The BLAST View of the Star Forming Region in Aquila (ell=45deg,b=0deg)

TL;DR

This study uses submillimeter observations from BLAST to analyze a massive star-forming region in Aquila, identifying various evolutionary stages of clumps and characterizing their properties and stellar content.

Contribution

First comprehensive submillimeter analysis of the Aquila star-forming region using BLAST data, linking infrared, radio, and molecular observations to characterize clumps and UCHIIRs.

Findings

Identified active star-forming clumps with temperatures of 35-40 K.

Massive clumps with ~10^3 solar masses and embedded OB clusters.

Detailed structure of UCHIIRs correlating with ionizing stars.

Abstract

We have carried out the first general submillimeter analysis of the field towards GRSMC 45.46+0.05, a massive star forming region in Aquila. The deconvolved 6 deg^2 (3\degree X 2\degree) maps provided by BLAST in 2005 at 250, 350, and 500 micron 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 HII regions (UCHIIRs) 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 (IRDCs). 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 Msun for a dust emissivity index beta=1.5. The clump evolutionary stages range from evolved sources, with extended HII regions and prominent IR stellar population, to massive young stellar objects, prior to the formation of an UCHIIR.The CORNISH data have revealed the details of the stellar content and structure of the UCHIIRs. 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.