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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

Bayesische Modellierung des GRB Nachleuchtens
Gamma-ray bursts (GRBs) are transient objects bright in gamma-rays that result from an intense relativistic stellar explosion. As this explosion expands, it begins to sweep up the surrounding interstellar gas which shines X-rays (so-called afterglow). These X-rays act as unique probes of the gas within the GRBs local host galaxy as they are photo-electrically absorbed by that gas. Thus, the X-ray afterglow can be used to examine the group properties of galactic gas which can shed light on star formation and galaxy evolution. However, to date, no study of properly grouping and analyzing these gas properties exists.

This thesis will use real and simulated data and an existing Bayesian hierarchal modeling software to explore the group properties of interstellar gas via the simultaneous fitting of X-ray spectra obtained with the Swift X-ray telescope (XRT). Comparisons of existing methodologies will be performed to understand the trade-offs of analyzing individual x-ray spectra with existing x-ray analysis software (3ML) vs dedicated hierchcical models. Finally, the observed properties will be compared to predictions of galaxy formation simulations.

Technically, this thesis involves (i) understanding GRB afterglows and their use as interstellar gas probes, (ii) simulation of a population of GRBs with existing with existing software, (iii) analysis of big-data sets via hierarchical Bayesian modeling, (iv) acquisition and reduction of XRT x-ray spectra (v) communication of results and advanced data visualization.

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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