CHP 28

5. Galaxies that we see as they were 11 billion years ago or more, as compared to galaxies today, are generally: a. bluer and smaller b. redder and smaller c. redder and larger d. bluer and larger e. pretty much the same

a. bluer and smaller

20. If you wanted to write a complete "cosmic address" for yourself, including every location or structure you live in, which of the following would NOT be part of that address? a. the Coma Cluster b. the Milky Way Galaxy c. the Local Group d. the Solar System e. planet Earth

a. the Coma Cluster

33. Which of the following statements about our modern ideas of how spiral galaxies form and develop is TRUE? a. the central bulges of spiral galaxies formed first and their disks formed later b. star formation in the spiral galaxies is much higher today than it was 8 billion years ago c. spiral galaxies formed pretty quickly after the Big Bang and already looked then the way they look today d. spiral galaxies have evolved until today they are all "red and dead", containing just old stars and showing almost no current star formation e. spiral galaxies cannot have a central super-massive black hole, so astronomers don't understand just how they formed

a. the central bulges of spiral galaxies formed first and their disks formed later

26. Which of the following can we NOT learn from studying the Doppler shifts in the spectrum of galaxies beyond our Local Group? a. whether they have Jupiter-mass planets around many of their stars b. their red shifts c. their rotation speeds d. their masses e. their distances

a. whether they have Jupiter-mass planets around many of their stars

29. How do astronomers know that there aren't significant amounts of dark matter within our solar system? a. so much dark matter would affect the amount of energy coming out of the Sun, and we see no evidence for that b. a lot of dark matter would affect the motions (orbits) of our spacecraft as the move through the solar system, and see no such effect c. the theory of dark matter, which now explains everything we want to know about it, tells us that it can only exist on the outside of galaxies d. such dark matter would affect the weather patterns on Earth, and we see no such effect e. astronomers have now discovered quite a bit of dark matter in the solar system, so the premise of the question is wrong

b. a lot of dark matter would affect the motions (orbits) of our spacecraft as the move through the solar system, and see no such effect

17. Roughly how many galaxies make up our Local Group? a. only three b. about 60 or so c. many hundreds d. thousands e. millions

b. about 60 or so

25. When astronomers have examined rich clusters of galaxies with their instruments, they have found that these clusters a. contain far more spiral galaxies in their central regions than elliptical galaxies b. are more likely to contain giant elliptical galaxies than poor clusters c. are the only places in the universe where galaxies find a way NOT to collide d. contain mostly galaxies dominated by the light of young stars (stars formed recently) e. are so big that there is a lot more space between the galaxies than in poor clusters like our Local Group

b. are more likely to contain giant elliptical galaxies than poor clusters

35. Astronomers believe that the large elliptical galaxies formed a. right after the Big Bang, looking just like they look today b. from the collision and merger of many smaller fragments c. only recently, less than a billion years ago (before that galaxies were spirals) d. without the presence of any super-massive black holes e. without any involvement of dark matter (just from matter we can detect)

b. from the collision and merger of many smaller fragments

13. Which of the following is a way that having an active galactic nucleus (AGN), with a supermassive black hole in the center, can affect the development of a galaxy? a. it can seriously reduce the total mass of the galaxy when lots of stars fall into the black hole b. huge energetic jets from the accretion disk can disturb and lessen star formation in the galaxy c. it can break apart the galaxy into several smaller galaxies d. it can cut off all electro-magnetic radiation from most of the galaxy, except for the visible light from the outermost stars e. sorry, I don't buy it; the black hole at the center is so small, there is simply no way that astronomers can think of that it could affect the development of the whole galaxy

b. huge energetic jets from the accretion disk can disturb and lessen star formation in the galaxy

