VLT near- to mid-IR imaging and spectroscopy of the M 17 UC1 – IRS5 region Zhiwei Chen, Dieter E. A. Nürnberger, Rolf Chini, Zhibo Jiang and Min Fang A&A, 578 (2015) A82 Published online: 10 June 2015 DOI: 10.1051/0004-6361/201424895