2020

Murabito, M. et al.,  Unveiling the magnetic nature of chromospheric vortices, A&A, 2020

Results: Authors present the detection of spectropolarimetric signals that manifest the magnetic nature of rotating structures in the chromosphere. Our observations show two long-lived structures of plasma that each rotate clockwise inside a 10 arcsec2 quiet-Sun region. Their circular polarisation signals are five to ten times above the noise level. Line-of-sight Doppler velocity and horizontal velocity maps from the observations reveal clear plasma flows at and around the two structures. A magnetohydrodynamics simulation shows these two structures are plausibly magnetically connected. Wave analysis suggests that the observed rotational vortex pattern could be due to a combination of slow actual rotation and a faster azimuthal phase speed pattern of a magnetoacoustic mode.

Conclusions: The results imply that the vortex structures observed in the Sun's chromosphere are magnetic in nature and that they can be connected locally through the chromosphere