34. According to our modern "bottom-up" model of the formation of large structures in the universe, the structures that formed first were about the mass of a a. star b. large globular cluster or a small galaxy c. giant elliptical galaxy d. supercluster of galaxies e. an ice-cold mug of root beer

b. large globular cluster or a small galaxy

4. There is some irony in the fact that the Hubble Space Telescope has shown that Edwin Hubble's classification scheme for galaxy shapes only works in the later stages of the universe. What have really deep pictures (going way back in time) taken with the Hubble Telescope shown about galaxies long ago (in the first few billion years after the Big Bang)? a. long ago, all the galaxies were spiral shaped; there were no other shapes at all b. long ago, galaxy shapes were not (for the most part) regular and organized; galaxies looks chaotic and lumpy c. long ago, there were no galaxies at all; stars were evenly distributed through space and had not yet formed galaxies d. long ago, galaxies were much larger than galaxies are today; those very large galaxies broke apart and made the galaxies we know e. you can't fool me; the Hubble Space Telescope has a smaller mirror than the largest telescopes on the ground. We can'

b. long ago, galaxy shapes were not (for the most part) regular and organized; galaxies looks chaotic and lumpy

2. If a very distant galaxy looks blue overall to astronomers, from this they can conclude that: a. the galaxy is moving toward us at great speed b. the galaxy must have a lot of young stars and thus active star formation must still be going in it c. the galaxy must be composed mostly of very old stars d. the galaxy must not be especially massive when compared to most galaxies e. the galaxy must have had a personal tragedy of some sort and needs a lot of love

b. the galaxy must have a lot of young stars and thus active star formation must still be going in it

16. When astronomers say that the groups of galaxies are distributed isotropically, they mean that a. all the galaxies are about the same size b. the way galaxies are arranged in space looks the same in all directions c. galaxies all have interstellar matter at the same temperature d. galaxies all have the same age e. galaxies all contain the same isotopes of elements

b. the way galaxies are arranged in space looks the same in all directions

19. The rich galaxy cluster that is closest to our Local Group of galaxies is the a. Coma Cluster b. Hercules Cluster c. Virgo Cluster d. Ursa Major Cluster e. Peanut Cluster

c. Virgo Cluster

1. Some astronomers searching for what the mysterious "dark matter" might be made of have pinned their hopes on MACHO's (MAssive Compact Halo Objects). What do they think these MACHO's are? a. huge concentrations of antimatter, outside of galaxies b. vast clouds of neutrinos, emitted by ancient supernovae c. black holes, brown dwarfs, and white dwarfs in the regions outside the main disk of our Galaxy d. "cannibal galaxies" that have swallowed smaller galaxy neighbors until they have grown very large e. large groups of college football players who have flunked astronomy, and now hang around the outskirts of town, just showing off their muscles

c. black holes, brown dwarfs, and white dwarfs in the regions outside the main disk of our Galaxy

10. According to our current understanding, giant elliptical galaxies form: a. by being located near the center of the Big Bang explosion and thus getting a major early push b. only in the giant voids that astronomers are discovering among the filaments and chains of galaxies c. by the merger (or swallowing) of a number of smaller galaxies in a cluster of galaxies d. when a black hole swallows enough material so that most of the stars in the galaxy are inside the black hole, leaving only a thin halo e. by watching too much football and drinking too much beer

c. by the merger (or swallowing) of a number of smaller galaxies in a cluster of galaxies

22. To map out how clusters of galaxies are distributed in the universe, astronomers needed to know where each cluster was in the sky AND a. how many galaxies were in each cluster b. how blue or red the galaxies in each cluster were c. how far away from us each cluster was d. whether any of the galaxies in each cluster acted like quasars e. whether any gravitational lensing could be seen in each cluster

c. how far away from us each cluster was

15. The cosmological principle in astronomy a. is only an assumption, for which we don't have any real evidence yet b. applies only to the Milky Way Galaxy, not to anything outside it c. is confirmed by many observations done by Hubble and many other astronomers since d. is contradicted by the existence of quasars e. is an old Greek idea, now completely discredited by modern observations

c. is confirmed by many observations done by Hubble and many other astronomers since

