Exploring the Cosmos - Galaxies and Large Scale Structure
1. Our Sun is situated
in a globular cluster in the galactic disc about half of its radius from the centre.
in the disc of the galaxy about two thirds of its radius from the centre.
in a globular cluster in the halo of the galaxy.
in the disc of the galaxy close to the edge of the disc.
2. Neutral hydrogen can be detected by astronomers because
it radiates a sharp 21 cm radio signal.
it forms dark clouds in the disc of a spiral galaxy.
it reflects blue light from nearby stars.
it glows with a bright blue colour.
3. Our Sun and solar system are
rotating about the centre of the Galaxy once every million years.
rotating around the centre of the Galaxy once every 240 million years.
moving directly towards a supermassive black hole at the centre of the Galaxy and will merge into the centre in 240 million years.
stationary in our Galaxy.
4. Recent observations have shown that there is much invisible matter in the outer regions of our Galaxy.
The observations have involved measurement of the velocities of stars in the spiral arms of the Galaxy.
The evidence has come from theoretical studies of black hole formation.
The current estimate is that around 50% of the mass of the Galaxy is in this invisible form.
The missing invisible material is likely to be completely accounted for by a large number of planets around stars.
5. The disk component of a spiral galaxy includes which of the following parts?
Halo
Bulge
Spiral arms
Globular clusters
6. By observing what astronomical objects was it first found that the Solar System is not located in the centre of the Milky Way?
Black holes
Globular clusters
Absorption nebulae
Cepheids
7. Our Sun is situated
in the disc of the galaxy about two thirds of its radius from the centre.
in a globular cluster in the galactic disc about half of its radius from the centre.
in a globular cluster in the halo of the galaxy.
in the disc of the galaxy close to the edge of the disc.
8. Of the stars in our galaxy
those in the disc component move in circular orbits that have random orientations.
those in the spherical component move in elliptical orbits that have a random orientation.
those in the nucleus orbit the centre in the opposite direction to those in the disc component.
those in the spherical component move in circular orbits that have random orientations.
9. The approximate position of the centre of the Milky Way galaxy was first found, using optical telescopes, by
observing stars moving round the massive black hole in the centre.
measuring the position of visible globular clusters.
measuring the position of visible open star clusters.
looking for the central bulge.
10. The diameter of the Milky Way Galaxy is
about 25 to 30 kpc.
about 25 to 30 pc.
about 250 to 300 pc.
about 25 to 30 Mpc.
11. Population II stars are
"metal" rich and typically found in the disc of a spiral galaxy.
"metal" poor and typically found in the nucleus and halo of a spiral galaxy.
"metal" poor and typically found in the disc of a spiral galaxy.
"metal" rich and typically found in the disc of a spiral galaxy.
12. Recent observations have shown that there is much invisible matter in the outer regions of our Galaxy.
The evidence has come from theoretical studies of black hole formation.
The current estimate is that around 50% of the mass of the Galaxy is in this invisible form.
The observations have involved measurement of the velocities of stars in the spiral arms of the Galaxy.
The missing invisible material is likely to be completely accounted for by a large number of planets around stars.
13. Several different measurements indicated that our galaxy is a spiral galaxy. Which of the following observations does not give evidence for the presence of spiral arms?
Infra-red measurements of the dust density in the Milky Way
Location of CO clouds within the galaxy
Location of nearby Globular clusters
Location of nearby O and B stars
14. The existence of dark matter was proposed to explain...
the shape of the orbits of halo stars and globular clusters.
the observation of strong sources of x-rays and radio waves at the galactic centre.
the flat region of the rotation curve far from the galactic centre.
the formation of galaxies with extremely luminous galactic centres (active galaxies).
15. In a galaxy such as ours, extremely young Population I stars are predominantly found...
in the disc component.
in the spiral arms.
in the nuclear bulge.
in the halo.
16. Globular clusters...
are usually found in the discs of galaxies and contain population I stars.
are usually found in the halos of galaxies and contain population II stars.
are usually found in the discs of galaxies and contain population II stars.
are usually found in the halos of galaxies and contain population I stars.
