The Limb Brightening and its Relationship with the Millimeter-wave   Cavity
  Through a detailed theoretical analysis of the local emission at millimeter,sub-millimeter and infrared wavelength regimes (from \~ 10 GHz up to \~ 10 THz), we found that, associated with the temperature minimum, there is an optically thin cavity surrounded by two regions of high local emissivity. We call this structure the Chromospheric Solar Millimeter Cavity (CSMC). In order to search for traces of this cavity in the available radio observations on the solar limb, we have developed a robust method to associate the radiation at different heights with the observed brightness temperatures. We foresee that this approach will allow us to determine the relationship between the CSMC and the solar limb brightening. 
Victor De la Luz, Miguel Chavez, and Emanuele Bertone
astro-ph.SR