Charla MFHG del 31/10/2012

Titulo de la charla: 
Properties and evolution of internetwork magnetic fields inside supergranular cells
Ponente: 
Milan Gosic
Lugar: 
Sala Reuniones del Nuevo Edificio
Resumen: 

To understand the formation of small-scale magnetic fields in the quiet Sun and their contribution to the solar activity, it is essential to investigate the properties and evolution of internetwork magnetic fields. Using Hinode/NFI line-of-sight magnetograms of very high sensitivity (6 Mx/cm^{2}), spatial resolution (0.16 arcsec/pixel), and cadence (90 s), we follow the evolution of magnetic elements inside of a supergranular cell located at disk center. In 5 hours of continuous measurements covering an area of 20.8 {\times} 23.2 arcsec^{2}, we manually track 1878 magnetic elements from appearance to disappearance and derive their physical properties. The median values of the magnetic flux, effective diameter, lifetime, and radial velocity are 3 {\times} 10^{17} Mx, 0.5 Mm, 7 min, and 0.5 km/s, respectively. Using this unique data set, we determine with unprecedented accuracy the flux emergence and disappearance rate in the solar internetwork. We also investigate spatial distribution of magnetic elements and how they interact with each other. Finally, we discuss what implications our results have for understanding of the origin of the quiet Sun internetwork magnetic fields.

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