The document is a chapter from an astronomy textbook about galaxies. It contains multiple choice questions about the properties of different types of galaxies like elliptical galaxies, spiral galaxies, and active galaxies. It discusses how Edwin Hubble discovered that more distant galaxies have greater redshifts, indicating the universe is expanding.
2. 1) disk and spiral arms. 2) halo. 3) central bulge. 4) open clusters. 5) companion galaxies, the Magellanic Clouds. Question 1 Based on their shapes and stars, elliptical galaxies are most like the Milky Way’s
3. 1) disk and spiral arms. 2) halo. 3) central bulge. 4) open clusters. 5) companion galaxies, the Magellanic Clouds. Question 1 Based on their shapes and stars, elliptical galaxies are most like the Milky Way’s Like the stars and globular clusters in our Halo, elliptical galaxies contain little or no gas and dust to make new stars.
4. 1) ongoing star formation 2) a disk, bulge, and halo 3) globular clusters in the halo 4) open clusters in the disk 5) all of the above Question 2 What property is shared by spiral galaxies?
5. 1) ongoing star formation 2) a disk, bulge, and halo 3) globular clusters in the halo 4) open clusters in the disk 5) all of the above Question 2 What property is shared by spiral galaxies? M-51, a Type Sb Spiral
6. 1) giant globular clusters in the halo. 2) small irregular galaxies that orbit the Milky Way. 3) large molecular clouds in the disk of the Galaxy. 4) the brightest ionized Hydrogen regions in our galaxy. 5) spiral nebulae originally discovered by Herschel. Question 3 The Magellanic Clouds are
7. 1) giant globular clusters in the halo. 2) small irregular galaxies that orbit the Milky Way. 3) large molecular clouds in the disk of the Galaxy. 4) the brightest ionized Hydrogen regions in our galaxy. 5) spiral nebulae originally discovered by Herschel. Question 3 The Magellanic Clouds are
8. 1) Most galaxies showed redshifts. 2) All galaxies showed blueshifts. 3) Galaxies showed about half redshifts and half blueshifts. 4) Galaxies showed no line shifts at all. 5) Some galaxies showed a redshift that changed into a blueshift at other times. Question 4 Hubble took spectra of galaxies in the 1930s. What did he find?
9. 1) Most galaxies showed redshifts. 2) All galaxies showed blueshifts. 3) Galaxies showed about half redshifts and half blueshifts. 4) Galaxies showed no line shifts at all. 5) Some galaxies showed a redshift that changed into a blueshift at other times. Question 4 Hubble took spectra of galaxies in the 1930s. What did he find? Redshifts of galaxies indicate they are moving away from us.
10. 1) more distant galaxies showing greater blue shifts. 2) distant quasars appearing proportionally dimmer. 3) more distant galaxies showing greater red shifts. 4) slowly varying Cepheid variables appearing brighter. 5) more distant galaxies appearing younger. Question 5 Hubble’s law is based upon
11. 1) more distant galaxies showing greater blue shifts. 2) distant quasars appearing proportionally dimmer. 3) more distant galaxies showing greater red shifts. 4) slowly varying Cepheid variables appearing brighter. 5) more distant galaxies appearing younger. Question 5 Hubble’s law is based upon v
12. 1) the density of galaxies in the universe. 2) the luminosity of distant galaxies. 3) the reddening of light from dust clouds. 4) the speed of a galaxy. 5) the rate of expansion of the universe. Question 6 Hubble’s constant measures
13. 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 o x Distance 1) the density of galaxies in the universe. 2) the luminosity of distant galaxies. 3) the reddening of light from dust clouds. 4) the speed of a galaxy. 5) the rate of expansion of the universe.
14. 1) the size of the universe. 2) distances to galaxies. 3) the speed of recession of galaxies. 4) the density of matter in the universe. 5) the temperature of the Big Bang. Question 7 To calibrate Hubble’s constant, astronomers must determine
15. 1) the size of the universe. 2) distances to galaxies. 3) the speed of recession of galaxies. 4) the density of matter in the universe. 5) 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.
16. 1) the universe is static. 2) the universe is collapsing. 3) the universe is expanding. 4) the Milky Way is the center of the universe. 5) There is no accepted interpretation. Question 8 Hubble’s discovery of galaxy redshifts means
17. 1) the universe is static. 2) the universe is collapsing. 3) the universe is expanding. 4) the Milky Way is the center of the universe. 5) There is no accepted interpretation. Question 8 Hubble’s discovery of galaxy redshifts means
18. 1) they generate energy partly through H to He fusion like stars. 2) they show spectra similar to extremely bright O stars. 3) their luminosity varies like eclipsing binary stars. 4) in short photographs, their images appear stellar. 5) they are dense concentrations of millions of stars. Question 9 Quasars are “quasi-stellar” because
19. 1) they generate energy partly through H to He fusion like stars. 2) they show spectra similar to extremely bright O stars. 3) their luminosity varies like eclipsing binary stars. 4) in short photographs, their images appear stellar. 5) they are dense concentrations of millions of stars. Question 9 Quasars are “quasi-stellar” because Although short-exposure images can appear starlike, many quasars show jets or other signs of intense activity. v
20. 1) supermassive black holes at their cores. 2) dark matter. 3) self-sustaining star formation. 4) spiral density waves. 5) hypernova explosions. Question 10 Seyfert and Radio galaxies could be powered by
21. 1) supermassive black holes at their cores. 2) dark matter. 3) self-sustaining star formation. 4) spiral density waves. 5) hypernova explosions. Question 10 Seyfert and Radio galaxies could be powered by The Circinus galaxy, a Seyfert galaxy about 4 Mpc away
22. 1) sudden bursts of star formation. 2) supernova chain reactions in the core. 3) the collapse of the core into a larger black hole. 4) close encounters with a nearby galaxy. 5) dark matter becoming visible and emitting light. Question 11 In active galaxies, the central engine can be “fed” by
23. 1) sudden bursts of star formation. 2) supernova chain reactions in the core. 3) the collapse of the core into a larger black hole. 4) close encounters with a nearby galaxy. 5) dark matter becoming visible and emitting light. Question 11 In active galaxies, the central engine can be “fed” by Collisions or tidal interaction between galaxies can provide new fuel to power the supermassive black hole engines of active galaxies.