Naslov
Radial Evolution of Well-Observed Slow CMEs in the Distance Range 2 – 30 Rsun

Autori
Shanmugaraju, A. ; Moon, Y.-J. ; Vršnak, Bojan ; Vrbanec, Dijana

Izvornik
Solar physics (0038-0938) 257 (2009), 2; 351-361

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Sun - Coronal mass ejections

Sažetak
We performed a detailed analysis of 27 slow coronal mass ejections (CMEs) whose heights were measured in at least 30 coronagraphic images and were characterized by a high quality index (≥ 4). Our primary aim was to study the radial evolution of these CMEs and their properties in the range 2 – 30 solar radii. The instantaneous speeds of CMEs were calculated by using successive height – time data pairs. The obtained speed – distance profiles [v(R)] are fitted by a power law v = a(R − b)c. The power-law indices are found to be in the ranges a = 30 – 386, b = 1.95 – 3.92, and c = 0.03 – 0.79. The power-law exponent c is found to be larger for slower and narrower CMEs. With the exception of two events that had approximately constant velocity, all events were accelerating. The majority of accelerating events shows a v(R) profile very similar to the solar-wind profile deduced by Sheeley et al. (Astrophys. J. 484, 472, 1997). This indicates that the dynamics of most slow CMEs are dominated by the solar wind drag.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA