1. Galaxies
Island Universes

2. Copyright – Adam Block, KPNO

3. Hubble Tuning Fork

4. Ellipticals

5. Ellipticals Huge No gas. No dust. No young stars.
Nothing but old stars.
Random orbits.

6. M 87 Copyright – Anglo-Australian Telescope Board
Copyright - HST

7. Hubble Tuning Fork

8. Copyright – Adam Block, KPNO

9. Spirals

10. Spirals Like Milky Way Disks and bulge. Young stars and old.
Gas and dust.
Stars forming.
Stars dying.
M81 and M82 – Copyright R. Gendler

11. M63 Copyright – S. Miyazaki, Suburu

12. NGC1365 Copyright – VLT

13. M31 The Andromeda Galaxy Copyright – Jason Ware
Copyright – S. Miyazaki, Suburu
M31 The Andromeda Galaxy Copyright – Jason Ware

14. M33 – Copyright NOAO

15. John P. Gleason
M51 - Copyright HST

16. NGC 4314

17. NGC 891 – Copyright WIYN
NGC 891 – Copyright J.C. Barentine, NOAO

18. Sombrero Galaxy – Copyright P. Barthel VLT
M10 – copyright Credner and Kohle
Sombrero Galaxy – Copyright P. Barthel VLT

19. NGC 4526

20. Irregulars

21. Groups

22. The Local Group

23. Clusters

24. The Virgo Cluster

25. The Hubble Deep Field

26. 21cm Radiation Neutral hydrogen (HI) gives off radiation at 21cm.
Milky Way HI emission – Copyright J. Dickey

27. Extragalactic HI Observe HI in other galaxies.
Measure wavelength of 21 cm radiation.
Get velocity away from us.

28. Hubble’s Law Measure the velocity of every galaxy.
Nearly all are redshifted.
Use Cepheids to measure distances to nearby galaxies.
Result: The faster it’s moving, the farther away it is.

29. Map the Universe
Measure v
Calculate d
Find:
Voids
Walls
Clusters

31. Homework #11 Read: Bennett Ch 21.1 – 21.4 Do Ch21:
Review Questions: 1, 2, 8
Problems: 1, 4, 5