The XMM-Newton survey of the ELAIS-S1 field - II. Optical identifications and multiwavelength catalogue of X-ray sources

Feruglio, C; Fiore, F; La Franca, F; Sacchi, N; Puccetti, S; Comastri, A; Berta, S; Brusa, M; Franceschini, Alberto; Gruppioni, C; Mathur, S; Matute, I; Mignoli, M; Pozzi, F; Vignali, C; Zamorani, G.