Share
Explore BrainMass

# Galaxy redshifts and distances away

See the attached file for clarity.

Q1a)
An astronomer observes two galaxies A and B which have redshifts of:
Galaxy A = 0.08 and Galaxy B = 0.01

Which galaxy is closest to us and what is its distance away from us? You may assume that the hubble constant is H_0 = 75 km S^(-1) Mpc^(-1) and the speed of light is c= 3.0 x 10^5 km S^(-1).

Choose correct option from the italics or fill in the blanks:
The closest galaxy is Galaxy A / Galaxy B it is at a distance of ____________ Mpc.

Q1b)
Assuming that Galaxy is intrinsically of identical luminosity to Galaxy B. How does its apparent brightness on the night sky compare to that Galaxy B?

Choose correct option from the italics or fill in the blanks:
Galaxy A is ___________ times fainter / brighter than Galaxy B.
Note: please enter numbers in numerals.

#### Solution Summary

This solution uses a numerical problem to illustrate how the redshifts of galaxies are related to their distances away, and subsequently their apparent brightnesses on the night sky.

\$2.19