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Large Scale Star Formation: Density Waves, Superassociations and Propagation

Published online by Cambridge University Press:  04 August 2017

Bruce G. Elmegreen
Bruce G. Elmegreen*
Affiliation:
IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, N.Y. 10598 USA

Abstract

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The hypothesis that density waves trigger star formation is critically examined. Much of the former evidence in favor of the hypothesis is shown to be inconsistent with modern observations. A comparison between galaxies with and without density waves reveals no significant difference in their star formation rates. A new role for density waves in the context of star formation might be based on four principles: 1. density waves are intrinsically strong, 2. the gas is compressed more than the stars in the wave, 3. star formation follows the gas, with no preferential trigger related to the wave itself, and 4. regions of star formation are larger in the spiral arms than they are between the arms. This new role for density waves is primarily one of organization: the waves place most of the gas in the arms, so most of the star formation is in the arms too. The waves also promote the coagulation of small clouds into large cloud complexes, or superclouds, by what appears to be a combination of collisional agglomeration and large-scale gravitational instabilities. Special regions where density waves do trigger a true excess of star formation are discussed, and possible reasons for the difference between these triggering waves and the more common, organizing, waves are mentioned. Other aspects of large-scale star formation, such as the occurrence of kiloparsec-size regions of activity and kiloparsec-range propagation, are illustrated with numerous examples. The importance of these largest scales to the overall mechanism of star formation in galaxies is emphasized.

Type
II. Large Scale Processes of Star Formation
Information
Symposium - International Astronomical Union , Volume 115: Star Forming Regions , 1987 , pp. 457 - 481
Copyright
Copyright © Reidel 1987 

References

Allen, R.J., Goss, W.M. and van Woerden, H. 1973, Astron. Astrophys., 29, 447.Google Scholar
Allen, R.J. and Goss, W.M. 1979, Astron. Astrophys. Suppl., 36, 135.Google Scholar
Allen, R.J., Atherton, P.D. and Tilanus, R.P.J. 1985, Nature, in press.Google Scholar
Ambartsumian, V.A. 1947, Stellar Evolution and Astrophysics, Armenian Academy of Sciences.Google Scholar
Ambartsumian, V.A., Iskudarian, S.G., Shahbazian, R.K., and Sahakian, K.A. 1963, Bull. Byurakan Obs., 33, 1.Google Scholar
Anderson, S., Hodge, P. and Kennicutt, R. Jr. 1983, Astrophy. J., 265, 132.CrossRefGoogle Scholar
Arp, H. and Sandage, A. 1985, Astron. J., 90, 1163.CrossRefGoogle Scholar
Baade, W. 1963, in The Evolution of Stars and Galaxies, ed. Payne-Gaposchkin, C., (Cambridge: Harvard University Press), Chapter 16.CrossRefGoogle Scholar
Baade, W. and Mayall, N.U. 1951, in Problems of Cosmical Aerodynamics, (Dayton Ohio: Control Air Document Office), p. 165.Google Scholar
Bajaja, E. and Shane, W.W. 1982, Astron. Astrophys. Suppl., 49, 245.Google Scholar
Balbus, S.A. 1984, Astrophys. J., 277, 550.CrossRefGoogle Scholar
Balbus, S.A. and Cowie, L.L. 1985, Astrophys. J., 297, 61.CrossRefGoogle Scholar
Balzano, V.A. 1983, Astrophys. J., 268, 602.CrossRefGoogle Scholar
Barkhatova, K.A. and Pavlovskaya, E.D. 1981, Astron. Tsirk., 1155, 4.Google Scholar
Bash, F.N. 1979, Astrophys. J., 233, 524.CrossRefGoogle Scholar
Bash, F.N., Green, E. and Peters, W.L. III 1977, Astrophys. J., 217, 464.CrossRefGoogle Scholar
Bash, F.N. and Visser, H.C.D. 1981, Astrophys. J., 247, 488.CrossRefGoogle Scholar
Benvenuti, P., Casini, C. and Heidmann, J. 1982, Monthly Not. Roy. Astron. Soc., 198, 825.CrossRefGoogle Scholar
Berkhuijsen, E.M. 1974, Astron. Astrophys., 35, 429.Google Scholar
