Study Guide Ch12

Chapter 12- The Milky way

Study Guide
Answer is slashed threw its not the right one if in red it might be the answer.

Question 1
Radio maps of the spiral arms of our galaxy
map the location of dense neutral hydrogen clouds.

Question 2
Our galaxy is suspected to be surrounded by a galactic halo or corona because the disk of the galaxy
rotates faster than expected in its outer region.

Question 3
Which of the following is not a characteristic of the stars of the disk component of our galaxy?
randomly inclined orbits

Question 4
The central areas of our Milky Way Galaxy contain
a nuclear bulge of stars.

Question 5
Which of the following can't be associated with the spiral arms of a galaxy?
metal poor stars

Question 6
Who first used RR Lyrae variable stars to determine distances in the Milky Way?
Harlow Shapley

Question 7
Refer to Figure 12-1. A Type II Cepheid has been located in a distant globular cluster with a period of 10 days. What is the star's absolute magnitude?
-1

Question 8
The chemical abundance of population I stars
indicates that the material they formed from had been enriched with material from supernovae.

Question 9
Population II stars
I. are primarily found in the disk of the galaxy.
II. contain more heavy metals than population I stars.
III. are primarily old low mass stars.
IV. are located in globular clusters.
III & IV

Question 10
The traditional “top-down” theory of the formation of our galaxy cannot explain why
all of the above

Question 11
The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on
observations of globular clusters.

Question 12
Pulsating variable stars are useful in determining
the mass of a star for which the distance is known.
the temperature of a star for which we know the luminosity.
the radius of the bulge of our galaxy.
the distance to globular clusters.
the mass of the Milky Way galaxy.

Question 13
The nuclear bulge of our galaxy
contains stars primarily associated with the spherical component of our galaxy.

Question 14
The energy source at the center of our galaxy
all of the above

Question 15
____ of the Milky Way contains mostly old (population II) stars and globular clusters.
The spherical halo component

Question 16
How did Harlow Shapley determine where the center of the galaxy lies?
He plotted the distribution of globular clusters.

Question 17
How is the age of the galaxy determined?
Finding the turnoff point in the H-R diagram of globular clusters.

Question 18
Sgr A* is believed to be the center of the Milky Way galaxy because
I. It lies in the general direction of the center of the galaxy based on observations of globular clusters in the plane of the Milky Way.
II. Long wavelength dust penetrating images show it to be a region crowded with stars.
III. Orbits of stars around it indicate a mass several million times that of the Sun within a volume a few light hours in size.
IV. Radio observations show it is a concentrated source at the center of swirling clouds of gas.
All of I, II, III & IV

Question 19
An approximately spherical cluster of over 100,000 stars that formed at the same time long ago in our galaxy is
a globular cluster.

Question 20
Younger stars have more heavy elements because
the heavy elements were made in previous generations of stars.


Question 4
Good tracers of the spiral arms of our galaxy are all
I. very old.
II. very young.
III. very luminous.
IV. moving with large radial velocities.
II & III

Question 5
The galactic halo or corona is believed to contain mostly
O and B stars.
G, K, and M stars.
open clusters.
globular clusters.
dark matter.

Question 9
The central areas of our Milky Way Galaxy contain
a nuclear bulge of stars.
a bar of stars.
a radio wave emitting “whirlpool” of gas.
a several million solar mass black hole.
all of the above

Question 10
The orbits of population I stars
I. are confined to disk of the galaxy.
II. are very elliptical.
III. are nearly circular.
IV. are randomly inclined to the disk of the galaxy.
I & III

Question 14
Who first determined that the energy/sec emitted by the luminosity of Cepheid variable stars is larger when the variation of their period is longer?
Henrietta Leavitt
Edwin Hubble
John Glenn
Carl Sagan
Harlow Shapley

Question 15
If the spiral density wave were the only thing producing spiral arms, it would be expected that
all galaxies would have only two smooth spiral arms.

Question 16
Which of the following can't be associated with the spiral arms of a galaxy?
metal poor stars

Question 17
The traditional “top-down” theory states that the galaxy formed
as a large spherical cloud of gas that was rotating very slowly.