ASTRO-110 Lecture Notes - Lecture 14: Barred Spiral Galaxy, Elliptical Galaxy, Spiral Galaxy
18 Sep 2020
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Document Summary
We study the life cycles of galaxies the same way we do stars. This is more difficult than for stars. Observe many different galaxies at various stages of their lives. Young galaxies are only found at great distances. The sizes of all three span a wide range from dwarf galaxies (contain 100 million stars) to giant galaxies (contain 1 trillion stars) Have a disk component and bulge & halo (spheroidal component) Disk contains an ism of gas & dust. Relative sizes of bulge disk & amount of ism vary among galaxies. White light due to combination of blue & red stars. Some spiral galaxies have a bar of stars cutting through their center. Spiral arms are attached to the ends of bars. The milky way is probably a barred galaxies. Solid body rotation near center of galaxy. Only have a spheroidal component no disk component. Usually appear reddish because they contain mostly red stars.
