Study of the X-ray activity of Sagittarius A* during the 2011 XMM-Newton campaign Enmanuelle Mossoux, Nicolas Grosso, Frédéric H. Vincent and Delphine Porquet A&A, 573 (2015) A46 Published online: 15 December 2014 DOI: 10.1051/0004-6361/201424682