Diffuse interstellar absorption bands between 2.9 and 4.0 µm

摘要: IRS7, the obscured M supergiant near galactic centre, is an excellent source against which to study interstellar absorption bands 3-µm wavelength. Previously we considered1 3.4-µm band as evidence that grains include organic component. We report here superior data between 2.9 and 4.0 µm, find a broad trough with numerous discrete features stretching from 3.6 µm. Although no definite identification of material producing this possible, there some indication complex molecules may be involved.