Photometric results of three δ Scuti stars, AD Ari, IP Vir and YZ Boo from new observations obtained at the Xinglong Station of the Beijing Astronomical Observ
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