Galaxies and the Universe Chapter 30 Review Galaxies and the Universe

What characteristic of radio waves makes them useful for determining the shape of a galaxy? their long wavelength their high frequency their easy visibility their variable energy

What method allows astronomers to locate the structures circled in the diagram? recording radio waves observing RR Lyrae variables measuring infrared radiation observing hydrogen emission spectra

Which of the following is a characteristics of a Population II star? trace amounts of heavy elements age of less than 10 billion years located in disk arms found in spiral galaxies

The Milky Way and the Andromeda are both________. stars galaxies nebulae quasars

A scientist who discovered a galaxy could use the following diagram to classify the galaxy according to its shape age color size

Which ratio best expresses the mass of the Sun compared to the mass of the Milky Way? 1: 100 billion 1: 100 million 1: 100 trillion 1: 100 thousand

Which line on the graph shows the relationship between the size and brightness of a variable star?

The pulsation period of four variable stars is indicated on the diagram. Which of the stars in a Cepheid Variable? A B C D

Which sentence best summarizes Hubble’s Law? The greater the distance to a galaxy, the greater its velocity. The greater the distance to a galaxy, the brighter its halo. The greater the distance to a galaxy, the greater its age. The greater the distance to a galaxy, the greater its mass.

Other galaxies were first believed to be ____. nebulae or star clusters within the Milky Way quasars outside the Milky Way constellations within the Milky Way the Andromeda galaxy

Elliptical galaxies are divided into subclasses based on ____. their elongated shapes the length of their diameters the ratio of their major and minor axes the length of their spiral arms

Cosmic background radiation has a wavelength of approximately 1 mm, which makes it ____. gamma ray radiation microwave radiation X-ray radiation infrared radiation

If the average density is higher than the critical density, the universe is ____. closed open flat round

Recent observations show that the rate of expansion of the universe is ____. slowing down stabilizing constantly changing speeding up

Study of the universe inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Core of a galaxy in which highly energetic objects or activities are located inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Gigantic formation of clusters of galaxies hundreds of millions of light-years in size inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

A value of approximately 70 kilometers per second per megaparsec inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

States that the universe began as a point and has been expanding ever since inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Proposes that the universe looks the same on large scales to all observers and that it has always looked that way inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Persistent noise discovered in 1965 that is caused by weak radiation from all directions in space inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Model that says the universe began as a fluctuation in a vacuum and expanded very rapidly for a fraction of a second before settling into a more orderly expansion inflationary universe cosmology Big Bang theory cosmic background radiation steady-state theory Hubble constant active galactic nucleus superclusters

Normal spiral E7 Irr a c SO EO S SB

Barred spiral E7 Irr a c SO EO S SB

Tightly wound arm and large, bright nucleus Irr a c SO EO S SB

Loosely wound arms and a small, dim nucleus Irr a c SO EO S SB

Flat disks that do not have spiral arms Irr a c SO EO S SB

Round elliptical E7 Irr a c SO EO S SB

Very elongated elliptical Irr a c SO EO S SB

Irregular galaxy E7 Irr a c SO EO S SB

Variable stars get brighter as they get larger. True False

The Sun is classified as a Population II star. True False

RR Lyrae and Cepheid are two categories of variable stars. True False

The Local Group is the galactic group that includes the Milky Way. True False

The galaxy in the diagram is categorized as E0 based on its shape. True False

The Milky Way and Andromeda are larger than other galaxies in the Local Group. True False

Redshift is used as evidence that the universe is contracting. True False

The equation v = Hd shows the relationship between the speed at which a galaxy moves and its distance. True False

The shaded area of the circle graph represents the percent of the universe composed of dark matter. True False

On a graph, Hubble’s law is represented by a straight line. True False

By measuring a star's period of pulsation, astronomers can determine its luminosity and calculate how far away a variable star must be to appear as dim or as bright as it does. True False

Astronomers have determined the shape of the Milky Way by using gamma waves because they penetrate the interstellar gas and dust without being scattered or absorbed. True False

Edwin Hubble's discovery of RR Lyrae variable stars in the Great Nebula in the Andromeda constellation proved the existence of galaxies outside the Milky Way. True False

The halo and bulge of the Milky Way are made of old stars which suggests that the halo and bulge formed first. True False

A(n) SBc galaxy is a normal spiral with loosely wound arms and a small, dim nucleus. True False

The farther away from Earth a galaxy is, the slower it is moving. True False

There are 35 known members of the Local Group, of which the Milky Way and Andromeda galaxies are the two largest. True False

The redshift in many quasars is very large, which means that those quasars are far away. True False

Most galaxies in the inner region of a large cluster are spirals. True False

Studies provide evidence that there is a great amount of unseen matter called dark matter composed of dim stellar remnants that have no mass. True False

Edwin Hubble measured the redshifts and distances of many galaxies and found that the redshift of a galaxy depends on its distance from Earth. True False

Cosmic background radiation provides information about conditions now in the expansion of the universe. True False

A key goal of the Fermilab is to gather data that would help to pinpoint the value for H, the Hubble constant. True False