Research Papers in Physics and Astronomy


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Published in The Astrophysical Journal 204. Copyright (c) 1976 The American Astronomical Society. Used by permission.


Implications of observed upper limits to the neutral hydrogen content of E and SO galaxies from Paper I are discussed. If gas shed by dying stars is completely retained by these galaxies and exists as H I, these upper limits will be exceeded in only 109 yr for E's and SO's and in only 2 x 108 yr for NGC 4472. Evidently, gas either is hidden in some undetectable form or is removed from the interstellar medium completely.

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