Question 1

Head-tail galaxies are

Accepted Answer

A)  found most often in clusters. 
B)  dependent on an inter-galactic medium. 
C)  powered by jets in the nucleus of the galaxy. 
D)  a and b 
E)  a,b,and c 
A)  found most often in clusters. 
B)  dependent on an inter-galactic medium. 
C)  powered by jets in the nucleus of the galaxy. 
D)  a and b 
E)  a,b,and c E

Question 2

The hydrogen Balmer line H$\beta$ has a wavelength of 486.1 nm in the laboratory.It is observed in a quasar at 2430.5 nm.What is the red shift of this quasar?

Accepted Answer

A)  5 
B)  0.5 
C)  0.25 
D)  4 
E)  1944.4 
A)  5 
B)  0.5 
C)  0.25 
D)  4 
E)  1944.4 D

Question 3

Most galaxies appear to be ...

Accepted Answer

A)  composed of one star and seven planets. 
B)  inside our Milky Way. 
C)  located on the Earth. 
D)  moving toward us. 
E)  moving away from us. 
A)  composed of one star and seven planets. 
B)  inside our Milky Way. 
C)  located on the Earth. 
D)  moving toward us. 
E)  moving away from us. E

Question 4

A(n)____ is observed if our line of sight is parallel to the plane of the dense disk of an active galactic nucleus.

Accepted Answer

A)  blazer 
B)  Type 1 Seyfert 
C)  Type 2 Seyfert 
D)  superluminal expansion 
E)  quasar 
A)  blazer 
B)  Type 1 Seyfert 
C)  Type 2 Seyfert 
D)  superluminal expansion 
E)  quasar

Question 5

Why do astronomers believe black holes are the source of an AGN's energy?

Accepted Answer

A)  It's expected since black holes have been found at the center of most galaxies. 
B)  Radio jets are seen in many AGN and those only come from black holes. 
C)  Black holes have been observed directly there. 
D)  Only black holes can produce so much energy in such a small place. 
A)  It's expected since black holes have been found at the center of most galaxies. 
B)  Radio jets are seen in many AGN and those only come from black holes. 
C)  Black holes have been observed directly there. 
D)  Only black holes can produce so much energy in such a small place.

Question 6

Some quasars have fuzz around them that produces spectra like that of normal galaxies.

Accepted Answer

A) True 
 B)False

Question 7

Radio lobes are held together by their magnetic fields.

Accepted Answer

A) True 
 B)False

Question 8

Encounters between galaxies would be ____ in the past versus now.

Accepted Answer

A)  the same 
B)  more frequent 
C)  less frequent 
A)  the same 
B)  more frequent 
C)  less frequent

Question 9

How does the study of quasars reveal information of the history of the universe?

Accepted Answer

A)  Quasars are very distant so we can view how galaxy evolution occurred in the past. 
B)  Quasars contain of stars of all ages. 
C)  Quasars typically act as host galaxies for gravitational lensing. 
D)  Quasars have been found to exist in every stage of the universe's evolution. 
A)  Quasars are very distant so we can view how galaxy evolution occurred in the past. 
B)  Quasars contain of stars of all ages. 
C)  Quasars typically act as host galaxies for gravitational lensing. 
D)  Quasars have been found to exist in every stage of the universe's evolution.

Question 10

In the unified model of active galactic nuclei,the broad line region in an active galactic nucleus is

Accepted Answer

A)  composed of clouds of gas and stars moving at very high orbital velocities. 
B)  composed of a super massive black hole. 
C)  responsible for producing the bright continuous radiation observed in blazars. 
D)  responsible for the narrow absorption lines seen in Type 2 Seyfert galaxies. 
E)  located further from the core than the narrow line emission region. 
A)  composed of clouds of gas and stars moving at very high orbital velocities. 
B)  composed of a super massive black hole. 
C)  responsible for producing the bright continuous radiation observed in blazars. 
D)  responsible for the narrow absorption lines seen in Type 2 Seyfert galaxies. 
E)  located further from the core than the narrow line emission region.

Question 11

Astronomers can estimate the mass of the black hole at the center of the active galaxy M87 from the

Accepted Answer

A)  orbital speed of the gas disk around it. 
B)  the distance of the orbiting gas from the center. 
C)  both a and B 
A)  orbital speed of the gas disk around it. 
B)  the distance of the orbiting gas from the center. 
C)  both a and B

Question 12

How are astronomers able to determine that quasars are so small?

