A novel approach to optimizing the image cleaning performance of Imaging Atmospheric Cherenkov Telescopes: Application to a time-based cleaning for H.E.S.S

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Ćelić, Jelena, Lang, Rodrigo Guedes, Steinmassl, Simon, Hinton, Jim, Funk, Stefan
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866915375654895616
author Ćelić, Jelena
Lang, Rodrigo Guedes
Steinmassl, Simon
Hinton, Jim
Funk, Stefan
author_facet Ćelić, Jelena
Lang, Rodrigo Guedes
Steinmassl, Simon
Hinton, Jim
Funk, Stefan
contents This study introduces a time-based cleaning method for H.E.S.S. using CT5 in monoscopic mode and presents an optimization workflow for image-cleaning algorithms to enhance telescope sensitivity while minimizing systematic biases. We evaluate three methods - tail-cut cleaning and two flavours of time-based cleaning TIME3D and TIME4D - and find best-cut configurations for two cases: optimal overall sensitivity and minimal energy threshold. TIME3D achieves a $\sim 15\%$ improvement with regard to the standard tail-cut cleaning for $E < 300$ GeV, with a $\sim 200\%$ improvement for the first energy bin (36.5 GeV < E < 64.9 GeV), providing a more stable performance across a wider energy range by preserving more signal. TIME4D achieves a $\sim 20\%$ improvement at low energies due to superior NSB noise suppression, allowing for an enhanced capability of detecting sources at the lowest energies. We demonstrate that using first-order estimations of the performance of a cleaning, such as image size retaining or NSB pixel reduction, cannot provide a full picture of the expected result in the final sensitivity. Beyond expanding the effective area at low energies, sensitivity improvement requires precise event reconstruction, including improved energy and directional accuracy. Enhanced gamma-hadron separation and optimized pre-selection cuts further boost sensitivity. The proposed pipeline fully explores this, providing a fair and robust comparison between different cleaning methods. The method is general and can be applied to other IACT systems like VERITAS, MAGIC. By advancing data-driven image cleaning, this work lays the groundwork for detecting faint astrophysical sources and deepening our understanding of high-energy cosmic phenomena.
format Preprint
id arxiv_https___arxiv_org_abs_2503_22361
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A novel approach to optimizing the image cleaning performance of Imaging Atmospheric Cherenkov Telescopes: Application to a time-based cleaning for H.E.S.S
Ćelić, Jelena
Lang, Rodrigo Guedes
Steinmassl, Simon
Hinton, Jim
Funk, Stefan
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
This study introduces a time-based cleaning method for H.E.S.S. using CT5 in monoscopic mode and presents an optimization workflow for image-cleaning algorithms to enhance telescope sensitivity while minimizing systematic biases. We evaluate three methods - tail-cut cleaning and two flavours of time-based cleaning TIME3D and TIME4D - and find best-cut configurations for two cases: optimal overall sensitivity and minimal energy threshold. TIME3D achieves a $\sim 15\%$ improvement with regard to the standard tail-cut cleaning for $E < 300$ GeV, with a $\sim 200\%$ improvement for the first energy bin (36.5 GeV < E < 64.9 GeV), providing a more stable performance across a wider energy range by preserving more signal. TIME4D achieves a $\sim 20\%$ improvement at low energies due to superior NSB noise suppression, allowing for an enhanced capability of detecting sources at the lowest energies. We demonstrate that using first-order estimations of the performance of a cleaning, such as image size retaining or NSB pixel reduction, cannot provide a full picture of the expected result in the final sensitivity. Beyond expanding the effective area at low energies, sensitivity improvement requires precise event reconstruction, including improved energy and directional accuracy. Enhanced gamma-hadron separation and optimized pre-selection cuts further boost sensitivity. The proposed pipeline fully explores this, providing a fair and robust comparison between different cleaning methods. The method is general and can be applied to other IACT systems like VERITAS, MAGIC. By advancing data-driven image cleaning, this work lays the groundwork for detecting faint astrophysical sources and deepening our understanding of high-energy cosmic phenomena.
title A novel approach to optimizing the image cleaning performance of Imaging Atmospheric Cherenkov Telescopes: Application to a time-based cleaning for H.E.S.S
topic High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2503.22361