Properties of low-mass objects in NGC 2024

We have obtained deep JHK imaging of the central region of the NGC 2024 embedded cluster, allowing three-color measurements of 151 sources. We show that contamination by background sources is small, and we reject a small number of sources that are probably foreground. We use a Monte Carlo isochrone fitting technique to estimate the luminosities and masses of the low-mass members of the embedded cluster. We find that the IMF between similar to 0.04 and similar to 0.5 M. can be fitted within the errors with a power law of slope -1.2 in linear mass units (or -0.2 in logarithmic units). There is no indication of a turnover of the IMF at the bottom of the main sequence; it appears to continue down to similar to 0.04 M. with no significant deviation (within our moderately large errors) from the power law. This estimate of the IMF includes only the primary members of binary (or multiple) systems. Of a subset of 35 sources, 24 (69%) appear to have infrared excesses indicating possible circumstellar disks, supporting arguments that disk formation is not inhibited in high-density clusters.