2007ApJS..171..447R

We present observations of 10.6 deg² of the Perseus molecular cloud at 24, 70, and 160 µm with Spitzer MIPS. The images show prominent, complex extended emission dominated by illuminating B stars on the east side of the cloud and by cold filaments of 160 µm emission on the west side. Of 3950 point sources identified at 24 µm, 1141 have 2MASS counterparts. A quarter of these populate regions of the K_s versus K_s-[24] diagram that are distinct from stellar photospheres and background galaxies and thus are likely to be cloud members with infrared excess. Nearly half (46%) of these 24 µm excess sources are distributed outside the IC 348 and NGC 1333 clusters. A significant number of IRAS PSC objects are not recovered by Spitzer MIPS, most often because the IRAS objects were confused by bright nebulosity. The intercluster region contains several tightly clumped (r∼0.1 pc) young stellar aggregates whose members exhibit a wide variety of infrared SEDs characteristic of different circumstellar environments. This could be explained by a significant age spread among the aggregate members, or if the members formed at the same time, a remarkably rapid circumstellar evolution would be required to account for the association of Class I and Class III sources at ages ≲1 Myr. We highlight important results for the HH 211 flow, where the bow shocks are detected at both 24 and 70 µm, and for the debris disk candidate BD +31 643, where the MIPS data show the linear nebulosity to be an unrelated interstellar feature. Our data, mosaics, and catalogs are available at the Spitzer Science Archive for use by interested members of the community.