Coronal and Chromospheric Signatures of Large-Scale Disturbances Associated with a Major Solar Eruption

TL;DR

This study analyzes large-scale coronal and chromospheric disturbances linked to a major solar eruption, revealing their hybrid wave and CME flank nature through multi-wavelength observations and kinematic analysis.

Contribution

It provides detailed observational evidence of the dual nature of solar disturbances, combining coronal and chromospheric data to distinguish wave and CME-related components.

Findings

SXI front propagates at 730 km/s with deceleration.

Southern chromospheric signatures coincide with SXI front.

Northern signatures deflect at coronal hole boundary.

Abstract

We present both coronal and chromospheric observations of large-scale disturbances associated with a major solar eruption on 2005 September 7. In GOES/SXI, arclike coronal brightenings are recorded propagating in the southern hemisphere. The SXI front shows an initially constant speed of 730 km s$^{-1}$ and decelerates later on, and its center is near the central position angle of the associated coronal mass ejection (CME) but away from flare site. Chromospheric signatures of the disturbances are observed in both MLSO/PICS H$\alpha$ and MLSO/CHIP He I 10830 {\AA}, and can be divided into two parts. The southern signatures occur in regions where the SXI front sweeps over, with the H$\alpha$ bright front coincident with the SXI front while the He I dark front lagging the SXI front but showing a similar kinematics. Ahead of the path of the southern signatures, oscillations of a filament are observed. The northern signatures occur near the equator, with the H$\alpha$ and He I fronts coincident with each other. They first propagate westward, and then deflect to the north at the boundary of an equatorial coronal hole (CH). Based on these observational facts, we suggest that the global disturbances are associated with the CME lift-off, and show a hybrid nature: a mainly non-wave CME flank nature for the SXI signatures and the corresponding southern chromospheric signatures, and a shocked fast-mode coronal magnetohydrodynamics (MHD) wave nature for the northern chromospheric signatures.