Speaker
Description
The X-ray binary system SS 433 launches mildly relativistic jets that extend over several tens of parsecs. The nonthermal emission detected from the jets is best explained by multi-TeV electrons producing X-ray synchrotron and inverse Compton emission of TeV gamma rays. The LHAASO detection of ultra-high-energy ($>$100 TeV) gamma-ray emission further establishes SS 433 as a potential PeVatron. A proper understanding of the conditions required for accelerating particles to PeV energies calls for detailed modeling of the full X-ray and gamma-ray dataset.
We construct a spatially dependent, one-dimensional cosmic-ray transport model for the jets of SS 433 that allows us to model the nonthermal emission. While we adopt a steady jet model, we reproduce a wide range of observational results, including the energy-dependent morphology of the emission regions in both the X-ray and gamma-ray bands. We report the theoretical implications of our findings, such as the required acceleration efficiency and its relation to the Bohm limit. Our results demonstrate the importance of a spatially dependent approach for understanding extreme Galactic particle accelerators.
