Using hierarchical octrees in Monte Carlo radiative transfer simulations W. Saftly, P. Camps, M. Baes, K. D. Gordon, S. Vandewoude, A. Rahimi and M. Stalevski A&A, 554 (2013) A10 Published online: 29 May 2013 DOI: 10.1051/0004-6361/201220854