| Popis: |
The Galactic Centre is nowadays, after its discovery in 1932 by Karl Jansky, still a major focus of current research in astrophysics. It still has a lot of secrets that are to be discovered and provides the unique opportunity to scrutinise new hypothesis. The crucial part for investigating the Galactic Centre and verifying or rejecting new theories is of course observing and measuring objects in the Galactic Centre. Primarily these measurements deal with position determination of celestial objects or determination of structures. The position determination is of great importance for proper motion measurements. Here, the position of a celestial object is measured through different epochs. These observations are not trivial and hold a lot of diffculties. One of the greatest inconveniences are disturbances in Earth’s atmosphere which must passed by signals from far away in order to reach ground based observatories. A solution is to place the observatories in space, but due to maintaining expenditure and cost for bringing the observatories into space, this solution is less practical, although of course space observatories are used for some applicatons. In order to build telescopes with bigger diameters and with a higher resolution, the only practical way is to work with ground based telescopes. In order to overcome the limitation of observing through Earth’s atmosphere, adaptive optics are used. Adaptive optics contain a deformable mirror. The surface of this mirror can be adjusted by servos such that it corrects incoming, disturbed wavefront. To do so a guiding source is required, so that the system has a reference for the correct, undisturbed wavefront. In this thesis the propagation through Earth’s atmosphere is simulated with the layer oriented simulation tools (LOST). The performed simulations contain atmospherical models and produce as result point spread functions (PSF). These PSFs contain the performed corrections of the adaptive optics and show the effects of both the corrected atmospherical and instrumental effects when imaging via ground based telescopes. The simulated telescope is the large binocular telescope (LBT) which is positioned on Mount Graham. Different constellations were simulated with different guiding stars. The obtained PSFs were convolved with different input images of the Galactic Centre which contained science cases in order to get the output image one would obtain when observing the Galactic Centre with the LBT. Finally this output image was de-convolved with PSF in order to get again the input image. This re-convolved input image was further investigated to understand how effciently the science cases can be reconstructed. A measure for the quality of the re-convolution is the error with which the science cases could be located in the re-convolved input image. |
