LORCAT - Low-Frequency Radio Catalog of Flat-Spectrum Sources
The Low-frequency Radio Catalog of Flat-spectrum Sources. Massaro F., Giroletti M., D'Abrusco R., Masetti N., Paggi A., Cowperthwaite Philip S., Tosti G., Funk S. <Astrophys. J. Suppl. 213, 3 (2014) =2014ApJS..213....3M>
The WSRT source identifier using the B1950.0 source coordinates and the 'WN' prefix for sources from the WENSS and the 'WISH' prefix for sources from that survey, e.g., 'WN2357.9+3900', 'WISH B2357.4-1408'. Both of these formats are the styles recommended by the CDS Dictionary of Nomenclature of Celestial Objects.
The NVSS source identifier using the J2000.0 source coordinates and the NVSS prefix, e.g., 'NVSS J000011+751002'.
The Right Ascension of the NVSS radio source in the selected equinox. This was given in J2000.0 sexagesimal coordinates to a precision of 0.01 seconds of time in the original table.
The Declination of the NVSS radio source in the selected equinox. This was given in J2000.0 sexagesimal coordinates to a precision of 0.1 arcseconds in the original table.
The Galactic Longitude of the NVSS radio source.
The Galactic Latitude of the NVSS radio source.
The angular separation between the WSRT and NVSS source positions, in arcseconds. The authors chose a maximum value of 95 arcseconds for the maximum angular separation between the WSRT and the NVSS positions in order to consider a 1.4-GHz radio source a reliable counterpart for a WSRT object.
The low-frequency radio spectral index, alphalow, defined as alphalow = -k1 * log (S_1400/Slow), where Slow is the integrated flux density at 325 MHz from the WENSS or the integrated flux density at 352 MHz as reported in the WISH, i.e., S325 or S352, respectively, S1400 is the integrated flux density of the corresponding NVSS source at 1.4 GHz, the k1 factor is equal to 1.58 and 1.67 (i.e., [log(1400/325)]-1 and [log(1400/352)]-1 ) for the WENSS and the WISH surveys, respectively, and all flux densities in units of mJy.
The uncertainty in the low-frequency radio spectral index, alphalow, calculated using equation (5) in the reference paper (q.v.).
The WSRT original survey name, either WENSS or WISH.