Exploring the Cosmos - Class Test 3 - Galaxies and Large Scale Structure
1. 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
two-thirds as bright as B.
2.25 (or 9/4) times brighter than B.
1.5 times brighter than B.
as bright as B.
2. The Great Wall is
a mechanism that explains the formation of the density waves that cause the creation of new stars in a spiral galaxy.
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 dense concentration of galaxies that stretches across much of the visible universe.
3. What two observable properties of a Cepheid variable are directly related to one another?
Its luminosity and its mass.
Its mass and its distance.
The period between its peaks of brightness and its distance.
The period between its peaks of brightness and its luminosity.
4. Which of the following terms does not refer to one of the major galaxy classes?
Spiral
Barred Elliptical
Barred Spiral
Elliptical
5. Which of the following conditions can be responsible for the creation of an irregular galaxy?
A quasar in the centre of the 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
6. Which of the following characteristics is true for elliptical Galaxies?
Elliptical galaxies often rotate fast.
In elliptical galaxies there is very little active star formation.
Elliptical galaxies mainly feature Population I stars.
Lots of interstellar medium is present in elliptical galaxies.
7. An S0 galaxy can evolve into which of the following galaxy types?
Galaxies cannot evolve from one type into another
Sc
SBb
Sa
8. 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 luminosity and its mass.
Its mass and its distance.
The period between its peaks of brightness and its luminosity.
9. What can cause a galactic fountain?
Winds and jets from newly-formed protostars.
A supernova occurring in the halo.
The combined effect of spiral density waves.
Multiple supernovae occurring together.
10. 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.
small stars with an extremely low luminosity because their mass is so small the almost failed to become stars.
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.
11. 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.
12. Elliptical galaxies are believed to have been formed by
matter that collected round a very massive black hole.
the very rapid collapse of a super-massive cloud of dust and gas.
the merger of two or more elliptical or other types of galaxies.
the collapse of a very large spiral galaxy.
13. 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.
has our Galaxy as one of the smaller members.
contains the galaxies of the Virgo cluster.
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