NEW EVIDENCES FOR INTERSTELLAR C-60(+)

The discovery and synthesis of fullerenes led to the hypothesis that t hey may be present and stable in interstellar space. As first evidence for the largest molecule ever detected in space, we have recently det ected two new diffuse interstellar bands (DIBs) in the near-infrared t hat are consistent with laboratory measurements of the C-60 cation. Th e inferred abundance (up to 0.9 % of cosmic carbon locked in C-60(+)) suggested that fullerenes may play an important role in interstellar c hemistry. We present new observations towards HD183143, HD37022 and HD 80077 at 9600 Angstrom from CFHT and ESO. The high quality of the spe ctra confirms without doubt the presence of the two DIBs at 9577 and 9 632 Angstrom and allows to measure reliably their strength, width and band ratio. The two correlated DIBs decrease in a UV shielded cold clo ud (HD80077) but increase in a region dominated by extreme UV radiatio n (HD37022), with a band ratio constant within errors. Both DIBs show the same width, also consistent with a common carrier. This width of 3 cm(-1) is compatible with rotational contours of C-60 fullerene molec ules. These results bring new evidences for C-60(+) in addition to the match with laboratory spectra.