@article{67148079a43a450aa1daa40035aec02b,
title = "Time variability of TeV cosmic ray sky map",
abstract = "The variation in the intensity of cosmic rays at small angular scales is attributed to the interstellar turbulence in the vicinity of the Solar system. We show that a turbulent origin of the small-scale structures implies that the morphology of the observed cosmic ray intensity skymap varies with our location in the interstellar turbulence. The gyroradius of cosmic rays is shown to be the length scale associated with an observable change in the skymap over a radian angular scale. The extent to which the intensity at a certain angular scale varies is proportional to the change in our location with a maximum change of about the amplitude of intensity variation at that scale in the existing skymap. We suggest that for TeV cosmic rays a measurable variation could occur over a time-scale of a decade due to the Earth's motion through the interstellar medium, if interstellar turbulence persists down to the gyroradius, about 300 μpc for TeV-ish cosmic rays. Observational evidence of the variability, or an absence of it, could provide a useful insight into the physical origin of the small-scale anisotropy.",
keywords = "Cosmic rays",
author = "Rahul Kumar and No{\'e}mie Globus and David Eichler and Martin Pohl",
note = "Funding Information: We thank D. J. McComas, A. Spitkovsky, and E. J. Zirnstein for helpful discussions. We acknowledge support from the Israel-U.S. Binational Science Foundation, the Israel Science Foundation (ISF), the ISF-University Grant Commission (India), and the Joan and Robert Arnow Chair of Theoretical Astrophysics. RK was partially supported by the Max-Planck/Princeton Center for Plasma Physics and NSF grant AST-1517638. NG acknowledges support from the Koret Foundation. MP acknowledges valuable discussion with the team 'The physical of the very local interstellar medium and its interaction with the heliosphere' at the International Space Science Institute in Bern, Switzerland. The analysis in this paper made use of HEALPIX package (G{\'o}rski et al. 2005). Numerical calculations in this paper used computational resources supported by PICSciE-OIT High Performance Computing Center. Funding Information: We thank D. J. McComas, A. Spitkovsky, and E. J. Zirnstein for helpful discussions. We acknowledge support from the Israel-U.S. Binational Science Foundation, the Israel Science Foundation (ISF), the ISF-University Grant Commission (India), and the Joan and Robert Arnow Chair of Theoretical Astrophysics. RK was partially supported by the Max-Planck/Princeton Center for Plasma Physics and NSF grant AST-1517638. NG acknowledges support from the Koret Foundation. MP acknowledges valuable discussion with the team {\textquoteleft}The physical of the very local interstellar medium and its interaction with the heliosphere{\textquoteright} at the International Space Science Institute in Bern, Switzerland. The analysis in this paper made use of HEALPIX package (G{\'o}rski et al. 2005). Numerical calculations in this paper used computational resources supported by PICSciE-OIT High Performance Computing Center. Publisher Copyright: {\textcopyright} 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.",
year = "2019",
month = feb,
day = "11",
doi = "10.1093/mnras/sty3141",
language = "English",
volume = "483",
pages = "896--900",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}