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Table of contents

Slide 1

Astro 10-Lecture 11: Other Galaxies and the Expanding Universe

1920: The Shapley-Curtis Debate

1920: The Shapley-Curtis Debate The Evidence

Slide 5

Late 1920s: The answer at last

Types of Galaxies

Spiral Galaxies

Elliptical Galaxies

Irregular and Peculiar Galaxies

Classification of Galaxies


Properties of Galaxies

Another look at the Virgo Cluster

Interacting Galaxies

Slide 16

Interacting Galaxies Is this how elliptical galaxies form?

cD Galaxies: Cluster Cannibals

How did spiral galaxies form?

Active Galactic Nuclei (AGN)

Active Galactic Nuclei (AGN) Jets

Active Galactic Nuclei (AGN) Radio Lobes

Active Galactic Nuclei (AGN) Bright Blue Nuclei & Emission Line Regions

Active Galactic Nuclei (AGN) Quasars & QSOs (Quasi-Stellar Objects)

Active Galactic Nuclei (AGN) Quasars & QSOs

So what is an AGN?

How do we figure out properties of galaxies?

Rule 1: If we don’t know the distance we don’t know anything.

Concept Test

How do we get the distances to farther galaxies?

“Standard Candles”

Slide 32

Now that we know the distance we can determine size,luminosity, mass,

Dark Matter: Clusters of Galaxies

Dark Matter: Gravitational Lensing

The Expanding Universe

Cosmological Red Shift

Slide 38

Slide 39

Slide 40

What does it mean?

Galaxy Evolution

Hubble Deep Field

What do we see?

Author: Eric Korpela

E-mail: korpela at


Further information:
For the educational use of the Vista Astro 10 class only