Overview of the region centred on ℓ = +328.2551, b = −0.5321 in Galactic coordinates. Left panel: the three-colour composite image is from the Spitzer/GLIMPSE (Benjamin et al. 2003) and MIPSGAL (Carey et al. 2009) surveys (blue: 4.5 μm, green: 8 μm, and red: 24 μm) and is shownin Galactic coordinates. The contours show the 870 μm continuum emission from the ATLASGAL survey (Schuller et al. 2009; Csengeri et al. 2014). The arrow marks the dust continuum peak of the targeted clump, and the circle corresponds to the region shown in the right panel. Right panel: line-free continuum emission imaged at 345 GHz with the ALMA 12 m array. The colour scale is linear from − 3σ to 120σ. The contour shows the 7σ level. The FWHM size of the synthesised beam is shown in the lower left corner.