The Impact of New EUV Diagnostics on CME-Related Kinematics

TL;DR

This paper demonstrates how novel EUV spectroscopic diagnostics reveal on-disk signatures of high-speed outflows associated with CMEs, emphasizing the importance of spectroscopic measurements for understanding CME kinematics and propagation.

Contribution

It introduces a new line profile asymmetry analysis applied to CME observations, highlighting the diagnostic's sensitivity to viewing geometry and its ability to detect on-disk outflows linked to CMEs.

Findings

Detection of high-speed outflows behind CME in dimming regions

Line profile asymmetry analysis reveals eruption signatures

Spectroscopic diagnostics improve CME propagation predictions

Abstract

We present the application of novel diagnostics to the spectroscopic observation of a Coronal Mass Ejection (CME) on disk by the Extreme Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. We apply a recently developed line profile asymmetry analysis to the spectroscopic observation of NOAA AR 10930 on 14-15 December 2006 to three raster observations before and during the eruption of a 1000km/s CME. We see the impact that the observer's line-of-sight and magnetic field geometry have on the diagnostics used. Further, and more importantly, we identify the on-disk signature of a high-speed outflow behind the CME in the dimming region arising as a result of the eruption. Supported by recent coronal observations of the STEREO spacecraft, we speculate about the momentum flux resulting from this outflow as a secondary momentum source to the CME. The results presented highlight the importance of spectroscopic measurements in relation to CME kinematics, and the need for full-disk synoptic spectroscopic observations of the coronal and chromospheric plasmas to capture the signature of such explosive energy release as a way of providing better constraints of CME propagation times to L1, or any other point of interest in the heliosphere.