Accepted Answer

A)  They are variable over a short period of time. 
B)  They emit mainly X-rays. 
C)  They are only found at very large distance. 
D)  The structure of a quasar is completely resolved in images. 
A)  They are variable over a short period of time. 
B)  They emit mainly X-rays. 
C)  They are only found at very large distance. 
D)  The structure of a quasar is completely resolved in images.

Question 13

Astronomers who discovered quasars found that they show ________ of their spectral lines and are thus probably much ________ than nearby galaxies.

Accepted Answer

A)  large red shifts,farther away 
B)  large blue shifts,farther away 
C)  no wavelength difference,nearer 
D)  large red shifts,nearer 
E)  large blue shift,nearer 
A)  large red shifts,farther away 
B)  large blue shifts,farther away 
C)  no wavelength difference,nearer 
D)  large red shifts,nearer 
E)  large blue shift,nearer

Question 14

If a quasar has a red shift of 0.98,then it is receding from the earth at 98 percent the speed of light.

Accepted Answer

A) True 
 B)False

Question 15

Jet-shaped regions of radio and optical emission have been observed in

Accepted Answer

A)  quasars. 
B)  radio galaxies. 
C)  the 3° Kelvin radiation. 
D)  both a and 
A)  quasars. 
B)  radio galaxies. 
C)  the 3° Kelvin radiation. 
D)  both a and

Question 16

The disks which have been observed in the centers of some active galaxies evidently have a ____ at their centers.

Accepted Answer

A)  black hole 
B)  main sequence star 
C)  terrestrial planet 
D)  jovian planet 
A)  black hole 
B)  main sequence star 
C)  terrestrial planet 
D)  jovian planet

Question 17

The hot gas of a radio lobe could be held together by

Accepted Answer

A)  collision with the intergalactic medium. 
B)  the lobe's magnetic field. 
C)  the lobe's gravitational field. 
D)  the angular momentum of the galaxy. 
E)  the shock wave from a nearby quasar. 
A)  collision with the intergalactic medium. 
B)  the lobe's magnetic field. 
C)  the lobe's gravitational field. 
D)  the angular momentum of the galaxy. 
E)  the shock wave from a nearby quasar.

Question 18

Head-tail galaxies are pairs of galaxies interacting with each other.

Accepted Answer

A) True 
 B)False

Question 19

Double-lobed radio galaxies appear to be emitting jets of gas and radiation.

Accepted Answer

A) True 
 B)False

Question 20

We suspect that quasars are the active centers of galaxies because

Accepted Answer

A)  quasar fuzz produces stellar spectra. 
B)  a few quasars have large red shifts. 
C)  some quasars fluctuate rapidly. 
D)  all of the above 
E)  none of the above 
A)  quasar fuzz produces stellar spectra. 
B)  a few quasars have large red shifts. 
C)  some quasars fluctuate rapidly. 
D)  all of the above 
E)  none of the above

Exam 17: Active Galaxies and Supermassive Black Holes

Head-tail galaxies are

The hydrogen Balmer line H β\betaβ has a wavelength of 486.1 nm in the laboratory.It is observed in a quasar at 2430.5 nm.What is the red shift of this quasar?

Most galaxies appear to be ...

A(n)____ is observed if our line of sight is parallel to the plane of the dense disk of an active galactic nucleus.

Why do astronomers believe black holes are the source of an AGN's energy?

Some quasars have fuzz around them that produces spectra like that of normal galaxies.

Radio lobes are held together by their magnetic fields.

Encounters between galaxies would be ____ in the past versus now.

How does the study of quasars reveal information of the history of the universe?

In the unified model of active galactic nuclei,the broad line region in an active galactic nucleus is

Astronomers can estimate the mass of the black hole at the center of the active galaxy M87 from the

How are astronomers able to determine that quasars are so small?

Astronomers who discovered quasars found that they show ________ of their spectral lines and are thus probably much ________ than nearby galaxies.

If a quasar has a red shift of 0.98,then it is receding from the earth at 98 percent the speed of light.

Jet-shaped regions of radio and optical emission have been observed in

The disks which have been observed in the centers of some active galaxies evidently have a ____ at their centers.

The hot gas of a radio lobe could be held together by

Head-tail galaxies are pairs of galaxies interacting with each other.

Double-lobed radio galaxies appear to be emitting jets of gas and radiation.

We suspect that quasars are the active centers of galaxies because

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The hydrogen Balmer line H $\beta$ has a wavelength of 486.1 nm in the laboratory.It is observed in a quasar at 2430.5 nm.What is the red shift of this quasar?

Astronomers who discovered quasars found that they show of their spectral lines and are thus probably much than nearby galaxies.