- ID:
- ivo://nasa.heasarc/ncp21cma
- Title:
- North Celestial Pole Region Radio Sources Detected by the 21cm Array
- Short Name:
- NCP21CMA
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12-hr observation made on 2013 April 13, with a frequency coverage from 75 to 175 MHz and an angular resolution of ~4 arcminutes. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called "w" term and ionospheric effects, the present analysis is restricted to the east-west baselines within 1500 m only. 624 radio sources are found within 5 degrees around the NCP down to ~0.1 Jy (100 mJy). These source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ~1 Jy, the authors find a flattening trend of source counts toward lower frequencies. While the thermal noise (~0.4 mJy) is well controlled to below the confusion limit, the dynamical range (~10<sup>4</sup>) and sensitivity of current 21CMA imaging are largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field, which result from the regular spacings of the 21CMA. The authors note that particular attention should be paid to the extended sources, and their modeling and removal may constitute a large technical challenge for current EoR experiments. Their analysis may serve as a useful guide to the design of next generation low-frequency interferometers like the Square Kilometre Array (SKA). The 21CMA is a ground-based radio interferometer dedicated to the detection of the EoR. The array, sited in the Ulastai valley of western China, consists of 81 pods or stations, and a total of 10,287 log-periodic antennas are deployed in two perpendicular arms along the east-west (6.1 km) (see Figure 1 in the reference paper) and north-south (4 km) directions, respectively. The spacing of these 81 pods is chosen such that a sufficiently large number of redundant baselines and a good uniform UV coverage can both be guaranteed. Each antenna element has 16 pairs of dipoles with lengths varying from 0.242 to 0.829 m, optimized to cover a frequency range of 50-200 MHz, which gives rise to an angular resolution of 3 arcminutes at 200 MHz. All of the antennas are fixed on the ground and point at the NCP for the sake of simplicity and economy. In the current work, the radio point sources observed with the 40 pods of the 21 Centimeter Array (21CMA) E-W baselines in an integration of 12 hours made on 2013 April 13 centered on the North Celestial Pole (NCP) are presented. An extra deep sample with a higher sensitivity from a longer integration time of up to years will be published later. The authors have detected a total of 624 radio sources over the central field within 3 degrees in a frequency range of 75-175 MHz band and in the outer annulus from 3-5 degrees in the 75-125 MHz band. By performing a Monte-Carlo simulation, the authors estimate a completeness of 50% at a flux density of ~0.2 Jy. This table was created by the HEASARC in May 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/832/190">CDS Catalog J/ApJ/832/190</a> file table3.dat. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/nvss
- Title:
- NRAO VLA Sky Survey Catalog
- Short Name:
- NVSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA) Sky Survey, the so-called NVSS Catalog. The NVSS Catalog covers the sky north of the J2000.0 Declination of -40 degrees (82% of the celestial sphere) at 1.4 GHz. The principal data products of the NVSS were (1) a set of 2326 4 degree by 4 degree continuum "cubes" with three planes containing Stokes I, Q, and U images, plus (2) a catalog of almost 2 million discrete sources stronger than a flux density S of about 2.5 mJy. The images all have 45 arcsecond FWHM angular resolution and nearly uniform sensitivity. Their rms brightness fluctuations are approximately 0.45 mJy/beam = 0.14 K (Stokes I) and approximately 0.29 mJy/beam = 0.09 K (Stokes Q and U). The rms uncertainties in right ascension and declination vary from <= ~1 arcsecond for the 400,000 sources stronger than 15 mJy to 7 arcseconds at the survey limit. The NVSS was made as a service to the astronomical community. All data products, user software, and updates were released via the World-Wide Web as soon as they were produced and verified. For more complete information on the NVSS, please refer to the NVSS website at <a href="http://www.cv.nrao.edu/nvss/">http://www.cv.nrao.edu/nvss/</a> This table was created by the HEASARC in October 2002 based on the file <a href="ftp://ftp.cv.nrao.edu/nvss/CATALOG/NVSSCatalog.text.gz">ftp://ftp.cv.nrao.edu/nvss/CATALOG/NVSSCatalog.text.gz</a> provided by the NVSS Catalog's authors. It was updated by the HEASARC in June 2009 to fix a problem with the original ingest in which the leading digit of some flux fields was lost. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cratesocrap
- Title:
- OCRA-p Survey of a Subset of CRATES Sources
- Short Name:
- CRATESOCRAP
