Card Set Information

2013-12-05 00:41:24

notes 4
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  1. 1. What perception of the Milky Way Galaxy did astronomers have
    at the beginning of last century?
  2. 2. Which is the correct
    description of the Sun's location within the Milky Way?
    8 kiloparseces from galactic center, minor spiral arms
  3. 3. Measuring which two
    quantities of our galaxy allow for a determination (calculation) of

    the Milky Way's mass?
    • (suns orbital velocity) Rotation 
    • speed and distance from the galactic center.
  4. 4. What observation of the
    Galaxy suggests that it is much larger than the halo component, and that it
    contains a large amount of matter not in the form of stars?
    • the rotation curve for the milky way galaxy shows that there must be
    • additional unseen matter beyond that radius, that is dark matter
  5. 5. Matter belonging to the
    Galaxy can be traced out to _______ [what distance] from the center.
  6. 6. The object located at the center of the Galaxy is calculated and
    predicted to be a ________.
    Black hole
  7. 7. All RR Lyrae stars have about the same ___
    luminosity of 100 suns
  8. 8. With respect to age, the stars in the Galactic disk are ____
    blue, young
  9. 9.The Sun's motion in our galaxy
    is in a(n) ________orbit.
  10. 10. Our solar system lives in the Milky Way's
    minor spiral arms
  11. 11. The nearest major galaxy to the Milky Way is the________galaxy
  12. 12. To determine a Cepheid variable's distance, one must measure
  13. 13. The rotation curve for our galaxy
    (speed vs distance from center) is ______, compared to the
    "Keplerian curve", at large distance from the center.
  14. 14. Most of the mass of the Milky Way is predicted to exist in the form of _______
    dark matter
  15. 15. The interstellar ______ absorbs light from stars
    and makes them appear fainter than they otherwise would appear.
    gas or dust
  16. 16. The fuzzy band across the sky which we call the Milky Way is actually the light from millions of stars in the ______ component of the Galaxy.
    galactic disk
  17. 17. Neutral hydrogen gas, bright young O and B stars, Cepheid variable stars, and emission nebulae all map out the position of the  ______, in the Milky Way.
    spiral arms
  18. 18.The Sun is currently
    estimated to be about ______ from the center of the Galaxy.
    • The sun is 8 kiloparsecs
    • from the center .

    • 248,000 million million
    • kilometers

    • 152,000 million million
    • miles

    • 26080 lightyears.
    • kiloparsecs=31 million
    • million kilometers, 19 million million miles, 3.26 light-years.
  19. 19. The age of our galaxy is estimated by determining the ages of the
    oldest objects in the _
  20. 20. Variable stars are stars
    whose ______ varies with time.
    apparent brightness
  21. 21. Which of the following
    types of galaxies is not one of the Hubble types of galaxy?
    • Irregular Lrr galaxy, active
    • galaxy, dwarf galaxy.
  22. 22. Which type of galaxy has a
    stellar disk but without gas or dust?
    So, spiral galaxy
  23. 23.  Elliptical galaxies tend to contain _____ stars and lack______
    x ray halo of hot gas, spiral structure
  24. 24. A spiral galaxy whose central region is a bright, bar-like source of light is called a(n) ______ galaxy.
    barred spiral
  25. 25. When two galaxies move very
    closely to each other, their ______ may dramatically
    rearrange their visible structures.
  26. 26. Giant elliptical galaxies
    may be the result of _
    the collision of two galaxies
  27. 28. Irregular galaxies, in size,
    tend to be _______ than spiral galaxies.
  28. 29. When galaxies collide, the individual
    stars, generally, do not collide. (True/False)
  29. 30. The Hubble Ultra Deep field is data from
    galaxies that are _____ .
  30. 31. Galaxies evolve by __
    mergers and interactions.
  31. 32. In terms of luminosity, quasars are _
  32. 27.Going from galaxy type Sa, to Sb, to Sc, there
    is a decline in the size of the galaxy's _______.
  33. 33. Star formation in the earliest galaxies of
    the universe was ____ .
  34. 34. Galaxies at high redshift
    (i.e. great distances, or equivalently, younger) are___ compared to low redshift
    galaxies (nearby and older).