Diffuse interstellar band

Diffuse interstellar bands (English: Diffuse Interstellar Bands; abbreviated DIBs ) are absorption bands of astronomical objects that are associated with the interstellar medium.

Diffuse interstellar bands are detected in the near infrared radiation in the ultraviolet and in the optical. The most prominent band is 4430 Angstroms with a width of 20 Å, a depth of 15 percent compared to the continuum and an equivalent width of 3 Å. Other strong bands are at 4765, 4880, 5780, 5800, 6180 and 6280 Å. Some bands extend over widths of up to 200 Å with a very small absorption depth. The equivalent widths of diffuse interstellar bands are correlated, but not strongly correlated with the interstellar extinction.

The diffuse interstellar bands are associated with solid particles with a diameter in the order of the affected electromagnetic radiation in combination. It is likely to be dust particles, which are mainly composed of polycyclic aromatic hydrocarbons, Buckminsterfullerene and silicates.

Itemization

• Interstellar matter