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Knowledge of the population of radio sources in the range ~ 2-200 GHz range is important for understanding their effects on measurements of the cosmic microwave background power spectrum. This table contains measurements of the 30-GHz flux densities of 605 radio sources from the Combined Radio All-sky Targeted Eight-GHz Survey (CRATES), which have been made with the One Centimetre Receiver Array-prototype (OCRA-p) on the Torun 32-m telescope. The flux densities of sources that were also observed by Wilkinson Microwave Anisotropy Probe (WMAP) and previous OCRA surveys are in broad agreement with those reported here, however a number of sources display intrinsic variability. The authors find a good correlation between the 30 GHz and Fermi gamma-ray flux densities for sources in common. In their paper, they examine the radio spectra of all observed sources and report a number of gigahertz-peaked and inverted spectrum sources. These measurements will be useful for comparison to those from the Low Frequency Instrument of the Planck satellite, which will make some of its most sensitive observations in the region covered here. The selection criteria for the subsample of CRATES sources observed by the OCRA-p are given in Section 2 of the reference paper (q.v.). Plots of the measurements of each source over time and the aggregated source spectra between 26 MHz and 150 GHz are available online at the authors' web site: <a href="http://www.jb.man.ac.uk/research/ocra/crates/">http://www.jb.man.ac.uk/research/ocra/crates/</a>. This table was created by the HEASARC in May 2011 based on an electronic version of Table 3 of the reference paper which was obtained from the authors' web site <a href="http://www.jb.man.ac.uk/research/ocra/crates/">http://www.jb.man.ac.uk/research/ocra/crates/</a>. Notice that the version here is the 10-Jan-2011 version which contains corrections to the 30-GHz flux densities and their errors of ~ 1% in the calibration and the application of the gain-elevation curve. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ovro31ghz
- Title:
- Owens Valley Radio Observatory 40-m 31-GHZ Radio Source Catalog
- Short Name:
- OVRO31GHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The 100m Robert C. Byrd Green Bank Telescope (GBT) and the 40m Owens Valley Radio Observatory (OVRO) telescope have been used to conduct a 31-GHz survey of 3165 known extragalactic radio sources over 143 deg<sup>2</sup> of the sky. Target sources were selected from the NRAO VLA Sky Survey (NVSS) in fields observed by the Cosmic Background Imager (CBI); most are extragalactic active galactic nuclei (AGNs) with 1.4-GHz flux densities of 3-10 mJy. Using a maximum-likelihood analysis to obtain an unbiased estimate of the distribution of the 1.4 - 31 GHz spectral indices of these sources, the authors find a mean 31 - 1.4 GHz flux ratio of 0.110 +/- 0.003 corresponding to a spectral index alpha = -0.71+/-0.01 (S<sub>nu</sub> ~ nu<sup>alpha</sup>); 9.0% +/- 0.8% of the sources have alpha > -0.5 and 1.2% +/- 0.2% have alpha > 0. By combining this spectral-index distribution with 1.4GHz source counts, the authors predict 31-GHz source counts in the range 1 mJy <S<sub>31</sub> < 4 mJy, N(>S<sub>31</sub>) = (16.7+/-1.7)deg<sup>-2</sup>(S<sub>31</sub>/1mJy)<sup>(-0.80+/-0.07)</sup>. In this study, the authors present a detailed characterization of the impact of the discrete source foreground on arcminute-scale 31-GHz anisotropy measurements based upon two observational campaigns. The first campaign (the results of which are given in this table) was carried out with the OVRO 40m telescope at 31 GHz from 2000 September through 2002 December. The second campaign (the results of which are given in the GBT31GHZ table) used the GBT from 2006 February to May. A companion paper (Sievers et al. 2009arXiv0901.4540S) presents the five-year CBI total intensity power spectrum incorporating the results of the point-source measurements discussed here. Reported error bars include a 10% and 5% rms gain uncertainty for GBT and OVRO measurements, respectively. Sources detected at greater than 4 sigma at 31 GHz are flagged (detection_flag = 'Y'); for this calculation, the random gain uncertainty was excluded. In all 3165 sources were observed. The GBT catalog (the HEASARC GBT31GHZ table) contains 1490 sources. Of the 2315 useful OVRO observations many of the non-detections (and a few detections) were superceded by more sensitive GBT observations; the OVRO catalog contained in the present table therefore contains data on 1675 sources. The detection rate of the OVRO measurements was 11%, and that of the GBT measurements 25%. In all, 18% of the sources were detected at 31 GHz. This table was created by the HEASARC in June 2012 based on CDS Catalpog J/ApJ/704/1433 file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pmn
- Title:
- Parkes-MIT-NRAO (PMN) Surveys
- Short Name:
- PMN
