Q3.2 COLLAPSE TIMESCALE (5 points possible)

Imagine that you live in a distant galaxy far far away. This galaxy is in a different universe, and so may have different cosmology.

It seems that in this distant universe, all galaxies have the same luminosity, which you have worked out is 7.0×1030W.

You are studying a particular galaxy which you have just discovered. You take a spectrum and find that it has a strong hydrogen line at a wavelength of 659.2 nm. In the laboratory, this line occurs at a wavelength of 656.3 nm.

What is the redshift of this galaxy?

- unanswered

You measure the flux from this galaxy and get a value of 3.6×10−18W m−2.

How far away (in Mega-parsecs) is this galaxy?

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If you assume that this universe is expanding at a constant rate, how old is this universe? Type your answer in billions of years.

- unanswered