Galaxy Redshift Exercise

In lectures we cover the fact that the universe is expanding and that galaxies are moving away from us. This discovery was made by Edwin Hubble, and in this exercise you will prove this for yourself. By using real astronomical data from catalogues maintained by the Royal Observatory of Edinburgh (ROE) you will be able to estimate the Hubble constant and the age of the universe. In order to get the right information, you will need to look at two separate catalogues; the Supercosmos Sky Survey (SSS) and the Six Degree Field Galaxy Redshift Survey (6dfGrs). Both of these are available online for the public and astronomers to access at the ROE website http://www.roe.ac.uk/.

You will estimate the distance to a galaxy from its observed size. This isn't as accurate as the techniques described in The Cosmic Perspective Section 20.2 (p610), but still works fairly well. You will also obtain the redshift from spectroscopy - which someone else has already done, and put the measured value in a catalogue which you can consult.

  1. Getting your galaxies
  2. Getting images of the galaxies
  3. Getting the redshifts of the galaxies
  4. Estimating the distances of the galaxies
  5. Making a Hubble diagram
  6. Writing your final report
  7. Submitting your work