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Galactic Gas Models Strongly Affect the Determination of the Diffusive Halo Height

Astrophysics of Galaxies 2024-08-27 v2 High Energy Astrophysical Phenomena High Energy Physics - Phenomenology

Abstract

The height of the Milky Way diffusion halo, above which cosmic-rays can freely escape the galaxy, is among the most critical, yet poorly known, parameters in cosmic-ray physics. Measurements of radioactive secondaries, such as 10^{10}Be or 26^{26}Al, which decay equivalently throughout the diffusive volume, are expected to provide the strongest constraints. This has motivated significant observational work to constrain their isotopic ratios, along with theoretical work to constrain the cross-section uncertainties that are thought to dominate radioactive secondary fluxes. In this work, we show that the imprecise modelling of the Milky Way spiral arms significantly affects our ability to translate 10^{10}Be and 26^{26}Al fluxes into constraints on the diffusive halo height, biasing our current results. Utilizing state-of-the-art spiral arms models we produce new predictions for the 10^{10}Be and 26^{26}Al fluxes that motivate upcoming measurements by AMS-02 and HELIX.

Keywords

Cite

@article{arxiv.2408.05179,
  title  = {Galactic Gas Models Strongly Affect the Determination of the Diffusive Halo Height},
  author = {Pedro De La Torre Luque and Tim Linden},
  journal= {arXiv preprint arXiv:2408.05179},
  year   = {2024}
}

Comments

Main text has 4 figures and 8 pages without references. 3 appendices with 7 figures and 3 tables