17. The approximate position of the centre of the Milky Way galaxy was first found, using optical telescopes, by...
looking for the central bulge.
measuring the position of visible globular clusters.
observing stars moving round the massive black hole in the centre.
measuring the position of visible open star clusters.
18. Gas and dust in the interstellar medium (ISM) is often seen in diffuse clouds called nebulae.
The gas in emission nebulae typically emits pink light when it is excited by high energy light from nearby stars.
The Pleiades is an example of an emission nebula.
Reflection nebulae show up as pink, due to the reflection by dust of light coming from nearby stars.
The difference in colour between emission and reflection nebulae arises from the Doppler effect and is due to their differing motion relative to us.
19. The speed of stars as they orbit in a nearby spiral galaxy can be measured by...
measuring the infra red spectrum from them.
using the red or blue shift of the spectrum from different parts of the disc.
determining their spectral class.
observing them for a long period and measuring the change in their position.
20. Star clusters in our Galaxy that are...
globular clusters mainly contain hot, young stars.
open clusters typically contain up to a few thousand stars.
open clusters typically occupy a volume of about 1 kpc across.
globular clusters mainly lie in the disk region.
21. Which of the following processes does not contribute to the formation of 'metals' (elements heavier than Hydrogen and Helium)?
Type 1a Supernovae
Emission nebulae
Planetary nebulae
Type 2 Supernovae
22. Today we know that the Milky Way has two disc components. Which of the following statements is correct?
The stars in the thick disc have an iron to oxygen ratio that suggests they were formed later than the thin disk.
The stars in the thin disc have an iron to oxygen ratio that suggests they were formed later than the thick disk.
The stars of the thin disk have a stronger oscillatory motion than stars in the thick disc.
The stars of the two disc components move in opposite direction around the galactic centre.
23. Interstellar medium can be classified in four different categories, each of which has different densities. Which of the following statements is wrong?
Dark giant molecular clouds are denser than diffuse gas clouds.
Very hot coronal gases have higher density than diffuse gas clouds.
Very hot coronal gas has lower density than inter-cloud media.
Inter-cloud media have a lower density than diffuse gas clouds.
24. In the Universe
galaxies tend to occur in super-clusters which occur randomly in space.
galaxies tend to occur in super-clusters which, in turn, form even larger structures which stretch across much of the known universe.
galaxies occur randomly in space.
galaxies tend to occur in clusters which occur randomly in space.
25. The correct order of the distance ladder from close to far is
Spectroscopic parallax, Cepheid Variables, Hubble’s Law, Supernovae 1a.
Supernovae 1a, Hubble’s Law, Spectroscopic parallax, Cepheid Variables.
Spectroscopic parallax, Supernovae 1a, Cepheid Variables, Hubble’s Law.
Spectroscopic parallax, Cepheid Variables, Supernovae 1a, Hubble’s Law.
26. A type Sb galaxy is
a barred spiral galaxy with moderately tightly wound arms.
a barred spiral galaxy with very open arms.
a spiral galaxy with moderately tightly wound arms.
a disc shaped galaxy with little gas and almost no new star formation.
27. A Seyfert galaxy is
a galaxy that is emitting an unusually large amount of energy due to a black hole at its centre.
another name for a type SO galaxy.
a galaxy that does not have a black hole at its centre and is free to radiate large amounts of energy.
a galaxy that has been distorted by a close encounter with another galaxy so that there is a high rate of formation of new stars.
28. Cepheid variable stars are important for distance measurements because
from their pulsation rate of their brightness, we can deduce their intrinsic average brightness.
they emit radio waves whose frequency allows the calculation of their distance.
from their pulsation rate of their brightness, we can deduce their rotational speed.
their brightness pulsates in a well defined way that allows them to be identified and their average brightness is independent of their size.
29. An S0 galaxy is
a galaxy with intense star formation due to a collision with another galaxy.
a very elongated elliptical galaxy.
a galaxy with a nucleus and a disc but little dust and gas.
a spiral galaxy with many arms.
