|Last: 12. Structure of the Milky Way||Next: 14. The Big Bang|
Several galaxies are shown in this image; the largest, just left of center, is a giant elliptical galaxy in the Coma galaxy cluster. The spiral galaxy on the right is also a member of Coma. The smaller galaxies elsewhere in the image are all much further away.
This is a disk galaxy with a large bulge. The disk contains both stars and dusty gas clouds; note how the disk is silhouetted against the luminous bulge.
This beautiful image shows a spiral galaxy with a large disk and a small central bulge. The outer disk is rich in gas and young stars and fairly blue. Closer to the center of the galaxy, the light from older stars dominates, giving these regions a yellowish tint.
This small irregular galaxy is a member of the Local Group. It contains several regions of ongoing star formation.
This is a compact group of spiral and elliptical galaxies. While groups of galaxies are common, only a small fraction are as compact as the one shown here.
The Hercules cluster is unusually rich in spiral galaxies. A number of interacting galaxies are visible in this image.
This animation shows a trip through the Local Supercluster, a region about 80 Mpc in diameter containing a number of galaxy clusters.
This image shows regions of high galaxy density. The box is about 400 Mpc across.
These fan-shaped surveys reveal the foam-like texture of the galaxy distribution. The Milky Way is at the point where the two fans meet; each fan extends to a distance of about 800 Mpc.
Computer simulation showing how the collision of two disk galaxies could create the famous `Antennae Galaxies'.
Further computer simulations of galactic collisions.
Homework 13: Testing Hubble's Law, due 11/24.
Quiz 13: What Kinds Of Galaxies?