PhD Defence Arne S Jegers

Principal supervisor:

• Senior Researcher Desiree Della Monica Ferreira, DTU

Co-supervisor:

• Erik Bergbäck Knudsen, Copenhagen Atomics

Examiners:

• Senior Researcher Christoph Köhn, DTU Space

• Dr. Julia Katharina Vogel, University of Zaragoza, Spain

• Professor Kim Lefmann, Niels Bohr Institute, Denmark

Chairperson at defence:

• Senior Researcher Bitten Gullberg

Summary

In space, X-rays are emitted by some of the hottest, densest and most magnetic astronomical objects. If we can observe them, they allow us to probe the extremes of physics and spacetime. It is, however, difficult to focus X-rays into a clear image with traditional lenses or mirrors, since they tend to either pass through, or be absorbed by them. This thesis presents ray-tracing simulations of the Athena X-ray observatory, an upcoming space telescope in development at ESA. Athena uses a new technolgy called Silicon Pore Optics, the latest in a long line of X-ray specific mirror optics. A number of variations of the optics is simulated observing different astronomical objects, and the resulting images are then analyzed. The optics variants are evaluated on two key measures of performance. The first is effective area, which represents how much light the telescope can capture. A high effective area is beneficial because it allows the telescope to see fainter, more distant objects. It also makes observations shorter, since it needs less time to collect enough light to see its target. The second measurement is the angular resolution, which describes how sharp and clear an image the optics produce. A smaller angular resolution means the telescope makes more detailed images, capturing smaller details.

The results of the simulations are then compared to find:

1. If all optics variants perform well enough to meet the requirements set by the Athena mission
2. How the variants compare to each other and to an idealized theoretical variant
3. If one or more optics variants stand out as the best choice for the mission