Decijansky radio flux BL Lacertae objects

BL Lac objects with radio flux in the range of [1, 10) decijanskys (dJy) are defined as observational class ''dJy.'' Because the radio fluxes of most radio-selected BL Lac objects (RBLs) are bigger than I Jy while the radio fluxes of most X-ray-selected BL Lac objects (XBLs) are less than 1 dJy, we investigate whether the dJy class forms a bridge connecting RBLs and XBLs on the alpha(ro)-alpha(ox) color-color diagram. We compose a dJy sample by collecting dJy class sources from radio and X-ray surveys as well as other means of observation. Our study shows that the dJy sample so collected does not form a bridge connecting RBLs and XBLs. Instead, the sources of the sample are mainly distributed in the main domains of RBLs and XBLs. We find no evidence of the existence of any specific observational class in the medium of the two classes. This suggests that RBLs and XBLs may not be unified merely through observational orientation, because such a unified scheme expects some observational class to form the bridge. In order to have a more reliable study, it is proposed that 1 dJy radio surveys that include some previously missed BL Lac objects should be made.