The blast view of the star-forming region in Aquila (ℓ = 45°, b = 0° )

Abstract

We have carried out the first general submillimeter analysis of the field toward GRSMC 45.46+0.05, a massive star-forming region in Aquila. The deconvolved 6 deg^2 (3° × 2°) maps provided by BLAST in 2005 at 250, 350, and 500 μm were used to perform a preliminary characterization of the clump population previously investigated in the infrared, radio, and molecular maps. Interferometric CORNISH data at 4.8 GHz have also been used to characterize the Ultracompact H_II regions (UCH_(II)Rs) within the main clumps. By means of the BLAST maps, we have produced an initial census of the submillimeter structures that will be observed by Herschel, several of which are known Infrared Dark Clouds. Our spectral energy distributions of the main clumps in the field, located at ~7 kpc, reveal an active population with temperatures of T ~ 35–40 K and masses of ~10^3 M_⊙ for a dust emissivity index β = 1.5. The clump evolutionary stages range from evolved sources, with extended H_II regions and prominent IR stellar population, to massive young stellar objects, prior to the formation of an UCH_(II)R. The CORNISH data have revealed the details of the stellar content and structure of the UCH_(II)Rs. In most cases, the ionizing stars corresponding to the brightest radio detections are capable of accounting for the clump bolometric luminosity, in most cases powered by embedded OB stellar clusters.

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