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The PMN database contains data from the Parkes-MIT-NRAO (PMN) Southern, Zenith, Tropical and Equatorial surveys. These surveys were made using the Parkes 64-m radio telescope at a frequency of 4850 Hz with the NRAO multibeam receiver mounted at the prime focus (for a full description of the observations see Griffith & Wright, 1993, Paper I). These surveys had a spatial resolution (full width half-maximum: FWHM) of approximately 4.2 arcminutes and were made during 1990 June and November. The PMN surveys were divided into several zones. These zones are listed below, together with approximate flux limits and survey areas: <pre> Zone Name DEC limits (degrees) Flux limits Area (sr) SOUTHERN -87.5< dec <-37 20 to 50 mJy 2.50 ZENITH -37 < dec <-29 72 mJy 0.67 TROPICAL -29 < dec < -9.5 42 mJy 2.01 EQUATORIAL -9.5< dec <+10.0 40 mJy 1.90 </pre> A point source catalog was compiled directly from each of the survey zones by using an optimum filter method, as described by Griffith & Wright in detail in Paper 1. In addition, a set of images was produced for each zone in a manner very similar to that used by Condon et al. for the northern survey (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/40">CDS Catalog VIII/40</a>): See e.g. Paper 4. These maps have an effective resolution (FWHM) of about 5 arcmin. For more details, refer to the publications listed in the References Section for the relevant zone. This updated version of the PMN database was created by the HEASARC in January 2001 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/38">CDS Catalog VIII/38</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pkscat90
- Title:
- Parkes Southern Radio Source Catalog, Version 1.01
- Short Name:
- Parkes
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- PKSCAT90 is the Parkes Catalog (1990) and consists of radio and optical data for 8,264 radio sources. It covers essentially all the sky south of declination +27 degrees but largely excludes the Galactic Plane and the Magellanic Cloud regions. The latter zones have been the subject of other, specialist surveys. A few data errors in Version 1.00 have been corrected in the present edition (see below). This version of the Parkes Radio Source Catalog is entitled "PKSCAT90 Version 1.01." The original Parkes radio catalog was compiled from major radio surveys with the Parkes radiotelescope at frequencies of 408 MHz and 2700 MHz. This work spanned a period of nearly 20 years and was undertaken largely by John Bolton and his colleagues. Since then, improved positions, optical identifications, and redshifts have been obtained for many of the sources in the catalog. Furthermore, flux densities at several frequencies have supplemented the original surveys so that the measurements now cover the frequency range 80-22,000 MHz. However, coverage at the highest frequencies is still sparse. Important contributions to the usefulness of the catalog have been radio data from the Molonglo 408-MHz survey and the 80-MHz Culgoora measurements of Slee et al. PKSCAT90 should thus be regarded as a compendium of radio and optical data about southern radio sources. However, at the moment, it contains only sources originally found in the Parkes 2700-MHz survey (see e.g. Part 14, Bolton et al, 1979, Aust J Phys, Astrophys Suppl, No. 46 and references therein.) The original radio survey data of the catalog and the optical identifications have been published in a series of papers in the Australian Journal of Physics (see above reference). The associated optical spectral data on which redshifts were obtained has also been published, mainly in Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. About the completeness levels of the catalog in various parts of the sky: users should note that the sky zone between -4 and +4 degrees has been the subject of a re-survey and is now complete to 0.25 Jy. The author Alan Wright notes that "PKSCAT90 was produced at a time when relational databases were in their infancy. In the future we anticipate making the individual data sources available separately -- through such search systems as SIMBAD -- rather than in an 'omnibus' catalog like PKSCAT90. For both the Northern and Southern hemispheres, superior and deeper finding surveys now exist: the 87GB catalog in the North (Gregory and Condon et al. 1991, ApJ, 75, 1011, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/14">CDS Catalog VIII/14</a>) and the PMN catalogs (Griffith and Wright 1993, AJ, 105, 1666, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/38">CDS Catalog VIII/38</a>, available at the HEASARC as the PMN table) in the South." This table was updated by the HEASARC in July 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/15">CDS Catalog VIII/15</a> file pkscat90.dat, replacing a version based on the original (version 1) PKSCAT90, which was created in 1995. It was further updated in September 2015 as noted in the "Version 1.01 Modifications" section above. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pds1p4ghz
- Title:
