Astronomy 9

Front 1

The concept that on the grandest of scales, the universe is similar in appearance everywhere is

Back 1

homogeneity.

Front 2

The darkness of the night sky in an infinite universe is addressed in

Back 2

Olbers's paradox.

Front 3

The concept that the direction of observation does not matter overall is

Back 3

isotropy.

Front 4

Synchrotron radiation produces a ________ spectrum.

Back 4

continuous nonthermal

Front 5

As we look at larger and larger scales in the universe, we find

Back 5

a larger and larger percentage of the matter is dark.

Front 6

Most of the mass in the universe is dark matter

Back 6

True

Front 7

Collisions between galaxies

Back 7

cause the gas and dust clouds to collide, leading to rapid star formation.

Front 8

Galaxies are moving away from us and into the vast, empty space of the outer universe beyond the Big Bang.

Back 8

False

Front 9

Collisions between galaxies have little effect on the individual stars.

Back 9

True

Front 10

Astronomers believe that a spiral galaxy may form

Back 10

from an interaction between a small and a large galaxy.

Front 11

Some quasars show absorption spectra with a smaller redshift than their emission spectra. This indicates that

Back 11

There is cooler gas between us and the quasar

Front 12

The total mass of a galaxy tends to be only slightly larger than the visible mass.

Back 12

False

Front 13

A galaxy that was once a quasar is likely to

Back 13

have a black hole at its nucleus

Front 14

The height of the quasar epoch was

Back 14

when there was still sufficient mass to fuel the supermassive black holes at their center.

Front 15

According to the HST data, very distant (and early) galaxies tend to be

Back 15

smaller, bluer, and more irregular than modern ones.

Front 16

The Milky Way is at the center of our Local Supercluster.

Back 16

False

Front 17

Gravitational lensing of distant, faint irregular galaxies may be the key to

Back 17

mapping dark matter

Front 18

The Andromeda galaxy will eventually collide with the Milky Way.

Back 18

True

Front 19

As with stars, binary galaxy pairs are useful in finding their total mass.

Back 19

True

Front 20

Homogeneity and isotropy, taken as assumptions regarding the structure and evolution of the universe, are known as

Back 20

the cosmological principle

Front 21

A radio galaxy whose lobes are swept back as if forming a tail probably indicates

Back 21

evidence for intracluster gas

Front 22

Rotation curves for spiral galaxies show

Back 22

most have dark halos

Front 23

In the larger clusters, colliding galaxies tend to pass through one another.

Back 23

True

Front 24

Based on galactic rotation curves and cluster dynamics, we think dark matter

Back 24

comprises over 90% of the entire mass of the universe.