X-ray line formation in the spectrum of SS 433

TL;DR

This paper investigates how radiative transfer and scattering affect X-ray line formation in SS 433's jets, highlighting the importance of high-resolution spectroscopy for jet diagnostics.

Contribution

It presents Monte Carlo simulations showing the impact of scattering on line intensity and broadening, aiding in jet parameter estimation.

Findings

Scattering reduces line intensity by up to 60%.

Line broadening can lead to overestimation of jet opening angles.

High-resolution X-ray spectroscopy is crucial for detailed jet diagnostics.

Abstract

The mechanisms for the formation of X-ray lines in the spectrum of SS 433 are investigated by taking into account the radiative transfer inside the jets. The results of Monte Carlo numerical simulations are presented. The effect of a decrease in line intensity due to scattering inside the jet turns out to be pronounced, but it does not exceed 60% in magnitude on the entire grid of parameters. The line broadening due to scattering, nutational motion, and the contribution of satellites can lead to overestimates of the jet opening angle $\Theta$ from the line widths in Chandra X-ray observations. The fine structure of the lines turns out to be very sensitive to the scattering effects. This makes its investigation by planned X-ray observatories equipped with high-resolution spectrometers (primarily Astro-H) a powerful tool for diagnosing the parameters of the jets in SS 433.