4. According to the Cosmological Principle, the universe a. has no beginning and no end b. cannot be understood by the use of scientific observations alone c. is isotropic and homogeneous d. consists only of galaxies that are exactly like the Milky Way e. has all the galaxies arranged in groups about the size of our Local Group

c. is isotropic and homogeneous

9. Why do galaxies collide, while stars almost never do? a. stars have a very strong negative charge on them, so they repel other stars that get near b. stars don't have very much mass, so their gravity is very small and can't pull things well c. stars are much further apart (compared to how big they are) than galaxies are d. stars are surrounded by planets, which prevent collisions; galaxies are not e. actually, stars collide all the time, but astronomers don't have any way of observing it

c. stars are much further apart (compared to how big they are) than galaxies are

32. How do astronomers currently think the amount of detectable (observable) matter in the universe compares to the amount of dark matter and dark energy? a. the amount of detectable matter is about equal to the amount of dark matter & energy b. the amount of detectable matter is far greater than the amount of dark matter & energy c. the amount of detectable matter is far less than the amount of dark matter & energy d. the amount of detectable matter is about 1/10th the amount of dark matter & energy e. there is no evidence for dark matter anywhere, so this is not a topic astronomers can make any estimates about

c. the amount of detectable matter is far less than the amount of dark matter & energy

6. An astronomer is observing a distant galaxy which looks blue. Which of the following can she conclude from this observation? a. the galaxy must be moving toward us (must have a blue shift) b. the galaxy must be extremely large (probably a giant elliptical) c. the galaxy must have a lot of star formation going on at the time we are seeing it d. the galaxy must be rotating very slowly or not at all e. the galaxy must contain only older stars (those that formed billions of years ago)

c. the galaxy must have a lot of star formation going on at the time we are seeing it

3. With enormous effort, a team of astronomers manages to collect enough light from a galaxy far, far away to produce a spectrum. That spectrum has lines from the elements carbon, silicon, and sulfur. This tells the team that a. the galaxy must be closer to us than 1 billion light years b. the galaxy must contain a quasar c. the galaxy must have had an entire generation of stars that was born, lived, and died d. the galaxy must be a massive elliptical galaxy e. what they are seeing is not a galaxy at all, but the remnant of one supernova

c. the galaxy must have had an entire generation of stars that was born, lived, and died

12. An astronomer discovers a massive galaxy which has four nuclei. What is a likely explanation for a galaxy having more than one nucleus? a. the nuclei of galaxies often split into two or more parts because of internal activity b. the galaxy must have been a quasar earlier in its life c. the galaxy must have swallowed several smaller galaxies that were its neighbors d. the galaxy must have had an unusual number of supernova explosions e. astronomers have no explanation for multiple nuclei in galaxies; it's baffling

c. the galaxy must have swallowed several smaller galaxies that were its neighbors

28. In which of the following domains of the universe have astronomers NOT found evidence for the presence of dark matter today? a. the Milky Way Galaxy b. other spiral galaxies c. the solar system d. clusters of galaxies e. superclusters of galaxies

c. the solar system

21. By examining rich clusters of galaxies, such as the Coma Clusters, astronomers have discovered that spiral galaxies a. grow to be very large and bright at the centers of these clusters b. turn out to be most of the galaxies in such clusters, and many are found throughout each cluster c. do not exist at all in such clusters d. are found mostly in the outer regions of such clusters, not in the middle e. are all tilted exactly the same way in such cluster; all their disks are fully aligned

d. are found mostly in the outer regions of such clusters, not in the middle

24. What do the surveys of the three-dimensional distribution of groups of galaxies reveal about how groups and clusters of galaxies are organized? a. galaxy groups are distributed completely evenly -- there is typically the same amount of space between them -- and so there is no structure evident b. galaxy groups make a huge spiral structure that resembles the Milky Way (but is much bigger) c. galaxy groups are organized into huge spherical "lumps" with concentric rings of groups of galaxies around each lump d. galaxy groups are organized into huge filaments with great voids between them -- something like the structure one would see taking a cross-section of some soap bubbles e. you can't fool me; astronomers cannot get any sense with our present-day instruments of how groups of galaxies are distributed on the large scale

d. galaxy groups are organized into huge filaments with great voids between them -- something like the structure one would see taking a cross-section of some soap bubbles

