Andreas Zoglauer

High-energy Astrophysics and beyond

The COSI gamma-ray telescope minutes before launch on a NASA super-pressure balloon from Wanaka, New Zealand. (Image credit: NASA/Bill Rodman)

The Universe in the hard X-ray and the medium-energy gamma-ray regime, ranging from a few ten keV up to several tens of MeV, is characterized by the most violent explosions (such as supernova) as well as the most powerful and dynamic sources (pulsars, AGNs, etc). The high penetration power of those X- and gamma rays allows a unique view into the inner engines of those objects, which are hidden at lower energies, and the nuclear lines generated by the decay of newly generated nuclei allow to decipher the origin of the elements.

My research concentrates on the next generation of space telescopes which will unravel the secrets of high-energy astronomy: from the idea to a first design concept and its optimization with detailed Monte-Carlo simulations, from building and calibrating the detectors to launching the full telescope into space, and to finally analyze all the gathered data. The leading instrument of this class is COSI, the Compton Spectrometer and Imager. COSI can be seen in the image minutes before its 2016 launch on a super-pressure balloon from Wanaka, New Zealand, to observe gamma-ray bursts and their polarization, Galactic nucleosynthesis and annihilation, as well as compact objects, such as pulsars and black holes.

This new generation of telescopes needs a leading edge software tool-set for simulation, performance estimation, calibration, data reconstruction, and analysis. For this task I have developed MEGAlib - the Medium-Energy Gamma-ray Astronomy library. It encompasses all tools necessary for the next generation of telescopes - in space and on ground. Since this toolset is very versatile and applicable to many different detector designs, MEGAlib allowed me to be involved in a multitude of projects. It all started with MEGA in 1998, a combined Compton scattering and pair creation telescope, which was designed, built, and calibrated at MPE in Garching Germany. Then there is NCT, a balloon-borne Compton telescope which was built in Berkeley and which had several successful stratospheric balloon flights, and its predecessor COSI. HEMI - the high efficiency multi-mode imager - is a combined coded-mask and Compton telescope which we constructed from ground up and flew on a helicopter to measure the contamination near Fukushima. GRIPS, a balloon-borne Compton telescope, is designed to look at the sun and observe solar flares and their polarization. NuSTAR is a very successful NASA space mission to explore the hard X-ray regime with unprecedented sensitivity and angular resolution. And then there are many instrument concepts and studies, in which MEGAlib (and therefore I) took a central role to simulate and optimize their design: ACT, GRIPS, GRI, GRASP, AstroMeV, GRX, and many more.

MEGAlib was and is used for all those missions, projects, concepts, and studies in some way. MEGAlib has its own website - fell free to take a look and determine for yourself if you can use it for your next X-ray or gamma-ray detector project - it is all open source and completely free!