Investigating the interstellar dust through the Fe K-edge D. Rogantini, E. Costantini, S. T. Zeegers, C. P. de Vries, W. Bras, F. de Groot, H. Mutschke and L. B. F. M. Waters A&A, 609 (2018) A22 Published online: 22 December 2017 DOI: 10.1051/0004-6361/201731664