Radiative hydrodynamic modelling and observations of the X-class solar flare on 2011 March 9 Michael B. Kennedy, Ryan O. Milligan, Joel C. Allred, Mihalis Mathioudakis and Francis P. Keenan A&A, 578 (2015) A72 Published online: 08 June 2015 DOI: 10.1051/0004-6361/201425144