Optical identification of radio sources using accurate radio and optical positions. II

Abstract

view Abstract Citations (52) References (103) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Optical identifications of radio sources using accurate radio and optical positions. II. Wills, B. J. Abstract Results of optical-position measurements are given for 321 objects within 10 arcsec (sometimes more) of 267 radio-source positions. A total of 137 QSO and QSO-like identification plus 57 galaxy identifications are suggested on the basis of position agreement between the second-of-arc radio positions and optical positions measured to about 0.4 arcsec. Apparent V magnitudes, position errors, and information on morphology, color, and previous identifications are also provided. The reliability of the identification is evaluated, the number of chance coincidence is estimated, and distributions of radio-minus-optical position differences are plotted for the various object types. About 10 neutral stellar objects and red stellar objects, some of which may be compact galaxies, are included in the QSO and QSO-like identifications; the galaxy identifications include faint red objects that should prove useful in studies of galactic evolution and the Hubble diagram. It is shown that the number of faint red and neutral stellar objects is not sufficient to explain the observed maximum in the QSO apparent-magnitude distribution as an observational selection bias against faint QSOs but that this effect can be explained in terms of a statistical relation between QSO radio and optical luminosities. Publication: The Astronomical Journal Pub Date: December 1976 DOI: 10.1086/111985 Bibcode: 1976AJ.....81.1031W Keywords: Astronomical Catalogs; Optical Properties; Position (Location); Quasars; Radio Sources (Astronomy); Astronomical Coordinates; Compact Galaxies; Galactic Structure; Hubble Diagram; Position Errors; Star Distribution; Stellar Luminosity; Astronomy full text sources ADS | data products SIMBAD (264)