Spectroscopy and Differential Emission Measure diagnostics of a coronal dimming associated with a fast halo CME

Abstract

We study the coronal dimming caused by the fast halo CME (deprojected speed v =1250 km s ${}^{-1})$ associated with the C3.7 two-ribbon flare on 2012 September 27, using Hinode/EIS spectroscopy and SDO/AIA Differential Emission Measure (DEM) analysis. The event reveals bipolar core dimmings encompassed by hook-shaped flare ribbons located at the ends of the flare-related polarity inversion line, and marking the footpoints of the erupting filament. In coronal emission lines of $\log T[\mathrm{K}]=5.8-6.3$, distinct double component spectra indicative of the superposition of a stationary and a fast up-flowing plasma component with velocities up to 130 km s${}^{-1}$ are observed at regions, which were mapped by the scanning EIS slit close in time of their impulsive dimming onset. The outflowing plasma component is found to be of the same order and even dominant over the stationary one, with electron densities in the upflowing component of $2\times 10^9$cm${}^{-3}$ at $\log T[\mathrm{K}]=6.2$. The density evolution in core dimming regions derived from SDO/AIA DEM analysis reveals impulsive reductions by $40-50\%$ within $\lesssim$10 min, and remains at these reduced levels for hours. The mass loss rate derived from the EIS spectroscopy in the dimming regions is of the same order than the mass increase rate observed in the associated white light CME ($1\times 10^{12}{\mathrm{g}\mathrm{s}}^{-1}$), indicative that the CME mass increase in the coronagraphic field-of-view results from plasma flows from below and not from material piled-up ahead of the outward moving and expanding CME front.

15 pages, accepted by ApJ

References in corpus (2)

• Modelling of EIS spectrum drift from instrumental temperatures
• The Temperature-Dependent Nature of Coronal Dimmings

Cited by in corpus (21)

• Upflows in the upper solar atmosphere
• The Great Dimming of Betelgeuse: a Surface Mass Ejection (SME) and its Consequences
• Constraining the Physical Properties of Stellar Coronal Mass Ejections with Coronal Dimming: Application to Far Ultraviolet Data of $\epsilon$ Eridani
• Deriving CME density from remote sensing data and comparison to in-situ measurements
• Observational Analysis on the Early Evolution of a CME Flux-rope: Pre-flare reconnection and Flux-rope's Footpoint Drift
• Complete replacement of magnetic flux in a flux rope during a coronal mass ejection
• Coronal dimmings associated with coronal mass ejections on the solar limb
• Using radio triangulation to understand the origin of two subsequent type II radio bursts
• External reconnection and resultant reconfiguration of overlying magnetic fields during sympathetic eruptions of two filaments
• Multi-point study of the energy release and transport in the 28 March 2022, M4-flare using STIX, EUI, and AIA during the first Solar Orbiter nominal mission perihelion
• Imaging evidence for solar wind outflows originating from a CME footpoint
• On the three-dimensional relation between the coronal dimming, erupting filament and CME. Case study of the 28 October 2021 X1.0 event
• The 2019 International Women's Day event: A two-step solar flare with multiple eruptive signatures and low Earth impact
• Pre-eruption Splitting of the Double-Decker Structure in a Solar Filament
• Coronal dimmings as indicators of early CME propagation direction
• The Automatic Identification and Tracking of Coronal Flux Ropes -- Part I: Footpoints and Fluxes
• Remote coronal dimmings related to a circular-ribbon flare
• Numerical study of solar eruption, extreme-ultraviolet wave propagation, and wave-induced prominence dynamics
• The Merging of a Coronal Dimming and the Southern Polar Coronal Hole
• Coronal dimmings from active region 13664 during the May 2024 solar energetic events
• Three-part structure of solar coronal mass ejection observed in low coronal signatures of Solar Orbiter