Emission nebulae / H II regions.
ɪ m ɪ ʃ ə n WORD_BOUNDARY n ɛ b j ʊ l iː WORD_BOUNDARY s l æ ʃ WORD_BOUNDARY eɪ t̠ʃ WORD_BOUNDARY ɹ oʊ m ə n WORD_BOUNDARY t uː WORD_BOUNDARY ɹ iː d̠ʒ ə n z WORD_BOUNDARY