Abstract
We present the first simulations evolving resolved spectra of cosmic rays
(CRs) from MeV-TeV energies (including electrons, positrons, (anti)protons, and
heavier nuclei), in live kinetic-MHD galaxy simulations with star formation and
feedback. We utilize new numerical methods including terms often neglected in
historical models, comparing Milky Way analogues with phenomenological
scattering coefficients $\nu$ to Solar-neighborhood (LISM) observations
(spectra, B/C, $e^+/e^-$, $p/p$, $^10$Be/$^9$Be, ionization). We
show it is possible to reproduce observations with simple single-power-law
injection and scattering coefficients (scaling with rigidity R), similar to
previous (non-dynamical) calculations. We also find: (1) The circum-galactic
medium in realistic galaxies necessarily imposes a ~10kpc CR scattering halo,
influencing the required $\nu(R)$. (2) Increasing the normalization of $\nu(R)$
re-normalizes CR secondary spectra but also changes primary spectral slopes,
owing to source distribution and loss effects. (3) Diffusive/turbulent
reacceleration is unimportant and generally sub-dominant to
gyroresonant/streaming losses, which are sub-dominant to adiabatic/convective
terms dominated by ~0.1-1 kpc turbulent/fountain motions. (4) CR spectra vary
considerably across galaxies; certain features can arise from local structure
rather than transport physics. (5) Systematic variation in CR ionization rates
between LISM and molecular clouds (or Galactic position) arises naturally
without invoking alternative sources. (6) Abundances of CNO nuclei require most
CR acceleration occurs around when reverse shocks form in SNe, not in OB wind
bubbles or later Sedov-Taylor stages of SNe remnants.
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