Formation of O VI lines in sunspots with pumping from H2

The O VI lines at 1031.96 Å and 1037.60 Å are about a factor of 60 more intense in sunspots than observed in the Quiet Sun. The contribution of sunspots to the total integrated disk spectrum seen by O VI ions in the corona is therefore non negligible. This has important consequences for the interpretation of O VI observations in the corona. Our goal is to understand the formation mechanisms of these lines in sunspots. We present an analysis of SUMER observations of a sunspot from March 18, 1999. A detailed analysis of the interaction between the emission of molecular hydrogen H2 line at 1031.87 Å is made through radiative transfer calculations, and the results are compared with the observations.