Biermann, P., Kippenhahn, R., Tscharnuter, W. and Yorke, H. 1972, Astron. Astrophys., 19, 113.Google Scholar
Blaauw, A. 1956, Astrophys. J., 123, 408.CrossRefGoogle Scholar
Blaauw, A. 1964, Ann. Rev. Astron. Astrophys., 2, 213.CrossRefGoogle Scholar
Blaauw, A. 1984, Irish Astron. J., 16, 141.Google Scholar
Blitz, L. 1985, Astrophys. J., 296, 481.CrossRefGoogle Scholar
Blitz, L., Israel, F.P., Neugebauer, G., Gatley, I., Lee, T.J. and Beattie, D.H. 1981, Astrophys. J., 249, 76.CrossRefGoogle Scholar
Blitz, L. and Shu, F.H. 1980, Astrophys. J., 238, 148.CrossRefGoogle Scholar
Blitz, L. and Glassgold, A.E. 1982, Astrophys. J., 252, 481.CrossRefGoogle Scholar
Bochkarëv, N.G. 1985, Pis 'ma Astron. Zh., 10, 184 (Sov. Astron. Letts. 10, 76).Google Scholar
Bodifée, G. and de Loore, C. 1985, Astron. Astrophys., 142, 297.Google Scholar
Boesgaard, A.M., Edwards, S. and Heidmann, J. 1982, Astrophys. J., 252, 487.CrossRefGoogle Scholar
Bok, B.J. 1955, Astron. J., 60, 146.CrossRefGoogle Scholar
Bosma, A., Goss, W.M. and Allen, R.J. 1981, Astron. Astrophys., 93, 106.Google Scholar
Bothun, G.D., Romanishin, W., Strom, S.E. and Strom, K.M. 1984, Astron. J., 89, 1300.CrossRefGoogle Scholar
Boulanger, F., Stark, A.A. and Combes, F. 1981, Astron. Astrophys., 93, L1.Google Scholar
Boulanger, F., Bystedt, J., Casoli, F. and Combes, F. 1984, Astron. Astrophys., 140, L5.Google Scholar
Boulesteix, J., Courtès, G., Laval, A., Monnet, G. and Petit, H. 1974, Astron. Astrophys., 37, 33.Google Scholar
Brand, P.W.J.L. and Zealey, W.J. 1975, Astron. Astrophys., 38, 363.Google Scholar
Braunsfurth, E. and Feitzinger, J.V. 1985, Astron. Astrophys., 144, 215.Google Scholar
Brinks, E. and Bajaja, E. 1983, in Internal Kinematics and Dynamics of Galaxies, IAU Symposium No. 100, ed. Athanassoula, E., (Dordrecht: Reidel), p. 139.CrossRefGoogle Scholar
Brosche, P. and Schwan, H. 1984, Mitt. Astron. Ges., 62, 332.Google Scholar
Casini, C. and Heidmann, J. 1976, Astron. Astrophys., 47, 371.Google Scholar
Casoli, F. and Combes, F. 1982, Astron. Astrophys., 110, 287.Google Scholar
Caux, E., Serra, G., Gispert, R., Puget, J.L., Ryter, C. and Coron, N. 1984, Astron. Astrophys., 137, 1.Google Scholar
Caux, E., Puget, J.L., Serra, G., Gispert, R. and Ryter, C. 1985, Astron. Astrophys., 144, 37.Google Scholar
Chance, D., Bally, J. and Elmegreen, B.G. 1986, in preparation.Google Scholar
Chiang, W.H. and Prendergast, K.H. 1985, Astrophys. J., 297, 507.CrossRefGoogle Scholar
Chiosi, C. and Matteuchi, F. 1985, preprint.Google Scholar
Cohen, R.S., Cong, H.I., Dame, T.M. and Thaddeus, P. 1980, Astrophys. J. (Letts.), 239, L53.CrossRefGoogle Scholar
Cohen, R.S., Grabelsky, D.A., Alvarez, H., Bronfman, L., May, J., and Thaddeus, P. 1985, Astrophys. J. (Letts.), 290, L15.CrossRefGoogle Scholar
Combes, F. and Gerin, M. 1985, Astron. Astrophys., 150, 85.Google Scholar
Comins, N.F. 1984, Astrophys. J., 284, 90.CrossRefGoogle Scholar
Comte, G. and Duquennoy, A. 1982, Astron. Astrophys., 114, 7.Google Scholar
Condon, J.J. 1983, Astrophys. J. Suppl., 53, 459.CrossRefGoogle Scholar
Courtès, G. and Dubout-Crillon, R. 1971, Astron. Astrophys., 11, 468.Google Scholar
Courtès, G., Boulesteix, J. and Sivan, J.-P. 1981, Acad. Sci. Paris, 292, Ser. II, 1521.Google Scholar
Cowie, L.L. 1981, Astrophys. J., 245, 66.CrossRefGoogle Scholar
Cowie, L.L., Songaila, A. and York, D.G. 1979, Astrophys. J., 230, 469.CrossRefGoogle Scholar
Cowie, L.L., Hu, E.M., Taylor, W. and York, D.G. 1981, Astrophys. J. (Letts.), 250, L25.CrossRefGoogle Scholar
Cowie, L.L. and Rybicki, G.B. 1982, Astrophys. J., 260, 504.CrossRefGoogle Scholar
Cox, D.P. 1983, Astrophys. J. (Letts.), 265, L61.CrossRefGoogle Scholar
Cox, D.P. 1985, Astrophys. J., 288, 465.CrossRefGoogle Scholar
Dame, T.M., Elmegreen, B.G., Cohen, R.S. and Thaddeus, P. 1986, Astrophys. J., in press.Google Scholar
