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PD Dr. rer. nat. habil. Jochen Greiner

Phone
30000-3847
Room
E-Mail
gu56sil@mytum.de
Links
Homepage
Page in TUMonline
Group
Max-Planck-Institue for Extraterrestrial Physics (MPE)
Job Title
PD at the Physics Department

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Die Physik von GRB Spektren
Gamma-ray bursts (GRBs) are flashes of gamma-rays resulting from the death of massive stars or the merger of neutron stars. Both are good candidates for neutrino production, and the latter also produce gravitational waves. The presently most prolific GRB detector is the "Gamma-Ray Burst Monitor" (GBM) on the Fermi satellite, containing 12 NaI scintillation detectors. The measured gamma-ray spectra can be fit with either heuristic functions (e.g. cut-off powerlaw) or physical models (synchrotron), but no consensus has been reached about the physical nature of the emission.

This thesis shall investigate a newly developed model, so-called proton synchrotron radiation. This shall be done by creating a large set of template spectra (with existing code), and fit those to the Fermi/GBM data of selected bright GRBs. This model provides a direct route for neutrino production, and thus has interesting implications for IceCube detections.

Technically, this thesis involves (i) learning the basics of GRBs, (ii) data analysis of non-imaging gamma-ray detectors, (iii) understanding and correcting detector effects, (iv) 'big-data' handling wrt. creating many thousands of template spectra, (v) fitting models to data and understanding the underlying (Bayesian) statistics.

Some background in astrophysics is advantegeous. Python knowledge is required, as well as good programming skills.

Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Jochen Greiner
GRB Lokalisierung mittels Triangulation
Gamma-ray bursts (GRBs) are flashes of gamma-rays resulting from either the death of massive stars (leading to long-duration GRBs) or the merger of two neutron stars (short-duration GRBs). Since the discovery of gravitational waves in conjunction with a short GRB in August 2017, the quest of accurately localizing short GRBs is of utmost importance. Present detectors with good localization capability detect predominantly long-duration GRBs, while detectors sensitive to short GRBs have bad localization accuracy.
We have developed a new concept for GRB light curve cross-correlation using Bayesian model forward-folding, which should provide more accurate localisations for GRBs than previous triangulation methods. The thesis shall take our code and implement it in our existing GRB reduction pipeline for the Fermi-GBM satellite by adding the INTEGRAL/ACS data. This shall allow to rapidly (within minutes) provide accurate localization annuli, providing a proof of concept for the new method. Moreover, comparison with the 30% GRB fraction which is also localized by the Swift satellite, the performance of the new method can be determined.
Technically, this thesis involves learning of (i) data analysis of non-imaging gamma-ray detectors, (ii) understanding and correcting detector effects, (iii) understanding low-count and Bayesian statistics, and (iv) learn about the forward-folding approach for light curve cross-correlation which is independent of the temporal binning of the data.
Some background in astrophysics is advantegeous. Python knowledge is required, and good programming skills and interest in Bayesian statistics are helpful. 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
Populationsanalyse von kurzen GRBs und Super-Ausbruechen von Magnetaren
Giant flares are known from very exceptional cases in our Galaxy and the Magellanic Clouds. When such flares are observed from outside the Galactic plane, they are indistinguishable from short GRBs. The population analysis aims at identifying the fraction of short GRBs which could be mis-identified as magnetars in bright nearby galaxies.
suitable as
  • Master’s Thesis Nuclear, Particle, and Astrophysics
Supervisor: Jochen Greiner
Untersuchung verschiedener Transient-Klassen mittels Fermi/GBM Daten
The recent detection of gravitational waves (GW) with the advanced LIGO/Virgo instruments in conjunction with a short gamma-ray burst (GRB) has surprised gamma-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 a previous Master thesis we have developed an automated search for gamma-ray transients in Fermi/GBM data.
This thesis shall improve this new procedure, and establish a Python program for recognizing certain types of transient sources. The work also involves learning about different transient source types, and their X-ray and gamma-ray characteristics.
The project includes elements from computational and observational high-energy astrophysics, and will allow for obtaining extensive knowledge on the broad class of high-energy transients. Some background in astrophysics is advantageous, 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
  • Bachelor’s Thesis Physics
Supervisor: Jochen Greiner
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