- Phoenix Deep Survey 1.4-GHz Catalog
- Short Name:
- PDS1P4GHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The initial Phoenix Deep Survey (PDS) observations with the Australia Telescope Compact Array (ATCA) have been supplemented by additional 1.4 GHz observations over the past few years. Here we present details of the construction of a new mosaic image covering an area of 4.56 deg<sup>2</sup> referred to as the Phoenix Deep field (PDF), an investigation of the reliability of the source measurements, and the 1.4 GHz source counts for the compiled radio catalog. The mosaic achieves a 1-sigma rms noise of 12 µJy at its most sensitive, and a homogeneous radio-selected catalog of over 2000 sources reaching flux densities as faint as 60 µJy has been compiled. The source parameter measurements are found to be consistent with the expected uncertainties from the image noise levels and the Gaussian source fitting procedure. A radio-selected sample avoids the complications of obscuration associated with optically selected samples, and by utilizing complementary PDS observations, including multicolor optical, near-infrared, and spectroscopic data, this radio catalog will be used in a detailed investigation of the evolution in star formation spanning the redshift range 0 < z < 1. The homogeneity of the catalog ensures a consistent picture of galaxy evolution can be developed over the full cosmologically significant redshift range of interest. The PDF covers a high-latitude region that is of low optical obscuration and devoid of bright radio sources. ATCA 1.4 GHz observations were made in 1994, 1997, 1999, 2000, and 2001 in the 6A, 6B, and 6C array configurations, accumulating a total of 523 hr of observing time. The initial 1994 ATCA observations (Hopkins et al. 1998, MNRAS, 296, 839; Hopkins 1998, PhD thesis) consisted of 30 pointings on a hexagonal tessellation, resulting in a 2 degrees diameter field centered on R.A. = 01<sup>h</sup> 14<sup>m</sup> 12.16<sup>s</sup>, Dec = -45<sup>o</sup> 44' 8.0" (J2000.0), with roughly uniform sensitivity of about 60 µJy rms. This survey was supplemented from 1997 to 2001 by extensive observations of a further 19 pointings situated on a more finely spaced hexagonal grid, centered on R.A. = 01<sup>h</sup> 11<sup>m</sup> 13.0<sup>s</sup>, Dec = -45<sup>o</sup> 45' 00" (J2000.0). The locations of all pointing centers are given in Table 1 of the reference paper. The final mosaic constructed from all 49 pointings was trimmed to remove the highest noise regions at the edges by masking out regions with an rms noise level greater than 0.25 mJy. The trimmed PDF mosaic image covers an area of 4.56 deg<sup>2</sup> and reaches to a measured level of 12 µJy rms noise in the most sensitive regions. The table contained here is the final merged catalog of PDS surveys based on the union of the 10% false discovery rate (FDR) threshold catalog (PDS_atca_fdr10_full_vis.cat) for the trimmed mosaic, visually edited to remove objects clearly associated with artifacts close to bright sources, containing 2058 sources, and the 10% FDR threshold catalog (PDS_atca_fdr10_deep.cat) for the 33' x 33' region centered on the most sensitive portion of the mosaic, containing 491 sources. The merged catalog was constructed to contain all unique catalogued sources; where common sources were identified, only the entry from PDS_atca_fdr10_deep.cat was retained. There are a total of 2148 sources in the final merged catalog, of which up to 10% may be false. This table was created by the HEASARC in November 2012 based on the file PDS_atca_fdr10_merge.cat, the merged PDS catalog (derived from the individual catalogs PDS_atca_fdr10_full_vis.cat and PDS_atca_fdr10_deep.cat as discussed in the Overview above), which was obtained from the first author's website <a href="https://web.archive.org/web/20171009234923/www.physics.usyd.edu.au/~ahopkins/phoenix/">https://web.archive.org/web/20171009234923/www.physics.usyd.edu.au/~ahopkins/phoenix/</a>. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pdsoid
- Title:
- Phoenix Deep Survey Optical and Near-Infrared Counterparts Catalog
- Short Name:
- PDSOID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Using a deep Australia Telescope Compact Array (ATCA) radio survey covering an area of ~3 deg<sup>2</sup> to a 4-sigma sensitivity of >= 100 µJy (µJy) at 1.4 GHz, the authors study the nature of faint radio galaxies. The region, 2 degrees in diameter and centered on RA and Dec (J2000.0) of 1<sup>h</sup> 14<sup>m</sup> 12.16<sup>s</sup>, -45<sup>o</sup> 44' 08.0" (Galactic latitude of -71<sup>o</sup>), is known as the Phoenix Deep Field. About 50% of the detected radio sources are identified with an optical counterpart revealed by CCD photometry to m<sub>R</sub> = 22.5 magnitudes. Near-infrared (K-band) data are also available for a selected sample of the radio sources, while spectroscopic observations have been carried out for about 40% of the optically identified