30. A possible explanation of the formation of a giant elliptical galaxy is
a giant spiral galaxy used up the gas and dust in its disc so that the generation of new stars ceased and the arms slowly broke up.
it has a giant black hole at its centre that attracts many stars.
it was formed by the merger of two or more galaxies.
a giant spiral galaxy evolved into an elliptical galaxy.
31. Which of the following is not a characteristic of rich galaxy clusters?
High density of galaxies.
Contains a large fraction of spiral galaxies.
The cluster at the centre is often formed by one or more giant elliptical galaxies.
Collisions of galaxies are likely to happen.
32. A super-massive black hole would be most likely found in our galaxy
in one of the open clusters of stars.
in one of its arms.
at the centre of a globular cluster.
in the nucleus.
33. Astronomers have been able to measure the speeds of stars near the centre of our galaxy using
X-ray telescopes.
radio telescopes.
modern optical telescopes.
infrared telescopes.
34. A bright red region observed round a bright star in our galaxy is usually
a dust cloud scattering the light of a red giant star.
a dust cloud that is absorbing the blue part of the light from the very luminous star and allowing only the red light to pass.
coloured dust ejected by a nearby supernova.
a region in which hydrogen atoms in a gas cloud are being excited and ionised by the very luminous nearby star and are emitting the red light.
35. Population II stars are
metal poor and typically found in the spiral arms of a galaxy.
metal rich and typically found in the nucleus and halo of a galaxy.
metal poor and typically found in the nucleus and halo of a galaxy.
metal rich and typically found in the spiral arms of a galaxy.
36. On average the density of gas in the interstellar medium (ISM) is
in the region of 1 hydrogen atom per cubic metre.
in the region of 1 hydrogen atom per cubic centimetre.
similar to that at the surface of the Sun.
similar to that in the Earth's atmosphere.
37. Which of the following comprise the oldest members of the Milky Way?
Globular clusters.
Red giant stars in spiral arms.
The Sun and other solar mass stars.
Type O stars.
38. What can cause a galactic fountain?
A supernova occurring in the halo.
The combined effect of spiral density waves.
Multiple supernovae occurring together.
Winds and jets from newly-formed protostars.
39. Two stars, A and B, have the same intrinsic brightness. The distance to A is two-thirds of the distance to B. Compared to B, A will appear to be
as bright as B.
two-thirds as bright as B.
2.25 (or 9/4) times brighter than B.
1.5 times brighter than B.
40. The Great Wall is
a dense concentration of galaxies that stretches across much of the visible universe.
a dense concentration of galaxies in the nearby Virgo cluster.
an unusually dense concentration of stars, gas and dust in a nearby spiral arm of our galaxy.
a mechanism that explains the formation of the density waves that cause the creation of new stars in a spiral galaxy.
41. What two observable properties of a Cepheid variable are directly related to one another?
The period between its peaks of brightness and its distance.
The period between its peaks of brightness and its luminosity.
Its luminosity and its mass.
Its mass and its distance.
42. Which of the following terms does not refer to one of the major galaxy classes?
Elliptical
Spiral
Barred Elliptical
Barred Spiral
43. Which of the following conditions can be responsible for the creation of an irregular galaxy?
Continuous inflow of atomic Hydrogen from outside the galaxy
A quasar in the centre of the galaxy
A super-massive black hole in the centre of the galaxy
Collision of two galaxies
44. Which of the following characteristics is true for elliptical Galaxies?
In elliptical galaxies there is very little active star formation.
Lots of interstellar medium is present in elliptical galaxies.
Elliptical galaxies mainly feature Population I stars.
Elliptical galaxies often rotate fast.
45. An S0 galaxy can evolve into which of the following galaxy types?
SBb
Sa
Galaxies cannot evolve from one type into another
Sc
46. What two observable properties of a Cepheid variable are directly related to one another?
Its mass and its distance.
Its luminosity and its mass.
The period between its peaks of brightness and its distance.
The period between its peaks of brightness and its luminosity.
47. What can cause a galactic fountain?
Multiple supernovae occurring together.
