A Cosmic Ray Resolution to the Superbubble Energy-Crisis

TL;DR

This paper proposes that cosmic ray acceleration within superbubbles explains the missing energy in these structures, supporting their role as sources of Galactic cosmic rays.

Contribution

It introduces the idea that cosmic ray acceleration accounts for the energy discrepancy in superbubbles, providing a potential solution to the energy crisis.

Findings

Cosmic ray acceleration likely accounts for a significant portion of unaccounted superbubble energy.

Supports the hypothesis that superbubbles are primary sites of Galactic cosmic ray origin.

Addresses the energy discrepancy observed in the SB 'DEM L192' in the LMC.

Abstract

Superbubbles (SBs) are amongst the greatest injectors of energy into the Galaxy, and have been proposed to be the acceleration site of Galactic cosmic rays. They are thought to be powered by the fast stellar winds and powerful supernova explosions of massive stars in dense stellar clusters and associations. Observations of the SB 'DEM L192' in the neighboring Large Magellenic Cloud (LMC) galaxy show that it contains only about one-third the energy injected by its constituent stars via fast stellar winds and supernovae. It is not yet understood where the excess energy is going, thus, the so-called 'energy crisis'. We show here that it is very likely that a significant fraction of the unaccounted for energy is being taken up in accelerating cosmic rays, thus bolstering the argument for the SB origin of cosmic rays.