NGC-2024 - EXCITATION OF THE DENSE CORES

We have used measurements of CS and C34S J = 7-6 toward five of the six millimetre continuum sources in NGC 2024 to estimate the excitation temperatures and column densities of warm, dense gas associated with the cores. For estimated CS source sizes of approximately 20 arcsec, the calculated excitation temperatures are greater than or similar to 24 K, consistent with previous studies. A correlation between CS column density and hydrogen column density derived from the thermal dust continuum shows that it is self-consistent to assume internally heated cores and a close relationship between the characteristic temperatures of the CS-traced gas and the dust traced by the millimetre continuum. The nature of the individual sources is also discussed.