Detection of the buckminsterfullerene cation (C60+) in space
  In the early 90s, C60+ was proposed as the carrier of two diffuse
interstellar bands (DIBs) at 957.7 and 963.2 nm, but a firm identification
still awaits gas-phase spectroscopic data. Neutral C60, on the other hand, was
recently detected through its infrared emission bands in the interstellar
medium and evolved stars. In this contribution, we present the detection of
C60+ through its infrared vibrational bands in the NGC 7023 nebula, based on
spectroscopic observations with the Spitzer space telescope, quantum chemistry
calculation, and laboratory data from the literature. This detection supports
the idea that C60+ could be a DIB carrier, and provides robust evidence that
fullerenes exist in the gas-phase in the interstellar medium. Modeling efforts
to design specific observations, combined with new gas-phase data, will be
essential to confirm this proposal. A definitive attribution of the 957.7 and
963.2 nm DIBs to C60+ would represent a significant step forward in the field.
