Figure 1
From: Transition in the Equilibrium Distribution Function of Relativistic Particles
Three-dimensional Maxwell-Jüttner velocity distributions, according to equation (1), for two different temperatures.
The blue (ξ = 20) and gray (ξ = 1) isosurfaces stand at 1/3 and 1/4 of their respective maxima. Shown in the inner region of each isosurface, is the color gradient of the distribution, with red and blue colors denoting high and low concentration of particles, respectively. Note that the spheres are plotted in velocity space, so that the maximum radius for the external isosurface is close to 
.
