density wave theory | has implication the density waves rotate more slowly than the galaxy's stars and gas | ![has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:34:02.0 has source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:34:02.0](facet.gif) |
has author Lindblad (1925) | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:34:03.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:34:03.0](facet.gif) |
has definition Spiral structure is modelled as a small-amplitude wave propagating with fixed angular velocity, as the compression wave goes through, it triggers star formation on the leading edge of the spiral arms. | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:34:02.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:34:02.0](facet.gif) |
is a kind of galaxy theory | ![2001-09-27 09:34:02.0 2001-09-27 09:34:02.0](facet.gif) |
galaxy theory | has domain extragalactic astronomy | ![2001-09-27 09:34:02.0 2001-09-27 09:34:02.0](facet.gif) |
theory | has validity correct or incorrect with caveats | ![2001-09-27 09:33:53.0 2001-09-27 09:33:53.0](facet.gif) |
has date or a range of dates for which the theory was active | ![2001-09-27 09:33:53.0 2001-09-27 09:33:53.0](facet.gif) |