Spitzer mid-infrared study of compact H II regions in the Magellanic Clouds

Vassilis Charmandaris (1, 2) , Mohammad Heydari-Malayeri (2) , E. Chatzopoulos (1)

1 Crete Center for Theoretical Physics, Department of Physics
2 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

Aims: We present a study of the mid-infrared properties and dust content of a sample of 27 H ii ``blobs'', a rare class of compact H ii regions in the Magellanic Clouds. A unique feature of this sample is that even though these H ii regions are of high and low excitation they have nearly the same physical sizes ~1.5-3 pc.
Methods: We base our analysis on archival 3-8 mum infrared imagery obtained with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope.
Results: 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 H ii regions. Higher excitation ``blobs'' (HEBs) display stronger 8 mum emission and redder colors than their low-excitation counterparts (LEBs).

Domaines: Astrophysique [astro-ph]

Vassilis Charmandaris, Mohammad Heydari-Malayeri, E. Chatzopoulos. Spitzer mid-infrared study of compact H II regions in the Magellanic Clouds. Astronomy and Astrophysics - A&A, 2008, 487, pp.567-573. ⟨10.1051/0004-6361:200809662⟩. ⟨hal-03785121⟩