A framework for resolving the origin, nature and evolution of the
  diffuse interstellar band carriers?
  The carriers of the diffuse interstellar bands (DIBs) still remain an unknown
commodity. Both dust and molecules have been suggested as carriers but none
proposed have yet been able to explain the nature and the diversity of the
DIBs. Hence, it is perhaps time to review the problem in terms of the
intermediate-sized nano-particles. It is here proposed that the DIB carriers
are the nm-sized and sub- nm-sized products of the UV photo-fragmentation of
hydrogenated amorphous carbon grains, a-C(:H), and their heteroatom-doped
variants, a-C:H:X (where X may be O, N, Mg, Si, Fe, S, Ni, P, ...). An
interstellar hydrogenated amorphous carbon dust evolutionary framework is
described within which a solution to the age-old DIB problem could perhaps be
found.