de Boer, K.S. and Nash, A.G. 1982, Astrophys. J., 255, 447.CrossRefGoogle Scholar
DeGioia-Eastwood, K., Grasdalen, G.L., Strom, S.E. and Strom, K.M. 1984, Astrophys. J., 278, 564.CrossRefGoogle Scholar
Dettmar, R.J., Heidmann, J., Klein, U. and Wielebinski, R. 1984, Astron. Astrophys., 130, 424.Google Scholar
de Vaucouleurs, G., de Vaucouleurs, A. and Corwin, G.G. Jr., 1976, Second Reference Catalog of Bright Galaxies, (Austin: The University of Texas Press).Google Scholar
Diaz, A.J. and Tosi, M. 1984, Monthly Not. Roy. Astron. Soc., 208, 365.CrossRefGoogle Scholar
Dibai, E.A. 1958, Sov. Astron. AJ, 2, 429.Google Scholar
Dickey, J.M. and Benson, J.M. 1982, Astron. J., 87, 278.CrossRefGoogle Scholar
Dixon, M.E. 1968, Monthly Not. Roy. Astron. Soc., 140, 287.CrossRefGoogle Scholar
Dixon, M.E. 1971, Astrophys. J., 164, 411.CrossRefGoogle Scholar
Dixon, K.I., Johnson, P.G. and Songsathaporn, R. 1981, Astrophys. Sp. Sci., 78, 189.CrossRefGoogle Scholar
Dolidze, M.V. 1981, Pis'ma Astron. Zh., 7, 666 (Sov. Astron. Letts., 7, 370).Google Scholar
Donas, J. and Deharveng, J.M. 1984, Astron. Astrophys., 140, 325.Google Scholar
Dopita, M.A. 1985, Astrophys. J. (Letts.), 295, L5.CrossRefGoogle Scholar
Dopita, M.A., Mathewson, D.S. and Ford, V.L. 1985, Astrophys. J., 297, 599.CrossRefGoogle Scholar
Dubout-Crillon, R. 1977, Astron. Astrophys., 56, 293.Google Scholar
Durret, F., Bergeron, J. and Boksenberg, A. 1985, Astron. Astrophys., 143, 347.Google Scholar
Dyson, J.E. 1979, Astron. Astrophys., 73, 132.Google Scholar
Edmunds, M.G. and Pagel, B.E.J. 1984, Monthly Not. Roy. Astron. Soc., 211, 507.CrossRefGoogle Scholar
Efremov, Yu. N. 1970, Astron. Tsirk. No. 579, p.3 Google Scholar
Efremov, Yu. N. 1978, Pis'ma Astron. Zh., 4, 125 (Sov. Astron. Letts. 4, 66).Google Scholar
Efremov, Yu. N. 1979, Pis'ma Astron. Zh., 5, 21 (Sov. Astron. Letts. 5, 12).Google Scholar
Efremov, Yu. N. 1980a, Pis'ma Astron. Zh., 6, 275 (Sov. Astron. Letts. 6, 152).Google Scholar
Efremov, Yu. N. 1980b, Pis'ma Astron. Zh., 6, 333 (Sov. Astron. Letts. 6, 184).Google Scholar
Efremov, Yu. N. 1982a, Pis'ma Astron. Zh., 8, 585 (Sov. Astron. Letts. 8, 314).Google Scholar
Efremov, Yu. N. 1982b, Pis'ma Astron. Zh., 8, 663 (Sov. Astron. Letts. 8, 357).Google Scholar
Efremov, Yu. N. 1985, Pis'ma Astron. Zh., 11, 69 (Sov. Astron. Letts. 11, 169).Google Scholar
Efremov, Yu. N. and Ivanov, G.R. 1982, Astrophys. Sp. Sci., 86, 117.CrossRefGoogle Scholar
Efremov, Yu. N. and Pavlovskaya, E.D. 1982, Pis 'ma Astron. Zh., 8, 9 (Sov. Astron. Letts. 8, 4).Google Scholar
Eggen, O.J. 1965, in Stars and Stellar Systems, Galactic Structure, 5, ed. Blaauw, A. and Schmidt, M. (Chicago: University of Chicago Press), p. 111.Google Scholar
Elmegreen, B.G. 1979, Astrophys. J., 231, 372.CrossRefGoogle Scholar
Elmegreen, B.G. 1982a, Astrophys. J., 253, 655.CrossRefGoogle Scholar
Elmegreen, B.G. 1982b, in Sub-Millimeter Wave Astronomy, ed. Beckman, J.E. and Phillips, J.P. (Cambridge: Cambridge Univ. Press), p. 1.Google Scholar
Elmegreen, B.G. 1983, Monthly Not. Roy. Astron. Soc., 203, 1011.CrossRefGoogle Scholar
Elmegreen, B.G. 1985a, in Birth and Evolution of Massive Stars and Stellar Groups, ed. Boland, W. and van Woerden, H., (Dordrecht: Reidel), p. 227.CrossRefGoogle Scholar
Elmegreen, B.G. 1985b, in Birth and Infancy of Stars, ed. Lucas, R., Omont, A. and Stora, R. (Amsterdam: Elsevier Science Publishers B.V.), p. 215.Google Scholar
Elmegreen, B.G. and Lada, C.J. 1977, Astrophys. J., 214, 725.CrossRefGoogle Scholar
Elmegreen, B.G. and Elmegreen, D.M. 1983a, Astrophys. J., 267, 31.CrossRefGoogle Scholar
Elmegreen, B.G. and Elmegreen, D.M. 1983b, Monthly Not. Roy. Astron. Soc., 203, 31.CrossRefGoogle Scholar
Elmegreen, B.G. and Elmegreen, D.M. 1985, Astrophys. J., 288, 438.CrossRefGoogle Scholar
Elmegreen, B.G. and Elmegreen, D.M. 1986, in preparation, (EE86).Google Scholar
Elmegreen, D.M. 1980, Astrophys. J. Suppl, 43, 37.CrossRefGoogle Scholar
