For Masjedi's paper I worked on the text on K-correcting the imaging subsamples. My loyal reader will recall that Masjedi's project involves cross-correlating the imaging galaxies fainter than LRGs with spectroscopic LRGs. In general, we don't know the redshifts of the imaging galaxies, but we do want a real-space correlation function. His K-correction method is very clever: We K-correct each imaging galaxy in each imaging–spectroscopic pair of galaxies using the spectroscopic galaxy's redshift. Then we K-correct differently when that same imaging galaxy appears in a pair with a different spectroscopic galaxy. It all comes out in the wash, because the excess pairs at small scales that survive the correlation analysis are all true pairs (statistically) and so we subtract away all the wrong K-corrections and are left with only the correct ones (statistically).
Did that make sense?
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