VLT near- to mid-IR imaging and spectroscopy of the M 17 UC1 – IRS5 regionZhiwei Chen, Dieter E. A. Nürnberger, Rolf Chini, Zhibo Jiang and Min FangA&A, 578 (2015) A82DOI: https://doi.org/10.1051/0004-6361/201424895