In the realm of astrophysics and energy research, a trio of scientists from Nagoya University in Japan—Jiro Shimoda, Katsuaki Asano, and Shu-ichiro Inutsuka—have been delving into the intricate dance between cosmic rays (CRs) and the interstellar medium (ISM). Their work, published in the Astrophysical Journal, offers insights that could have implications for our understanding of galactic winds and the local proton spectrum, which are indirectly relevant to the energy sector, particularly in space-based energy applications and radiation shielding technologies.
The researchers employed spherically symmetric CR-hydrodynamical simulations to study the effects of escaping CRs on the ISM around their source. Their simulations took into account the evolution of the CR energy spectrum, radiative cooling, and thermal conduction. The study revealed that escaping CRs can accelerate and heat the ISM fluid, with the extent of heating depending on the CR diffusion coefficient.
One of the significant findings of this research is the potential responsibility of CR heating effects for the recent observations of unexpected Hα and [OIII]λ5007 lines in old supernova remnants. These observations have puzzled astronomers, and the current study offers a plausible explanation. The implied gas outflow driven by CRs could be comparable to the Galactic star formation rate. This is notable because it aligns with the Galactic wind required for the metal-polluted halo gas and the production of eROSITA bubbles, which are large-scale structures in the Milky Way.
The researchers also proposed alternative interpretations for the Galactic CR proton spectrum around the Earth, as measured by instruments like CALET, AMS02, and Voyager I. They suggest that a locally suppressed CR diffusion and a few nearby CR sources in the Local Bubble could account for the observed spectrum.
For the energy industry, understanding the behavior of cosmic rays and their interactions with the interstellar medium can have practical applications. For instance, in the development of space-based solar power systems, knowledge of the radiation environment is crucial for designing effective shielding to protect the infrastructure. Additionally, insights into galactic winds and the local proton spectrum can inform the development of advanced materials and technologies for space exploration and energy harvesting in the harsh conditions of space.
In summary, the work of Shimoda, Asano, and Inutsuka provides valuable insights into the complex interplay between cosmic rays and the interstellar medium, with potential implications for the energy sector, particularly in space-based applications. Their findings contribute to our broader understanding of the universe and the fundamental processes that shape it, which can ultimately drive innovation in energy technologies.
This article is based on research available at arXiv.