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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

Detektierung von schwachen Transient Quellen
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 be devoted to test this new procedure, and establish a Python program for studying these newly identified transients in existing data of other missions, primarily the Swift/BAT survey, with the goal of a good localization.
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
Die Physik unterschiedlicher Gammastrahlungs-Transienten
The gamma-ray sky is very active, much more than the optical or X-ray sky. In addition, deep sky surveys for neutrinos, gravitational waves, radio or TeV Transients is presently performed. The understanding of these transients is helped dramatically by using multi-wavelength and multi-messenger information. With two previous Master theses we have developed a sophisticated program package for an automated daily search for gamma-ray transients in Fermi/GBM data, and a subsequent follow-up search in the all-sky Swift survey for better localization.

This thesis shall be devoted to use this software package to (i) detect transients over one year, (ii) analyse the GBM data for these transients (derive position, spectrum), (iii) identify X-ray counterparts with Swift, (iv) establish a "population" analysis of such bright transients according to different source types, (v) correlate with other surveys such as eROSITA, HAWC, SKA, and (vi) investigate the different physical mechanisms underlying the diverse types of transients.

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
  • Master’s Thesis Nuclear, Particle, and Astrophysics
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
Verbesserung der Positionsbestimmung von GRBs

Gamma-ray bursts (GRBs) are flashes of gamma-rays resulting from the death of massive stars or the merger of neutron stars. 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 position is derived by comparing the relative count rates in the differently oriented scintillator planes.

This thesis shall use existing flight data of the brightest gamma-ray source on the sky (the Crab nebula) and improve the spatial resolution of the response matrix of selected detectors. The result shall be tested by localizing selected GRBs with GBM, and comparison against known positions of these GRBs from other satellites (e.g. Swift).

Technically, this thesis involves learning of (i) learning the basics of GRBs, (ii) data analysis of non-imaging gamma-ray detectors, (iii) understanding and correcting detector effects, (iv) fitting light curves with different count statistics, and (v) analyzing and combining large amounts of individual constraints into a coherent picture.

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