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30 Cards in this Set
- Front
- Back
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A barred-spiral galaxy with a very large central bulge and small spiral arms would be classified as what type of galaxy? |
SBa |
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What is the origin of synchrotron radiation in radio galaxies? |
High speed electrons spiralling around the magnetic field lines |
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Where in the universe are supermassive black holes found? Choose all that apply. WARNING: Negative points are given for each incorrect selection. 1) powering the centers of quasars.Correct Response 2) In the centers of active galaxiesCorrect Response 3) In the centers "normal" inactive galaxies.Correct Response 4) In the center of the Milky Way. |
All are true. |
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What is the difference between radio-lobe and core-halo galaxies? |
They are they same type of galaxy; just seen from different points of view. |
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Why are active galaxies known to be rotating rapidly? |
because of their line-broadening seen in their spectra |
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What type of galaxy is almost exclusively made of very old cool stars? |
elliptical |
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You measure Cepheid variables in galaxy A and galaxy B. Both Cepheids have the same period but the one in Galaxy B appears 16 times brighter than the other. You conclude |
Galaxy A is 4 times more distant than galaxy B. |
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Astronomers believe that the X-ray radiation from the nuclei of active galaxies comes from _____. |
From the accretion disk around a massive black hole |
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What type of galaxy has no coherent structure; lots of gas and dust; and regions of vigorous star formation? |
irregular |
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What would be the classification of an elliptical galaxy that is nearly spherical in shape? |
E0 |
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A Seyfert galaxy resembles what type of normal galaxy? |
Spiral galaxy |
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Which of the following is true about giant ellipticals? |
They are composed of mostly population II stars. |
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_____ type galaxies contain ____ because they have not used up their gas and dust in making _____. |
Irregular; large amounts of gas and dust; stars |
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A(n) ___ type galaxy is ___ with elongated central regions. |
SB; a spiral galaxy |
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What causes the spiral arm structure of a galaxy? |
A density wave moving around the disc of the galaxy |
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What are quasars? |
very young; energetic; and compact galaxies |
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A barred-spiral galaxy with a very small central bulge and clumpy spiral arms would be classified as what type of galaxy? |
SBc |
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A Radio galaxy resembles what type of normal galaxy? |
elliptical |
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_____ galaxies contain mostly Population II stars; while _____ galaxies contain both Population I and Population II stars. |
Elliptical; spiral |
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In what region of a spiral galaxy are globular clusters found? |
halo |
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What would be the classification of an elliptical galaxy that is strongly elliptical (flattened) in shape? |
E7 |
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What is one piece of evidence for dark matter? |
The fact that the rotation curves of most galaxies become flat at large distances from the center |
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Hubble's law implies that the _____ galaxies have larger _____ in their spectral lines. |
More distant; red shift |
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The "density wave theory" is an attempt to explain |
how spiral arms maintain their shape |
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Which of the following statements about quasars is not correct? 1. Their spectra have the largest red shifts observed 2. They are probably the most distant observable objects 3. They have abnormally high luminosities 4. Their cores are extremely large probably several thousand light years across 5. Sometimes they appear in pairs due to gravitational lenses formed by intervening galaxies |
4. Their cores are extremely large probably several thousand light years across |
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Which of the following galaxy types are associated with active star formation? Choose all that apply. 1) Spirals 2) Dwarf ellipticals 3) Giant ellipticals 4) Irregulars |
1) Spirals 2)Irregulars |
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Willie is an giant E0 elliptical galaxy and Jase is a Sa spiral galaxy (the exact Hubble class isn't all that important here). According to the "Lambda-Cold-Dark-Matter" Model of Galaxy Formation, all but which of the following is true? |
Jase formed with hotter star-forming gas than Willie. |
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Hubble originally created his 'Tuning Fork' diagram to... |
simply classify the various galaxies; nothing more. |
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Starburst galaxies... |
are likely the result of recent galaxy interactions or mergers. |
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What observational evidence suggests that the centers of quasars are small about a fraction of a light year? |
The intensity of their radiation fluctuates over periods of months |
