NGC 4104: A shell galaxy in a forming fossil group G. B. Lima Neto, F. Durret, T. F. Laganá, R. E. G. Machado, N. Martinet, J.-C. Cuillandre and C. Adami A&A, 641 (2020) A95 Published online: 15 September 2020 DOI: 10.1051/0004-6361/201936098