  We present the first simultaneous infrared (IR) and visible
spectro-polarimetric observations of a solar internetwork region. The Fe I
lines at 6301.6 A, 6302.5 A, 15648 A, and 15652 A were observed, with a lag of
only 1 min, using highly sensitive spectro-polarimeters operated in two
different telescopes (VTT and THEMIS at the Observatorio del Teide). Some 30%
of the observed region shows IR and visible Stokes V signals above noise. These
polarization signals indicate the presence of kG magnetic field strengths
(traced by the visible lines) co-existing with sub-kG fields (traced by the
infrared lines). In addition, one quarter of the pixels with signal have
visible and IR Stokes V profiles with opposite polarity. We estimate the
probability density function of finding each longitudinal magnetic field
strength in the region. It has a tail of kG field strengths that accounts for
most of the (unsigned) magnetic flux of the region.

Astrophysics