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Using the Multiband Imaging Photometer for Spitzer (MIPS) and Infrared Array Camera (IRAC) instruments on the Spitzer Space Telescope, we have investigated an aggregate of at least nine candidate bright young stellar objects in the southern region of the Lynds 1228 cloud in Cepheus. The spectral energy distributions (SEDs) encompass both infrared Class II and Class III types, and at least one object has no excess at wavelengths shorter than 24 μm. There are five known IRAS sources in the region. We find that the fluxes of these sources are generally overestimated by IRAS because of confusion, and one appears in both the IRAS Point Source and Faint Source Catalogs. This small group of young stellar objects provides a good example of the power of Spitzer to resolve star-forming regions confused in the IRAS catalogs. The SEDs of these sources illustrate that there can be a diversity of disk evolutionary states within a coeval stellar aggregate.

We have obtained images of the obscured massive star-forming region DR 21 using both the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS) instruments aboard the Spitzer Space Telescope. Our images cover an area of more than half a square degree. The unprecedented high sensitivity and resolution of both IRAC and MIPS allow us to reveal the complexity of this region for the first time. Our images show extended outflows from a dense disk of material. Previously observed molecular outflows from the center of DR 21 are clearly visible in our images and are embedded in a much larger region of diffuse filaments apparently flowing out from DR 21. Many of the point sources in the region seen by Spitzer at 8 and 24 μm are both very obscured and intrinsically red. We discuss the properties of some of these extremely red objects and indicate that they are likely to be Class I or earlier protostars. Other features observed include mid-infrared dark clouds that occasionally appear as swept up features from extremely red objects, including a 15 pc long north-south filament to the south of DR 21 itself.

We present the Early Release Observations of the HH 46/47 system and HH 46 IRS 1 source, taken with the three instruments aboard the Spitzer Space Telescope. The optically invisible southwest lobe, driven by the HH 47C bow shock, is revealed in full detail by the Infrared Array Camera (IRAC) images and displays a 'loop'-like morphology. Both of the mid-infrared outflow lobes are narrower than those of CO flow. We believe that the combination of emission by H2 rotational lines [S(11)-S(4)] and some atomic lines, which fall within the IRAC passbands, are responsible for the bulk of the observed emission, although contributions from the 3.3, 6.2, and 7.7 micron polycyclic aromatic hydrocarbon emission bands cannot be ruled out. Weak spectral features corresponding to these emitters are present in the Infrared Spectrograph spectrum of the HH 47A bow shock. The spectrum of HH 46 IRS 1 shows remarkable similarities to those of high-mass protostars, which include the presence of H2O, CO2, CH4, and possibly NH3, CH3OH, and ices. The high ice abundances and the lack of signs of thermal processing indicate that these ices in the envelope are well shielded from the powerful outflow and its cavity. Emission from the Bok globule at 24 micron is detected and displays a similar structure to that observed at 8 micron.

We present observations of ~7 square degrees of the North American and Pelican Nebulae region at 24, 70, and 160 microns with the Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS). We incorporate the MIPS observations with earlier Spitzer Infrared Array Camera (IRAC) observations, as well as archival near-infrared (IR) and optical data. We use the MIPS data to identify 1286 young stellar object (YSO) candidates. IRAC data alone can identify 806 more YSO candidates, for a total of 2076 YSO candidates. Prior to the Spitzer observations, there were only ~200 YSOs known in this region. Three subregions within the complex are highlighted as clusters: the Gulf of Mexico, the Pelican, and the Pelican's Hat. The Gulf of Mexico cluster is subject to the highest extinction (Av at least ~30) and has the widest range of infrared colors of the three clusters, including the largest excesses and by far the most point-source detections at 70 microns. Just 3% of the cluster members were previously identified; we have redefined this cluster as about 10-100 times larger (in projected area) than was previously realized., Accepted to ApJS. Full data tables available at http://web.ipac.caltech.edu/staff/rebull/research.html

We have discovered an error in the scaling of our IRAC 8 m and MIPS 70 m data, which affected the caption for Figure 1 and the vertical axis scales for Figure 2. The original units in the images displayed in Figure 1 were MJy sr 1 for 8 m and Jy arcsec 2 for MIPS 24 and 70 m. We incorrectly multiplied our IRAC data by 0.0425 (the conversion from Jy arcsec 2 to MJy sr ), but neglected to multiply our MIPS 70 m data by that factor. (MIPS 24 m data were scaled correctly.) Thus, contrary to the caption of Figure 1, the gray levels for panels (a) and (b) actually range from 6.7 to 7.8 MJy sr , and the gray levels for panels (e) and ( f ) actually range from 0.85 to 20.8MJy sr . The power spectra in Figure 2 should have been normalized such that the integral over the spectrum equals the mean square image surface brightness. In the original paper, however, the IRAC power spectrumwas incorrectly multiplied by (0.0425), whereas theMIPS 70 m spectrum should have been multiplied by this factor but was not. We correct this in a revised version of Figure 2 included here. We thank Rick Arendt for calling our attention to this error.