PCCS044GHZ - Planck Catalog of 44-GHz Compact Sources Release 1
The PCCS (Planck Catalog of Compact Sources) is the list of sources detected in the first 15 months of the Planck "nominal" mission. It consists of nine single-frequency catalogs of compact sources, both Galactic and extragalactic, detected over the entire sky. The PCCS covers the frequency range 30-857 GHz with higher sensitivity (it is 90% complete at 180 mJy in the best channel) and better angular resolution than previous all-sky surveys in the microwave band. By construction its reliability is >80% and more than 65% of the sources have been detected at least in two contiguous Planck channels. Many of the Planck PCCS sources can be associated with stars with dust shells, stellar cores, radio galaxies, blazars, infrared luminous galaxies and Galactic interstellar medium features.
For each source in the PCCS the authors have obtained four different measures of the flux density. They are determined by the source detection algorithm, aperture photometry, point spread function (PSF) fitting. and Gaussian fitting. Only the first is obtained from the filtered maps, and the other measures are estimated from the full-sky maps at the positions of the sources. The source detection algorithm photometry, the aperture photometry and the PSF fitting use the Planck band average effective beams, calculated with FEBeCoP (Fast Effective Beam Convolution in Pixel space). Notice that only the PSF fitting uses a model of the PSF that depends on the position of the source and the scan pattern.
The entire PCCS contains sources observed in the 9 Planck frequency bands. These are described in Table 1 of the reference paper:
(------LFI------) (-------------HFI-----------------) Channel [GHz] 030 044 070 100 143 217 353 545 857 Frequency [GHz] 28.4 44.1 70.4 100.0 143.0 217.0 353.0 545.5 857.0 Wavelength [um] 10561 6807 4260 3000 2098 1382 850 550 350 Beam FWHM (') 32.38 27.10 13.30 9.65 7.25 4.99 4.82 4.68 4.33 Flux limit [mJy] 461 825 566 266 169 149 289 457 658 90%complete[mJy] 575 1047 776 300 190 180 330 570 680 uncertainty[mJy] 109 198 149 61 38 35 69 118 166 position error (') 1.8 2.1 1.4 1.0 0.7 0.7 0.8 0.5 0.4
This table contains the PCCS Public Release 1 table of sources detected at 44 GHz.
Planck Compact Source Catalogue Public Release 1 Planck Collaboration <Astron. Astrophys.> =2013arXiv1303.5088P
The full name by which it is recommended to designate a source in this table, 'PCCS1 xxx GLLL.ll+BB.bb', where PCCS stands for 'Planck Compact Source Catalogue, public release 1', 'xxx' is the frequency in this GHz ('044' for this table of 44-GHz sources), and 'GLLL.ll+BB.bb' is the Galactic position of the source.
The Right Ascension of the source in the selected equinox obtained from the extraction algorithm. This was given in J2000.0 decimal degrees to a precision of 10-4 degrees in the original table.
The Declination of the source in the selected equinox obtained from the extraction algorithm. This was given in J2000.0 decimal degrees to a precision of 10-4 degrees in the original table.
The Galactic Longitude of the source.
The Galactic Latitude of the source.
The flux density of the source determined by the detection pipeline photometry (DETFLUX), in mJy. As described in Section 2.2 of the reference paper, the detection pipelines assume that sources are point-like. The amplitude of the detected source is converted to flux density using the area of the beam and the conversion from map units into intensity units. If a source is resolved, its flux density will be underestimated. In this case it may be better to use the GAUFLUX estimation.
The 1-sigma uncertainty in the flux of the source determined by the detection pipeline photometry, in mJy.