Winds and jets from newly-formed protostars.
A supernova occurring in the halo.
The combined effect of spiral density waves.
48. Quasars are seen to be unusual because they are very
small bright objects whose large red shift indicates that they are very distant.
compact distant galaxies with a large red shift that have many bright O type stars that makes them very luminous.
bright stars near the centre of our galaxy whose light is very red-shifted by the intense gravitational field from the super-massive black hole at the centre.
small stars with an extremely low luminosity because their mass is so small the almost failed to become stars.
49. A Seyfert galaxy is a
spiral galaxy with a high rate of creation of new stars.
large elliptical galaxy with jets of matter that are ejected at high speed from its centre.
disc shaped galaxy with a central bulge, little gas and dust and a low rate of generation of new stars.
spiral galaxy whose nucleus is a very strong emitter of radio waves and sometimes X-rays.
50. Elliptical galaxies are believed to have been formed by
the collapse of a very large spiral galaxy.
the very rapid collapse of a super-massive cloud of dust and gas.
matter that collected round a very massive black hole.
the merger of two or more elliptical or other types of galaxies.
51. The "Local Group" of galaxies
contains galaxies that are spread in a volume that is nearly 10 million light years in diameter.
consists of about 200 galaxies.
contains the galaxies of the Virgo cluster.
has our Galaxy as one of the smaller members.
52. Which class of galaxies predominantly contains Population II stars and little or no gas and dust?
Barred spirals.
Elliptical galaxies.
Spirals.
Seyfert galaxies.
53. If a galaxy’s disc rotates in the direction opposite to the rotational direction of the core, this is a likely indication of
a spiral galaxy.
a galaxy with a large recessional velocity.
a supermassive black hole in the centre of the galaxy.
a merger of two galaxies.
54. The existence of dark matter was proposed to explain
the flat region of the rotation curve far from the galactic centre.
the shape of the orbits of halo stars and globular clusters.
the formation of active galaxies.
the observation of strong sources of X-rays and radio waves at the galactic centre.
55. Rich clusters typically contain a high fraction of
elliptical (E) and S0-type galaxies.
grand design galaxies.
Sa, Sb and Sc galaxies.
SBa, SBb and SBc galaxies.
56. Assuming a value of H0 = 70km/s/Mpc for the Hubble constant, and a measured recessional velocity of a galaxy of v = 350km/s, what is the distance to this galaxy according to Hubble’s law?
none of the above
0.2Mpc
24.5Gpc
5Mpc
57. The distance to a Cepheid variable star can be determined by using the relation between
its pulsation period and its luminosity.
its mass and its velocity.
its mass and its luminosity.
its pulsation period and its velocity.
58. The theory of density waves explains the structure of
flocculent galaxies.
elliptical galaxies.
Seyfert galaxies.
grand design galaxies.
59. Galaxies of type Sa have
a large nucleus and tightly wound spiral arms.
a small nucleus and tightly wound spiral arms.
a large nucleus and loosely wound spiral arms.
a small nucleus and loosely wound spiral arms.
60. In a galaxy such as ours, extremely young Population I stars are predominantly found
in the nuclear bulge.
in the disc component.
in the halo.
in the spiral arms.
61. Which of the following properties does not apply to typical Type I Seyfert galaxies?
The galactic centres are strong emitters of x-rays and ultraviolet radiation.
The sources of the emitted radiation, the active galactic nuclei, are extremely large.
The emission spectra show broad spectral lines of highly ionized atoms.
The velocity of matter near their centres is much higher than in normal galaxies.
62. The spectra of Seyfert galaxies show:
broad absorption lines from highly ionised molecules,
narrow emission lines from highly ionised atoms.
broad emission lines from highly ionised atoms.
narrow absorption lines from highly ionised atoms.
63. Which of the following statements about quasars is wrong?
Quasars are very distant galaxies.
Spectra from quasars are strongly red-shifted.
Optically, quasars seem to be a single star.
In the radio band, quasars look like single stars.
64. The period of Cepheid variable stars is about
1 to 60 minutes.
1 to 60 seconds.
