On the coincidence of OB stars with neutral hydrogen in the Cygnus arm

Abstract

view Abstract Citations (4) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the coincidence of OB stars with neutral hydrogen in the Cygnus arm Muhleman, Duane O. ; Walker, Russel G. Abstract A study is presented of the spatial coincidence of high4uminosity stars and the H r density distribution for one galaxy model exemplifying rotation only and one exemplifying both rotation and expansion. The theory of H ii regions (Stromgren 1948) predicts that in the neighborhood of stars of high temperature and high luminosity the hydrogen will be ionized. This leads one to expect that regions containing a high spatial density of early-type stars (optical arms) will necessarily be regions of low H I density. Evidence is presented which indicates a lack of coincidence between 0 stars and dense H I concentrations over the galactic plane within 4 kpc of the sun. An extensive region in the Cygnus arm of the Galaxy with a high con- centration of OB stars is found to be coincident with a region of low H I density. The ionization of the H I caused by the luminosity of the stellar distribution is computed and the low density of the H I in the part of the Cygnus arm that contains a high concentration of OB stars is shown to be consistent with the density computed from the ionized regions considered here. Publication: The Astronomical Journal Pub Date: February 1964 DOI: 10.1086/109237 Bibcode: 1964AJ.....69...95M full text sources ADS |