Spectral energy distribution of N 157B. The data shown are radio emission (Lazendic et al. 2000, blue triangles), non-thermal X-rays (Chen et al. 2006, blue band), and TeV gamma rays (H.E.S.S., this work, black circles). The green, thick lines represent the model with a cooling break depending on the magnetic field and the age of the remnant. The red, thin lines denote the conservative model that minimises the energy content of electrons. The blue, long-dashed line represents a hadronic scenario.