SPITZER SAGE Observations of Large Magellanic Cloud Planetary Nebulae

TL;DR

This paper presents infrared observations of planetary nebulae in the Large Magellanic Cloud using the Spitzer Space Telescope, analyzing their spectral components, comparing them to Galactic PNe, and exploring infrared luminosity functions.

Contribution

It provides the first comprehensive IR imaging and photometry of LMC PNe, analyzing their spectral components and comparing their properties to Galactic counterparts.

Findings

185 PNe detected in IRAC bands

161 PNe detected in MIPS 24 micron images

IR luminosity functions resemble [O III] luminosity functions

Abstract

We present IRAC and MIPS images and photometry of a sample of previously known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in the survey field, 185 objects were detected in at least two of the IRAC bands, and 161 detected in the MIPS 24 micron images. Color-color and color-magnitude diagrams are presented using several combinations of IRAC, MIPS, and 2MASS magnitudes. The location of an individual PN in the color-color diagrams is seen to depend on the relative contributions of the spectral components which include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared forbidden line emission from the ionized gas, warm dust continuum, and emission directly from the central star. The sample of LMC PNe is compared to a number of Galactic PNe and found to not significantly differ in their position in color-color space. We also explore the potential value of IR PNe luminosity functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form as the well-established [O III] LFs although there are several PNe with observed IR magnitudes brighter than the cut-offs in these LFs.