7. If we want to see what galaxies looked like at a time close to the beginning of the universe, where should we look? a. in the Local Group of galaxies b. within the nearest 100 million light years from the Milky Way c. near the center of the Virgo Cluster of galaxies d. in a direction away from the plane of the Milky Way, where we can see very faint galaxies that are more than 10 billion light years away e. it doesn't matter; you can look at any galaxy, because all galaxies look pretty much the same today as they did in the early days of the universe

d. in a direction away from the plane of the Milky Way, where we can see very faintgalaxies that are more than 10 billion light years away

11. Which of the following does NOT happen when two galaxies collide? a. large interstellar gas clouds collide b. the rate of star formation increases c. the shape of the galaxy is often changed d. many of the stars in one galaxy collide with the stars in the other e. a smaller galaxy may wind up inside a larger one

d. many of the stars in one galaxy collide with the stars in the other

27. The Sloan Digital Sky Survey a. searches for planets around neighbor stars by looking for changing Doppler shifts in their spectra b. searches for Trans-Neptunian objects, small icy bodies in the outer solar system, whose orbits sometimes resemble Pluto's c. searches for supernova remnants that could have pulsars inside and then try to find the pulsars d. takes images and spectra of millions of objects, to find the positions and redshifts of as many galaxies and quasars as possible e. searches to see whether extra-terrestrial civilizations are sending any digitally recorded music our way

d. takes images and spectra of millions of objects, to find the positions and redshifts of as many galaxies and quasars as possible

8. One important way astronomers can learn in some detail about what happens when galaxies collide is a. to watch the Andromeda Galaxy (M31,) which is on a collision course with us, for a decade b. to look at the supermassive black hole at the center of the Milky Way c. to examine the satellite galaxies presently orbiting the Milky Way d. to simulate galaxy collisions on a large computer and watch what the simulation predicts e. to look at videos of car accidents that are particularly violent

d. to simulate galaxy collisions on a large computer and watch what the simulation predicts

23. The "great voids" that astronomers studying galaxies are finding are: a. regions where a number of black holes have cleared out space in the center of a galaxy b. empty regions between the spiral arms of the Milky Way Galaxy c. huge regions inside spiral galaxies, where the powerful radiation from a very hot star has cleared out the local interstellar material d. very large regions of intergalactic space, where relatively few galaxies or galaxy clusters can be found e. regions inside the brains of astronomy students where information about astronomy topics should have been located, but has been los

d. very large regions of intergalactic space, where relatively few galaxies or galaxy clusters can be found

18. Which of the following is not true about the Local Group of galaxies (of which the Milky Way is a member)? a. it is a member of the same supercluster as the Virgo Cluster b. it has few galaxies when compared to a rich cluster c. the Milky Way is one of its more massive members d. it has more elliptical galaxy members than spiral galaxies e. it has about a thousand member galaxies

e. it has about a thousand member galaxies

30. Which of the following is not a way that astronomers can find how much dark matter there is in cluster of galaxies? a. measuring the speeds with which the galaxies are moving around, to estimate the mass of the cluster needed to keep them from moving away b. measuring how much slower galaxies in a rich cluster or supercluster are moving than the Hubble Law would predict c. observing x-rays from the hot gas in the cluster, and using the amount of x-ray radiation to estimate the mass of the cluster d. using gravitational lensing effects to make a map of how much mass a cluster of galaxies contains e. observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them

e. observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them

1. Astronomers can now report that active star formation was going on at a time when the universe was only 20% as old as it is today. When astronomers make such a statement, how can they know what was happening inside galaxies way back then? a. they look at the open clusters in the Milky Way Galaxy b. they look at radio waves coming from nearby active galaxies c. they look at a graph that shows the way galaxy redshifts change with time d. they look at the elements in comets, which formed when our solar system was first forming e. they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find

e. they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find