|
Description
The Planck Australia Telescope Compact Array (Planck-ATCA) Co-eval Observations (PACO) have provided flux density measurements of well-defined samples of Australia Telescope 20-GHz (AT20G) radio sources at frequencies below and overlapping with Planck frequency bands, almost simultaneously with Planck observations. The authors have observed with the ATCA a total of 482 sources in the frequency range between 4.5 and 40 GHz in the period between 2009 July and 2010 August. Several sources were observed more than once. In their paper, the authors present the aims of the project, the selection criteria, and the observation and data reduction procedures. They also discuss the data in total intensity for a complete sample of 189 sources with 20-GHz flux densities > 500 mJy, Galactic latitude |b| > 5 degrees and Declination < -30 degrees, and some statistical analysis of the spectral behavior and variability of this sample, referred to as the 'bright PACO sample'. Finally, the authors discuss how these data could be used to transfer absolute calibrations to ground-based telescopes using the cosmic microwave background dipole calibrated flux densities measured by the Planck satellite, and they provide some test fluxes on bright calibrators. This table contains the catalog of 1004 observations of 180 of the 189 sources that comprise the 'bright PACO sample'. Thus, each row in this table corresponds to a specific observation of a source, and there can be several rows for any source, corresponding to different observations. The ATCA observations were made in 6 2-GHz wide observing bands: 4732 - 6780 MHz, 8232 - 10280 MHz, 17232 - 19280 MHz, 23232 - 25280 MHz, 32232 - 34280 MHz and 38232 - 40280 MHz. In order to properly define the detailed source spectral behavior, the authors have split each 2-GHz band into 4 x 512 MHz sub-bands, and calibrated each sub-band independently. Thus, for each observation, the flux density at 24 frequencies is given. The frequency identifier in the flux density appears (at least to this HEASARC scientist) to be the lower frequency of the sub-band rather than its central frequency. In order to provide the easiest way to extrapolate the observed counts or model predictions from one frequency to another, the authors have modeled the observed source spectra. As their observations covered a wide frequency range from 4.5 to 40 GHz over which a single power law is not enough to describe the spectral behavior of the sources, they studied the spectra of the 174 point-like sources in this sample by fitting the observed data with a double power law of the form S<sub>nu</sub> = S<sub>0</sub>/[(nu/nu<sub>0</sub>)<sup>-a</sup> + (nu/nu<sub>0</sub>)<sup>-b</sup>], where nu is the frequency, S<sub>nu</sub> is the flux density in Jy, and S<sub>0</sub>, nu<sub>0</sub>, a and b are free parameters. The authors considered only those sources for which they had at least four data points for each of the 2 x 2 GHz bands considered. Full details of the fitting procedure are given in Section 3.1 of the reference paper. This table was created by the HEASARC in January 2014 based on the machine-readable version of Table S1 from the reference paper which was obtained from the CDS (their catalog J/MNRAS/415/1597 file table1.dat). This is a service provided by NASA HEASARC .
|