Elmegreen, D.M. 1981, Astrophys. J. Suppl., 47, 229.CrossRefGoogle Scholar
Elmegreen, D.M. and Elmegreen, B.G. 1982, Monthly Not. Roy. Astron. Soc., 201, 1021.CrossRefGoogle Scholar
Elmegreen, D.M. and Elmegreen, B.G. 1984, Astrophys. J. Suppl., 54, 127.CrossRefGoogle Scholar
Elmegreen, D.M. and Elmegreen, B.G. 1986, in preparation.Google Scholar
Emerson, D.T. 1974, Monthly Not. Roy. Astron. Soc., 169, 607.CrossRefGoogle Scholar
Feitzinger, J.V. and Schwerdtfeger, H. 1982, Astron. Astrophys., 116, 117.Google Scholar
Feitzinger, J.V. and Seiden, P.E. 1983, in Internal Kinematics and Dynamics of Galaxies, IAU Symposium No. 100, ed. Athanassoula, E., (Dordrecht: Reidel), p. 137.CrossRefGoogle Scholar
Franco, J. and Shore, S.N. 1984, Astrophys. J., 285, 813.CrossRefGoogle Scholar
Freedman, W.L. and Madore, B.F. 1984, Astrophys. J., 280, 592.CrossRefGoogle Scholar
Freeman, K.C. 1970, Astrophys. J., 160, 811.CrossRefGoogle Scholar
Fukunaga, M. and Tosa, M. 1987, in Star Forming Regions, IAU Symposium No. 115, ed. Peimbert, M. and Jugaku, J. (Dordrecht: Reidel).Google Scholar
Gallagher, J.S. and Hunter, D.A. 1983, Astrophys. J., 274, 141.CrossRefGoogle Scholar
Gallagher, J.S. and Hunter, D.A. 1984, Ann. Rev. Astron. Astrophys., 22, 37.CrossRefGoogle Scholar
Gehrz, R.D., Sramek, R.A. and Weedman, D.W. 1983, Astrophys. J., 267, 551.CrossRefGoogle Scholar
Geller, M. and Huchra, J. 1983, Astrophys. J. Suppl., 52, 61.CrossRefGoogle Scholar
Georgelin, Y.M. and Georgelin, Y.P. 1916, Astron. Astrophys., 49, 57.Google Scholar
Gerola, H. and Seiden, P.E. 1978, Astrophys. J., 223, 129.CrossRefGoogle Scholar
Gerola, H. and Seiden, P.E. 1979, in Photometry, Kinematics and Dynamics of Galaxies, ed. Evans, D.S., (Austin: The University of Texas Press), p. 475.Google Scholar
Gerola, H., Seiden, P.E. and Schulman, L.S. 1980, Astrophys. J., 242, 517.CrossRefGoogle Scholar
Goldreich, P. and Lynden-Bell, D. 1965, Monthly Not. Roy. Astron. Soc., 130, 97.CrossRefGoogle Scholar
Gosachinskij, I.V. and Khersonskij, V.K. 1982, Astron. Zh., 59, 237 (Sov. Astron., 26, 146).Google Scholar
Grabelsky, D.A. 1985, Ph.D. Dissertation, Columbia University.Google Scholar
Grosb⊘l, P.J. 1977, Astron. Astrophys., 57, 461.Google Scholar
Gum, C.S. and de Vaucouleurs, G. 1953, Observatory, 73, 152.Google Scholar
Güsten, R. and Mezger, P.G. 1983, Vistas Astron., 26, 159.CrossRefGoogle Scholar
Hamajima, K. and Tosa, M. 1975, Pub. Astron. Soc. Japan, 27, 561.Google Scholar
Hausman, M.A. and Roberts, W.W. Jr. 1984, Astrophys. J., 282, 106.CrossRefGoogle Scholar
Hayward, R. 1964, Pub. Astron. Soc. Pacific, 76, 35.CrossRefGoogle Scholar
Heidmann, J. 1983, Highlights of Astronomy, 6, 609.CrossRefGoogle Scholar
Heiles, C. 1979, Astrophys. J., 229, 533.CrossRefGoogle Scholar
Henderson, A.P., Jackson, P.D. and Kerr, F.J. 1982, Astrophys. J., 263, 116.CrossRefGoogle Scholar
Herbst, W. and Assousa, G.E. 1977, Astrophys. J., 217, 473.CrossRefGoogle Scholar
Hilton, J.L. and Bash, F. 1982, Astrophys. J., 255, 217.CrossRefGoogle Scholar
Hindman, J.V. 1967, Aust. J. Phys., 20, 147.CrossRefGoogle Scholar
Hippelein, H. and Fried, J.W. 1984, Astron. Astrophys., 141, 49.Google Scholar
Hodge, P.W. 1967, Pub. Astron. Soc. Pacific, 79, 29.CrossRefGoogle Scholar
Hubble, E.P. 1936, Astrophys. J., 84, 158.CrossRefGoogle Scholar
Huchra, J. and Geller, M. 1982, Astrophys. J., 257, 423.CrossRefGoogle Scholar
Hughes, V.A. and Routledge, D. 1972, Astron. J., 77, 210.CrossRefGoogle Scholar
Humason, M.L., Mayall, N.V. and Sandage, A.R. 1956, Astron. J., 61, 97.CrossRefGoogle Scholar
Humphreys, R.M. and Sandage, A. 1980, Astrophys. J. Suppl., 44, 319.CrossRefGoogle Scholar
Hunter, D. 1982, Astrophys. J., 260, 81.CrossRefGoogle Scholar
Hunter, J.H. Jr. and Horak, T. 1983, Astrophys. J., 265, 402.CrossRefGoogle Scholar
Ichikawa, T., Nakano, M., Tanaka, Y.D., Saito, M., Nakai, N., Sofue, Y. and Kaifu, N. 1985, Pub. Astron. Soc. Japan, 37, 439.Google Scholar
