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Max-Planck-Institue for Extraterrestrial Physics (MPE)

Research Field

A description of the fascinating research topics follows soon.

Address/Contact

Giessenbachstrasse 1
85748 Garching b. München

Members of the Research Group

Scientists

Other Staff

Teaching

Course with Participations of Group Members

Offers for Theses in the Group

Confinement of charged nanoparticles: Quadrupole Ion Trap - particle detection
Charged particles trapping and isolation, originally started in fundamental physics some 60 years ago, has nowadays numerous applications with interdisciplinary impact from astrophysics to biology. In laboratory astrophysics, ion traps are one of the few instruments allowing studies at conditions approaching those in the interstellar medium, where low temperatures (tens of K) and number densities (<10^10 cm^-3) prevail. In this project the main goal is to develop an detection system for a charged and trapped nanoparticles of sizes ~500 nm in an cryogenic quadrupole ion trap. This is an experimental physics project, the participant will work to integrate the hardware (laser, detector, DAq) together with customised software in order to accomplish the task. This project will offer a deep insight into photon detection using APD (avalanche-photodiode), signal filtering and processing using Fourier transforms and data acquisition using customized hardware. Contact: Dr. Pavol Jusko Prof. Paola Caselli
suitable as
  • Master’s Thesis Nuclear, Particle, and Astrophysics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Frank Eisenhauer
Localizing GRBs with 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
Interferometric imaging with GRAVITY

GRAVITY [1] is a novel instrument which combines the light of four telescope at the ESO VLTI observatory. Employing the techniques of fringe tracking and phase referencing, it allows to measure complex visibilities at IR wavelengths and for imaging at unprecedented angular resolution in this part of the electromagnetic spectrum. Our group's particular interest is the use of GRAVITY for high-precision studies of the galactic center, where it has enabled several breakthrough discoveries [2]. To cope with the data complexity, we are developing a novel imaging code, based on the framework of Information Field Theory [3], which is written in python and based on the NIFTy [4] package. The goal of this master project is to investigate instrumental systematics, their impact on image reconstruction and to implement a model or correction. Eventually, a better description of the instrument will push the sensitivity towards fainter objects and allow to study Sagittarius A*, the radio source associated with the massive black hole in the center of the Milky Way, in greater detail.

Contact: Dr. Julia Stadler <jstadler@mpe.mpg.de>


[1] GRAVITY collaboration, "First light for GRAVITY: Phase referencing optical interferometry for the Very Large Telescope Interferometer", Astronomy & Astrophysics, Volume 602, id.A94, 23 pp.

[2] GRAVITY collaboration, "GRAVITY and the Galactic Center", ESO Messenger Vol. 178, 2019

[3] T. Enßlin, "Information Theory: Information Theory for Fields", Annalen der Physik, vol. 531, issue 3, p. 1970017

[4] P. Arras et al., " NIFTy5: Numerical Information Field Theory v5", Astrophysics Source Code Library, record ascl:1903.008

suitable as
  • Master’s Thesis Nuclear, Particle, and Astrophysics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Frank Eisenhauer
Studying the chemical signature of protostellar binary interactions through simulations

More than half of the stars forms in multiple systems. The dynamical interactions between the multiple stars can have a profound influence on the formation and evolution of stars and planets. This, however, is not well understood, especially at the early stages of star formation, due to the difficulty of observing young stars obscured by its surrounding natal cloud. Recent high-resolution ALMA (the Atacama Large Millimeter/submillimeter Array) observations have spatially resolved the emission from complex organic molecules around a very young protostellar binary system [1], also constraining the stellar masses and orbital parameters. The emission from these molecules coincides with features seen in the dust around the binary accretion disks, possibly corresponding to spirals or tightly wound structures. These features are difficult to explain if the emission arises solely due to heating from the forming protostars, the most common scenario used to explain the appearance of warm complex organic molecule emission around protostars. We propose to investigate the role of shocks created by the binary interactions in the production and distribution of molecular tracers at scales from a few up to 100 astronomical units. Gravitational forces from the binary stars can create shocks in the disk surrounding them. Detailed numerical simulations will be needed to investigate the temperature and density structure created by the interaction. This study will shed light on how the binary interactions can influence the chemical inventory in multiple systems at planet formation scales. During this master project, the student will carry out 3D hydrodynamical simulations with the orbital and gas properties observed in the protostellar binary [2]. Detailed thermo-dynamics will be built to investigate the origin of the high temperature and density tracers seen in the gas phase towards this embedded binary system. The student will analyze the spirals or other types of shocks features formed in the simulations, and how it depends on the numerical and physical parameters.

