IRS-TR 12001: Spectral Pointing-Induced Throughput Error and Spectral
  Shape in Short-Low Order 1
  We investigate how the shape of a spectrum in the Short-Low module on the IRS
varies with its overall throughput, which depends on how well centered a source
is in the spectroscopic slit. Using flux ratios to quantify the overall slope
or color of the spectrum and plotting them vs. the overall throughput reveals a
double-valued function, which arises from asymmetries in the point spread
function. We use this plot as a means of determining which individual spectra
are valid for calibrating the IRS.
