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Lehrstuhl für Astronomie

AG Mannheim · AG Kadler· AG Dröge

Gamma-Ray Astronomy

MAGIC is a system of two 17m Cherenkov telescopes, equipped with classical photo-multipliers on the Canary Island of La Palma.  This highly sensitive system explores cosmic gamma-ray sources, such as gamma ray bursts, active galactic nuclei, supernova remnants and pulsars.  The group has access to observing time.  Projects involve data taking shifts on La Palma, data analysis and the theoretical interpretation of the data in the context of a large international collaboration.

FACT is the First G-APD Cherenkov Telescope located right next to the MAGIC telescopes on La Palma, and a technological pathfinder for CTA. The major scientific goal is the long-term monitoring of bright TeV blazars. Possible topics range from rather technical projects, over data analysis and simulation, to interpretation of results and studies including other wavelengths. Also topics including a lot of programming (e.g. for aerospace informatics - marked as [info]) are possible. Depending on the scope of the project, it is possible to conduct it as student project [S], bachelor thesis [B], master thesis [M] or PhD [P] thesis. Some topics can be extended or combined to more extensive theses in case of interest. Both English and German are possible for the theses. In all projects, remote observations with FACT are possible. More information on the project and further reading: 


More FACT/MAGIC topics are available. For more information, please contact dorner<at>astro.uni-wuerzburg.de

Influence of wobble positions on the data quality
In Cherenkov astronomy the so-called wobble mode is used to increase the sensitivity of the instrument and avoid gaps in the observation. Instead of observing the source first in on-mode and then observe a dark patch in the sky to determine the background, the source is observed 0.6 degree off-centre to determine both the on- and the off-measurement from the same FoV simultaneously. Having a bright star in the FoV, as it is the case for the observations of the Crab Nebula, can influence the homogeneity of the camera. The aim of this work is to study the influence of the wobble position on the analysis result. The work could also include Monte Carlo simulations or analysis of different sources for more investigations. [B,M]
Rain sensors 
Aiming at robotic operation, knowing the weather conditions is very important for FACT. For example in case of rain, operation should be stopped and the camera lid closed. To do so, the automatic operation system needs to know whether it is raining. Other weather conditions as fog should be clearly distinguished from this. One idea is to use rain sensors as in cars. The aim of this work is to do a small test setup to study whether such sensor provide the needed information and work in all possible conditions. Further steps could be onsite tests and an implementation to the operation system. [B,M]
Development of Observation Strategy
One of the major goals of FACT is the long-term monitoring of bright TeV blazars. Depending on the flux of the source, a flux measurement can be achieved in a few minutes or many hours of observation are needed. To study the blazars in detail a light curve with high sampling density is needed. The aim of the project is to evaluate different observing strategies optimizing the scientific outcome of the FACT observations. It is possible to include in this topic the evaluation of gamma-ray-burst alerts. [B,M]
GRB observation strategy for FACT
Aiming at new interesting physics, gamma-ray-burst (GRB) could be interesting targets for FACT. As these bright phenomena are very short in time, a special alert network (GCN) exists. FACT is already receiving these alerts, but does not evaluate them or do any observations of GRBs. The aim of the project is to evaluate the logs of previous alerts to develop a observation strategy. This may include the implementation of the evaluation of and reaction to GCN alerts in the automatic operation system. [B,M]
Analysis of 1ES 1959+650 observations by FACT
Having the goal of long-term monitoring of bright TeV blazars, FACT is observing a sample of about 5 sources. So far mainly the two brightest sources Mrk421 and Mrk501 have been studied in detail. Also from 1ES 1959+650 more than 200 hours of data are available. The aim of this project is to analyse all data of this source checking also the light curve for short-term flares. The project can be extended by small improvements of the analysis chain or small data quality studies (as described in other projects). [B,M,P]
Webinterface to reset analysis
In FACT, the processing of the data is done with an automatic pipeline where the status is stored in a mysql database. Reprocessing can be done by resetting the content of the database. The aim of the project is to program a webinterface or graphical interface to allow to reset without having to know the underlying database. [B,info]
Improvement of Analysis Methods
The first step of the FACT analysis chain is the detector calibration. Recently, a new calibration has be implemented using the advantage of the stable performance of the G-APDs. The aim of the project is to evaluate the new calibration and check the consistency of the results. [B,M]
Improvement of Analysis Methods
The major information used in the analysis are the light content and arrival time of each pixel of the 1440 pixel camera of FACT. Therefore, one important part of the analysis is the extraction of these values from the pulse stored by the data acquisition. The aim of the project is to evaluate and optimize the signal and timing extraction and check the influence on the result. Implementing and testing of a new algorithm is a possible extension of the project. [B,M]
Improvement of Analysis Methods
After detector calibration and signal extraction, the next step of the analysis is the image cleaning where pixels containing only noise are removed from the image. The aim of the project is to study different image cleaning algorithms and compare the results. Implementing and testing of a new algorithm is a possible extension of the project. [B,M]
Flare alerts
On-site there is a quick look analysis running which is analysing the data once they are written to disk. This has been set up to be able to send fast alerts to other instruments and trigger multi-wavelength observations. Aim of the project is to evaluate the existing data and define based on this an algorithm for the decision when to send an alert. In addition, a webinterface where people can register for receiving alerts and setting trigger criteria themselves could be done. [B,M,info]
Quick look analysis website
On-site there is a quick look analysis running which is analysing the data once they are written to disk. This has been set up to be able to send fast alerts to other instruments and trigger multi-wavelength observations. So far the quick look analysis produces light curve plots from a mysql database which are then displayed on a website. The aim of the project is to program a webinterface to display the light curves directly from the database. [B,M,info]
Automatic ratescans
FACT is aiming at fully robotic operation. A large fraction of the data taking procedure has been automatized already. Few measurements still need manual interaction of the observer, like e.g. the ratescans where a dark patch at small zenith distance has to be chosen. The aim of the project is to write a program which evaluates a star catalog and suggests possible rate scan positions to the user. In addition this algorithm could be implemented to the data takin procedure. [B,info]
General list of possible topics:
  • data analysis
  • interpretation of results
  • correlation with other wavelengths
  • simulations
  • small hardware projects