Parkes Half-Jansky sample

[ CATS home ] [ Back to CATS list ] [ ftp ] 1997MNRAS.284...85Drinkwater+ MNRAS Volume 284, Issue 1, pp. 85-125.-> The Parkes Half-Jansky Flat-Spectrum Sample DRINKWATER, M. J., WEBSTER, R. L., FRANCIS, P. J., CONDON, J. J., ELLISON, S. L., JAUNCEY, D. L., LOVELL, J., PETERSON, B. A., SAVAGE, A. Abstract We present a new sample of Parkes half-jansky flat-spectrum radio sources, having made a particular effort to find any previously unidentified sources. The sample contains 323 sources selected according to a flux limit of 0.5Jy at 2.7GHz, a spectral index measured between 2.7 and 5.0GHz of alpha_2.7/5.0>-0.5, where S(nu)~nu ^alpha, Galactic latitude |b|>20 deg and -45 deg< declination (B1950) <+10 deg. The sample was selected from a region 3.90 steradians in area. We have obtained accurate radio positions for all the unresolved sources in this sample, and combined these with accurate optical positions from digitized photographic sky survey data to check all the optical identifications. We report new identifications based on R- and Kn-band imaging and new spectroscopic measurements of many of the sources. We present a catalogue of the 323 sources, of which 321 now have identified optical counterparts and 277 have measured spectral redshifts. The columns in the table are as follows: name: the Parkes source name. S_2.7, S_5.0, alpha, Rf: the 2.7 and 5.0GHz source fluxes and corresponding spectral index as published in reference Rf (see Table: refradio_surveys). RA(B1950), Dec(B1950), Rc: the accurate B1950 (i.e. equinox B1950 and epoch B1950) radio source positions from reference Rc. comment: (1) a brief description of the radio morphology if the source is resolved using the terminology of Downes et al. (1986): ``P'' for partially resolved sources, ``Do'' for double sources with no central component with the position defined by the centroid of the source, ``Do+CC'' for double sources with a central component or peak giving a well-defined position, ``H'' for a diffuse halo around a central source, and ``HT'' for a complex head-tail morphology. (2) comments in parentheses refer to the optical identification. In cases where there was no match to the sky catalogues but the source was identified using CCD data, these are indicated as ``(B)'', ``(R)'', ``(I)'' and ''(K)'' for the respective wavebands. If the CCD imaging did not identify the source, the comment ``null'' is made and ``STR'' indicates a source too near a bright star. If the source was confused with a close neighbour in the sky catalogues, but separated by a CCD image the comment ``merge'' is made followed by the waveband used; in some cases the Digitized Sky Survey data was used to separate the object (``DSS''). Delta RA, Delta Dec, Delta r, cl, bj: the position offsets (arcsec, in the sense optical-radio) of the corresponding optical image (if any), the total separation, the image classification (``g'' galaxy, ``s'' stellar, ``f'' too faint to classify, ``m'' merged) and the apparent bj magnitude if the counterpart was found in the sky survey data. z, Rz, Rsp: the emission redshift of the source obtained from reference code Rz. If no emission redshift has been measured, but absorption lines have been identified these are used to place a lower limit on the source redshift indicated in the form ``>0.500''. If a spectrum has been published it can be found in reference Rsp. RA(J2000), Dec(J2000): the corresponding J2000 positions.