blue galaxy overlaps red galaxy, which is closer?
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by
Budgieye
moderator
The target galaxy is a blue spiral, and "close" at z=0.62
1 GOODS J033234.06-273952.7 03h32m34.0s -27d39m53s G >30000 0.628900 22.6R 0.000
The red galaxy is much further away, at z=1.11
*COMBO-17 50682 03h32m34.1s -27d39m53s G >30000 1.111800 22.3R 0.012
Homework:
Is the blue galaxy closer to us, or to the red galaxy?
Redshift Tool
https://www.wolframalpha.com/input/?i=cosmological+redshift&a=*C.cosmological+redshift-_*Formula-
Click on Use as a Formula
Input each redshift and press equal
Ignoring expansion of the universe
blue galaxy 5.85 billion light-years away, or about 40% to the edge of our observable universe
red galaxy 8.19 billion light-years or 60% to the edge of our observable universe.
So the galaxies are over 2 billion light-years apart.
The blue galaxy is closer to the red galaxy, than it is to us. But it is very far away.
Funny, but the red one looks closer, doesn't it?
Posted