Ichikawa, T., Nakano, M. and Tanaka, Y.D. 1987, in IAU Sympoisium No. 115, Star Forming Regions, ed. Peimbert, M. and Jugaku, J. (Dordrecht: Reidel).Google Scholar
Ikeuchi, S., Habe, A. and Tanaka, K. 1984, Monthly Not. Roy. Astron. Soc., 207, 909.CrossRefGoogle Scholar
Israel, F. 1980, Astron. Astrophys., 90, 246.Google Scholar
Israel, F.P., Goss, W.M. and Allen, R.J. 1975, Astron. Astrophys., 40, 421.Google Scholar
Jensen, E.B. 1977, Ph.D. Dissertation, University of Arizona.Google Scholar
Jensen, E.B., Strom, K. and Strom, S.E. 1976, Astrophys. J., 209, 748.CrossRefGoogle Scholar
Jog, C. and Solomon, P.M. 1984, Astrophys. J., 276, 114.CrossRefGoogle Scholar
Jura, M. 1976, Astron. J., 81, 178.CrossRefGoogle Scholar
Kalnajs, A.J. 1972, Astrophys. Letts., 11, 41.Google Scholar
Kalnajs, A.J. 1978, in IAU Symposium No. 77, Structure and Properties of Nearby Galaxies, ed. Berkhuijsen, E.M. and Weilebinski, R. (Dordrecht: Reidel), p. 113.CrossRefGoogle Scholar
Kaufman, M. 1981, Astrophys. J., 250, 534.CrossRefGoogle Scholar
Kennicutt, R.C. 1983, Astrophys. J., 272, 54.CrossRefGoogle Scholar
Kennicutt, R.C. 1984, Astrophys. J., 287, 116.CrossRefGoogle Scholar
Kennicutt, R.C. and Hodge, P.W. 1980, Astrophys. J., 241, 573.CrossRefGoogle Scholar
Kennicutt, R.C. and Hodge, P.W. 1982, Astrophys. J., 253, 101.CrossRefGoogle Scholar
Kennicutt, R.C. and Hodge, P.W. 1984, Pub. Astron. Soc. Pac., 96, 944.CrossRefGoogle Scholar
Kennicutt, R.C. and Edgar, B.K. 1986, Astrophys. J., 300, in press.CrossRefGoogle Scholar
Kevanishvili, G. Th. 1969, Byull. Abastumansk. Astrofiz. Obs., No. 37, 117.Google Scholar
Kevanishvili, G. Th. 1975, Byull. Abastumansk. Astrofiz. Obs., No. 46, 101.Google Scholar
Khachikian, E. Ye. 1984, Astronomy with Schmidt-type Telescopes, ed. Capaccioli, M., (Dordrecht: Reidel), p. 427.CrossRefGoogle Scholar
Kulkarni, S.R. 1983, Ph.D. Dissertation, University of California at Berkeley.Google Scholar
Kwan, J. and Valdes, F. 1983, Astrophys. J., 271, 604.CrossRefGoogle Scholar
Lacey, C.G. and Fall, S.M. 1985, Astrophys. J., 290, 154.CrossRefGoogle Scholar
Larson, R.B. 1980, Phil. Trans. Roy. Soc. London, Ser. A, 269, 299.Google Scholar
Larson, R.B. 1982, Monthly Not. Roy. Astron. Soc., 200, 159.CrossRefGoogle Scholar
Lattanzio, J.L., Monaghan, J.J., Pongracic, H. and Schwarz, M.P. 1985, Monthly Not. Roy. Astron. Soc., 215, 125.CrossRefGoogle Scholar
Latyshev, I.N. 1980, Astron. Tsirk., 1141, 7.Google Scholar
Lesh, J.R. 1968, Astrophys. J. Suppl., 17, 371.CrossRefGoogle Scholar
Liebovitch, L.S. and Lin, C.C. 1978, Bull. American Astron. Soc., 9, 639.Google Scholar
Lin, C.C. and Shu, F.H. 1964, Astrophys. J., 140, 646.CrossRefGoogle Scholar
Lin, C.C. and Shu, F.H. 1967, in Radio Astronomy and the Galactic System, IAU Symposium No. 31, ed. van Woerden, H., (London: Academic Press), p. 313.Google Scholar
Lin, C.C. 1968, in Galaxies and the Universe, ed. Woltjer, L., (New York: Columbia University Press), p. 33.Google Scholar
Lindblad, P.O. 1967, Bull. Astron. Inst. Neth., 19, 34.Google Scholar
Lindblad, P.O., Grope, K., Sandqvist, Aa. and Schober, J. 1973, Astron. Astrophys., 24, 309.Google Scholar
Linke, R.A. 1982, in Extragalactic Molecules, ed. Blitz, L. and Kutner, M. (Green Bank: NRAO Publications Office), p. 87.Google Scholar
Loose, H.H. and Fricke, K. 1982a, Mitt. Astron. Ges., 55, 100.Google Scholar
Loose, H.H. and Fricke, K. 1982b, in The Most Massive Stars, ESO Workshop, Garching, p. 269.Google Scholar
Loose, H.H., Krügel, E. and Tutukov, A. 1982, Astron. Astrophys., 105, 342.Google Scholar
Lortet, M.C., Testor, G., Heydari-Malayeri, M. and Niemela, V. 1987, in Star Forming Regions, IAU Symposium No. 115, ed. Peimbert, M. and Jugaku, J. (Dordrecht: Reidel).Google Scholar
Lynden-Bell, D. 1966, Observatory, 86, 57.Google Scholar
Lyngå, G. and Wramdemark, S. 1984, Astron. Astrophys., 132, 58.Google Scholar
