Speaker
Description
LHAASO observations of SS433 and Cygnus X-3, well-known microquasars, have suggested that microquasars are likely galactic PeVatrons. We study the potential contribution of microquasars to the knee region of the Cosmic Ray (CR) spectrum, accounting for the stochastic nature of CR source ages and positions. We found that, in combination with SNRs with a maximum energy $\approx$ 50 TeV, microquasars can reproduce the measured flux. We investigated a case in which large-scale magnetic turbulence does not cascade to smaller scales, resulting in energy-independent diffusion. We reproduced the flux with minor adjustments to the injected spectrum. The maximum energies of SNR in this case are quite constrained, as they would overproduce the fluxes at $\approx$ 300 TeV if they were to vary by a factor of 2. We found the dipole moment of CRs to be sensitive to the sources' positions and ages in each realisation. It is also larger (close to 10 times) than observed, not just due to the contribution from the youngest and nearest source, but also the large-scale non-uniform distribution of sources.