How to turn a Supernova into a PeVatron

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Brose, Robert, Sushch, Iurii, Mackey, Jonathan
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916831049023488
author Brose, Robert
Sushch, Iurii
Mackey, Jonathan
author_facet Brose, Robert
Sushch, Iurii
Mackey, Jonathan
contents Context. It is important to determine which Galactic cosmic-ray sources can accelerate particles to the knee of the cosmic ray spectrum at a few PeV, and in particular whether supernova remnants may contribute. Current models for particle acceleration in very young remnants assume the circumstellar material consists of smooth, freely expanding winds. There is strong evidence that some supernovae expand into much denser circumstellar material including dense shells ejected by eruptions shortly before explosion. Aims. We investigate the effects of dense circumstellar shells on particle acceleration in supernova shocks during the first few years post-explosion, to quantify whether such interaction supernovae may act as PeVatrons. Methods. We used the pion code to model the circumstellar medium around Luminous Blue Variables after having a brief episode with a mass-loss rate of up to dM/dt = 2Msol/yr. Consequently, we performed spherically symmetric 1-D simulations using our time-dependent acceleration-code RATPaC in which we simultaneously solve the transport equations for cosmic-rays, magnetic turbulence, and the hydrodynamical flow of the thermal plasma in the test-particle limit. Results. We find that the interaction with the circumstellar shells can significantly boost the maximum energy by enhancing particle escape during the onset of the shock-shell interaction followed by the reacceleration of the shock propagating into a medium with a pre-amplified field. Early interactions boost the maximum energy to a greater degree and interactions within the first 5 months after explosion can increase Emax to more then 1 PeV.
format Preprint
id arxiv_https___arxiv_org_abs_2504_20601
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle How to turn a Supernova into a PeVatron
Brose, Robert
Sushch, Iurii
Mackey, Jonathan
High Energy Astrophysical Phenomena
Context. It is important to determine which Galactic cosmic-ray sources can accelerate particles to the knee of the cosmic ray spectrum at a few PeV, and in particular whether supernova remnants may contribute. Current models for particle acceleration in very young remnants assume the circumstellar material consists of smooth, freely expanding winds. There is strong evidence that some supernovae expand into much denser circumstellar material including dense shells ejected by eruptions shortly before explosion. Aims. We investigate the effects of dense circumstellar shells on particle acceleration in supernova shocks during the first few years post-explosion, to quantify whether such interaction supernovae may act as PeVatrons. Methods. We used the pion code to model the circumstellar medium around Luminous Blue Variables after having a brief episode with a mass-loss rate of up to dM/dt = 2Msol/yr. Consequently, we performed spherically symmetric 1-D simulations using our time-dependent acceleration-code RATPaC in which we simultaneously solve the transport equations for cosmic-rays, magnetic turbulence, and the hydrodynamical flow of the thermal plasma in the test-particle limit. Results. We find that the interaction with the circumstellar shells can significantly boost the maximum energy by enhancing particle escape during the onset of the shock-shell interaction followed by the reacceleration of the shock propagating into a medium with a pre-amplified field. Early interactions boost the maximum energy to a greater degree and interactions within the first 5 months after explosion can increase Emax to more then 1 PeV.
title How to turn a Supernova into a PeVatron
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2504.20601