Question

15. Redshift. Astronomers use the redshift (2) as a measure of distance between an astronomical object and earth and is is defined as 1+2 = femit = V1+ue Currently, the objects with the highest known redshifts are galaxies and the objects producing gamma ray bursts. The most reliable redshifts are from spectroscopic data, and the highest confirmed spectroscopic redshift of a galaxy is that of UDFy-38135539 at a redshift of z=8.6. How fast is this galaxy moving away from us? (1 point)

Answer 1

It 8-6= tuli l-vlc - (85)3 8 lete Let V/ c = x (9.6² (1-2) = line 92.16-82.160 = 1tr = 93.16x= 41.16 7 a= 0.9785 v=0.8785- -2.94x108 m/sec Please uprote if my auswe helped you have anice day.

Answer 2

SOLUTION :

Redshift , z, is  a measure of distance between an astronomical object 

And the earth and defined as under :

1 + z = sqrt ((1 + v/c) / (1 - v/c))

So, for galaxy with 8.6 :

1 + 8.6 = sqrt ((1 + v/c) / (1 - v/c))

=> 9.6 = sqrt ((1 + v/c) / (1 - v/c))

=> 9.6^2 =  ((1 + v/c) / (1 - v/c))

=> 92.16 ( 1 - v/c) = (1 + v/c)

=> 92.16 - 92.16 v/c = 1 + v/c

=> 93.16 v/c = 91.6 

=> v = 91.6 c / 93.16 = 91.6 * 3 * 10^8 / 93.16

=> v = galaxy moving away at a speed of = 2.95 * 10^8 m/s (ANSWER).