On the Nature of Faint Blue Objects in High Galactic Latitudes. I. Photometry, Proper Motions, and Spectra in PHL Field 1:36+6° and Richter Field M3, II
Astrometric, photometric, and spectrographic data are given for a representative sample of objects in a single field of 40 sq deg of the PHL catalogue. F and G subdwarfs, white dwarfs, and "radio-quiet" quasi-stellar galaxies (QSG) are the most frequent types of objects, although a few horizontal-branch stars, U Gem variables, and RR Lyrae stars are also present. Ten positive QSG identifications have been made from spectra of candidate objects in a list compiled from the bluest objects of small proper motion. The redshifts, Ax/x0, of PHL 1127,1194, and 3424 are 1.990, 0 298, and 1.847, respectively. Spectra of PHL 1027,1070,1072,1186, 1222, 1226, and 3375 prove these to be definite QSG also, but with undetermined redshifts. PHL 1092 is a possible QSG. A firm lower limit for the surface density of QSG in this field is S = 0 25 QSG/sq deg to B = 18 mag, based on ten QSG in 40 sq deg, but the true density is undoubtedly larger, since not all objects in the field have been spectrographically sampled An upper limit is S = 0 5 QSG/sq deg to B = 18 mag A small photometric sample of the Richter-Sahakjan list gives S between 1 QSG/sq deg and 3 QSG/sq deg to an optical limit of 19.7 mag These values far exceed S = 0004 QSS/sq deg for radio quasi-stellar sources in the 3C R catalogue. It is shown that very strong observational selection operates against finding QSGs of small absolute radio power when optical identifications are made from existing radio catalogues (Fig 4). The number of QSGs may exceed 100,000 over the entire sky to an optical limit of B = 19.7 mag.