The well correlated diffuse interstellar bands at λλ 6196, 6614 Å and their possible companions

Considered here is the interrelation between five diffuse interstellar bands (DIBs), lambda lambda 5545, 6113, 6196, 6445 and 6614 angstrom. Two DIBs (lambda lambda 6196 and 6614 angstrom) are already known as being well correlated with each other; their relation with three other weaker bands is investigated for the first time. To accomplish this task, high-resolution spectra (lambda/delta lambda approximate to 1100 000) with high signal-to-noise ratios (S/N) of 54 hot O-B stars with reddening 0.12-1.45 mag were used. Analysis of measured equivalent widths has allowed us to establish linear dependences and evaluate linear correlation coefficients as high as 0.968-0.988 between the intensities of these five DIBs. Such a degree of correlation may indicate their common origin. Several spacings in wavenumbers found between these DIBs correspond to the energies of vibrational transitions in some polycyclic aromatic hydrocarbons resulting in IR emissions at lambda lambda 16.4, 11.3, 7.7, 6.2 and 3.3 mu m.