constructed a near-IR catalog by matching individual filter photometry lists with the aid of [TOPCAT]{} [@Taylor:2005uq]. We replaced saturated sources and a small number of missing detections in the Calar Alto images with values from the 2MASS Point Source Catalog, obtained at the Infrared Processing and Analysis Center (IPAC, Caltech). The 10 percent photometric depth values –indicated by the average brightness at which photometric error reaches a value of 0.1 mag– are 21.5, 20.0 and 18.75 mag in $J$, $H$ and $K$, respectively, and are good indicators of the completeness of the data. These limits are enough to sample the young star population in DR15 down to 0.09 M$_\odot$ in regions of low to moderate extinction ($A_V<25.0$ mag).

![image](f1.pdf){width="6.0in"}

Spitzer Cygnus-X Legacy Survey data  {#obs:mir}
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The *Spitzer Space Telescope* has observed the DR15 cluster with the IRAC and MIPS detectors as part of the CXLS. We obtained archival enhanced product mosaics from the Spitzer Heritage Archive as well as a photometric catalog coincident with our region of interest directly from the CXLS Data Release 1 (DR1). The catalog contains calibrated magnitudes for sources detected with IRAC in its four cryogenic mission channels (3.6, 4.5, 5.8 and 8.0 $\mu$m), as 