The magazine MAQ September 2018 The magazine MAQ June 2018 | Page 145

Prime resources are data obtained from the X-ray observatories XMM-Newton launched in December 1999 and Chandra launched in July 1999. The ROSAT all-sky survey data as well as the data from more than 9000 pointed observations performed provide an inexhaustible harvest of valuable scientific data. (Figure22)