12–23 Jul 2021
Online
Europe/Berlin timezone

Stochastic Fluctuations of Low-Energy Cosmic Rays and the Interpretation of Voyager Data

19 Jul 2021, 18:00
1h 30m
04

04

Talk CRD | Cosmic Ray Direct Discussion

Speaker

Vo Hong Minh Phan (TTK, RWTH Aachen University)

Description

The propagation distances of MeV cosmic rays is significantly limited due to ionisation loss in the interstellar medium. Therefore, the density of cosmic rays will depend sensitively on the exact distribution of the sources in space and time. For an ensemble of source distributions, the fluxes will follow a strongly non-Gaussian distribution. Here, we show that the typical flux, that is the median of the distribution, significantly deviates from the average flux, that is the expectation value of the distribution. Taking this into account allows for a consistent fit of data from Voyager 1 and AMS-02 without any unmotivated breaks in the source spectrum or mean-free path where earlier models needed to introduce those in an ad hoc fashion. We conclude with a discussion of the implication of these results for the discrepancy between the observed and predicted ionization rate induced by low-energy cosmic rays.

Keywords

Cosmic-Ray Transport; Supernova Remnants; Ionization Rate; Stochastic Fluctuations

Subcategory Theoretical Results

Primary authors

Vo Hong Minh Phan (TTK, RWTH Aachen University) Philipp Mertsch (TTK, RWTH Aachen University) Prof. Stefano Gabici (Université de Paris, APC) Sarah Recchia Mr Florian Schulze (TTK, RWTH Aachen University)

Presentation materials