The evolution of young HII regions - I. Continuum emission and internal dynamics P. D. Klaassen, K. G. Johnston, J. S. Urquhart, J. C. Mottram, T. Peters, R. Kuiper, H. Beuther, F.F.S. van der Tak and C. Goddi A&A, 611 (2018) A99 Published online: 18 April 2018 DOI: 10.1051/0004-6361/201731727