| Description |
At a given mass, the amount of galaxy clusters within some volume greatly depends on certain cosmological parameters. Examples of such parameters are: how much total mass there is (nm), the equation of state parameter of dark energy (w), and the scale of fluctuations (o8). These quantities can be measured by finding the number of galaxy clusters as a function of mass. This would require finding accurate masses for these galaxy clusters, but finding such masses requires us to make underlying assumptions in order to make estimates and depends on how good the calibration was of the instruments that were used. By obtaining approximately 107 kiloseconds of Chandraobservations of galaxy cluster Abell 2029, we can use the Chandra telescope's detection of Abell 2029's hot gas to derive its total enclosed mass. As mentioned above, deriving this total enclosed mass requires assumptions to be made. Such assumptions include assuming some kind of symmetry to simplify the problem, as well as assuming the equipment was calibrated correctly. By testing how the derived mass of Abell 2029 changes when we change our underlying assumptions, we can find out which assumption dominate the systematic uncertainty of galaxy cluster mass measurements. Knowing which of these assumptions dominates the uncertainty helps guide us in what we need to do in order to better refine cosmological parameters. |