1 to 60 weeks.
1 to 60 days.
65. Which of the following objects is usually not used as a standard candle?
0 class stars.
Seyfert galaxies.
Supernovae Ia.
Planetary nebulae
66. The Tully-Fisher relation relates
the rotation direction of a galaxy to its intrinsic luminosity.
the rotation direction of a galaxy to its apparent luminosity.
the rotation rate of a galaxy to its intrinsic luminosity.
the rotation rate of a galaxy to its apparent luminosity.
67. The correct order of the distance ladder from close to far is
Spectroscopic parallax, Cepheid Variables, Hubble’s Law, Supernovae 1a.
Supernovae 1a, Hubble’s Law, Spectroscopic parallax, Cepheid Variables.
Spectroscopic parallax, Supernovae 1a, Cepheid Variables, Hubble’s Law.
Spectroscopic parallax, Cepheid Variables, Supernovae 1a, Hubble’s Law.
68. Interstellar medium can be classified in four different categories, each of which has different densities. Which of the following statements is wrong?
Very hot coronal gases have higher density than diffuse gas clouds.
Dark giant molecular clouds are denser than diffuse gas clouds.
Inter-cloud media have a lower density than diffuse gas clouds.
Very hot coronal gas has lower density than inter-cloud media.
69. What evidence supports the hypothesis that a super-massive black hole is in the centre of the galaxy?
We can directly observe the black hole by detecting the gravitational waves it emits.
We can directly see the black hole using infrared telescopes.
Black holes regularly swallow stars close to the centre of the Milky Way.
The stars close to the centre of the Milky Way move at very high speed.
70. The Milky Way features two discs. Which of the following statements is wrong?
New stars are formed mainly in the thin disc.
The stars in the thin disc have more circular orbits than the ones in the thick disc.
The stars in the thin disc are younger than ones in the thick disc.
The stars in the thick disc have more circular orbits than the ones in the thin disc.
71. Which of the following four objects does not contribute to the production of metals?
Planetary Nebulae
Supernovae Type 1a
Quasars
Supernovae Type 2
72. Which of the following is not a characteristic of Population I stars
Population I stars are 'metal rich'.
Population I stars are often found in open clusters.
Population I stars are 'metal poor'.
Population I stars often have a bluish colour.
73. Which of the following items can be explained by the density wave theory?
Irregular galaxies
Elliptical galaxies
Flocculent galaxies
Grand design galaxies
74. Which of the following statements is correct?
Our galaxy is currently not active, but has been active in the past.
Our galaxy currently shows features of being an active Seyfert galaxy.
Our galaxy can be classified as a quasar.
Our galaxy has never been active.
75. Which of the following is not a characteristic of rich galaxy clusters?
Collisions of galaxies are likely to happen.
Contains a large fraction of spiral galaxies.
The cluster at the centre is often formed by one or more giant elliptical galaxies.
High density of galaxies.
76. Which of the following objects cannot be used as a standard candle for measuring distances?
Cepheids
RR Lyrae
Supernovae, Type II
Supernovae, Type Ia
77. Which of the following is the correct sorting for distance measurement methods from far to near?
Tully Fisher, Hubble’s law , Spectrospic parallax, parallax method.
Spectrospic parallax, Hubble’s law, parallax method, Tully Fisher.
Hubble’s law, Tully Fisher, Spectrospic parallax, parallax method.
Hubble’s law, Spectrospic parallax, parallax method, Tully Fisher.
78. Which of the following is a characteristic of elliptical galaxies?
Relatively strong emission of the 21cm line.
Relatively weak emission of the 21cm line.
Active stellar recycling.
Contains Population I and II stars.
79. Which of the following statements is correct?
Elliptical galaxies are as common as spiral galaxies.
Spiral galaxies are more common than irregular galaxies.
Spiral galaxies are more common than elliptical galaxies.
Spiral galaxies are as common as irregular galaxies.
80. Which of the following galaxy types features no disc?
S0
Sa
E0
Sba
81. Which of the following statements is incorrect?
In the centre of our galaxy sits a super massive black hole of 2.6 million solar masses.
