Spitzer Mid-infrared Study of Compact HII Regions in the Magellanic Clouds

Abstract

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).

8 pages, 4 figures, Accepted for publication in Astronomy & Astrophysics (higher resolution version is available in http://www.physics.uoc.gr/~vassilis/papers/blobs_spitzer.pdf)

References in corpus (10)

• Toward Understanding Massive Star Formation
• The Calibration of Mid-Infrared Star Formation Rate Indicators
• Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results
• The Spitzer Survey of the Small Magellanic Cloud: S3MC Imaging and Photometry in the Mid- and Far-Infrared Wavebands
• Triggered star formation on the borders of the Galactic HII region RCW 120
• The Massive Star Content of NGC 3603
• Chemical composition and mixing in giant HII regions: NGC3603, 30Doradus, and N66
• Absolute diffuse calibration of IRAC through mid-infrared and radio study of HII regions
• Clustered Star Formation in the Small Magellanic Cloud. A Spitzer/IRAC View of the Star-Forming Region NGC 602/N 90
• Low-excitation blobs in the Magellanic Clouds

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• Probing the Excitation of Extreme Starbursts: High Resolution Mid-IR Spectroscopy of Blue Compact Dwarfs
• $K$-band integral field spectroscopy and optical spectroscopy of massive young stellar objects in the Small Magellanic Cloud
• The Luminosity and Stellar Mass Functions of Red W1-W2 Galaxies
• VLT/NACO near-infrared imaging and spectroscopy of N88A in the SMC
• Radio Planetary Nebulae in the Small Magellanic Cloud