An algorithm to resolve γ-rays from charged cosmic rays with DAMPE

• Published in: Research in astronomy and astrophysics Vol. 18; no. 3; pp. 27 - 38
• Main Authors: Xu, Zun-Lei, Duan, Kai-Kai, Shen, Zhao-Qiang, Lei, Shi-Jun, Dong, Tie-Kuang, Gargano, Fabio, Garrappa, Simone, Guo, Dong-Ya, Jiang, Wei, Li, Xiang, Liang, Yun-Feng, Mazziotta, Mario Nicola, Munoz Salinas, Maria Fernanda, Su, Meng, Vagelli, Valerio, Yuan, Qiang, Yue, Chuan, Zang, Jing-Jing, Zhang, Ya-Peng, Zhang, Yun-Long, Zimmer, Stephan
• Format: Journal Article
• Language: English
• Published: Beijing National Astronomical Observatories, CAS and IOP Publishing Ltd 01.03.2018; IOP Publishing
• Subjects: Algorithms; Astrophysics; Charged particles; Chinese space program; Computer simulation; Cosmic rays; Dark matter; Energy; Fluxes; Gamma ray sources; gamma rays: general; instrumentation: detectors; Light curve; methods: data analysis; Monte Carlo simulation; Particle physics; Pulsars; Satellite observation; Space telescopes
• ISSN: 1674-4527
• DOI: 10.1088/1674-4527/18/3/27

The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, which was launched on 2015 December 17, is a new high energy cosmic ray and γ-ray satellite-borne observatory. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy γ-rays with accurate energy, angular and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays, it is challenging to identify γ-rays with sufficiently high efficiency, minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at ∼ 10GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.