Luminous and dark formations of intergalactic matter

APR 01, 1953

Recent advances in astronomical observation have added greatly to our store of information about the visible universe, but they have also led to a great increase in the number of unanswered questions concerning the distribution and nature of distant galaxies.

DOI: 10.1063/1.3061224

Fritz Zwicky

As astronomy pushed its limits from the solar system to the stars of the Milky Way and to the distant galaxies and clusters of galaxies, the following three problems suggested themselves automatically. Is there matter spread throughout interplanetary space? Is there matter in interstellar space? Are the enormous intergalactic spaces empty or not?

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References

1. F. Zwicky, Carnegie Institution of Washington, Year Book, No. 48, 1948–1949, p. 20;
No. 49, 1949–1950, p. 15;
No. 50 1950–1951, p. 21.
F. Zwicky, Experientia, 6, 441–445, 1950.https://doi.org/EXPEAM
2. F. Zwicky, Astrophys. J., 86, 217 (1937); https://doi.org/ASJOAB
F. Zwicky, Phys. Rev., 61, 489 (1942).https://doi.org/PHRVAO
3. F. Zwicky, Theodore von Karman Anniversary Volume, pp. 137–153, California Institute of Technology, 1941.
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see also P. C. Keenan, Astrophys. J., 81, 355 (1935). https://doi.org/ASJOAB
Keenan in this paper, as far as I know, published the first photograph of a fairly widely separated pair of galaxies, NGC 5216–5218. the two members of which are connected by a luminous band. This system apparently remained an isolated case until the author during the past few years found a great number of similar cases.
6. H. Schlichting, Grenzschichtttheorie, p. 326. Ed. G. Braun Karlsruhe, 1951.
7. E. P. Hubble, The Realm of the Nebulae, p. 170. Vale University Press, 1936.
8. W. Baade and L. Spitzer, Astrophys. J., 113, 413 (1951).https://doi.org/ASJOAB

More about the authors

Fritz Zwicky, California Institute of Technology.