2007ApJ...663.1139H

We present maps of 1.5 deg² of the Serpens dark cloud at 24, 70, and 160 µm observed with the Spitzer Space Telescope MIPS camera. We describe the observations and briefly discuss the data processing carried out by the c2d team on these data. More than 2400 compact sources have been extracted at 24 µm, nearly 100 at 70 µm, and four at 160 µm. We estimate completeness limits for our 24 µm survey from Monte Carlo tests with artificial sources inserted into the Spitzer maps. We compare source counts, colors, and magnitudes in the Serpens cloud to two reference data sets: a 0.50 deg^ 2^ set on a low-extinction region near the dark cloud, and a 5.3 deg² subset of the SWIRE ELAIS N1 data that was processed through our pipeline. These results show that there is an easily identifiable population of young stellar object candidates in the Serpens cloud that is not present in either of the reference data sets. We also show a comparison of visual extinction and cool dust emission illustrating a close correlation between the two and find that the most embedded YSO candidates are located in the areas of highest visual extinction.