3He-Rich Solar Energetic Particles from Sunspot Jets. (arXiv:1812.07735v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bucik_R/0/1/0/all/0/1">R. Bucik</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wiedenbeck_M/0/1/0/all/0/1">M. E. Wiedenbeck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mason_G/0/1/0/all/0/1">G. M. Mason</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gomez_Herrero_R/0/1/0/all/0/1">R. Gomez-Herrero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nitta_N/0/1/0/all/0/1">N. Nitta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_L/0/1/0/all/0/1">L. Wang</a>

Solar sources of suprathermal (<1 MeV/nucleon) 3He-rich solar energetic particles (SEPs) have been commonly associated with jets originating in small, compact active regions at the periphery of near-equatorial coronal holes. Sources of relatively rare, high-energy (>10 MeV/nucleon) 3He-rich SEPs remain
unexplored. Here we present two of the most intense 3He-rich (3He/4He>1) SEP
events of the current solar cycle 24 measured on the Advanced Composition
Explorer at energy >10 MeV/nucleon. Although 3He shows high intensities, Z>2
ions are below the detection threshold. The events are accompanied by type-III
radio bursts, but no type-II emission as typically seen for suprathermal
3He-rich SEPs. The corresponding solar sources were analyzed using
high-resolution, extreme-ultraviolet imaging and photospheric magnetic field
observations on the Solar Dynamics Observatory. We find the sources of these
events associated with jets originating at the boundary of large sunspots with
complex beta-gamma-delta magnetic configuration. Thus, details of the
underlying photospheric field apparently are important to produce 3He to high
energies in the examined events.

Solar sources of suprathermal (<1 MeV/nucleon) 3He-rich solar energetic
particles (SEPs) have been commonly associated with jets originating in small,
compact active regions at the periphery of near-equatorial coronal holes.
Sources of relatively rare, high-energy (>10 MeV/nucleon) 3He-rich SEPs remain
unexplored. Here we present two of the most intense 3He-rich (3He/4He>1) SEP
events of the current solar cycle 24 measured on the Advanced Composition
Explorer at energy >10 MeV/nucleon. Although 3He shows high intensities, Z>2
ions are below the detection threshold. The events are accompanied by type-III
radio bursts, but no type-II emission as typically seen for suprathermal
3He-rich SEPs. The corresponding solar sources were analyzed using
high-resolution, extreme-ultraviolet imaging and photospheric magnetic field
observations on the Solar Dynamics Observatory. We find the sources of these
events associated with jets originating at the boundary of large sunspots with
complex beta-gamma-delta magnetic configuration. Thus, details of the
underlying photospheric field apparently are important to produce 3He to high
energies in the examined events.

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