HYDROXYL CATION IN TRANSLUCENT INTERSTELLAR CLOUDS
High-quality spectra acquired at the European Southern Observatory enabled us to discover a very weak spectral feature of the OH{sup +} molecule, near 3584 A. The species likely shares environments with another molecular ion, CH{sup +}. Its abundance is by a factor of 30 lower than that of neutral OH.
74 ATOMIC AND MOLECULAR PHYSICS↗