Speaker
sarah recchia
(Gran Sasso Science Institute)
Description
The transport of cosmic rays (CRs) in the Galaxy is known to be
affected by the presence of winds launched from the Galactic disc.
When these winds are pre-assigned, it is easy to check that the
effects on transport are limited to energies below $\sim 10$ GeV.
Moreover a boundary condition needs to be imposed at large distances
(above and below the disc) to ensure the stationarity of the problem.
However, a Galactic wind can be driven by the gradient in the CR
pressure, and the hydrodynamics of such winds has been studied in the
past. We discuss a semi-analytical kinetic calculation of CR transport
in a CR driven wind, that allows one to determine the CR spectrum and
spatial distribution in the Galaxy, as well as the characteristics of
the wind itself. In this highly non-linear approach, diffusion is due
to scattering on self-generated Alfven waves and both diffusion
coefficients and slope of the B/C ratio are outputs of the problem.
Moreover, no artificial boundary condition at spatial infinity is
needed. We discuss the implications of this physical model for the
following observables: 1) CR spatial distribution in the disc of the
Galaxy; 2) CR anisotropy; 3) Spatial profile of the diffuse radiation
due to CR interactions. We also discuss preliminary results of the
case in which neutral hydrogen in the circum-disc region is
transported by the wind due to charge exchange reactions.
| Registration number following "ICRC2015-I/" | 656 |
|---|---|
| Collaboration | -- not specified -- |
Primary authors
Pasquale Blasi
(INAF)
sarah recchia
(Gran Sasso Science Institute)
