CAS Key Laboratory for Research in Galaxies and Cosmology;
Department of Astronomy;
University of Science and Technology of China;
Hefei 230026;
China;
xwshu @mail.ustc.edu.cn;
Department of Physics and Astronomy;
The Johns Hopkins University;
Baltimore;
MD 21218;
USA;
galaxies:; active; --; galaxies:; individual; (NGC; 7590); --; galaxies:; nuclei--; X-rays:; galaxies;