Universität zu Köln

Graf, Sabine (2022). Planet-disk interactions in the binary system Kepler-38 and contribution to the METIS/ELT instrument. PhD thesis, Universität zu Köln.

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Abstract

The scope of this dissertation is two-fold. The first part studies the planet-disk interactions in the binary system Kepler-38. Close binary stars like Kepler 38 hosting a circumbinary planet are, with 23 systems known, not unusual. A number of those systems exhibit a non-zero mutual inclination between the planetary orbit and the orbital plane of the central binary. Such systems are excellent laboratories to test theories describing the dynamical interactions between the binary star, the primordial circumbinary disk and the planet during its formation process. In order to address the question of the physical mechanisms at the origin of the observed misalignment between any of the three different components of the system (binary star, CB planet, CB disk), three-dimensional hydrodynamic simulations are required. In this thesis, in contrast to previous works, the orbital evolution of a circumbinary Saturn-Mass planet in a scenario of primordial co-alignment of the system (binary orbit, planet orbit, disk mid-plane) is studied. Based on the hypothesis that due to the tidal influence of the central binary turbulence across the disk develops, such turbulence could generate hydrodynamical forces onto an existing, migrating, planet, in a plane not co-planar with the binary orbit and the disk mid-plane. This could trigger an initial inclination of the planet orbit, which can be investigated with three-dimensional hydrodynamical codes (and only with 3D codes). As such inclination effects are expected to be small, the system Kepler 38 is adopted as a test case, in which the circumbinary planet is tilted by less than 0.2°, and it is investigated how the disk properties (in particular its mass and viscosity) combined to the dynamical interaction with the central binary may result in inhomogeneities in the vertical disk’s structure that may directly influence the inclination of the planetary orbit. In particular, the comparison between the single star and binary star cases evidences the possible role of the binary-excited turbulence to induce a non-zero mutual inclination. The second part of this dissertation describes the laboratory research work completed for the METIS project, one of the first-light instrument of the ELT with high relevance of high angular resolution studies of circumstellar disks and binary systems. The mid-infrared imager and spectrograph (METIS) will be equipped with a warm calibration unit (WCU), which is developed at the University of Cologne. Its task will be to deliver simulated sources for the test and calibration of the METIS instrument. In this thesis, general concepts of the WCU are presented together with the laboratory work to validate those concepts. This thesis aimed to produce the prototyping measurement to document and verify the temporal and spatial properties delivered by the integrating sphere. Furthermore, the calibration accuracy is determined, and the contribution to the development of the aperture mask and the pinhole wheels are presented.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Graf, Sabine sgraf@ph1.uni-koeln.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-640651
Date:	2022
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute of Physics I
Subjects:	Natural sciences and mathematics
Uncontrolled Keywords:	Keywords Language hydrodynamics, methods: numerical, software: simulations, planets and satellites: physical evolution, planet–disk interactions, planet–star interactions, protoplanetary disks -- binaries: close UNSPECIFIED Warm Calibration Unit, METIS, spatial uniformity, integrating sphere, uncooled thermal camera, black body, temporal stability, aperture mask UNSPECIFIED
Date of oral exam:	2022
Referee:	Name Academic Title Labadie, L. Prof. Dr. Eckart, A. Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/64065