1. Universe Tenth Edition Chapter 22 Our Galaxy Roger Freedman Robert Geller William Kaufmann III Clicker Questions

2. William Herschel tried to locate the center of our Galaxy by counting the number of stars in different directions. This did not work because A.stars are not uniformly distributed. B.more distant stars are obscured by dust and gas. C.there are very few stars near the center of our Galaxy. D.most of the brighter stars are in the outer regions of our Galaxy. E.interstellar reddening gave rise to an incorrect count. Q22.1

3. William Herschel tried to locate the center of our Galaxy by counting the number of stars in different directions. This did not work because A.stars are not uniformly distributed. B.more distant stars are obscured by dust and gas. C.there are very few stars near the center of our Galaxy. D.most of the brighter stars are in the outer regions of our Galaxy. E.interstellar reddening gave rise to an incorrect count. A22.1

4. It is possible to obtain high-resolution images of the center of our Galaxy A.at radio and visible wavelengths. B.equally at all wavelengths. C.only at radio wavelengths. D.at infrared and radio wavelengths. E.only at visible wavelengths. Q22.2

5. It is possible to obtain high-resolution images of the center of our Galaxy A.at radio and visible wavelengths. B.equally at all wavelengths. C.only at radio wavelengths. D.at infrared and radio wavelengths. E.only at visible wavelengths. A22.2

6. Which of the following best describes how globular clusters are distributed in our Galaxy? A.They are distributed about the center of our Galaxy within the disk. B.They are distributed above the center of our Galaxy in a ring shape. C.They are distributed spherically about the center of our Galaxy in the halo. D.They are only found in the spiral arms. E.They are only found in the nucleus. Q22.3

7. Which of the following best describes how globular clusters are distributed in our Galaxy? A.They are distributed about the center of our Galaxy within the disk. B.They are distributed above the center of our Galaxy in a ring shape. C.They are distributed spherically about the center of our Galaxy in the halo. D.They are only found in the spiral arms. E.They are only found in the nucleus. A22.3

8. The distance to and location of the center of our Galaxy was first estimated by mapping out the positions of A.globular clusters. B.the spiral arms. C.intense infrared sources. D.strong radio sources. E.x-ray sources. Q22.4

9. The distance to and location of the center of our Galaxy was first estimated by mapping out the positions of A.globular clusters. B.the spiral arms. C.intense infrared sources. D.strong radio sources. E.x-ray sources. A22.4

10. Our solar system is located A.near a globular cluster in the halo of our Galaxy. B.near a globular cluster in a spiral arm of our Galaxy. C.in a spiral arm of our Galaxy. D.in the nucleus of our Galaxy. E.in the disk of our Galaxy, but not within a spiral arm. Q22.5

11. Our solar system is located A.near a globular cluster in the halo of our Galaxy. B.near a globular cluster in a spiral arm of our Galaxy. C.in a spiral arm of our Galaxy. D.in the nucleus of our Galaxy. E.in the disk of our Galaxy, but not within a spiral arm. A22.5

12. Which of the following are not found in the halo of our Galaxy? A.Relatively young objects B.Relatively old objects C.Low-mass stars D.Population II stars E.Metal-poor stars Q22.6

13. Which of the following are not found in the halo of our Galaxy? A.Relatively young objects B.Relatively old objects C.Low-mass stars D.Population II stars E.Metal-poor stars A22.6

14. Which objects outline the shape of the spiral arms of our Galaxy? A.O and B stars B.H I clouds C.H II regions D.A and B, but not C E.All of A, B, and C Q22.7

15. Which objects outline the shape of the spiral arms of our Galaxy? A.O and B stars B.H I clouds C.H II regions D.A and B, but not C E.All of A, B, and C A22.7

16. Which of the following correctly describes our current understanding of our Galaxy ’ s spiral arms? A.The spiral arms are created by density waves that sweep around the Galaxy. B.The spiral arms are the sites for the formation of new stars. C.Stars that are formed in a spiral arm remain in that spiral arm. D.A and B are correct, but not C. E.All of A, B, and C are correct. Q22.8

17. Which of the following correctly describes our current understanding of our Galaxy ’ s spiral arms? A.The spiral arms are created by density waves that sweep around the Galaxy. B.The spiral arms are the sites for the formation of new stars. C.Stars that are formed in a spiral arm remain in that spiral arm. D.A and B are correct, but not C. E.All of A, B, and C are correct. A22.8

18. Most astronomers think that there is dark matter in our Galaxy because A.stars in the outer edges of our Galaxy move faster than expected. B.stars in the outer edges of our Galaxy move slower than expected. C.large amounts of matter can be seen at infrared wavelengths. D.large amounts of matter can be seen at radio wavelengths. E.large amounts of matter can be seen at x-ray wavelengths. Q22.9

19. Most astronomers think that there is dark matter in our Galaxy because A.stars in the outer edges of our Galaxy move faster than expected. B.stars in the outer edges of our Galaxy move slower than expected. C.large amounts of matter can be seen at infrared wavelengths. D.large amounts of matter can be seen at radio wavelengths. E.large amounts of matter can be seen at x-ray wavelengths. A22.9

20. What observation suggests that a supermassive black hole is at the center of our Galaxy? A.We do not see any light emanating from the center of our Galaxy. B.We see large amounts of gravitational radiation coming from the center of our Galaxy. C.Stars close to the center of our Galaxy are moving at high speeds. D.Light from the center of our Galaxy has a large gravitational redshift. E.Light from the center of our Galaxy has a large gravitational blueshift. Q22.10

21. What observation suggests that a supermassive black hole is at the center of our Galaxy? A.We do not see any light emanating from the center of our Galaxy. B.We see large amounts of gravitational radiation coming from the center of our Galaxy. C.Stars close to the center of our Galaxy are moving at high speeds. D.Light from the center of our Galaxy has a large gravitational redshift. E.Light from the center of our Galaxy has a large gravitational blueshift. A22.10