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We present a study of the mid-infrared properties and dust content of a sample of 27 HII ``blobs, a rare class of compact HII regions in the Magellanic Clouds. A unique feature of this sample is that even though these HII regions are of high and low excitation they have nearly the same physical sizes ~1.5-3 pc. We base our analysis on archival 3-8 microns infrared imagery obtained with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. We find that despite their youth, sub-solar metallicity and varied degrees of excitation, the mid-infrared colors of these regions are similar to those of typical HII regions. Higher excitation ``blobs (HEBs) display stronger 8 micron emission and redder colors than their low-excitation counterparts (LEBs).
To show the importance of high-spatial resolution observations of HII regions when compared with observations obtained with larger apertures such as ISO, we present mid-infrared spectra of two Magellanic Cloud HII regions, N88A and N160A. We obtained
We present data from mid-infrared Keck Telescope imaging of 18 radio-selected ultra-compact HII region candidates at diffraction-limited resolution. The goal of these observations is to determine the sizes, luminosities, and morphologies of the mid-i
We observed a sample of evolved stars in the Large and Small Magellanic Clouds (LMC and SMC) with the Infrared Spectrograph on the Spitzer Space Telescope. Comparing samples from the SMC, LMC, and the Galaxy reveals that the dust-production rate depe
[abridged] We present 52-93 micron spectra obtained with Spitzer in the MIPS-SED mode, of a representative sample of luminous compact far-IR sources in the LMC. These include carbon stars, OH/IR AGB stars, post-AGB objects and PNe, RCrB-type star HV2
We investigate the diffuse absolute calibration of the InfraRed Array Camera on the Spitzer Space Telescope at 8.0microns using a sample of 43 HII regions with a wide range of morphologies near GLON=312deg. For each region we carefully measure sky-su