PoS - Proceedings of Science
Volume 444 - 38th International Cosmic Ray Conference (ICRC2023) - Cosmic-Ray Physics (Indirect, CRI)
Feasibility of cosmic ray backtracking through future sparse local measurements of the galactic magnetic field
S. Romanopoulos
Full text: pdf
Pre-published on: September 27, 2023
Published on:
Future optopolarimetric surveys of stars, including PASIPHAE and SOUTH POL, offer the potential for acquiring high-quality local measurements of the Galactic magnetic field (GMF) at interstellar cloud locations. However, the inherent sparsity of these measurements raises concerns regarding the feasibility of accurately backtracking Ultra High-Energy Cosmic Rays (UHECR) to their sources, a crucial aspect of charge-particle astronomy. In this study, we assess the accuracy of UHECR backtracking using mock sparse local GMF data derived from the Jansson & Farrar 2012 (JF12) GMF model. By creating 1000 mock UHECR datasets that trace back within a $3^{\circ}$ angular range from the galaxy M82, we investigate the impact of varying GMF measurement sparsity and rescaling of the GMF strength. Our findings demonstrate that an average GMF strength of $1,\mu G$ yields satisfactory backtracking results even with sparse measurements, requiring an average GMF measurement spacing of approximately 1600 pc. However, when the average GMF strength is increased by a factor of 3 or 10, the accuracy of backtracking diminishes significantly, resulting in breakdowns at measurement spacings of 1600 pc and 400 pc, respectively. These findings emphasize the challenges associated with precise charge-particle astronomy using sparse local GMF measurements and underscore the importance of obtaining dense and high-quality GMF data through surveys like PASIPHAE and SOUTH POL to enable accurate backtracking of UHECR.
DOI: https://doi.org/10.22323/1.444.0499
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.