The super massive black hole at the galactic centre swallows on average 30 stars per year.
Stars close to the galactic centre feature velocities of about 3 million miles per hour.
Star orbits around the galactic centre with a period as low as 15 years have been observed.
82. Which of the following is a characteristic of Population I stars?
Population I stars are often found in globular clusters.
Population I stars are 'metal rich'.
Population I stars are 'metal poor'.
Population I stars often have a reddish colour.
83. Which of the following is a source of heavy elements?
Emission nebulae.
Planetary nebulae.
Dark nebulae.
Reflection nebulae.
84. Which of the following galaxy types belongs to the barred spiral galaxies?
SBa
S0
E4
Sb
85. Which of the following parts of our Galaxy can we not observe using visible light?
Open clusters
Spiral arms
Galactic centre
Globular clusters
86. Which of the following characteristics is true for elliptical Galaxies?
Elliptical galaxies often rotate fast.
Elliptical galaxies mainly feature Population I stars.
In elliptical galaxies there is very little active star formation.
Lots of interstellar medium is present in elliptical galaxies.
87. Which part of our galaxy features strong star formation?
Halo
Spiral arms
Central bulge
Globular clusters
88. An S0 galaxy can evolve into which of the following galaxy types?
Sa
Galaxies cannot evolve from one type into another.
SBb
Sc
89. Which of the following are not active galaxies?
Infrared galaxies
Seyfert galaxies
Quasars
Radio galaxies
90. Which of the following statements is not correct?
The central bulge is thicker than the galactic disk.
The halo components move in nearly circular orbit around the centre of the galaxy.
Our Galaxy has two disks.
Open clusters are mainly found in the disk.
91. Which of the following statements is correct?
The position of the solar system within our galaxy was first determined using the position of nearby O and B stars.
The position of the solar system within our galaxy was first determined using the 21 cm line.
The position of the solar system within our galaxy was first determined using the position of globular clusters.
The position of the solar system within our galaxy was first determined using the position of open clusters.
92. How does the solar system move with respect to the galactic centre?
It is spiralling inwards to the galactic centre
It moves in a strongly elliptical orbit around the galactic centre
It moves in a nearly circular orbit around the galactic centre
It does not move in respect to the galactic centre
93. Which of the following is a characteristic of Population II stars?
Population II stars are 'metal rich'
Population II stars are usually very young
Population II stars are often O or B class stars
Population II stars are 'metal poor'
94. Which of the following processes does not contribute to the creation of 'metals' (elements heavier than Hydrogen and Helium)?
Planetary nebulae
Supernova, Type 1a
Emission nebulae
Supernova, Type 2
95. By observing what astronomical objects was it first found that the Solar System is not located in the centre of the Milky Way?
Absorption nebulae
Black holes
Cepheids
Globular clusters
96. Which of the following terms does not refer to one of the major galaxy classes?
Barred Elliptical
Elliptical
Barred Spiral
Spiral
97. Which of the following characteristics is true for Spiral Galaxies?
In spiral galaxies there is very little active star formation
Very little interstellar medium is present in spiral galaxies
Spiral Galaxies mainly feature Population II stars.
Spiral Galaxies feature Population II stars as well as Population I stars
98. Several different measurements indicated that our galaxy is a spiral galaxy. Which of the following observations does not give evidence for the presence of spiral arms?
Location of nearby Globular clusters
Infra-red measurements of the dust density in the Milky Way
Location of nearby O and B stars
Location of CO clouds within the galaxy
99. Which of the following conditions can be responsible for the creation of an irregular galaxy?
A super-massive black hole in the centre of the galaxy
Continuous inflow of atomic Hydrogen from outside the galaxy
Collision of two galaxies
A quasar in the centre of the galaxy
100. Which of the following Galaxy types does not belong to the Spiral Galaxies?
SBb
S0
Sa
Sc
101. Today we know that the Milky Way has two disk components. Which of the following statements is correct?
The stars of the thin disk have a stronger oscillatory motion than stars in the thick disc.
