Simultaneous HESS and Chandra observations of Sagitarius A during an X-ray flare - Aharonian, F.; Akhperjanian, A.; Barres de Almeida, U.; Bazer-Bachi, R.; Becherini, Y.; Behera, B.; Benbow, W.; Bernlöhr, K.; Boisson, C.; Bochow, A.; Borrel, V.; Braun, I.; et al. (EDP Sciences, 2008)