Exploring the Cosmos - Degree Exam 2013 - Galaxies and Large Scale Structure
1. The spectra of Seyfert galaxies show:
narrow absorption lines from highly ionised atoms.
broad emission lines from highly ionised atoms.
broad absorption lines from highly ionised molecules,
narrow emission lines from highly ionised atoms.
2. Which of the following statements about quasars is wrong?
Spectra from quasars are strongly red-shifted.
Quasars are very distant galaxies.
In the radio band, quasars look like single stars.
Optically, quasars seem to be a single star.
3. The period of Cepheid variable stars is about
1 to 60 weeks.
1 to 60 minutes.
1 to 60 seconds.
1 to 60 days.
4. Which of the following objects is usually not used as a standard candle?
Supernovae Ia.
Seyfert galaxies.
0 class stars.
Planetary nebulae
5. The Tully-Fisher relation relates
the rotation direction of a galaxy to its apparent luminosity.
the rotation rate of a galaxy to its intrinsic luminosity.
the rotation direction of a galaxy to its intrinsic luminosity.
the rotation rate of a galaxy to its apparent luminosity.
6. The correct order of the distance ladder from close to far is
Spectroscopic parallax, Cepheid Variables, Supernovae 1a, Hubble’s Law.
Spectroscopic parallax, Supernovae 1a, Cepheid Variables, Hubble’s Law.
Spectroscopic parallax, Cepheid Variables, Hubble’s Law, Supernovae 1a.
Supernovae 1a, Hubble’s Law, Spectroscopic parallax, Cepheid Variables.
7. 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 gas has lower density than inter-cloud media.
Very hot coronal gases have higher density than diffuse gas clouds.
Inter-cloud media have a lower density than diffuse gas clouds.
Dark giant molecular clouds are denser than diffuse gas clouds.
8. 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.
The stars close to the centre of the Milky Way move at very high speed.
Black holes regularly swallow stars close to the centre of the Milky Way.
9. The Milky Way features two discs. Which of the following statements is wrong?
The stars in the thick disc have more circular orbits than the ones in the thin disc.
New stars are formed mainly in the thin disc.
The stars in the thin disc are younger than ones in the thick disc.
The stars in the thin disc have more circular orbits than the ones in the thick disc.
10. Which of the following four objects does not contribute to the production of metals?
Quasars
Planetary Nebulae
Supernovae Type 1a
Supernovae Type 2
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