Planetary Nebulae Detected in the Spitzer Space Telescope GLIMPSE II Legacy Survey

TL;DR

This study identifies and analyzes infrared counterparts of planetary nebulae in the GLIMPSE II survey, revealing their morphology, spectral energy distributions, and distinguishing features from HII regions using Spitzer data.

Contribution

First comprehensive infrared analysis of planetary nebulae in the GLIMPSE II survey, including morphology, spectral energy distributions, and differentiation from HII regions.

Findings

Most nebulae are very red and compact in IRAC bands.

Nebulae are bright and extended at 24μm.

Infrared data helps distinguish PNs from HII regions.

Abstract

We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24mum, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24mum band. The infrared morphology of these objects are compared with Ha images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and HII regions and be able to reject non-PNs from the optical catalogue (e.g., PNG 352.1-00.0). Spectral energy distributions (SEDs) are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.