DETECTION OF INTERSTELLAR $H^{+}_{3}$

$^{m}$T. Oka, {Phil. Trans. R. Soc. Lond}. A303, 543 (1981) $^{n}$T.R. Geballe and T. Oka, {Astrophys. J}. 342, 855 (1989) $^{o}$T.R. Geballe and T. Oka, {Nature} 384, 334 (1996)Author Institution: Joint Astronomy Centre; Department of Astronomy and AstrophysicsAfter more than 15 years of $searching,^{m,n} H^{+}_{3}$ has finally been detected in interstellar $space.^{o}$ Three vibration-rotation transitions in the 3.7 $\mu m$ region, R(1,0) of ortho-$H^{+}_{3}$, and R(1,1)$^{+}$ and R(1,1)$^{-}$ of para-$H^{+}_{3}$ have been observed in absorption using the CGS4 infrared spectrometer at the United Kingdom Infrared Telescope towards young stellar objects GL2136 and W33A which are deeply embedded in dense molecular clouds. The observation the most direct evidence supporting the ion-neutral scheme of interstellar chemistry proposed initally by Herbst and Klemperer and by Watson