Prerequisites: Basic knowledge in programming (C/C++ and Python will be used).

Contact: Dr. Munan Gong <munan@mpe.mpg.de>, Dr. Maria Jose Maureira <maureira@mpe.mpg.de>, Prof. Dr. Paola Caselli <caselli@mpe.mpg.de>

[1] Maureira et el. 2020, "Orbital and Mass Constraints of the Young Binary System IRAS 16293-2422 A". The Astrophysical Journal 897.

[2] Moody et al. 2019, "Hydrodynamic Torques in Circumbinary Accretion Disks", The Astrophysical Journal 875.

suitable as
  • Master’s Thesis Nuclear, Particle, and Astrophysics
Supervisor: Frank Eisenhauer
Testing an Anger camera for gamma-ray spectroscopy

The improvements of Silicon photo-multipliers (SiPM) over the last years qualify them as promising replacements for classical photo-multiplier tubes (PMT). This is particularly interesting for cases where the high voltages and large dimensions of PMTs are difficult to afford, such as for space applications. For the simplest version of gamma-ray detectors, a scintillator crystal read out by SiPMs, the size of the scintillator determines the sensitivity, and thus should stay large. This suggests an Anger camera principle as the most efficient way for a gamma-ray detector in space: a mosaic of sparsely distributed single-cell SiPMs instead of the coverage of the full scintillator area.

This Master thesis shall test and optimize a 5x5 cm^2 sized CeBr3 scintillator read out with a mosaic of SiPMs. Measurements of the spatial and spectral resolution as well as efficiency (noise) and power consumption are foreseen, and form the basic parameters for the trade-off study. The set-up has two potential applications: (i) in the ComPol Cubesat mission pursued within the Origins Cluster of Excellence, and (ii) the POLAR-2 gamma-ray burst polarisation mission developed within the SFB "Neutrinos and Dark Matter".

Interest in electronics and ASIC readout is required, and some background in astrophysics is advantegeous. The lab-work will be done at MPP Freimann, shared with Prof. S. Mertens group.
 
Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

suitable as
  • Bachelor’s Thesis Physics
  • Master’s Thesis Nuclear, Particle, and Astrophysics
Supervisor: Jochen Greiner
Studying gamma-ray transients
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 two previous Bachelor theses we have developed a physical background model, and an ongoing Master thesis is finalizing the development of an automated daily search for gamma-ray transients in Fermi/GBM data. This thesis shall be devoted to establishing a Python program for studying these newly identified transients, i.e. localize them on the sky, and derive basic properties (spectrum, light curve), and obtain follow-up observations. Two potential sub-topics to focus on are (i) so-called ultra-long GRBs, a rare sub-class, or (ii) the predicted seasonal variation of the gamma-ray background due to axions. 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 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 Condensed Matter Physics
Supervisor: Jochen Greiner
Improving the localization of 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

Current and Finished Theses in the Group

Testing mass measurements of clusters of galaxies
Abschlussarbeit im Masterstudiengang Physik (Kern-, Teilchen- und Astrophysik)
Themensteller(in): Frank Eisenhauer
Abschlussarbeit im Masterstudiengang Physics (Applied and Engineering Physics)
Themensteller(in): Frank Eisenhauer
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