Large-scale dissociation of molecular gas in galaxies by newly formed stars

R. J. Allen, P. D. Atherton, R. P.J. Tilanus

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


Molecular hydrogen is thought to form from atomic hydrogen on the surface of dust grains in the interstellar medium, and to be dissociated primarily by ultraviolet radiation from hot stars1. This process has been modelled on the 1 pc length scale for the case of dense interstellar clouds2 and near newly formed ionizing stars3. Observational evidence that molecular hydrogen is indeed dissociated in shells around young OB stars in the Galaxy has been presented recently4-6. We suggest here that the same dissociation process occurs on the kpc scale in active star-forming regions of some galaxies, and that this dissociation may strongly affect the observed morphology of atomic hydrogen in spiral arms.

Original languageEnglish (US)
Pages (from-to)296-298
Number of pages3
Issue number6051
StatePublished - 1986
Externally publishedYes

ASJC Scopus subject areas

  • General


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