Unveiling the X-ray point source population of the Young Massive Cluster Westerlund 1 J. S. Clark, M. P. Muno, I. Negueruela, S. M. Dougherty, P. A. Crowther, S. P. Goodwin and R. de Grijs A&A, 477 1 (2008) 147-163 Published online: 23 October 2007 DOI: 10.1051/0004-6361:20077186