The Unreasonable Effectiveness of the Air-Fluorescence Technique in Determining the EAS Shower Maximum

Autor:	Sokolsky, P., D'Avignon, R.
Rok vydání:	2021
Předmět:	Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Instrumentation and Methods for Astrophysics
Druh dokumentu:	Working Paper
DOI:	10.1134/S1063776122040100
Popis:	We review all existing air-fluorescence measurements of the elongation rate of extensive air showers (slope of mean EAS shower maximum (Xmax) vs log of shower energy E) above 1017 eV. We find remarkable agreement for all current and historic experiments over a 30 year period for the energy range from 1017 to 3x1018 eV. The mean elongation rate in this energy interval is near 80 gm/cm2/decade Above this energy, experiments in the Northern hemisphere are in good agreement with an average elongation rate of 48 +/- 10 gm/cm2/decade while Southern hemisphere experiments have a flatter elongation rate of 26 +/- 2 gm/cm2/decade We point out that, given the agreement at lower energies, possible systematic reasons for this difference are unlikely. Given this, the world elongation rate data alone may indicate a composition difference of UHECR in the Northern and Southern hemisphere and thus a diversity of UHECR sources in the Northern and Southern sky. Comment: Accepted by JETP
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2110.09588 Zobrazit plný text záznamu View this record from Arxiv