English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

3He-rich solar energetic particles (SEPs) are believed to be accelerated insolar flares or jets by a mechanism that depends on the ion charge-to-mass(Q/M) ratio. It implies that the flare plasma characteristics (e.g.,temperature) may be effective in determining the elemental abundances of3He-rich SEPs. This study examines the relation between the suprathermal (<0.2MeV/nuc) abundances of the He-Fe ions measured on the Advanced CompositionExplorer and temperature in the solar sources for 24 3He-rich SEP events in theperiod 2010-2015. The differential emission measure technique is applied toderive the temperature of the source regions from the extreme ultravioletimaging observations on the Solar Dynamics Observatory. The obtainedtemperature distribution peaks at 2.0-2.5 MK that is surprisingly consistentwith earlier findings based on in-situ elemental abundance or charge statemeasurements. We have found a significant anti-correlation between 3He/4Heratio and solar source temperature with a coefficient -0.6. It is most likelycaused by non-charge-stripping processes, as both isotopes would be fullyionized in the inferred temperature range. This study shows that the elementalratios 4He/O, N/O, Ne/O, Si/O, S/O, Ca/O, Fe/O generally behave withtemperature as expected from abundance enhancement calculations at ionizationequilibrium. The C and Mg, the two species with small changes in the Q/M ratioin the obtained temperature range, show no such behavior with temperature andcould be influenced by similar processes as for the 3He/4He ratio.

Temperature in Solar Sources of 3He-rich Solar Energetic Particles and Relation to Ion Abundances