Einladung zum Promotionsvortrag von Herrn Giacomo Principe:
„The extremes of the Fermi-LAT energy ranges: the Fermi Low-Energy (1FLE) catalog and a detailed investigation of HESS J1825-137 above 100 GeV“
In the last decades, important improvements have been made in the γ-ray astronomy. Thanks to the fact that photons travel in straight lines it is possible to search and localize the sites where γ rays are produced in the Universe. Several γ-ray source analyses have been performed in the MeV to TeV energies.
The talk focuses on the γ-ray sources observed at the extremes of the Fermi Large Area Telescope (LAT) energy range.
In the MeV range, the imaging Compton telescope (COMPTEL) onboard NASA’s Compton Gamma-Ray Observatory detected sources below 30 MeV, while catalogs of point sources released by the Fermi LAT and EGRET collaborations use energies above 100 MeV. Because the Fermi LAT is able to detect γ rays with energies as low as 20 MeV, the first catalog of γ-ray sources detected with Fermi LAT below 100 MeV has been developed as a part of this thesis. This catalog closes the gap of point source analysis between the COMPTEL catalog and the Fermi-LAT catalogs. The analysis and results of the first catalog of γ-ray sources detected between 30 and 100 MeV with Fermi LAT will be discussed in the first part of the talk.
In the second part of the talk a detailed study of the evolution of the pulsar wind nebula (PWN) HESS J1825-137 is presented. The analysis of the HESS J1825-137 has been performed using 10 years of Fermi-LAT data between 1 GeV and 1 TeV. This PWN is an archetypal system making it a perfect laboratory for studying particle transport mechanisms. Combining this analysis with recent results from the High Energy Stereoscopic System (H.E.S.S.) collaboration enables a more complete picture of the nebula. (Vortrag auf Englisch)
Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.