BibTex format
@article{Desai:2025:2041-8213/ada697,
author = {Desai, MI and Drake, JF and Phan, T and Yin, Z and Swisdak, M and McComas, DJ and Bale, SD and Rahmati, A and Larson, D and Matthaeus, WH and Dayeh, MA and Starkey, MJ and Raouafi, NE and Mitchell, DG and Cohen, CMS and Szalay, JR and Giacalone, J and Hill, ME and Christian, ER and Schwadron, NA and McNutt, RL and Malandraki, O and Whittlesey, P and Livi, R and Kasper, JC},
doi = {2041-8213/ada697},
journal = {Astrophysical Journal Letters},
title = {Magnetic Reconnection-driven Energization of Protons up to ∼400 keV at the Near-Sun Heliospheric Current Sheet},
url = {http://dx.doi.org/10.3847/2041-8213/ada697},
volume = {985},
year = {2025}
}
RIS format (EndNote, RefMan)
TY - JOUR
AB - We report observations of direct evidence of energetic protons being accelerated above ∼400 keV within the reconnection exhaust of a heliospheric current sheet (HCS) crossing by NASA’s Parker Solar Probe (PSP) at a distance of ∼16.25 solar radii (R<inf>s</inf>) from the Sun. Inside the exhaust, both the reconnection-generated plasma jet and the accelerated protons up to ∼400 keV propagated toward the Sun, unambiguously establishing their origin from HCS reconnection sites located antisunward of PSP. Within the core of the exhaust, PSP detected stably trapped energetic protons up to ∼400 keV, which is ≈1000 times greater than the available magnetic energy per particle. The differential energy spectrum of the accelerated protons behaved as a pure power law with spectral index of ∼−5. Supporting simulations using the kglobal model suggest that the trapping and acceleration of protons up to ∼400 keV in the reconnection exhaust are likely facilitated by merging magnetic islands with a guide field between ∼0.2 and 0.3 of the reconnecting magnetic field, consistent with the observations. These new results, enabled by PSP’s proximity to the Sun, demonstrate that magnetic reconnection in the HCS is a significant new source of energetic particles in the near-Sun solar wind. Our findings of in situ particle acceleration via magnetic reconnection at the HCS provide valuable insights into this fundamental process, which frequently converts the large magnetic field energy density in the near-Sun plasma environment and may be responsible for heating the Sun’s atmosphere, accelerating the solar wind, and energizing charged particles to extremely high energies in solar flares.
AU - Desai,MI
AU - Drake,JF
AU - Phan,T
AU - Yin,Z
AU - Swisdak,M
AU - McComas,DJ
AU - Bale,SD
AU - Rahmati,A
AU - Larson,D
AU - Matthaeus,WH
AU - Dayeh,MA
AU - Starkey,MJ
AU - Raouafi,NE
AU - Mitchell,DG
AU - Cohen,CMS
AU - Szalay,JR
AU - Giacalone,J
AU - Hill,ME
AU - Christian,ER
AU - Schwadron,NA
AU - McNutt,RL
AU - Malandraki,O
AU - Whittlesey,P
AU - Livi,R
AU - Kasper,JC
DO - 2041-8213/ada697
PY - 2025///
SN - 2041-8205
TI - Magnetic Reconnection-driven Energization of Protons up to ∼400 keV at the Near-Sun Heliospheric Current Sheet
T2 - Astrophysical Journal Letters
UR - http://dx.doi.org/10.3847/2041-8213/ada697
VL - 985
ER -