There is strong evidence for the existence of black holes (BHs) in someX-ray binaries and in most galactic nuclei based on different types of measurement,but bl
We study the relation between the infrared colors, [OIII] emission lines, gaseous absorbing column density (NH),and the detectability of the polarized (hidden)
The relativistic beaming model is adopted to discuss quantitatively the observational differences between radio-selected BL Lac objects (RBLs) and X-ray-selecte