High-resolution studies of protoplanetary disks [Elektronische Ressource] / presented by Oliver Schütz

Dissertationsubmitted to theCombined Facultiesfor the Natural Sciences and for Mathematicsof the Ruperto-Carola Universityof Heidelberg, Germanyfor the degree ofDoctor of Natural Sciencespresented by¨Dipl.-Phys. Oliver Schutzborn in: Munich, GermanyOral examination:February 9th, 2005High-Resolution Studies ofProtoplanetary DisksReferees: Prof. Dr. Thomas HenningProf. Dr. Immo AppenzellervAbstract:This work presents a multi-wavelength search (near-IR, mid-IR, mm) for previously unknowncircumstellar disks and a study of those disk candidate objects which are not yet well char-acterised in the literature. 22 candidate stars, most of these constituting known exoplanetsystems, were examined for circumstellar material using the Adaptive Optics instrument ADO-NIS at La Silla Observatory (Chile). With the new Adaptive Optics system NAOS-CONICAat Paranal (Chile) we tested the technique of Polarimetric Differential Imaging. Advances inmid-IR data reduction were achieved, e.g., a method was developed to correct the chromaticand airmass dependent extinction. We show new N-band photometry and spectra for eightpre-main sequence stars, six main sequence stars and one post-MS object using the TIMMI2camera at La Silla, and model the emission spectra with a mixture of silicates consisting ofdifferent grain sizes and composition. The most important result thereof is the discovery oftwo previously unknown circumstellar disks around HD 72106 and HD 113766.