We present SCUBA-2 450 \micron and 850 \micron observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope ( JCMT ) Gould Belt Survey ( GBS ) of nearby star-forming regions .
We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index , \beta = 1.8 , and a beam convolution kernel to achieve a common 14.8 ^ { \prime \prime } resolution .
We identify 82 clumps ranging between 10 and 36 K with a mean temperature of 20 \pm 3 K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust .
We identify 31 clumps that have cores with densities greater than 10 ^ { 5 } cm ^ { -3 } .
Thirteen of these cores contain embedded Class 0/I protostars .
Many cores are associated with bright-rimmed clouds seen in Herschel 70 \micron images .
From JCMT HARP observations of the ^ { 12 } CO 3–2 line , we find contamination of the 850 \micron band of up to 20 per cent .
We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact H ii regions using archival VLA data and find the contribution is limited to individual stars , accounting for 9 per cent of flux per beam at 450 \micron or 12 per cent at 850 \micron in these cases .
We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region , favouring Jeans stable clouds in the warm east and fragmentation in the cool west .