1. LECTURE 22, NOVEMBER 18, 2010 ASTR 101, SECTION 3 INSTRUCTOR, JACK BRANDT jcbrandt@unm.edu 1ASTR 101-3, FALL 2010

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11. a) ongoing star formation b) a disk, bulge, and halo c) globular clusters in the halo d) open clusters in the disk e) all of the above Question 2 What property is shared by spiral galaxies? 11ASTR 101-3, FALL 2010

12. a) ongoing star formation b) a disk, bulge, and halo c) globular clusters in the halo d) open clusters in the disk e) all of the above Question 2 What property is shared by spiral galaxies? M-51, a Type Sb spiral 12ASTR 101-3, FALL 2010

13. a) giant globular clusters in the halo. b) small irregular galaxies that orbit the Milky Way. c) large molecular clouds in the disk of our Galaxy. d) the brightest ionized hydrogen regions in our Galaxy. e) spiral nebulae originally discovered by Herschel. Question 3 The Magellanic Clouds are 13ASTR 101-3, FALL 2010

14. a) giant globular clusters in the halo. b) small irregular galaxies that orbit the Milky Way. c) large molecular clouds in the disk of our Galaxy. d) the brightest ionized hydrogen regions in our Galaxy. e) spiral nebulae originally discovered by Herschel. Question 3 The Magellanic Clouds are 14ASTR 101-3, FALL 2010

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23. a) more distant galaxies showing greater blueshifts. b) distant quasars appearing proportionally dimmer. c) more distant galaxies showing greater redshifts. d) slowly varying Cepheid variables appearing brighter. e) more distant galaxies appearing younger. Question 5 Hubble’s law is based on 23ASTR 101-3, FALL 2010

24. a) more distant galaxies showing greater blueshifts. b) distant quasars appearing proportionally dimmer. c) more distant galaxies showing greater redshifts. d) slowly varying Cepheid variables appearing brighter. e) more distant galaxies appearing younger. Question 5 Hubble’s law is based on 24ASTR 101-3, FALL 2010

25. Question 6 Hubble’s constant measures a) the density of galaxies in the universe. b) the luminosity of distant galaxies. c) the reddening of light from dust clouds. d) the speed of a galaxy. e) the rate of expansion of the universe. 25ASTR 101-3, FALL 2010

26. a) the density of galaxies in the universe. b) the luminosity of distant galaxies. c) the reddening of light from dust clouds. d) the speed of a galaxy. e) the rate of expansion of the universe. Question 6 Hubble’s constant measures Hubble’s law relates how fast galaxies are moving away from us at different distances. A larger value for H 0 implies a faster expansion rate. Velocity = H 0 x Distance 26ASTR 101-3, FALL 2010

27. a) the size of the universe. b) distances to galaxies. c) the speed of recession of galaxies. d) the density of matter in the universe. e) the temperature of the Big Bang. Question 7 To calibrate Hubble’s constant, astronomers must determine 27ASTR 101-3, FALL 2010

28. a) the size of the universe. b) distances to galaxies. c) the speed of recession of galaxies. d) the density of matter in the universe. e) the temperature of the Big Bang. Question 7 To calibrate Hubble’s constant, astronomers must determine Distances to galaxies are determined using a variety of “standard candles,” including Cepheid variables, supernova explosions, model galaxies, and model clusters. 28ASTR 101-3, FALL 2010

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40. a) supermassive black holes at their cores. b) dark matter. c) self-sustaining star formation. d) spiral density waves. e) hypernova explosions. Question 10 Seyfert and radio galaxies could be powered by 40ASTR 101-3, FALL 2010

41. a) supermassive black holes at their cores. b) dark matter. c) self-sustaining star formation. d) spiral density waves. e) hypernova explosions. Question 10 Seyfert and radio galaxies could be powered by The Circinus Galaxy, a Seyfert galaxy about 4 Mpc away 41ASTR 101-3, FALL 2010

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