Role of continual and selective absorption in the wing of the 4.3-μm CO2 band at high pressures and temperatures

The absorption coefficient at a given frequency can be roughly represented as a sum of two terms. One of them accounts for absorption at the nearest line and another represents some background due to absorption at a distant line. This intuitive representation has been used for a long time, especially in studies of the absorption by water vapor. In this case, probably for the first time, special term was introduced for the second term, namely, the continual absorption. The contributions of these two constituents in one and the same spectral region can drastically vary under different thermodynamic conditions.