Paper

High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Tanaka, T, Aharonian, F, Borowska, J, Shapopi, J N S, Einecke, S, Sharma, A, Kostunin, D, Steinmassl, S, Panter, M, Cerruti, M, Jamrozy, M, Montanari, A, Holler, M, Sol, H, Celic, J, B Bi, Kosack, K, Backes, M, Fegan, S, Vecchi, M, Katarzynski, K, Schüssler, F, Burger-Scheidlin, C, Olivera-Nieto, L, Reville, B, Casanova, S, Gabici, S, Leuschner, F, Funk, S, Batzofin, R, Brun, F, Khatoon, R, Pühlhofer, G, J -P Lenain, Regeard, M, Wierzcholska, A, Mohrmann, L, Peron, G, Dmytriiev, A, Spencer, S, Vink, J, Mbarubucyeye, J Damascene, Hofmann, W, Marinos, P, Kluzniak, W, Terrier, R, Rieger, F, Tsirou, M, Feijen, K, Schäfer, J, Zdziarski, A A, Ren, H, Wach, T, Ostrowski, M, Huang, Zhiqiu, Mitchell, A, Glicenstein, J F, Punch, M, M de Bony de Lavergne, Moulin, E, Marx, R, Reis, I, Cotter, G, Schutte, H M, Zywucka, N, Salzmann, H, Bruno, B, Kasai, E, Djuvsland, J, Egberts, K, Moderski, R, Lang, R G, Takahashi, T, Boisson, C, Wagner, S J, Heß, B, Chandra, S, Bernlöhr, K, Khelifi, B, Leitl, F, Pensec, U, Böttcher, M, Niemiec, J, Bouyahiaoui, M, Marti-Devesa, G, de Naurois, M, Suzuki, H, Lemoine-Goumard, M, Zacharias, M, Quirrenbach, A, Bolmont, J, V Barbosa Martins, Marandon,

2024

Overview

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than \\(10^{4}\\). The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from \\(\\Gamma_1 = 3.25\\) \\(\\pm\\) 0.02 (stat) \\(\\pm\\) 0.2 (sys) to \\(\\Gamma_2 = 4.49\\) \\(\\pm\\) 0.04 (stat) \\(\\pm\\) 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms.

• Publisher: Cornell University Library, arXiv.org
• Subject: Constraints / Cooling rate / Cosmic ray propagation / Dark matter / Electrons / Particle accelerators / Positrons