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Ionized hydrogen in astrophysics is generally indicated by the abbreviation HII or H II (pronounced "H two") if it is a positive ion (i.e., no electron; a more common symbol across science is H+). HII regions are volumes of interstellar medium (ISM) defined by the presence a significant number of such ions, formed from the ultraviolet electromagnetic radiation (EMR) from early stars, whose presence implies recent star formation. The same radiation heats such regions to thousands of degrees. Most of the ISM is basically HII (and free electrons), but with a much lower density than what are termed HII regions.
Negative hydrogen ions (H-, with two electrons orbiting, a hydrogen anion) do exist in space as well. Left alone, they can persist, but one requires only a small disturbance to strip the extra electron: a nearby positive ion or a photon, even if it has substantially less energy than the 13.6 eV that would be necessary to ionize neutral atomic hydrogen.