Chapter 33, Problem 28P

To determine

Redshift parameter for a galaxy moving away from Earth.

Answer to Problem 28P

Redshift parameter for a galaxy moving away is $0.732$ .

Explanation of Solution

Given:

Speed of a galaxy traveling away from Earth is $v=0.50c$

Formula used:

Redshift parameter is calculated as

  $z=\sqrt{\frac{1+\raisebox{1ex}{$v$}\!\left/ \!\raisebox{-1ex}{$c$}\right.}{1-\raisebox{1ex}{$v$}\!\left/ \!\raisebox{-1ex}{$c$}\right.}}-1$

Calculation:

Redshift parameter of the galaxy is

  $\begin{array}{c}\text{z =}\sqrt{\frac{1+\text{0}\text{.50}}{1-\text{0}\text{.50}}}-1\\ =\sqrt{\frac{1.5}{0.5}}-1\\ =\sqrt{3}-1\\ =1.732-1\\ =0.732\end{array}$

Conclusion:

Thus, redshift parameter for a galaxy moving away is $0.732$ .