Relevant timescales. The cooling timescale as a function of electron energy (black dashed line) assuming B = 3 μG and the same ambient radiation field as used in the broadband modelling. The contributions from IC and synchrotron are shown in orange and blue, respectively. The loss timescale of proton-proton interactions (Kafexhiu et al. 2014) is depicted with a dotted green line for density values of n = 0.2 cm⁻³. A solid vertical line indicates 1 PeV particle energy. The purple dashed-dotted line indicates the propagation time of a flow moving with v = 0.12c, over 50 pc. The red dashed-double-dotted line shows the gyro-radius time defined as t_gyro = 2πr_g/c where r_g is the particle gyro-radius for B = 3 μG. For n = 0.2 cm⁻³ the bremsstrahlung loss timescale is ≈10⁸ yr, and thus only relevant for energies lower than those shown in this figure.