Applications of galactic microlensing [Elektronische Ressource] / by Daniel Kubas

Applications of Galactic MicrolensingbyDaniel KubasA thesis submitted in partial ful llmen t of the requirements for the degree ofDoctor Rerum Naturaliumin Astrophysicsat the Mathematisch-Naturwissenschaftliche Fakult atder Universit at Potsdam.March 31, 2005TO MY GRANDPARENTSILSE, GOTTFRIED, OTTILIE AND LEOMY PARENTS, VERONIKA AND GUNTERMY SISTER ANTONIAAND MR. SPOCK, GOLDENBOY AND CARLOS GARDEL2AbstractSubject of this work is the study of applications of the Galactic Microlensing e e ct, wherethe light of a distant star (source) is bend according to Einstein’s theory of gravity by thegravitational eld of intervening compact mass objects (lenses), creating multiple (howevernot resolvable) images of the source. Relative motion of source, observer and lens leads toa variation of de ection/magni cation and thus to a time dependant observable brightnesschange (lightcurve), a so-called microlensing event, lasting weeks to months.The focus lies on the modeling of binary-lens events, which provide a unique tool tofully characterize the lens-source system and to detect extra-solar planets around the lensstar. Making use of the ability of genetic algorithms to e cien tly explore large and intricateparameter spaces in the quest for the global best solution, a modeling software (Tango) forbinary lenses is developed, presented and applied to data sets from the PLANET microlens-ing campaign.