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The L1622 cloud as seen by Spitzer (3.6 µm blue, 8 µm green, and 24 µm red). Emission from UV heated hydrocarbons appears greenish-yellow. Stars with large infrared excesses show prominent red colors due to their strong 24 µm fluxes.

The L1622 cloud as seen by Spitzer (3.6 µm blue, 8 µm green, and 24 µm red). Emission from UV heated hydrocarbons appears greenish-yellow. Stars with large infrared excesses show prominent red colors due to their strong 24 µm fluxes.

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The molecular cloud complex encompassing the cometary clouds L1617 and L1622 is located just outside of Barnard's Loop in Orion. It lies to the northeast of the Orion Nebula Cluster at a projected distance of 60 pc. The two clouds have radial velocities that differ by about 10 km/s, suggesting that they are not physically associated. Both clouds sh...

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... Spitzer space telescope mapped L1622 with the IRAC and MIPS cameras ( Figures 10 and 11) as part of a survey of the Orion molecular cloud complex ( Megeath et al. 2008a). The resulting 3.6, 4.5, 5.8, 8 and 24 µm photometry were used to identify young stellar objects with infrared excesses, the techniques and criteria used are dis- cussed by Allen et al. (2007), Winston et al. (2007) and Megeath et al. (2008b) (also see chapter by Peterson & Megeath in this volume). ...
Context 2
... and eighteen young stars with disks are identified with the Spitzer photometry. These include the emission line stars LkHα 335, LkHα 337 and all three components of the LkHα 336 system. In addition, the HBC 515 system is detected. However, the HBC 515 binary is not fully resolved in the Spitzer data and is not included as a YSO system in Fig. 10 or Table 1. The infrared companion is detected at 3.6-24 µm and identified as a YSO by its IR-excess. Although the IR companion is much brigher at 24 µm than the binary, the tabulated 24 µm photometry of the IR companion may be slightly boosted by contamination from the binary. We note that with the addition of the HBC 515 binary, the ...
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... the flow is impressive at infrared wavelengths, in the optical there is only a faint [SII]-bright counterpart, indicating that the flow is mostly embedded. Towards the center of the L1622 cloud, the Spitzer images seen in Figure 10 reveal an embedded s-shaped outflow. A more detailed view is provided in Figure 12 which shows that the flow is imposing at infrared wavelengths, but in the optical there is only a faint [SII]-bright counterpart, known as HH 962, suggesting that the flow is mostly embedded. ...

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... L 1622 has been described as a cometary cloud (e.g. Reipurth et al. 2008). Its overall shape is suggestive of being subject to radiation or wind from the south-west. ...
... The emission around 10 km s −1 is much more diffuse (Fig. 7, bottom), and may trace the outskirts of the L 1617 complex of cometary clouds, located about 1 degree to the north-west (e.g. Reipurth et al. 2008). The velocity maps in Fig. B.1 indicate an overall rather smooth velocity field, with indications for a velocity gradient along the clouds minor axis. ...
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