SIMBAD references

The wavelength displacements of the diffuse interstellar bands (DIBs) at 4502, 5705, 5780, 6284 and 7224 Å, with respect to the well-known, narrow atomic/molecular interstellar lines (of CaII and Nai), have been measured in the spectra of the two Orion Trapezium stars, HD 37022 and HD 37020, using the HARPS-N spectrograph, attached to the 3.5-m Telescopio Nazionale Galileo, and the Bohyunsan Optical Astronomy Observatory (BOAO) echelle spectrograph (BOES), attached to the 1.8-m Korean telescope. The redshift is ∼ 25 km/s for all these DIBs. We discuss the various possible origins of this very peculiar wavelength shift in the light of the particular physical conditions in the Orion Trapezium. The above-mentioned shift is seemingly absent in the DIBs at 6196 and 6993 Å.