger distances the jets become unobservable, possibly because of weakening of the interaction of the jet with the ambient medium.…”

“…At larger distances the jets become unobservable, possibly because of weakening of the interaction of the jet with the ambient medium. The jet there would 1 1 = 0.67 · 10 17 cm at the observer distance of D = 4.5 kpc, accepted hereinafter (Stirling et al 2002;Panferov 2010;Marshall et al 2013; see also Lockman et al 2007, andPanferov 2014 for discussion on the distance); data from the literature are compiled to this distance.…”