Using new data from the MeerKAT Galaxy Cluster Legacy Survey (MGCLS), a Faraday rotation study is presented of the Abell 85 magnetic field structure. A rotation measure (RM) grid of 58 deg−2 was...Show moreUsing new data from the MeerKAT Galaxy Cluster Legacy Survey (MGCLS), a Faraday rotation study is presented of the Abell 85 magnetic field structure. A rotation measure (RM) grid of 58 deg−2 was constructed using linearly polarized background and intracluster sources. Radial RM and depolarization profiles were then constructed that are close to discerning between magnetic field models within a single cluster. In the south east of Abell 85, a region of high (σRM > 20 rad m−2) depolarization was found that coincides with a stream of subclusters falling into the center of Abell 85. The MGCLS was found to be highly capable for performing Faraday rotation analysis with a more than tenfold increase in RM grid density and a twofold increase in fit parameter precision compared to the Jansky Very Large Array (VLA). The constraints and quality of the MGCLS data for Faraday rotation studies were investigated through basic source simulations and a comparison with results from the VLA. A limit was identified in its depolarization range of (σRM ∼ 35 rad m−2), in addition to systematiShow less
At the Old Observatory in Leiden the seeing on clear nights is 3.20” 0.28”. To improve the quality of observations we have created a design for a tip tilt adaptive optics system for the Student...Show moreAt the Old Observatory in Leiden the seeing on clear nights is 3.20” 0.28”. To improve the quality of observations we have created a design for a tip tilt adaptive optics system for the Student Telescope at the Old Observatory. The aim of this system is to improve the resolution of images to 1.60” by using tip tilt adaptive optics. For this design we have first used the y, y diagram for a general optical design, followed by refinement of the optical design with Zemax. This resulted in a set up with a field of view of 1/2 of the original field of view that needs a star of at least 10.06 magnitude in the center of the image, so it can easily be found by the control system. Finally a mechanical design was created using Autodesk Inventor. We have created a design that meets the requirements, fits within the space envelope and matches the interfaces provided and can be easily assembled with off-the-shelf components and lenses with only minor modifications. The final mechanical design has two levels, contained in a circular enclosure. The design has been optimized to allow for easy integration and testing. First integration and testing is expected by the end of this summer, followed by on sky testing in early September. An upgrade path towards a full AO system is available.Show less
