AST201H1 Chapter Notes - Chapter 21: Elliptical Galaxy, Lenticular Galaxy, Spiral Galaxy

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

The angular momentum of a protogalactic cloud may determine whether it ends up spiral or elliptical. A protogalactic cloud that starts with little or no angular momentum may end up as an elliptical galaxy. A protogalactic cloud with more angular momentum spins faster as it contracts ending up as a spiral galaxy. The density of a protogalactic cloud may determine whether it ends up spiral or elliptical. A dense protogalactic cloud may form its stars before it settles into a disk . and ends up as an elliptical galaxy. Gas in a less dense protogalactic cloud forms stars more slowly and settles into a disk ending up as a spiral galaxy. All the stars in these elliptical galaxies formed almost simultaneously and very early in the history of the universe, which in consistent with the idea that all the stars formed before a disk could develop.