sample. These provide redshifts and information on the stellar content. Emission-line ratios imply that most of the emission-line sources are star-forming galaxies, with a small contribution (~ 10%) from Seyfert 1/Seyfert 2 type objects. The authors also find a significant number of absorption-line systems, likely to be ellipticals. These dominate at high flux densities ( > 1 mJy) but are also found at sub-mJy levels. Using the Balmer decrement, they find a visual extinction A<sub>V</sub> = 1.0 for the star-forming faint radio sources. This moderate reddening is consistent with the (V - R) and (R - K) colors of the optically identified sources. For emission-line galaxies, there is a correlation between the radio power and the H-alpha luminosity, in agreement with the result of Benn et al. (1993, MNRAS, 263, 98). This suggests that the radio emission of starburst radio galaxies is a good indicator of star formation activity. When calculating luminosities, the authors assume a cosmology with a Hubble constant H<sub>0</sub> of 50 km s<sup>-1</sup> Mpc<sup>-1</sup> and a deceleration parameter q<sub>0</sub> of 0.5. This table was created by the HEASARC in June 2013 based on an electronic version of Table 1 from the reference paper, which details the photometric (optical and near-infrared), radio, spectroscopic and intrinsic properties of the faint radio sources in the PDS with established redshifts, which was obtained from the CDS web site (their catalog J/MNRAS/306/708 file table1.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pdsoid2
- Title:
- Phoenix Deep Survey Optical and Near-Infrared Counterparts Catalog 2
- Short Name:
- PDSOID2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Phoenix Deep Survey (PDS) is a multi-wavelength galaxy survey based on deep 1.4-GHz radio imaging. The revised version of the radio source catalog was published by Hopkins et al. (2003). The primary goal of the PDS is to investigate the properties of star formation in galaxies and to trace the evolution in those properties to a redshift z = 1, covering a significant fraction of the age of the universe. By compiling a sample of star-forming galaxies based on selection at radio wavelengths, Sullivan et al. (2004, the reference paper for this present catalog) eliminate possible biases due to dust obscuration, a significant issue when selecting objects at optical and ultraviolet wavelengths. In this study, they present the catalogs and results of deep optical (UBVRI) and near-infrared (K<sub>s</sub>) imaging of the deepest region of the existing decimetric radio imagery. The observations and data processing are summarized and the construction of the optical source catalogs described in their paper, together with the details of the identification of candidate optical counterparts to the radio catalogs. Based on their UBVRIK<sub>s</sub> imaging, photometric redshift estimates for the optical counterparts to the radio detections are explored. Two pointings (labeled 7 and 3 in Table 1 of the reference paper) were observed in BVRi, and one (pointing 11 in ibid.) in BVi on the nights of 2001 August 13 and 14, with the WFI camera on the Anglo-Australian Telescope (AAT). The same three pointings were also observed in U with the Mosaic-II camera on the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco telescope on 2002 September 3. Finally, four of the PDS fields (2, 3, 6, 7) were observed in U with the WFI on the European Southern Observatory (ESO) 2.2-m telescope on the night of 2001 August 18. The NIR imaging data come from the Hawaii HgCdTe 1024 x 1024 pixel array SoFI camera on the 3.6-m ESO New Technology Telescope (NTT). The field of view was 4.9' x 4.9' with a pixel scale of 0.29". Nine contiguous pointings, in a 3 x 3 pattern, were observed over the deepest region of the PDS (a sub-region of pointing 7; see Fig. 1 of the reference paper), during 2000 October 10 and October 11. Throughout this study, the authors assume an Omega<sub>Lambda</sub> = 0.7, Omega<sub>M</sub> = 0.3, h = 0.70 (where H<sub>0</sub> = 100 h km s<sup>-1</sup> Mpc<sup>-1</sup>) cosmology. This table was created by the HEASARC in June 2013 based on an electronic version of Table 6 from the reference paper, which details the photometric (optical and near-infrared) properties and redshifts of 778 radio sources in the PDS, which was obtained from the CDS web site (their catalog J/ApJS/155/1 file table6.dat). The HEASARC has changed the name prefixes of the sources in this table from 'PDS' (Phoenix Deep Survey) to 'PDF' (Phoenix Deep Field) as recommended by the CDS Dictionary of Astronomical Nomenclature. Three duplicate entries were removed from the catalog in June 2019. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/pacobscat
- Title:
- Planck-ATCA Co-eval Observations (PACO) Project Bright Sample Catalog
- Short Name:
- PACOBSCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- 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 .
