This list of proposed Bachelor and Master research projects should only give a short overview of possibilities. If you have other suggestions or are interested in other aspects of research related to star clusters and evolutionary synthesis modelling simply contact me and we can discuss it. Bachelor projects: ------------------ 1) Project name: "How colour transformations can influence your parameter determination" Project supervisor: Dr Peter Anders research area: -Evolution of Stars and Stellar Populations --Star Clusters & Resolved Stellar Populations Project description: Each telescope and instrument has its own set of filters and detectors, creating a unique photometric system. In order to compare observations made with different telescopes, standard stars with known photometric properties in a defined standard system have to be observed, in order to establish colour (and magnitude) transformations of observations into the defined photometric standard system. Such transformations are naturally not perfect, and available only for a certain parameter range of standard stars. No special standard photometry is available for star clusters. By comparing photometric models of star clusters with observations, the physical parameters of clusters can be determined. This comparison can be done either in the photometric system of the observations (i.e. by creating models in the unique photometric system of the instrument used for the observations) or by transforming the observations into the standard system and compare with models in the standard system. On the example of the colour transformations from the Hubble Space Telescope photometric system into the standard ground-based system, the student will study and quantify the effects introduced by the colour transformations. A first small-scale study (de Grijs et al. 2005) suggested already a strong impact. The results will most likely be published as a small paper. 2) Project name: "Getting extinction determinations right" Project supervisor: Dr Peter Anders, probably additional advice by Daniela Calzetti (STScI, Baltimore, USA), a leading expert in dust extinction research area, choose from: -Evolution of Stars and Stellar Populations --Star Clusters & Resolved Stellar Populations Project description: The wavelength-dependent light dimming (extinction) due to dust is usually described by analytical formulae, the strength of extinction parametrised e.g. by E(B-V) = difference between extinction in the B and in the V band. In principle, by comparing spectra reddened by a given extinction law with a given E(B-V) to the unreddened spectra should yield the input E(B-V) value. However, first tests show that this in true only for a small range in the parameter space. Following discussions with Daniela Calzetti, this effect seems to be known of to observers, though was never systematically studied, despite errors as large as 20%. The student will test and quantify the deviations of the real values from the input parameters. The results will be published to give observers a guide how to correct their observations accordingly. 3) Project name: "Parameter determination of star clusters: Which tool to use?" Project supervisor: Dr Peter Anders, Prof Henny Lamers, Dr Soeren Larsen research area, choose from: -Evolution of Stars and Stellar Populations --Star Clusters & Resolved Stellar Populations Project description: Star clusters are a powerful tool to examine the properties of galaxies. They are bright (=easy to detect) and are normally well-seperated (=can be studied individually). By comparing their integrated magnitudes in a range of passbands to evolutionary synthesis models one can determine the physical parameters of each cluster. A number of programs to perform this comparison (including error estimates of the resulting parameters) was developed, mainly based on Chi^2 minimization techniques. To which degree these various tools give similar results is largely unstudied, though. The student will learn about evolutionary synthesis modelling and parameter determination. By using synthetic and/or observed cluster photometry (s)he will study how different the results determined by the analysis tools are, and how reliable parameter estimates based on different analyses can be. Master project: --------------- 1) Project name: "The young star clusters in the nearest major galaxy merger, the Antennae Galaxies" Project supervisor: Dr Peter Anders, with additional support by Prof. Uta Fritze-v. Alvensleben (U Hertfordshire, UK), a leading expert in photometric star cluster modelling and Prof Richard de Grijs (U Sheffield, UK & U Beijing, China) on observational aspects Image: http://antwrp.gsfc.nasa.gov/apod/image/0610/antennae_hst_big.jpg research area: -Evolution of Stars and Stellar Populations --Star Clusters & Resolved Stellar Populations Project description: Background: Star clusters can be found in almost every galaxy observed to date. The study of extragalactic star clusters, especially of young star clusters in actively star forming regions, has received much interest in the past years, in particular due to the superb spatial resolution of the Hubble Space Telescope. Star clusters can be studied individually to much greater distances and in more detail/with less restricting assumptions than individual stars or integrated galaxy light (because all stars in a star cluster have the same age and metallicity). By comparing observed cluster photometry with star cluster models one can derive the physical parameters, like ages and masses, of the observed clusters. The age distribution of star clusters gives strong hints on the star formation history of the host galaxy/galaxies, like pronounced bursts of star formation or a more continuous one. The mass distribution (or more observationally, the luminosity distribution) holds vital clues on the physical processes underlying star (cluster) formation. The main question here is: Do the properties of the young star clusters are either similar to the star cluster progenitors (i.e. giant gas clouds) or to their potential successors (i.e. old globular clusters)? Aims: The student will study primarily the luminosity distributions and other parameter distributions of the (young) star clusters in the nearest major galaxy merger, the Antennae galaxies. This study will help to answer the question whether star formation in a highly active star forming region like in a galaxy merger is alike or fundamentally different compared to less actively starforming galaxies nearby. This is a long standing and controversial question in modern astrophysics. Techniques: The project combines observational as well as theoretical aspects. On the observational side, the student will learn to retrieve, reduce and analyse optical HST imaging data (the main data are the new high spatial-resolution dataset from HST/ACS), wherever possible supplemented by near-UV and near-infrared HST observations. The theoretical side introduces photometric modelling and analysis of the observations (to determine the physical properties of the star clusters), using one of the world-leading codes for star cluster (and galaxy) analysis.