Mathewson, D.S., van der Kruit, P.C. and Brouw, W.N. 1972, Astron. Astrophys., 17, 468.Google Scholar
McCall, M.L. 1982, Ph.D. Dissertation, University of Texas, Publ. in Astronomy No. 20.Google Scholar
McGee, R.X. and Milton, J.A. 1964, Austral. J. Phys., 17, 128.CrossRefGoogle Scholar
McGee, R.X. and Milton, J.A. 1966, Austral. J. Phys., 19, 343.Google Scholar
Meaburn, J. 1980, Monthly Not. Roy. Astron. Soc., 192, 365.CrossRefGoogle Scholar
Melnick, J., Moles, M. and Terlevich, R. 1985, Astron. Astrophys., 149, L24.Google Scholar
Mezger, P.G. 1970, in The Spiral Structure of the Galaxy, IAU Symposium No. 38, ed. Becker, W. and Contopoulos, G. (Dordrecht: Reidel), p. 107.CrossRefGoogle Scholar
Moffat, A.F.J., Seggewiss, W. and Shara, M.M. 1985, Astrophys. J., 295, 109.CrossRefGoogle Scholar
Moore, J.H. and FitzGerald, P.M. 1973, J. Roy. Astron. Soc. Canada, 67, 291.Google Scholar
Morgan, W.W., Sharpless, S. and Osterbrock, D. 1952, Astron. J., 57, 3.CrossRefGoogle Scholar
Morgan, W.W., Whitford, A.E. and Code, A.D. 1953, Astrophys. J., 118, 318.CrossRefGoogle Scholar
Morozov, A.G. 1985, Astron. Zh., 62, 209 (Soviet Astron., 29, 120).Google Scholar
Mountain, C.M., Hawarden, T.G., Joseph, R.D., Leggett, S.K. 1987, in Star Forming Regions, IAU Symposium No. 115, ed. Peimbert, M. and Jugaku, J. (Dordrecht: Reidel).Google Scholar
Mouschovias, T. Ch., Shu, F.H. and Woodward, P. 1974, Astron. Astrophys., 33, 73.Google Scholar
Mueller, M.W. and Arnett, W.D. 1976, Astrophys. J., 210, 670.CrossRefGoogle Scholar
Myers, P.C., Dame, T.M., Thaddeus, P., Cohen, R.S., Silverberg, R.F., Dwek, E. and Hauser, M.G. 1986, Astrophys. J., 301, in press.CrossRefGoogle Scholar
Nepveu, M. and Robnik, M. 1984, Astron. Astrophys., 138, 201.Google Scholar
Newton, K. 1980a, Monthly Not. Roy. Astron. Soc., 190, 689.CrossRefGoogle Scholar
Newton, K. 1980b, Monthly Not. Roy. Astron. Soc., 191, 615.CrossRefGoogle Scholar
Nozakura, T. and Ikeuchi, S. 1984, Astrophys. J., 279, 40.CrossRefGoogle Scholar
Ögelman, H.B. and Maran, S.P. 1916, Astrophys. J., 209, 124.CrossRefGoogle Scholar
Olano, C.A. 1982, Astron. Astrophys., 112, 195.Google Scholar
Ondrechen, M.P. 1985, Astron. J., 90, 1474.CrossRefGoogle Scholar
Oort, J.H. 1954, Bull. Astron. Inst. Neth., 12, 177.Google Scholar
Oort, J.H. 1962, in Interstellar Matter in Galaxies, ed. Woltjer, L., (New York: Benjamin), p. 234.Google Scholar
Öpik, E.J. 1953, Irish Astron. J., 2, 219.Google Scholar
Page, T. and Carruthers, G.R. 1981, Astrophys. J., 248, 906.CrossRefGoogle Scholar
Pagel, B.E.J. and Edmunds, M.G. 1981, Ann. Rev. Astron. Astrophys., 19, 77.CrossRefGoogle Scholar
Pellet, A., Astier, N., Viale, A., Courtès, G., Maucherat, A., Monnet, G., Simien, F. 1978, Astron. Astrophys. Suppl., 31, 439.Google Scholar
Pérault, M., Falgarone, E. and Puget, J.L. 1985, Astron. Astrophys., 152, 371.Google Scholar
Persi, P., Tapia, M., Roth, M. and Ferrari-Toniolo, M. 1985, Astron. Astrophys., 144, 275.Google Scholar
Petrosyan, A.R., Saakyan, K.A., Khachikyan, Eh.E. 1984a, Astrofizika, 19, 619 (Astrophys., 19, No. 4).Google Scholar
Petrosyan, A.R., Saakyan, K.A., Khachikyan, Eh.E. 1984b, Astrofizika, 20, 51 (Astrophys., 20, No. 1).Google Scholar
Petrosyan, A.R., Saakyan, K.A., Khachikyan, Eh.E. 1984c, Astrofizika, 21, 57 (Astrophys., 21, No. 1).Google Scholar
Phillips, S. and Disney, M. 1985, preprint.Google Scholar
Pikel'ner, S.B. 1970, Astron. Zh. Akad. Nauk SSSR, 47, 752 (Sov. Astron. AJ 14, No.4).Google Scholar
Pismis, P. and Hasse, I. 1982, Rev. Mex. Astron. Astrophys., 5, 161.Google Scholar
Quiroga, R.J. and Schlosser, W. 1977, Astron. Astrophys., 57, 455.Google Scholar
Roberts, W.W. Jr. 1969, Astrophys. J., 158, 123.CrossRefGoogle Scholar
Roberts, W.W. Jr. and Yuan, C. 1970, Astrophys. J., 161, 877.CrossRefGoogle Scholar
Roberts, W.W. Jr. and Shu, F.H. 1972, Astrophys. Letts., 12, 43.Google Scholar
