Lectures

Fall Term

Courses Fall Term 2012:

September 17, 2012 - December 21, 2012

The lectures can be found on KSL: 

 KSL

Praktikum and Lecture Notes

Informations about the Physics beginner practical course can be found on the following Page.

 Physics beginner practical course (Prof. Dr. Wurz Peter)

Curent Bachelor Thesis Projects

1. Formation of astroid families during the formation of Jupiter

In the astroid belt between Mars and Jupiter, several families of astroids with similar orbits exist. In this bachelor thesis it is studied whether these families form during the formation of Jupiter, namely at the moment when Jupiter rapidly accreted a large amount of hydrogen and helium gas to become a gas giant planet. For this, an existing computer code is modified that numerically integrates the orbits of thousands of astroids under the gravitational influence of the forming Jupiter and the Sun. This not only yields a prediction about the resulting asteroid families, but also about the enrichment of Jupiter in other elements besides hydrogen and helium, because many asteroids impact into Jupiter. These predictions are then compared with the observational data on the astroid families and Jupiter's composition. This will allow us to understand at which rate Jupiter accreted gas, and at which position this planet that dominates the dynamics of the Solar System formed.
An animation to this project can be found here (proto-Jupiter is at coordinates 5,0):

 https://www.dropbox.com/s/4bponjiwucglzrj/Distrtibution.mov?dl=0

Contact:  Mordasini(at)mpia.de

2. Long-term evolution of Jupiter and extrasolar planets with a new equation of state

From the observation of the mass and radius of Jupiter, but also of extrasolar planets, it is possible to learn about the internal composition of these planets, which is today only poorly known. However, to do this, an equation of state is necessary that yields for example the density of the material inside of the planets as a function of temperature and pressure. In this bachelor thesis, a new equation of state is coupled with an existing computer code that allows to calculate the internal structure and evolution of giant planets. This new equation of state was derived from quantum-mechanical molecular dynamics simulations. Once coupled, it is studied in the thesis how planets evolve in time (how they cool and contract from their initially hot state). The predicted radius and luminosity of the giant planets at the current age of the Solar System is then compared with observations. This allows to estimate how much ice and rock is contained in these planets, and how strongly this new equation of state differs from older, classical approaches. 

Contact:  Mordasini(at)mpia.de

3. Calculation of a grid of atmospheric models for extrasolar giant planets

The observation of extrasolar planets via spectroscopic measurements of their atmospheres is a fascinating new aspect of modern astrophysics. It allows to measure the pressure and temperature in the atmosphere of planets around other stars, as well as the chemical composition. In this work an existing radiative transfer model for atmospheric structures is used to calculate a grid of atmospheric models for giant extrasolar planets at large distances. The spectra and predicted magnitudes (the luminosity/brightness in a certain wavelength interval) are compared with other atmospheric models. This allows to understand what kind of differences in the composition can be identified with a new observational instrument (SPHERE) that was recently installed at the Very Large Telescope (VLT) in Chile.

Contact:  Mordasini(at)mpia.de

4. Edelgase in Eisenmeteoriten

Edelgasmassenspektrometrie ist die momentan sensitivste Analysenmethode, typische Nachweisgrenzen liegen im Bereich von ppt (10-12g/g) oder darunter. Wir haben nun eines unserer Edelgasmassenspektrometer mit einem Laserablationssystem verbunden, um die guten Nachweisgrenzen mit einer hohen Ortsauflösung zu kombinieren. Dieses System wird momentan ausserordentlich erfolgreich für Mineralseparate aus Steinmeteoriten verwendet. Im Rahmen der Bachelorarbeit soll nun das Verfahren auf eisenreiche Minerale aus Eisenmeteoriten angewendet werden. Ziel ist es, He, Ne, Ar, Kr, und Xe-Isotope in Troilit (FeS), einem wichtigen Mineral in vielen Eisenmeteoriten, zu messen. Die Ergebnisse der Xe-Messungen werden uns dabei helfen quantitative Aussagen über die Konstanz der kosmischen Teilchenstrahlung zu machen.

Ansprechpartner: Prof. I. Leya, Parkterrasse 331a, Tel 4413,
Email:  Ingo.Leya(at)space.unibe.ch

5. ILENA

Die Gruppe von Prof. Peter Wurz hat in den letzten Jahren ein einzigartiges Konzept entwickelt, um niederenergetische neutrale Teilchen im Weltraum zu messen. Das Hauptproblem im Nachweis von diesen neutralen Teilchen ist es, dass die Teilchen zuerst ionisiert werden müssen, bevor sie analysiert werden können, und die Bedingungen an Bord eines Satelliten stellen dabei ganz besondere technologische Herausforderungen. Die Lösung dieses Problems ist es, die neutralen Teilchen mittels Stossionisation bei Streuung an einer Oberfläche zu ionisieren, und Instrumente, die nach diesem Konzept funktionieren, sind mittlerweile an mehreren Weltraummissionen beteiligt, wie z.B. Chandrayaan-1 (Mond, Indien), IBEX (interstellares Gas, NASA) und BepiColombo (Merkur, ESA & JAXA). Dabei hat sich gezeigt, dass das Verständnis des Streuprozesses an der Oberfläche von entscheidender Bedeutung für das Verständnis und die Leistungsdaten des gesamten Instrumentes ist.

In der Bachelorarbeit wird es nun darum gehen, den Streuprozess zwischen geeigneten Oberflächen und einfachen Atomen (H, O, ...) zu untersuchen. Dafür steht eine Anlage (ILENA) zur Verfügung, an der nach kurzer Einarbeitungszeit selbstständig gearbeitet werden kann, natürlich mit fortwährender Betreuung.

Interessierte Studenten wenden sich bitte an
Dr. André Galli ( andre.galli(at)space.unibe.ch) oder
Prof. Peter Wurz ( peter.wurz@space(at)unibe.ch).

6. Studies of elemental and isotopic composition to get an insight to age and formation processes of planetary materials

From the measurements of molecular and elemental/isotopic composition one can learn about the formation processes of the solar bodies, one can determine formation and transformation times and get an insight to possible past and current life processes on the planetary surfaces. We have designed a miniature mass spectrometer (LMS) with laser ion source that measures the chemical composition of solid materials. These can be stones, organic deposits, meteorites, or ancient fossils in minerals. LMS has also capabilities for detailed investigations of extraterrestrial samples including meteorites or sample returned from the surfaces of solar bodies by space missions. LMS is planned to be used to search for fossils on the surface of Mars.

We are looking for a talented and motivated person who enjoys experimental physics and have interest in the application of the mass spectrometric methods to study the age of meteorites, search for biomarkers or find the molecular composition of the surface deposits.

Applicants should contact:
PD Dr. Marek Tulej / Prof. Dr. Peter Wurz
Phone +41-31-631 44 26/ +41-13-631 44 19
E-Mail:  marek.tulej(at)space.unibe.ch