Multiwavelength Observations of the SS 433 Jets

TL;DR

This study combines multiwavelength observations of SS 433 jets, revealing their emission regions, dynamics, and composition, including jet length, density, and elemental overabundance, providing insights into jet interactions and origin.

Contribution

It offers the first simultaneous X-ray, optical, and radio analysis of SS 433 jets, detailing emission region relationships, jet kinematics, and elemental abundances, advancing understanding of jet physics.

Findings

X-ray and optical emission regions are related but not coincident.

Jet Doppler shifts indicate a distance of 4.5 kpc to SS 433.

Overabundance of nickel by a factor of 10 relative to solar.

Abstract

We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and VLBA observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3e14 cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 +/- 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to >~ 2e12 cm. The base jet density is in the range 1e(10-13)/cm^3, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 10 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.