When neutrons come in contact with the magnetic atoms in a material, those atoms will cause the neutrons to scatter. When they scatter, the neutrons lose some kinetic energy. The energy the neutrons lose excites the magnetic fluctuations in the material. This graph shows the results of the neutron scattering experiment with CeCu6Au. They measured the number of neutrons scattered, seen here on the Y axis, for a given amount of energy transferred to the material, the X axis. We call this graph the spectrum of magnetic fluctuations. Each of these different curves is showing the results of neutron scattering at different temperatures. At higher temperatures, the spectrum of the magnetic fluctuations was wide, which means the fluctuations are disorganized and easy to excite. But as they lowered the temperature the spectrum of the fluctuations got narrower and narrower.