Exploring the Cosmos - Degree Exam 2014 - Galaxies and Large Scale Structure
1. Which class of galaxies predominantly contains Population II stars and little or no gas and dust?
Elliptical galaxies.
Spirals.
Barred spirals.
Seyfert galaxies.
2. If a galaxy’s disc rotates in the direction opposite to the rotational direction of the core, this is a likely indication of
a supermassive black hole in the centre of the galaxy.
a galaxy with a large recessional velocity.
a merger of two galaxies.
a spiral galaxy.
3. 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.
4. Rich clusters typically contain a high fraction of
Sa, Sb and Sc galaxies.
SBa, SBb and SBc galaxies.
grand design galaxies.
elliptical (E) and S0-type galaxies.
5. 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
5Mpc
24.5Gpc
0.2Mpc
6. The distance to a Cepheid variable star can be determined by using the relation between
its mass and its luminosity.
its pulsation period and its luminosity.
its mass and its velocity.
its pulsation period and its velocity.
7. The theory of density waves explains the structure of
grand design galaxies.
Seyfert galaxies.
flocculent galaxies.
elliptical galaxies.
8. Galaxies of type Sa have
a large nucleus and tightly wound spiral arms.
a small nucleus and loosely wound spiral arms.
a small nucleus and tightly wound spiral arms.
a large nucleus and loosely wound spiral arms.
9. In a galaxy such as ours, extremely young Population I stars are predominantly found
in the spiral arms.
in the nuclear bulge.
in the disc component.
in the halo.
10. Which of the following properties does not apply to typical Type I Seyfert galaxies?
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.
The sources of the emitted radiation, the active galactic nuclei, are extremely large.
The galactic centres are strong emitters of x-rays and ultraviolet radiation.
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