Roberts, W.W. Jr., Roberts, M.S. and Shu, F.H. 1975, Astrophys. J., 196, 381.CrossRefGoogle Scholar
Roberts, W.W. Jr. and Hausman, M.A. 1984, Astrophys. J., 277, 744.CrossRefGoogle Scholar
Romanishin, W. 1985, Astrophys. J., 289, 570.CrossRefGoogle Scholar
Rosa, M. and Solf, J. 1984, Astron. Astrophys., 130, 29.Google Scholar
Rosa, M., Joubert, M. and Benvenuti, P. 1984, Astron. Astrophys. Suppl., 57, 361.Google Scholar
Rots, A.H. 1975, Astron. Astrophys., 45, 43.Google Scholar
Rumstay, K.S. and Kaufman, M. 1983, Astrophys. J., 274, 611.CrossRefGoogle Scholar
Safronov, V.S. 1960, Ann.d' Astrophys., 23, 979.Google Scholar
Sandage, A. 1961, The Hubble Atlas of Galaxies, (Washington: The Carnegie Institute of Washington).Google Scholar
Sandage, A. and Tammann, G.A. 1981, A Revised Shapley Ames Catalog of Galaxies, (Washington: Carnegie Institute of Washington).Google Scholar
Sandage, A., Binggeli, B. and Tammann, G.A. 1985, Astron. J., 90, 395.CrossRefGoogle Scholar
Sanders, R.H. and Huntley, J.M. 1976, Astrophys. J., 209, 53.CrossRefGoogle Scholar
Sanders, R.H. and Tubbs, A.D. 1980, Astrophys. J., 235, 803.CrossRefGoogle Scholar
Sanz Fernández de Córdoba, L. and Benvenuti, P. 1984, ESA Special Pub. ESA SP-218, p. 73.Google Scholar
Sargent, W.L.W. and Searle, L. 1970, Astrophys. J. (Letts.), 162, L155.CrossRefGoogle Scholar
Schlosser, W. and Görnandt, V. 1984, Astron. Astrophys., 137, 287.Google Scholar
Schlosser, W. and Musculus, D. 1984, Astron. Astrophys., 131, 367.Google Scholar
Schmidt, M. 1959, Astrophys. J., 129, 243.CrossRefGoogle Scholar
Schmidt-Kaler, Th. and Schlosser, W. 1973, Astron. Astrophys., 25, 191.Google Scholar
Schweizer, F. 1976, Astrophys. J. Suppl., 31, 313.CrossRefGoogle Scholar
Scoville, N. and Young, J.S. 1983, Astrophys. J., 265, 148.CrossRefGoogle Scholar
Seiden, P.E. 1983, Astrophys. J., 266, 555.CrossRefGoogle Scholar
Seiden, P.E. and Gerola, H. 1979, Astrophys. J., 233, 56.CrossRefGoogle Scholar
Seiden, P.E., Schulman, L.S. and Gerola, H. 1979, Astrophys. J., 232, 702.CrossRefGoogle Scholar
Seiden, P.E. and Gerola, H. 1982, Fundamentals of Cosmic Physics, 7, 241.Google Scholar
Seiden, P.E., Schulman, L.S. and Feitzinger, J.V. 1982, Astrophys. J., 253, 91.CrossRefGoogle Scholar
Seiden, P.E., Schulman, L.S. and Elmegreen, B.G. 1984, Astrophys. J., 282, 95.CrossRefGoogle Scholar
Sellwood, J.A. and Carlberg, R.G. 1984, Astrophys. J., 282, 61.CrossRefGoogle Scholar
Shahbazian, R.K. 1968, Astrofizika, 4, 273.Google Scholar
Shahbazian, R.K. 1970, Astrofizika, 6, 367.Google Scholar
Shevchenko, V.S. 1979, Astron. Zh., 56, 279 (Sov. Astron. AJ. 23, 163).Google Scholar
Shevchenko, V.S. 1980, Astron. Zh., 57, 1162 (Sov. Astron. AJ. 24, 670).Google Scholar
Shore, S.N. 1981, Astrophys. J., 249, 93.CrossRefGoogle Scholar
Shore, S.N. 1983, Astrophys. J., 265, 202.CrossRefGoogle Scholar
Shu, F.H., Stachnik, R.V. and Yost, J.C. 1911, Astrophys. J., 166, 465.CrossRefGoogle Scholar
Shu, F.H., Milione, V., Gebel, W., Yuan, C., Goldsmith, D.W. and Roberts, W.W. Jr. 1972, Astrophys. J., 173, 557.CrossRefGoogle Scholar
Skillman, E.D. 1985, Astrophys. J., 290, 449.CrossRefGoogle Scholar
Skillman, E.D. and Balick, B. 1984, Astrophys. J., 280, 580.CrossRefGoogle Scholar
Smith, G., Elmegreen, B.G. and Elmegreen, D.M. 1984, Monthly Not. Roy. Astron. Soc., 210, 399.CrossRefGoogle Scholar
Solomon, P. 1983, in Internal Kinematics and Dynamics of Galaxies, IAU Symposium No. 100, ed. Athanassoula, E., (Dordrecht: Reidel), p. 35.CrossRefGoogle Scholar
Solomon, P.M. and Sanders, D.B. 1980, in Giant Molecular Clouds in the Galaxy, eds. Solomon, P.M. and Edmunds, M.G., (New York: Pergamon), p. 41.CrossRefGoogle Scholar
Solomon, P., Sanders, D.B. and Rivolo, A.R. 1984, Astrophys. J. (Letts.), 292, L19.CrossRefGoogle Scholar
Stal'bovskii, O.I. and Shevchenko, V.S. 1981, Astron. Zh., 58, 45 (Sov. Astron. AJ. 25, 25).Google Scholar
Stark, A.A. 1979, Ph.D. Dissertation, Princeton University.Google Scholar
