Approximation of dimensionless emissivity as a function of photon energy E for the case of a condensed iron surface at B = 10¹³ G. Top panel: the magnetic field is normal to surface. The different curves correspond to different angles α between emergent photon direction and surface normal. Bottom panel: the emergent photon direction is inclined 45° to the surface. The different curves correspond to different angles Φ between magnetic field lines and surface normal.