How to weigh a galaxy
How do Astronomers know how much matter is in a galaxy?
How do they know dark matter exists?
In this project, you will get access to some real galaxy data from the SAMI Galaxy Survey and learn to use the same tools that astronomers use to measure how fast the galaxy is rotating. From this you will calculate the amount of mass in your galaxy, and by comparing that with the expected values from other measurements we can make some assumptions about the existence of Dark Matter.
Resources
Use the data from the following table in conjunction with the WAG Worksheets.
| Catalogue ID | M_star | r_e | z_tonry | SAMI Data |
|---|---|---|---|---|
| 106389 | 10.2 | 5.95 |
0.04094
|
download |
| 202673 | 10.81 | 3.48 | 0.05494 | download |
| 618992 | 10.81 | 4.23 | 0.05569 | download |
| 376121 | 11.02 | 6.36 | 0.05253 | download |
| 184122 | 10.54 | 3.69 | 0.04800 | download |
| 485834 | 10.69 | 5.19 | 0.05705 | download |
| 106507 | 10.22 | 5.94 | 0.05559 | download |
| 209807 | 10.54 | 8.41 | 0.05093 | download |
JS9: Astronomical Image Tool
The JS9 Astronomical imaging tool is free web app that was developed for astronomers to quickly and easily visualise telescope data no matter what wavelength it has been observed in. It accepts astronomical FITS files from local and remote sources, as well as data cubes, and pngs or jpg files.
