Answer to Question #50702 in Astronomy | Astrophysics for Nikhil

Question

4.
a) Distinguish between spiral and barred spiral galaxies giving examples of each type of
galaxy.

b) What is a Seyfert galaxy? Explain how broad-line and narrow-line regions originate in a
Seyfert galaxy.

c) Using the virial theorem, explain why there is a need to postulate the existence of dark
matter.

d) A galaxy of absolute magnitude of −20 is at a distance of 100 kpc. Would it be visible to
the naked eye?