Naslov
Solar velocity field determined tracking coronal bright points

Autori
Brajša, Roman ; Sudar, Davor ; Skokić, Ivica ; Saar, S. H. ; Žic, Tomislav

Izvornik
Central European astrophysical bulletin (1845-8319) 39 (2015); 21-28

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

Ključne riječi
Sun - rotation ; coronal bright points ; proper motions ; random walk ; diffusion model

Sažetak
Preliminary data from Atmospheric Imaging Assembly (AIA) instrument on board Solar Dynamics Observatory (SDO) satellite were used to determine solar differential rotation and related phenomena. A segmentation algorithm, which uses multiple AIA channels in search for intensity enhancements in EUV and X-ray parts of the spectrum compared to the background intensity, was applied to obtain positional information of coronal bright points (CBPs). More than 60000 position measurements of more than 10000 identified CBPs from the period 1 - 2 January 2011 were analyzed. Rotational and meridional velocities were determined by tracking identified CBPs and various filters were used to exclude erroneous results. Also, proper motions of CBPs were calculated from rotation velocity residuals and meridional velocities. Proper motions of CBPs were investigated using a random walk model and the diffusion constant was calculated. These results were compared with the previous ones obtained by other instruments and methods (especially with the SOHO-EIT and Hinode data) and a striking agreement of the obtained diffusion constant with results from other studies was found.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA