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

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measuredsoft X-ray emission in the 1-15 keV energy range during the deep solar minimumof 2009 with a sensitivity much greater than GOES. Several intervals areidentified when the X-ray flux was exceptionally low, and the flux and solarX-ray luminosity are estimated. Spectral fits to the emission at these timesgive temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3and 1.1 x 10^48 cm^-3. Comparing SphinX emission with that from the HinodeX-ray Telescope, we deduce that most of the emission is from general coronalstructures rather than confined features like bright points. For one of 27intervals of exceptionally low activity identified in the SphinX data, theSun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT(0.1-2.4 keV) was less than most nearby K and M dwarfs.

Sphinx measurements of the 2009 solar minimum x-ray emission