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PD Dr. rer. nat. habil. Jochen Greiner

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Alarm-Software fuer Gammastrahlungs-Transienten

The recent detection of gravitational waves (GW) with the advanced LIGO/Virgo i\nstruments in conjunction with a short gamma-ray burst (GRB) has surprised gamm\a-ray astronomers because of the substantially different properties of the GRB  signal as compared to canonical GRBs. This motivates an "open-mind" search for untriggered transient events in the data stream of the gamma-ray burst monitor (GBM) on the Fermi satellite. With two previous Bachelor theses we have develop\ed a physical background model, paving the way for automated searches, and subs\equent source and background fitting.
 
This thesis shall be devoted to establishing a Python program for identifying l\ong-term (> few minutes up to a year) transients in Fermi/GBM data, localizing \them on the sky, and deriving basic properties (spectrum, light curve). One pot\ential application is to determine the spectral properties of the predicted sea\sonal variation of the background due to axions. The project includes elements from computational and observational high-energy astrophysics, and will allow f\or obtaining extensive knowledge on the broad class of high-energy transients. 
 
Some background in astrophysics is advantegeous, but affinity with Python programming is a must. 
 
Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

suitable as
  • Master’s Thesis Nuclear, Particle, and Astrophysics
Supervisor: Jochen Greiner
GEANT-4 Simulation eines Compton Teleskopes

The COMPTEL instrument measured the 0.7-30 MeV emission of the sky for nearly 10 years in the 90ies. This energy range includes interesting nuclear lines from elements which are produced in the winds of massive stars, or in supernova explosions. In addition, the instrument is a perfect polarimeter - and X-/gamma-ray polarimetry is still considered the holy grail of astrophysics. Even now, 20 years later, its data are unique, and no future mission is on the horizon for the next 20 years. However, our computational tools have drastically improved, allowing analysis types which were completely impractical at the time COMPTEL was operated.

This thesis shall take our mass model and perform GEANT4 simulations for two cases: (i) line emission from stellar gamma-ray sources, and (ii) polarized continuums emission. Based on the simulated data, new cuts in the multi-dimentional data space should be found which separate background photons from source photons. Finally, these cuts should be applied to a test data set of COMPTEL in order to evaluate the improvement in the performance.

Technically, this thesis involves learning about (i) data analysis of Compton gamma-ray detectors, (ii) understanding detector effects, (iii) simulating an observation with different levels of statistics, and (iv) characterizing a multi-dimentional parameter space using e.g. principal component analysis.

Some background in astrophysics is advantegeous, and experience with GEANT4 would be perfect. Some Python knowledge is required. Joy in data analysis is required.

Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

suitable as
  • Bachelor’s Thesis Physics
Supervisor: Jochen Greiner
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