Stark, A.A. 1985, in The Milky Way Galaxy, IAU Symp. No. 106, ed. van Woerden, H., Allen, R.J. and Burton, W.B., (Dordrecht: Reidel), p. 445.CrossRefGoogle Scholar
Stark, A.A. and Blitz, L. 1978, Astrophys. J. (Letts.), 225, L15.CrossRefGoogle Scholar
Stone, M.E. 1970, Astrophys. J., 159, 293.CrossRefGoogle Scholar
Stothers, R. and Frogel, J.A. 1974, Astron. J., 79, 456.CrossRefGoogle Scholar
Strom, S.E. 1980, Astrophys. J., 237, 686.CrossRefGoogle Scholar
Strom, S., Jensen, E. and Strom, K. 1976, Astrophys. J. (Letts.), 206, L11.CrossRefGoogle Scholar
Struck-Marcell, C. and Scalo, J.M. 1984, Astrophys. J., 277, 132.CrossRefGoogle Scholar
Talbot, R.J. Jr. 1980, Astrophys. J., 235, 821.CrossRefGoogle Scholar
Talbot, R.J. Jr. and Arnett, W.D. 1975, Astrophys. J., 197, 551.CrossRefGoogle Scholar
Talbot, R.J. Jr., Jensen, E.B. and Dufour, R.J. 1979, Astrophys. J., 229, 91.CrossRefGoogle Scholar
Telesco, C.M. 1984, in Occasional Reports Roy. Obs. Edinburgh, Proceedings of the Workshop on Star Formation, ed. Wolstencroft, R.D., No. 13.Google Scholar
Terlevich, R. 1984, Observatory, 104, 59.Google Scholar
Terlevich, R. and Melnick, J. 1981, Monthly Not. Roy. Astron. Soc., 195, 839.CrossRefGoogle Scholar
Tomisaka, K. 1984, Publ. Astron. Soc. Japan, 36, 457.Google Scholar
Tomisaka, K. 1985, preprint.Google Scholar
Tomisaka, K., Habe, A. and Ikeuchi, S. 1981, Astrophys. Sp. Sci., 78, 273.CrossRefGoogle Scholar
Toomre, A. 1964, Astrophys. J., 139, 1217.CrossRefGoogle Scholar
Toomre, A. 1981, in The Structure and Evolution of Normal Galaxies, ed. Fall, S.M. and Lynden-Bell, D. (Cambridge: Cambridge Univ. Press), p. 111.Google Scholar
Turner, E.L. 1976, Astrophys. J., 208, 20.CrossRefGoogle Scholar
Turner, E.L. and Gott, J.R. 1976, Astrophys. J. Suppl., 32, 409.CrossRefGoogle Scholar
Unwin, S.C. 1980a, Monthly Not. Roy. Astron. Soc., 190, 551.CrossRefGoogle Scholar
Unwin, S.C. 1980b, Monthly Not. Roy. Astron. Soc., 192, 243.CrossRefGoogle Scholar
van Albada, G.D. 1980, Astron. Astrophys., 90, 123.Google Scholar
van den Bergh, S. 1960, Astrophys. J., 131, 215.CrossRefGoogle Scholar
Venger, A.P., Gosachinskij, I.V., Grachev, V.G., Egorova, T.M., Ryzhkov, N.F. and Khersonskij, V.K. 1984, Astrophys. Sp. Sci., 107, 271.CrossRefGoogle Scholar
Viallefond, F., Allen, R.J. and Goss, W.M. 1981, Astron. Astrophys., 104, 127.Google Scholar
Viallefond, F., Goss, W.M. and Allen, R.J. 1982, Astron. Astrophys., 115, 373.Google Scholar
Viallefond, F., Donas, J. and Goss, W.M. 1983, Astron. Astrophys., 119, 185.Google Scholar
Wakamatsu, K. and Nishida, M.T. 1980, Pub. Astron. Soc. Japan, 32, 389.Google Scholar
Weaver, H. 1979, in Large Scale Characteristics of the Galaxy, IAU Symposium No. 84, ed. Burton, W.B., (Dordrecht: Reidel), p. 295.CrossRefGoogle Scholar
Weedman, D.W., Feldman, F.R., Balzano, V.A., Ramsey, L.W., Sramek, R.A. and Wu, C.C. 1981, Astrophys. J., 248, 105.CrossRefGoogle Scholar
Westerlund, B.E. and Mathewson, D.S. 1966, Monthly Not. Roy. Astron. Soc., 131, 371.CrossRefGoogle Scholar
Wevers, B.M.H.R. 1984, Ph.D. Dissertation, Groningen.Google Scholar
Woltjer, L. 1965, in Stars and Stellar Systems, Galactic Structure, 5, ed. Blaauw, A. and Schmidt, M. (Chicago: University of Chicago Press), p. 531.Google Scholar
Woodward, P.R. 1976, Astrophys. J., 207, 484.CrossRefGoogle Scholar
Wouterloot, J. 1981, Ph.D. Dissertation, Leiden.Google Scholar
Wray, J.D. and de Vaucouleurs, G. 1980, Astron. J., 85, 1.CrossRefGoogle Scholar
Wright, M.C.H. 1971, Astrophys. J., 166, 455.CrossRefGoogle Scholar
Wynn-Williams, C.G. and Becklin, E.E. 1985, Astrophys. J., 290, 108.CrossRefGoogle Scholar
Young, J.S. and Scoville, N. 1982a, Astrophys. J., 258, 467.CrossRefGoogle Scholar
Young, J.S. and Scoville, N. 1982b, Astrophys. J. (Letts.), 260, L11.CrossRefGoogle Scholar
Yuan, C. and Grosb⊘l, P.J. 1981, Astrophys. J., 243, 432.CrossRefGoogle Scholar