2010MNRAS.402.2583D

We present Spitzer Infrared Array Camera (IRAC) mid-infrared photometry on the massive star-forming region AFGL 437 (IRAS 03035+5819). From the IRAC colour-colour diagram, we identify several new embedded young stellar objects (YSOs) within 64arcsec of the central compact cluster. Using the IRAC ratio images, we investigate the molecular outflows associated with the highly embedded YSO WK34 in the central cluster. We attribute the lobes seen (extended to ∼0.16pc in the north) in the ratio map to shocked molecular hydrogen emission. IRAC images reveal a large diffuse nebulosity associated with the central cluster and extending up to ∼8.0pc from south-west to north-east direction with its brightness gradually increasing from 3.6 to 8.0µm. A dense boxcar-shaped nebula (more than 2.0pc in size) situated to the south-west of the cluster shows molecular hydrogen emission that may have been caused by shock waves from the compact cluster sources. It seems that these sources are also responsible for the infrared-bright nebulosity. Using a 2D radiative transfer model, we derive from the spectral energy distributions (SEDs), the mass, age and luminosity of all the YSOs identified within the central cluster. The SED modelling shows that the driving engine of the outflows, WK34, appears to be massive but very young and deeply embedded. The weighted mean values of the masses and ages of the 21 YSOs derived from the model are in the range 1-10M_☉ and 10^4.1–6.4yr, respectively, while their luminosities are in the range of 10^0.47–3.48L_☉.