Dependence of the Peak Fluxes of Solar Energetic Particles on CME 3D Parameters from STEREO and SOHO

• Published in: The Astrophysical journal 2017-07, Vol.844 (1), p.17
• Main Authors: Park, Jinhye, Moon, Y.-J., Lee, Harim
• Format: Article
• Language: English
• Subjects: Angular speed; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Coronal mass ejection; Correlation; CORRELATIONS; Dependence; EMISSION; Energetic particles; Fluctuations; Fluxes; MASS; Parameters; Regression analysis; Separation; SOLAR CORONA; Solar energetic particles; SOLAR FLARES; SOLAR PARTICLES; SPACE VEHICLES; Spacecraft; SUN; Sun: activity; Sun: coronal mass ejections (CMEs); Sun: particle emission; VELOCITY
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aa794a

We investigate the relationships between the peak fluxes of 18 solar energetic particle (SEP) events and associated coronal mass ejection (CME) 3D parameters (speed, angular width, and separation angle) obtained from SOHO, and STEREO-A/B for the period from 2010 August to 2013 June. We apply the STEREO CME Analysis Tool (StereoCAT) to the SEP-associated CMEs to obtain 3D speeds and 3D angular widths. The separation angles are determined as the longitudinal angles between flaring regions and magnetic footpoints of the spacecraft, which are calculated by the assumption of a Parker spiral field. The main results are as follows. (1) We find that the dependence of the SEP peak fluxes on CME 3D speed from multiple spacecraft is similar to that on CME 2D speed. (2) There is a positive correlation between SEP peak flux and 3D angular width from multiple spacecraft, which is much more evident than the relationship between SEP peak flux and 2D angular width. (3) There is a noticeable anti-correlation (r = −0.62) between SEP peak flux and separation angle. (4) The multiple-regression method between SEP peak fluxes and CME 3D parameters shows that the longitudinal separation angle is the most important parameter, and the CME 3D speed is secondary on SEP peak flux.