Probing Velocity Dispersion inside CMEs in Inner Corona: New Insights on CME Initiation

Abstract

This work studies the kinematics of the leading edge and the core of 6 Coronal Mass Ejections (CMEs) in the combined field of view of Sun Watcher using Active Pixel System detector and Image Processing (SWAP) on-board PRoject for On-Board Autonomy (PROBA-2) and the ground-based K-Cor coronagraph of the Mauna Loa Solar Observatory (MLSO). We report, for the first time, on the existence of a critical height h${}_{\mathrm{c}}$, which marks the onset of velocity dispersion inside the CME. This height for the studied events lies between 1.4-1.8 R${}_{\odot }$, in the inner corona. We find the critical heights to be relatively higher for gradual CMEs, as compared to impulsive ones, indicating that the early initiation of these two classes might be different physically. We find several interesting imprints of the velocity dispersion on CME kinematics. The critical height is strongly correlated with the flux-rope minor radius and the mass of the CME. Also, the magnitude of velocity dispersion shows a reasonable positive correlation with the above two parameters. We believe these results will advance our understanding of CME initiation mechanisms and will help provide improved constraints to CME initiation models.

16 Pages, 9 Figures, Accepted for publication in The Astrophysical Journal Letters

References in corpus (14)

• The Solar Orbiter mission -- Science overview
• MPI-AMRVAC for Solar and Astrophysics
• Multi-scale Gaussian normalization for solar image processing
• JHelioviewer - Time-dependent 3D visualisation of solar and heliospheric data
• The Depiction of Coronal Structure in White Light Images
• Defining the Middle Corona
• Connecting 3D evolution of Coronal Mass Ejections to their Source Regions
• Toward a Unified Explanation for the Three-part Structure of Solar Coronal Mass Ejections
• Investigating width distribution of slow and fast CMEs in solar cycles 23 and 24
• A Coronal Mass Ejection Source Region Catalogue and their Associated Properties
• An Insight into the Coupling of CME Kinematics in Inner and Outer Corona and the Imprint of Source Regions
• Analysis and interpretation of a fast limb CME with eruptive prominence, C-flare and EUV dimming
• On the Variation of Volumetric Evolution of CMEs from Inner to Outer Corona
• Interaction of coronal mass ejections and the solar wind. A force analysis

Cited by in corpus (1)

• Lateral Deformation of Large-scale Coronal Mass Ejections during the Transition from Non-radial to Radial Propagation