Dust-scattered X-ray halos around two Swift gamma-ray bursts: GRB 061019 and GRB 070129 G. Vianello, A. Tiengo and S. Mereghetti A&A, 473 2 (2007) 423-427 Published online: 06 August 2007 DOI: 10.1051/0004-6361:20077968