Which type of hydrogen region is characterized by ionized hydrogen ($ ext{H}^+$) and is often called an emission nebula?

Answer

H II Regions

H II Regions consist of ionized hydrogen ($ ext{H}^+$), where electrons have been stripped away, usually by intense ultraviolet radiation from hot nearby stars.

Which type of hydrogen region is characterized by ionized hydrogen ($	ext{H}^+$) and is often called an emission nebula?
SpaceastronomynebulaGases