Radiation astronomy/Superluminals/Quiz

Superluminal astronomy is a lecture from the department of radiation astronomy. It is included in the advanced undergraduate course on the principles of radiation astronomy.

Superluminal motion in quasar 3C279 is shown in a "movie" mosaic of five radio images made over seven years. Credit: NRAO/AUI.

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1 Yes or No, Faster-than-light (superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light.


2 The first astronomical superluminal source in the constellation Indus is likely to be which of the following?

the Sun
the Small Magellanic Cloud
Scorpius X-1
the Large Magellanic Cloud
a Seyfert 1 galaxy

3 Under the

theory of relativity, a particle (that has

mass) with subluminal velocity needs

energy to accelerate to the speed of light.

4 Phenomena associated with apparent superluminal motion are

an optical illusion
the object partly moving in the direction of the observer
large amounts of mass moving at close to half the speed of light
speed calculations assume it does not move in the direction of the observer
velocities close to the speed of light relative to our reference frame

5 Complete the text:

Having a speed greater than

is called a


6 Complete the text:

Match up the type of speed effect with each of the possibilities below:
superluminal - A
luminal - B
subluminal - C
transluminal - D
tachyons - E
tardyons - F
speeds which cross the speed of light

speed equal to that of light

particles moving at speeds slower than light

speed less than light

particles moving at speeds faster than light

speed greater than light


7 Complete the text:

Match up the observation with the phenomena:
B1828+487 - A
PKS0521-36 - B
Fanaroff-Riley (FR) type II radio source - C
prototypical type 2 Seyfert - D
Frank–Tamm formula - E
a type 1 Seyfert - F






8 Which of the following is not an astronomical superluminal source?

3C 345
3C 48
3C 263
3C 179
3C 245
3C 279

9 True or False, The very fast neon nova GK Persei rivalled the brightness of Vega at the peak of its outburst in 1901.


10 Which of the following is associated with the first superluminal motion phenomenon in our galaxy?

the Spring of 1994
4,000 light-years away
VLT observations
GRS 1915
Jodrell Bank

11 True or False, X-ray outbursts are associated with pulsars not quasars.


12 Anomalous dispersion is associated with which of the following?

refractive index
decrease in index
Scorpius X-1
group velocity can be boosted to beyond the velocity of its constituent waves
resonance of ionized hydrogen

13 In the dispersed image, a single cloud of gas with small

motions have a single


14 Chemistry phenomena associated with superluminal sources are

galactic recession
Hubble parameter
current density
synchrotron radiation

15 Complete the text:

The spectra of active galactic

are noteworthy in showing species with a large range in

at once.

16 Complete the text:

Match up the type of radiation with each of the superluminal possibilities below:
meteors - A
electrons - B
neutrinos - C
gamma rays - D
X-rays - E
opticals - F
superluminal signal transfer

sychrotron emission through the optical into the X-ray regime

conelike illumination pattern

electroweak Cherenkov radiation

index of refraction is often greater than 1



17 Complete the text:

Match up the superluminal detector with the image:
Hopkins Ultraviolet Telescope - A
International Ultraviolet Explorer - B
C. Donald Shane telescope - C
2.3m Bok Telescope - D
LHCb - F
AMS-02 - G







18 Which of the following are not known as an astronomical superluminal source?

magnetic Cherenkov radiation
the solar wind
Askaryan radiation
inflationary epoch comoving distance
3C 380

19 True or False, The paths of small-scale jets are not always radial to the nucleus.


20 Which of the following are associated with the envelope of the polarization current density?

emission of electromagnetic radiation from a superluminal charged particle
intensity of some components decays as the inverse of the distance from the source
non-spherically-decaying sources
emission contains very high frequencies not present in the synthesis of the source
non-spherically decaying components of the radiation do not violate energy conservation
strong electromagnetic fields are compensated by weak fields elsewhere


  1. Questions can be used to take students through the faster-than-light analysis.

See alsoEdit

External linksEdit

{{Radiation astronomy resources}}