CONGRuENTS (COsmic-ray, Neutrino, Gamma-ray and Radio Non-Thermal Spectra). I. A predictive model for galactic non-thermal emission

Starburst Nuclei and Cosmic-Rays Transport Mechanisms: Future Opportunities for Neutrino Astronomy and Beyond Standard Model Studies

“…[3][4][5][6] and the model put forward by [13] which was also used by Ref. [14,15]. The former, which we call model A (see also [5] for more details), assumes that the nucleus is spherical and the diffusion is described by a Kolmogorov-like scenario in a regime of strong turbulence with an external magnetic field B.…”

“…In this model, τ diff > τ adv , hence the escape timescale is driven by the winds. The latter, namely model B, on the other hand, assumes a cilindrical geometry and, consequently, the calorimetric fraction is given by [5,[13][14][15]:…”

“…where M A 2 is the mach number and 0 F 1 is the generalized hypergeometric function [13][14][15]. The cosmic ray transport description, in this model, is different since neglects advection phenomena arguing that they could only affect the ionised gas and it is still not clear whether they could also affect the cold interstellar medium gas or not.…”

“…Furthermore, it considers diffusion driven by the selfturbulence by the alven waves generated by CRs themselves. In this framework the diffusion coefficient is proportional to the streaming velocity of cosmic rays [5,[13][14][15]:…”

“…[1][2][3][4] indicate external turbulence as diffusion mechanism, while Refs. [13][14][15] have proposed diffusion driven by self-induce interactions with Alfen waves generated though streaming instability. In this proceeding, we analyze the imprints left by different cosmic-ray transport mechanisms inside SBGs on gamma-ray observations (see [5] for more details).…”