ISP 205 Lecture Notes - Lecture 12: Spiral Galaxy, Galaxy Formation And Evolution, Molecular Cloud
3 Sep 2018
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Week 12: our milky way and other galaxies, ch. Infrared light passes more easily though dusty gas clouds which absorb visible light gas=interstellar medium. Stars orbit same direction; little up and down motion, orbits of stars in bulge and halo random orientation, halo star orbit-green, bulge star orbit-red, disk star orbit-yellow. Star gas star cycle; atomic hydrogen clouds, molecular cloud, star formation, nuclear fusion in stars, returning gas, hot bubbles. Halo-no ionization nebulae or blue stars=no star formation. Spiral: groups, spiral arms, flat white disks with yellowish bulge centers. Elliptical: clusters, redder and rounder elongated like football, older star population. Outside view=bulge-center; halo-outside colors; disk-colors, inside spiral arms but before bulge edge-on=disk-flat; bulge-bulge; halo-outside. Different colors; can see different things happening using x rays, visible light, radio, infrared than if only studied with visible light or only one these like infrared or radio or x- rays.
