The type of radio galaxy that reveals its motion through the intergalactic medium is called a:
A)quasar.
B)dual lobe.
C)bipolar jet.
D)head-tail.
E)Seyfert.

Question

Quizplus · Accepted Answer

A head-tail radio galaxy has a distinct shape in which two lobes of emission extend from the galaxy's nucleus in opposite directions, with the emission in the downstream lobe forming a 'tail'. As the galaxy moves through the intergalactic medium, this tail will be bent and distorted, revealing the galaxy's motion. Head-tail radio galaxies reveal their motion through the intergalactic medium, as their radio emission is stretched out in the direction of their motion, forming a distinctive "head-tail" shape. Quasars, dual lobes, bipolar jets, and Seyfert galaxies all refer to different types of active galactic nuclei and do not necessarily reveal their motion through the intergalactic medium in the same way as head-tail radio galaxies.

The Type of Radio Galaxy That Reveals Its Motion Through