Global energetics of solar flares. XIII. The Neupert effect and acceleration of coronal mass ejections

Abstract

Our major aim is a height-time model $r(t)$ of the propagation of {\sl Coronal Mass Ejections (CMEs)}, where the lower corona is self-consistently connected to the heliospheric path. We accomplish this task by using the Neupert effect to derive the peak time, duration, and rate of the CME acceleration phase, as obtained from the time derivative of the {\sl soft X-ray (SXR)} light curve. This novel approach offers the advantage to obtain the kinematics of the CME height-time profile $r(t)$, the CME velocity profile $v(t)=dr(t)/dt$, and the CME acceleration profile $a(t)=dv(t)/dt$ from {\sl Geostationary Orbiting Earth Satellite (GOES)} and white-light data, without the need of {\sl hard X-ray (HXR)} data. We apply this technique to a data set of 576 (GOES X and M-class) flare events observed with GOES and the {\sl Large Angle Solar Coronagraph (LASCO)}. Our analysis yields acceleration rates in the range of $a_A=0.1-13$ km s${}^{-2}$, acceleration durations of ${\tau }_A=1.2-45$ min, and acceleration distances in the range of $d_A=3-1063$ Mm, with a median of $d_A=39$ Mm, which corresponds to the hydrostatic scale height of a corona with a temperature of $T_e\approx 0.8$ MK. The results are consistent with standard flare/CME models that predict magnetic reconnection and synchronized (primary) acceleration of CMEs in the low corona (at a height of ~0.1 R_sun), while secondary (weaker) acceleration may occur further out at heliospheric distances.

arXiv comment11 pages text + 9 Figures