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Interpreting redshift

Let us summarise our discussion about Cosmological Redshift.

 

hubbleflow

 

It is important to note that the only thing in the context of this discussion that we can measure,
and fortunately very accurately, is Redshift z.
The conclusions we attach to those observations depend on the particular cosmological interest we have,
and if that pertains to distance, it depends on the type of distance indicator we use.

 

Cosmology is a very complex field of astronomy, and it is no wonder that the idea of “distance” in the context of large redshifts is often misquoted and misunderstood in the popular media.

Cosmologist Ned Wright has set up an online calculator for various distance related concepts,
within a particular choice of cosmological model, as:

 

function of redshift

or

light travel time 

 

 

Practice

The largest redshift object ever measured to date is the galaxy GN-z11 that has a redshift of 11.09.

Using the calculators linked above, find out the value of the various distance indicators for this galaxy.

Note: First enter the redshift in the first calculator, and then enter the obtained value for light travel time in the second calculator.
How old was the Universe when the light left the source?

 

 

 

 

 

 

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