Iterative techniques for the decomposition of long-slit spectra

Two iterative techniques are described for decomposing a long-slit spectrum into the individual spectra of the point sources along the slit and the spectrum of the underlying background. One technique imposes the strong constraint that the spectrum of the background be spatially invariant; the other relaxes this constraint. Both techniques are applicable even when there are numerous overlapping point sources superposed on a structurally complex background. The techniques are tested on simulated, as well as real, long-slit data from the ground and from space.