The flux density of the source determined by aperture photometry (APERFLUX), in mJy. This is estimated by integrating the data in a circular aperture centered at the position of the source. An annulus around the aperture is used to evaluate the level of the background. The annulus is also used to make a local estimate of the noise to calculate the uncertainty in the estimate of the flux density. The flux density is corrected for the fraction of the beam solid angle falling outside the aperture and for the fraction of the beam solid angle falling in the annulus. The aperture photometry was computed using an aperture with radius equal to the average FWHM of the effective beam, and an annulus with an inner radius of 1 FWHM and an outer radius of 2 * FWHM. The effective beams were used to compute the beam solid angle corrections. For details see Appendix A.1 of the reference paper.
The 1-sigma uncertainty in the flux of the source determined by aperture photometry, in mJy.
The flux density of the source determined by PSF fitting (PSFFLUX), in mJy. This is obtained by fitting a model of the PSF at the position of the source to the data. The model has two free parameters, the amplitude of the source and a background offset. The PSF is obtained from the effective beam. For details see Appendix A.2 of the reference paper.
The 1-sigma uncertainty in the flux of the source determined by PSF fitting, in mJy.
The flux density of the source obtained by fitting a 2-dimensional Gaussian model to the source (GAUFLUX), in mJy. The Gaussian is centered at the position of the source and its amplitude, size and shape are allowed to vary, as is the background offset. The flux density is calculated from the amplitude and the area of the Gaussian. For details see Appendix A.3 of the reference paper.
The 1-sigma uncertainty in the flux of the source determined by fitting a Gaussian model, in mJy.
The major axis of the 2-dimensional Gaussian model fit to the source, in arcminutes.
The 1-sigma uncertainty in the major axis of the 2-dimensional Gaussian model fit to the source, in arcminutes.
The minor axis of the 2-dimensional Gaussian model fit to the source, in arcminutes.
The 1-sigma uncertainty in the minor axis of the 2-dimensional Gaussian model fit to the source, in arcminutes.
The orientation of the major axis of the 2-dimensional Gaussian model fit to the source, in degrees, measured Eastwards from the North Galactic direction.
The 1-sigma uncertainty in the orientation of the major axis of the 2-dimensional Gaussian model fit to the source, in degrees.
The effective FWHM of the source from the Gaussian fit, FWHMeff, in arcminutes. This is calculated as the geometric mean (the square root of the product) of the major and minor axes of the 2D Gaussian model fit to the source.
This flag parameter indicates if the source is considered to be extended (1) or point-like (0). A source is classified as extended if FWHMeff >= 1.5 * FWHMnom, where FWHMnom is the nominal beam size for the selected channel and the quantity FWHMeff is the geometric mean (the square root of the product) of the major and minor axes of the 2D Gaussian model fit to the source. The choice of the threshold being set at 1.5 times the beam width is motivated by the accuracy with which source profiles can be measured from maps where the point spread function is critically sampled (1.7 arcmin pixel scale for a FHWM of ~ 4 arcmin). Naturally, faint sources for which the Gaussian fitting failed do not have the EXTENDED flag set.
Sources in the HFI channels (frequency bands >= 100 GHz) have a cirrus indicator, CIRRUS_N. This is the number of sources detected at 857 GHz (using a uniform S/N threshold of 5) within a 1 degree radius of the source. Many 857-GHz detections at this S/N threshold in the Galactic region will be from cirrus knots, so it provides a useful indicator of the presence of cirrus.
This flag parameter (called EXT_VAL in the reference paper) summarizes the cross-matching of the source with external catalogs (radio catalogs for LFI channels, IRIS extractions for HFI). Possible values are:
0 = source has no clear counterpart in any of the external catalogs and it has not been detected in other Planck channels 1 = source has no clear counterpart in any of the external catalogs, but it has been detected in other Planck channels 2 = source has a clear counterpart in the radio catalogs (LFI). For the HFI channels, the source either has a clear counterpart in the radio catalogs or in both the IRIS catalog and all the higher Planck channels
The designation of the corresponding source in the Early Release Compact Source Catalog (ERCSC, CDS Cat. VIII/88) table of the same frequency band, if there is one.