2
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Inferences About the Magnetic Field Structure of a CME with Both In Situ and Faraday Rotation Constraints

      Preprint

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          On 2012 August 2, two CMEs (CME-1 and CME-2) erupted from the west limb of the Sun as viewed from Earth, and were observed in images from the white light coronagraphs on the SOHO and STEREO spacecraft. These events were also observed by the Very Large Array (VLA), which was monitoring the Sun at radio wavelengths, allowing time-dependent Faraday rotation observations to be made of both events. We use the white-light imaging and radio data to model the 3-D field geometry of both CMEs, assuming a magnetic flux rope geometry. For CME-2, we also consider 1 au in situ field measurements in the analysis, as this CME hits STEREO-A on August~6, making this the first CME with observational constraints from stereoscopic coronal imaging, radio Faraday rotation, and in situ plasma measurements combined. The imaging and in situ observations of CME-2 provide two clear predictions for the radio data; namely that VLA should observe positive rotation measures (RMs) when the radio line of sight first encounters the CME, and that the sign should reverse to negative within a couple hours. The initial positive RMs are in fact observed. The expected sign reversal is not, but the VLA data unfortunately end too soon to be sure of the significance of this discrepancy. We interpret an RM increase prior to the expected occultation time of the CME as a signature of a sheath region of deflected field ahead of the CME itself.

          Related collections

          Author and article information

          Journal
          18 June 2020
          Article
          2006.10794
          ddcbe944-7349-4968-8063-f17a7fb5affc

          http://arxiv.org/licenses/nonexclusive-distrib/1.0/

          History
          Custom metadata
          17 pages, 11 figures, to appear in The Astrophysical Journal
          astro-ph.SR

          Solar & Stellar astrophysics
          Solar & Stellar astrophysics

          Comments

          Comment on this article