The stars in the thin disc have an iron to oxygen ratio that suggests they were formed later than the thick disk.
The stars in the thick disc have an iron to oxygen ratio that suggests they were formed later than the thin disk.
The stars of the two disc components move in opposite direction around the galactic centre.
102. Which of the following comprise the oldest members of the Milky Way?
Red giant stars in spiral arms.
Type O stars.
The Sun and other solar mass stars.
Globular clusters.
103. What makes up the interstellar medium?
O and B stars
Gas and dust
Open clusters
K and M stars
104. How does the interstellar medium obscure our view of most of the galaxy?
It absorbs visible, ultraviolet, and some infrared light.
It reflects most light from far distances of the galaxy away from our line of sight.
It produces so much visible light that it is opaque and blocks our view of anything beyond it.
It absorbs all wavelengths of light.
105. How can we see through the interstellar medium?
By observing at high-energy wavelengths such as X rays and long wavelengths of light such as radio waves.
By using only the biggest telescopes.
By using telescopes above the Earth’s atmosphere.
By observing only the brightest visible sources.
106. Where are heavy elements made?
In the interstellar medium.
In the Big Bang, when the universe first began.
In none of the above.
In stars and supernovae.
107. What can cause a galactic fountain?
A supernova occurring in the halo.
Multiple supernovae occurring together.
Winds and jets from newly-formed protostars.
The combined effect of spiral density waves.
108. Compared with our Sun, most stars in the halo are
young, red, and dim and have fewer heavy elements.
young, blue, and bright and have much more heavy element material.
old, red, and dim and have much more heavy element material.
old, red, and dim and have fewer heavy elements.
109. The disk component of a spiral galaxy includes which of the following parts?
Globular clusters
Halo
Spiral arms
Bulge
110. What evidence suggests that the protogalactic cloud that formed the Milky Way resulted from several collisions among smaller clouds?
The stars in the halo of the Milky Way are organized into several dense clusters arranged throughout the halo.
The Milky Way resembles an elliptical galaxy more than other spirals do.
The bulge of the Milky Way is surrounded by many globular clusters, just as elliptical galaxies are.
Halo stars differ in age and heavy-element content, but these variations do not seem to depend on the stars’ distance from the galactic centre.
111. What two observable properties of a Cepheid variable are directly related to one another?
The period between its peaks of brightness and its distance.
Its mass and its distance.
Its luminosity and its mass.
The period between its peaks of brightness and its luminosity.
112. The age of our galaxy is about
100 to 150 million years.
10 to 15 thousand million years.
1.0 to 1.5 million million years.
100 to 150 thousand million years.
113. Our Sun is
in a globular cluster in the spherical component of our galaxy.
in one of the arms of the disc of our galaxy about a third of the distance in from its edge.
a halo star in the disc of our galaxy about a third of the distance in from its edge.
in one of the arms of the disc of our galaxy, close to its edge.
114. In our galaxy, dense concentrations gas and dust are found
in the central bulge.
everywhere in the galaxy.
everywhere in the disc.
in the thin disc.
115. Population I stars are found in the
arms of a spiral galaxy and have strong absorption lines in their spectra.
spherical component of a spiral galaxy and have strong absorption lines in their spectra.
arms of a spiral galaxy and have weak absorption lines in their spectra.
spherical component of a spiral galaxy and have weak absorption lines in their spectra.
116. Elliptical galaxies are believed to have been formed by
the collapse of a very large spiral galaxy.
matter that collected round a very massive black hole.
the merger of two or more elliptical or other types of galaxies.
the very rapid collapse of a super-massive cloud of dust and gas.
117. A Seyfert galaxy is a
spiral galaxy whose nucleus is a very strong emitter of radio waves and sometimes X-rays.
large elliptical galaxy with jets of matter that are ejected at high speed from its centre.
spiral galaxy with a high rate of creation of new stars.
disc shaped galaxy with a central bulge, little gas and dust and a low rate of generation of new stars.
