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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We describe the energy budget of a coronal mass ejection (CME) observed on1999 May 17 with the Ultraviolet Coronagraph Spectrometer (UVCS). We constrainthe physical properties of the CME's core material as a function of heightalong the corona by using the spectra taken by the single-slit coronagraphspectrometer at heliocentric distances of 2.6 and 3.1 solar radii. We useplasma diagnostics from intensity ratios, such as the O VI doublet lines, todetermine the velocity, density, temperature, and non-equilibrium ionizationstates. We find that the CME core's velocity is approximately 250 km/s, and itscumulative heating energy is comparable to its kinetic energy for all of theplasma heating parameterizations that we investigated. Therefore, the CME'sunknown heating mechanisms have the energy to significantly affect the CME'seruption and evolution. To understand which parameters might influence theunknown heating mechanism, we constrain our model heating rates with theobserved data and compare them to the rate of heating generated within asimilar CME that was constructed by the MAS code's 3D MHD simulation. The rateof heating from the simulated CME agrees with our observationally constrainedheating rates when we assume a quadratic power law to describe a self-similarCME expansion. Furthermore, the heating rates agree when we apply a heatingparameterization that accounts for the CME flux rope's magnetic energy beingconverted directly into thermal energy. This UVCS analysis serves as a casestudy for the importance of multi-slit coronagraph spectrometers for CMEstudies.

Constraining the CME Core Heating and Energy Budget with SOHO/UVCS