1. GALAXIES
Pages

2. Galaxies
Def: large scale groups of stars (approx. 100 billion) bound by gravitational attraction
Also contain nebulae and solar systems

3. Milky Way Structure Barred spiral galaxy
About 100,000 light-years wide
Sun is 30,000 light-years from the center
Rotates every 200 million years around “galactic center”

4. Milky Way

5. Face-on view of the Milk Way Galaxy

6. Edge-on view of the Milk Way Galaxy

7. Andromeda (M31)
A large galaxy neighbor
2,900,000 ly

8. Elliptical(60%)- old stars Irregular (10%)- young stars
Types of Galaxies
Spiral (30%)
Barred Spiral
Elliptical(60%)- old stars
Irregular (10%)- young stars

9. NCG 6946

10. A barred spiral galaxy

11. Elliptical galaxy

12. Irregular galaxy

13. Nearest galaxy 150,000 ly
Small Magellanic Cloud

14. Large Magellanic cloud
LMC

15. M104 (The Sombrero Galaxy)

16. Hubble’s Law
Galaxies are receding at a speed proportional to their distance
Farther galaxies are moving faster than nearby galaxies

18. Raisin bread analogy of an expanding universe

19. What would cause this? EXPANDING UNIVERSE!
Cosmological red shift- supports this

20. Is the center of every galaxy a supermassive black hole?

21. Chandra image Jan. 2008 Centaurus A
Evidence
of spinning

22. NGC 3384
M105

23. Hubble deep field

24. Merger of two Spirals to form an Elliptical

25. Colliding galaxies movie

26. Local group Local Group Milky way and nearest galaxies
Contains at least 28 galaxies

27. AMAZING FACT
Our known Universe contains at least 1,000,000 billions ( Thats One Million, Billions) of other Galaxies...like our own Milky Way. There is no doubt that there are other vast Universes in existence on top of our Universe

28. LARGEST TO SMALLEST
UNIVERSE
LOCAL GROUPS
GALAXIES
SOLAR SYTEMS

29. Power of Ten

30. Galaxy Song from Monty Python