AST201H1 Lecture Notes - Lecture 7: Orbital Speed, Edwin Hubble, Blueshift

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Marija Stankovic

Document Summary

Flat, white disks with yellowish bulges in the center. Disks are filled with cool gas and dust. Well-developed spiral arms which line a disk, older stars. Look white because they contain stars of different colours and ages. The rotation curve is flat because gas clouds orbiting far from the galactic center have approx. the same orbital speed as gas clouds located further inward. 3 dimensional, egg shaped/circular or oval, redder because most of their light is from old, red stars. Low mass stars, little gas, mainly made out of light. Dead and red stars, no ongoing star formation. Lack a significant disk component, come in a wide range of sizes but mostly small (most. Compared to spiral galaxies they contain very little cool gas and dust, though they are very hot and have ionized gas. No specific shape, result of an interaction of larger galaxies, galactic winds.