Emissive map
From polycount
Emissive Map
A texture that receives no lighting, so the pixels are shown at full intensity. Also called a Fullbright Map, Glow Map, Incandescence Map, or Self-Illumination Map. This is used for a glow in the dark effect, but does not emit light onto adjacent surfaces.
This can be used alongside a Diffuse map to add a glow effect, such as magic runes on a sword or the heated material on a torch.