# No Need for an Extreme Jet Energy in the Black-Hole X-Ray Binary MAXI J1348--630

**Authors:** Andrzej A. Zdziarski, Marek Sikora, Michal Szanecki, Markus Boettcher  
**arXiv:** [2303.01349](https://arxiv.org/abs/2303.01349)  
**Date:** 2023-03-02  
**Summary page:** https://www.summarizepaper.com/en/paper/2303.01349v1/

## Key points

- Study focuses on discrete jet ejection from black-hole X-ray binary MAXI J1348-630 during 2019 outburst
- Previous research estimated kinetic energy in ejection to be greater than $10^{46}$ erg, raising questions about understanding of accretion processes
- Model presented accounting for transition layer with exponential density growth between cavity and interstellar medium
- Results show estimate of kinetic energy reduced to realistic values of around $10^{44}$ erg by considering transition layer
- Jet decelerates mostly in regions with densities lower than 1 cm$^{-3}$, significantly reducing energy requirement and providing new insights into understanding accretion processes
- Large required jet masses rule out significant number of electron-positron pairs being present
- Observations of MAXI J1348-630 discussed, highlighting importance of considering surrounding medium properties when modeling jet ejections.

## Summary

This study focuses on the main discrete jet ejection from the black-hole X-ray binary MAXI J1348-630 during its outburst in 2019. Previous research estimated the kinetic energy in the ejection to be greater than $10^{46}$ erg, which would require the jet power to be about two orders of magnitude above the standard maximum. This finding raised questions about our understanding of accretion processes in such systems. In this letter, the authors present a model that considers the presence of a transition layer with an exponential density growth separating the cavity and interstellar medium. The results show that by accounting for this transition layer, it is possible to reduce the estimate of kinetic energy to realistic values of around $10^{44}$ erg. The jet decelerates mostly in regions with densities lower than 1 cm$^{-3}$, significantly reducing the energy requirement and providing new insights into understanding accretion processes in black-hole X-ray binaries. Furthermore, large required jet masses rule out any significant number of electron-positron pairs being present. The authors also discuss their observations of MAXI J1348-630 and consider dependencies on distance estimates, highlighting the importance of considering surrounding medium properties when modeling jet ejections.