arXiv subjects

Fabian Leuschner

Publications and source records attributed to Fabian Leuschner.

4 recordsLinked to original sources

arXiv2024

H.E.S.S.: The High Energy Stereoscopic System

The High Energy Stereoscopic System H.E.S.S. is an array of Cherenkov Telescopes located in the Khomas Highlands in Namibia. H.E.S.S. started operations in 2003 and has been operated very successfully since then. With its location in the Southern hemisphere, the system provides a privileged view of the Milky Way and the Galactic center region. With H.E.S.S., a large variety of new TeV emitters has been discovered, both in our Galaxy and in extragalactic space. We provide a description of the individual telescopes and of the system as a whole, and review the scientific highlights that have been achieved with the instrument.

astro-ph.IM↗

arXiv2023

Validating Monte Carlo simulations for an analysis chain in H.E.S.S

Imaging Air Cherenkov Telescopes (IACTs) detect very high energetic (VHE) gamma rays. They observe the Cherenkov light emitted in electromagnetic shower cascades that gamma rays induce in the atmosphere. A precise reconstruction of the primary photon energy and the source flux depends heavily on accurate Monte Carlo (MC) simulations of the shower propagation and the detector response, and therefore also on adequate assumptions about the atmosphere at the site and time of a measurement. Here, we present the results of an extensive validation of the MC simulations for an analysis chain of the H.E.S.S. experiment with special focus on the recently installed FlashCam camera on the large 28 m telescope. One goal of this work was to create a flexible and easy-to-use framework to facilitate the detailed validation of MC simulations also for past and future phases of the H.E.S.S. experiment. Guided by the underlying physics, the detector simulation and the atmospheric transmission profiles were gradually improved until low level parameters such as cosmic ray (CR) trigger rates matched within a few percent between simulations and observational data. This led to instrument response functions (IRFs) with which the analysis of current H.E.S.S. data can ultimately be carried out within percent accuracy, substantially improving earlier simulations.

astro-ph.IM↗

arXiv2021

Performance of the New FlashCam-based Camera in the 28\,m Telescope of H.E.S.S

In October 2019, the central 28 m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the Medium-Sized Telescopes of the Cherenkov Telescope Array (CTA), with emphasis on cost and performance optimization and on reliability. The fully digital design of the trigger and readout system makes it possible to operate the camera at high event rates and to precisely adjust and understand the trigger system. The novel design of the front-end electronics achieves a dynamic range of over 3,000 photoelectrons with only one electronics readout circuit per pixel. Here we report on the performance parameters of the camera obtained during the first year of operation in the field, including operational stability and optimization of calibration algorithms.

astro-ph.IM↗

arXiv2021

Science verification of the new FlashCam-based camera in the 28m telescope of H.E.S.S

In October 2019 the central 28m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the medium-sized telescopes of the Cherenkov Telescope Array (CTA). We report here on the results of the science verification program that has been performed after commissioning of the new camera, to show that the camera and software pipelines are working up to expectations.

astro-ph.IM↗