Astronomy Exam 4

Front 1

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.

Back 1

A) Galactic Disk.

Front 2

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

Back 2

E) spiral arms

Front 3

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

Back 3

B) barred spiral galaxy

Front 4

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

Back 4

A) globular clusters

Front 5

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

Back 5

A) Cepheids

Front 6

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

Back 6

E) the rotation curve

Front 7

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

Back 7

B) globular clusters

Front 8

An intermediately wound barred spiral galaxy would, in Hubble's system, be:
A) S2B.
B) BSE.5.
C) SBb.
D) BS2.
E) SIrr.

Back 8

C) SBb.

Front 9

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

Back 9

D) E

Front 10

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.

Back 10

C) dwarf ellipticals, similar to the companions of M-31.

Front 11

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.

Back 11

E) The greater the distance to a galaxy, the greater its redshift.

Front 12

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.

Back 12

C) a close encounter with a neighbor galaxy.

Front 13

The most elongated of the elliptical galaxies are Hubble's class:
A) SBE9.
B) E7.
C) F2.
D) E9.
E) SE5.

Back 13

B) E7.

Front 14

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.

Back 14

C) small irregular galaxies that move in orbit around our Milky Way.

Front 15

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.

Back 15

c) as it was 1 billion years ago.

Front 16

Based on galactic rotation curves and motions in clusters of galaxies, dark matter

Back 16

makes up about 90 percent of the matter in the universe

Front 17

collisions between galaxies

Back 17

cause gas and dust clouds to collide leading to rapid star formation

Front 18

when spiral galaxies collide the greatest impact occurs on their giant molecular clouds

Back 18

their giant molecular clouds

Front 19

due to the density and collisions among galaxies, _______ are rare in the center of clusters

Back 19

spirals

Front 20

the large-scale distribution of galaxies in the universe reveals

Back 20

Large voids, with most of the galaxies lying in filaments and sheets

Front 21

the rapid variation of brightness of quasars indicates

Back 21

the source of energy is very small

Front 22

the lensing of a distant quasar is produced in a foreground galaxy by its

Back 22

total mass of stars, gas, and dark matter

Front 23

Which type of galaxy can grow to the greatest mass and possess the largest number of globular clusters?

Back 23

elliptical

Front 24

How do we get Doppler velocity independent distances to more distant galaxies

Back 24

-Period-luminosity

Front 25

You see distant b-type star like rigel in

Back 25

2 & 3

Front 26

Most galaxies (99%) are

Back 26

Rushing away from us

Front 27

Galaxy distance and Doppler red shift are correlated for galaxies, what is this called

Back 27

Hubble law

Front 28

What is the H in V=Hr

Back 28

hubble constant

Front 29

We estimate the value of H by getting what measure for many galaxies at different

Back 29

distance

Front 30

How would we get Doppler velocity independent distance to the nearest galaxies.

Back 30

comparing brightest stars/clusters/nebulae with similar objects in MW

Front 31

The period-luminosity relationship is a crucial component of

Back 31

measuring distances with cepheid variable stars

Front 32

21- cm radio radiation is useful in studying our galaxy because

Back 32

it can be used to map out the cool hydrogen in spiral arms

Front 33

in the formation of our galaxy

Back 33

the globular clusters formed first

Front 34

what suggests that the mass of our galaxy extends farther than its visible disk?

Back 34

the rotation curve of the outer edges of the galaxy

Front 35

The leading explanation for the existence of spiral arms are

Back 35

the spiral density waves through interstellar medium

Front 36

star formation ceased first in the

Back 36

Halo

Front 37

What two observations allow us to estimate the galaxies mass

Back 37

the orbital period and distance from the center

Front 38

How did Hubble prove that the andromeda nebula was infact an external galaxy

Back 38

He found cepheids in the Nebula