# How to turn a Supernova into a PeVatron

**Authors:** Robert Brose, Iurii Sushch, Jonathan Mackey  
**arXiv:** [2504.20601](https://arxiv.org/abs/2504.20601)  
**Date:** 2025-04-29  
**Summary page:** https://www.summarizepaper.com/en/paper/2504.20601v1/

## Key points

- Study focused on effects of dense circumstellar shells on particle acceleration in supernova shocks post-explosion
- Methodology involved using pion code to model circumstellar medium and conducting 1-D simulations with time-dependent acceleration-code RATPaC
- Results showed interactions with dense circumstellar shells can enhance particle escape, leading to reacceleration of shocks into a medium with pre-amplified magnetic fields
- Early interactions within first 5 months after explosion can boost maximum energy levels to over 1 PeV, suggesting supernovae interacting with dense circumstellar material may serve as powerful accelerators of high-energy particles (PeVatrons)
- Research highlights role of certain supernovae in accelerating particles to extreme energies by considering impact of dense circumstellar shells on particle acceleration processes

## Summary

The researchers conducted a study on the effects of dense circumstellar shells on particle acceleration in supernova shocks during the first few years post-explosion. They focused on determining which Galactic cosmic-ray sources can accelerate particles to the knee of the cosmic ray spectrum at a few PeV. Their methodology involved using the pion code to model the circumstellar medium around Luminous Blue Variables and conducting spherically symmetric 1-D simulations with their time-dependent acceleration-code RATPaC. The results showed that interactions with dense circumstellar shells can significantly enhance particle escape during shock-shell interactions, leading to reacceleration of shocks into a medium with pre-amplified magnetic fields. The researchers found that early interactions within the first 5 months after explosion can boost maximum energy levels to over 1 PeV, suggesting that supernovae interacting with dense circumstellar material may serve as powerful accelerators of high-energy particles known as PeVatrons. This research sheds light on how certain types of supernovae may play a crucial role in accelerating particles to extreme energies in our galaxy by considering the impact of dense circumstellar shells on particle acceleration processes. It contributes valuable insights into understanding cosmic-ray sources and mechanisms responsible for generating particles at PeV energies.