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38 Cards in this Set
- Front
- Back
The part of the Milky Way we are most familiar with is the:
A) Galactic Disk. B) Halo. C) Galactic Bulge. D) Corona. E) Galactic Center. |
A) Galactic Disk.
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Most of the new star formation in the Milky Way Galaxy is found in the
A) bulge B) halo C) galactic center D) globular clusters E) spiral arms |
E) spiral arms
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Detailed measurements of the disk and central bulge region of our galaxy suggest that our Milky Way is a(n)
A) dusty irregular galaxy B) barred spiral galaxy C) active galaxy D) Seyfert galaxy E) very flat elliptical galaxy |
B) barred spiral galaxy
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It was the distribution of ________ that showed Harlow Shapley we were no where near the center of the Milky Way in the 1920s.
A) globular clusters B) supernova remnants C) open clusters D) emission nebulae E) planetary nebulae |
A) globular clusters
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For what type of object is the period-luminosity relation used for determining distances?
A) Cepheids B) RR Lyrae variables C) Planetary nebulae D) T Tauri variables E) Cataclysmic variables |
A) Cepheids
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What observation of the Galaxy suggests it is much larger than the halo and contains a large amount of matter not in the form of stars?
A) motions of the globular clusters B) infrared observations of the center of the Galaxy C) the shape of the spiral arms D) tidal streams in the halo E) the rotation curve |
E) the rotation curve
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Which of the following is not typical of the Galaxy's spiral arms?
A) emission nebulae B) globular clusters C) OB associations D) giant molecular clouds E) young star clusters |
B) globular clusters
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An intermediately wound barred spiral galaxy would, in Hubble's system, be:
A) S2B. B) BSE.5. C) SBb. D) BS2. E) SIrr. |
C) SBb.
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The greatest variation in size and mass occurs in which type of galaxy?
A) Irr I B) Irr II C) SB D) E E) Sc |
D) E
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Most galaxies in the Local Group are:
A) larger spirals than either the Milky Way or M-31 in Andromeda. B) brown dwarfs, with even more dust than our own Galaxy. C) dwarf ellipticals, similar to the companions of M-31. D) small irregulars similar to the Magellanic Clouds. E) dwarf spirals. |
C) dwarf ellipticals, similar to the companions of M-31.
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Which of the following paraphrases Hubble Law?
A) The more distant a galaxy is, the younger it appears. B) The greater the distance to a galaxy, the fainter it is. C) The older the galaxy appears to us, the more luminous it is. D) The faster the galaxy spins, the more massive and luminous it is. E) The greater the distance to a galaxy, the greater its redshift. |
E) The greater the distance to a galaxy, the greater its redshift.
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In active galaxies, the central engines may be temporarily fed by
A) the sudden collapse of the core into a supermassive black hole. B) the fusion of helium into carbon in their cores. C) a close encounter with a neighbor galaxy. D) a series of supernovae around the core. E) a sudden surge of star formation. |
C) a close encounter with a neighbor galaxy.
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The most elongated of the elliptical galaxies are Hubble's class:
A) SBE9. B) E7. C) F2. D) E9. E) SE5. |
B) E7.
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The Magellanic Clouds are:
A) the brightest H II regions in the sky, with active star formation. B) spiral nebulae originally described by William Herschel. C) small irregular galaxies that move in orbit around our Milky Way. D) dust clouds in the southern Milky Way near the Southern Cross. E) the nearest of the globular star clusters. |
C) small irregular galaxies that move in orbit around our Milky Way.
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A galaxy seen 1 billion light-years away means we see it
a) as it was when the universe was 1 billion years old. b) as it will be 1 billion years from now. c) as it was 1 billion years ago. d) as it is today, but redshifted 10 percent of the speed of light. e) as it was just after the Big Bang. |
c) as it was 1 billion years ago.
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Based on galactic rotation curves and motions in clusters of galaxies, dark matter
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makes up about 90 percent of the matter in the universe
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collisions between galaxies
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cause gas and dust clouds to collide leading to rapid star formation
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when spiral galaxies collide the greatest impact occurs on their giant molecular clouds
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their giant molecular clouds
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due to the density and collisions among galaxies, _______ are rare in the center of clusters
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spirals
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the large-scale distribution of galaxies in the universe reveals
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Large voids, with most of the galaxies lying in filaments and sheets
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the rapid variation of brightness of quasars indicates
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the source of energy is very small
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the lensing of a distant quasar is produced in a foreground galaxy by its
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total mass of stars, gas, and dark matter
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Which type of galaxy can grow to the greatest mass and possess the largest number of globular clusters?
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elliptical
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How do we get Doppler velocity independent distances to more distant galaxies
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-Period-luminosity
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You see distant b-type star like rigel in
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2 & 3
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Most galaxies (99%) are
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Rushing away from us
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Galaxy distance and Doppler red shift are correlated for galaxies, what is this called
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Hubble law
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What is the H in V=Hr
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hubble constant
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We estimate the value of H by getting what measure for many galaxies at different
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distance
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How would we get Doppler velocity independent distance to the nearest galaxies.
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comparing brightest stars/clusters/nebulae with similar objects in MW
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The period-luminosity relationship is a crucial component of
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measuring distances with cepheid variable stars
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21- cm radio radiation is useful in studying our galaxy because
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it can be used to map out the cool hydrogen in spiral arms
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in the formation of our galaxy
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the globular clusters formed first
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what suggests that the mass of our galaxy extends farther than its visible disk?
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the rotation curve of the outer edges of the galaxy
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The leading explanation for the existence of spiral arms are
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the spiral density waves through interstellar medium
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star formation ceased first in the
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Halo
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What two observations allow us to estimate the galaxies mass
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the orbital period and distance from the center
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How did Hubble prove that the andromeda nebula was infact an external galaxy
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He found cepheids in the Nebula
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