Spectroscopic studies of extended astronomical sources at optical wavelengths are hampered by the two-dimensional nature of current photon detectors. Most photons of interest are not utilized because a spectrometer must scan in the spatial or …
Magnetic flux at the surface of the Sun is predominantly concentrated in discrete areas with kilogauss field strengths. Except for sunspots, these areas are too small to have been resolved by conventional observations. These magnetic flux tubes are …
Circularly polarized images with high spatial resolution (better than 1 arcsec) of a solar active region, obtained with a tunable filter in the wings of Fe I 5247.1 A and Fe I 5250.2 A, have been analyzed in terms of the magnetic line ratio technique …