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We compare H-alpha, radio continuum, and Spitzer Space Telescope (SST) imagesof 58 planetary nebulae (PNe) recently discovered by the Macquarie-AAO-Strasbo-urg H-alpha PN Project (MASH) of the SuperCOSMOS H-alpha Survey. Using InfraRedArray Camera (IRAC) data we define the IR colors of PNe and demonstrate goodisolation between these colors and those of many other types of astronomicalobject. The only substantive contamination of PNe in the color-color plane weillustrate is due to YSOs. However, this ambiguity is readily resolved by theunique optical characteristics of PNe and their environs. We also examine therelationships between optical and MIR morphologies from 3.6 to 8.0um andexplore the ratio of mid-infrared (MIR) to radio nebular fluxes, which is avaluable discriminant between thermal and nonthermal emission. MASH emphasizeslate evolutionary stages of PNe compared with previous catalogs, enabling studyof the changes in MIR and radio flux that attend the aging process. Spatiallyintegrated MIR energy distributions were constructed for all MASH PNe observedby the GLIMPSE Legacy Project, using the H-alpha morphologies to establish thedimensions for the calculations of the Midcourse Space Experiment (MSX), IRAC,and radio continuum (from the Molonglo Observatory Synthesis Telescope and theVery Large Array) flux densities. The ratio of IRAC 8.0-um to MSX 8.3-um fluxdensities provides a measure of the absolute diffuse calibration of IRAC at 8.0um. We independently confirm the aperture correction factor to be applied toIRAC at 8.0um to align it with the diffuse calibration of MSX. The resultagrees with the recommendations of the Spitzer Science Center and with resultsfrom a parallel study of HII regions. These PNe probe the diffuse calibrationof IRAC on a spatial scale of 9-77 arcsec.

Spitzer IRAC observations of newly-discovered planetary nebulae from the Macquarie-AAO-Strasbourg H-alpha Planetary Nebula Project