118. In elliptical galaxies
there is a disc and a central bulge but little generation of new stars due to a lack of gas and dust.
there is much formation of new stars that is triggered by the formation of the galaxy in a collision of two or more galaxies.
the star move round the centre on random orbits, there is little gas and dust and very little formation of new stars.
the stars move round the centre on random orbits, there is much gas and dust but very little formation of new stars due to the lack of a disc structure.
119. Two stars, A and B, have the same intrinsic brightness. The distance to A is twothirds of the distance to B. Compared to B, A will appear to be
as bright as B.
2.25 (or 9/4) times brighter than B.
two-thirds as bright as B.
1.5 times brighter than B.
120. The Great Wall is
a dense concentration of galaxies that stretches across much of the visible universe.
a dense concentration of galaxies in the nearby Virgo cluster.
an unusually dense concentration of stars, gas and dust in a nearby spiral arm of our galaxy.
a mechanism that explains the formation of the density waves that cause the creation of new stars in a spiral galaxy.
121. Quasars are seen to be unusual because they are very
small bright objects whose large red shift indicates that they are very distant.
compact distant galaxies with a large red shift that have many bright O type stars that makes them very luminous.
bright stars near the centre of our galaxy whose light is very red-shifted by the intense gravitational field from the super-massive black hole at the centre.
small stars with an extremely low luminosity because their mass is so small the almost failed to become stars.
122. Our galaxy
is a barred spiral galaxy with the Solar System between a half and two thirds the way out from the centre towards the edge of the nucleus.
is a grand design galaxy with the Solar System between a half and two thirds the way out from the centre to the visible edge of the disc.
is a grand design galaxy with the Solar System between a half and two thirds the way out from the centre to the edge of the nucleus.
is a barred spiral galaxy with the Solar System between a half and two thirds the way out towards the visible edge of the disc.
123. A type Sb galaxy is
a barred spiral galaxy with very open arms.
a barred spiral galaxy with very open arms.
a spiral galaxy with moderately tightly wound arms.
a barred spiral galaxy with moderately tightly wound arms.
124. Globular clusters
are usually found in the halos of galaxies and contain population II stars.
are usually found in the discs of galaxies and contain population I stars.
are usually found in the discs of galaxies and contain population II stars.
are usually found in the halos of galaxies and contain population I stars.
125. Cepheid variable stars are important for distance measurements because
they emit radio waves whose frequency allows the calculation of their distance.
from their pulsation rate of their brightness, we can deduce their intrinsic average brightness.
from their pulsation rate of their brightness, we can deduce their rotational speed.
their brightness pulsates in a well defined way that allows them to be identified and their average brightness is independent of their size.
126. The inverse square law of light propagation means that a star that is half the distance of another identical star will appear to be
four times as bright as the other star.
a quarter as bright as the other star.
equally as bright as the other star.
two times as bright as the other star.
127. Population I stars in our galaxy are
typically found in regions with little new star formation and are "metal" rich.
typically found in regions with little new star formation and are "metal" poor.
typically found in regions with new star formation and are "metal" rich.
typically found in regions with new star formation and are "metal" poor.
128. Spiral galaxies are more easily seen than other types of galaxy because
they are free of dust which obscures the light from stars in other galaxies.
they have a very large and prominent nucleus that contains bright O and B stars.
they are much bigger than any other kind of galaxy.
they have bright O and B stars in their arms.
129. The Large and Small Magellanic Clouds are
irregular galaxies close to our own galaxy.
dark dust clouds obscuring part of the Milky Way.
reflection nebulae in Orion.
emission nebulae in the disc of our galaxy.
130. A "starburst" galaxy is
one in which the stars are being thrown outwards, away from the centre.
one with unusually intense new star formation due to the collision of two of its spiral arms.
one in which stars are colliding.
one with intense new star formation due to a close interaction with another galaxy.
131. The distance to very remote galaxies can be measured by
measuring the angular size of their globular clusters and then by using trigonometry.
measuring the apparent brightness of a type 1a supernova in them and / or measuring the red shift of the light from them.
measuring the period and apparent brightness of their Cepheid variables.
identifying the spectral classes of their stars and then using spectral parallax.
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