- ID:
- ivo://nasa.heasarc/noras
- Title:
- Northern ROSAT All-Sky (NORAS) Galaxy Cluster Survey Catalog
- Short Name:
- NORASGalClus
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- In the construction of an X-ray-selected sample of galaxy clusters for cosmological studies, the authors have assembled a sample of 495 X-ray sources which were found to show extended X-ray emission in the first processing of the ROSAT All-Sky Survey (RASS I), the Northern ROSAT All-Sky (NORAS) Galaxy Cluster Survey Catalog. The sample covers the celestial region with declination >=0 degrees and Galactic latitude |b| >= 20 degrees, and comprises sources with a Position Sensitive Proportional Counter (PSPC) count rate >= 0.06 counts/s and a source extent likelihood of L >= 7. In an optical follow-up identification program, the authors found 378 (76%) of these sources to be clusters of galaxies. It was necessary to reanalyze the sources in this sample with a new X-ray source characterization technique to provide more precise values for the X-ray flux and source extent than obtained from the standard processing. This new method, termed growth curve analysis (GCA), has the advantage over previous methods in its ability to be robust, to be easy to model and to integrate into simulations, to provide diagnostic plots for visual inspection, and to make extensive use of the X-ray data. The source parameters obtained assist the source identification and provide more precise X-ray fluxes. This reanalysis is based on data from the more recent second processing of the ROSAT Survey, RASS II. The authors present a catalog of the cluster sources with the X-ray properties obtained as well as a list of the previously flagged extended sources that are found to have a non-cluster counterpart. In their paper, they discuss the process of source identification from the combination of optical and X-ray data. To investigate the overall completeness of the cluster sample as a function of the X-ray flux limit, they extended the search for X-ray cluster sources to the RASS II data for the northern sky region between 9 and 14 hours in right ascension. They included the search for X-ray emission from known galaxy clusters as well as a new investigation of extended X-ray sources. In the course of this search, they found X-ray emission from 85 additional Abell clusters and 56 very probable cluster candidates among the newly found extended sources. A comparison of the X-ray cluster number counts of the NORAS sample with the ROSAT-ESO Flux-limited X-ray (REFLEX) Cluster Survey results leads to an estimate of the completeness of the NORAS sample of ROSAT All-Sky Survey (RASS) I extended clusters of about 50% at an X-ray flux of FX(0.1-2.4 keV) = 3 x 10-12 ergs s<sup>-1</sup> cm<sup>-2</sup>. The estimated completeness achieved by adding the supplementary sample in the study area amounts to about 82% in comparison to REFLEX. The low completeness introduces an uncertainty in the use of the sample for cosmological statistical studies that will be cured with the completion of the continuing Northern ROSAT All-Sky (NORAS) Cluster Survey project. This table was created by the HEASARC in June 2005 based on CDS table J/ApJS/129/435, table1.dat through table9.dat inclusive. 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/nuaftl
- Title:
- NuSTAR As-Flown Timeline
- Short Name:
- NUAFTL
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The NUAFTL database table records the As-Flown Timeline for the Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observatory. NuSTAR observes the sky in the high energy X-ray (3 - 79 keV) region of the electromagnetic spectrum using focusing optics. The as-flown timeline provides a summary of what NuSTAR has observed and is updated automatically when each observation is completed. This HEASARC database table is updated automatically within a day or so of updates to the referenced URL. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/nucosmosfc
- Title:
- NuSTAR COSMOS Field X-Ray Source Catalog
- Short Name:
- NUCOSMOSFC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- To provide the census of the sources contributing to the X-ray background peak above 10 keV, the Nuclear Spectroscopic Telescope Array (NuSTAR) is performing extragalactic surveys using a three-tier "wedding cake" approach. In their paper, the authors present the NuSTAR survey of the COSMOS field, the medium sensitivity, and medium area "tier",covering 1.7 deg<sup>2</sup> and overlapping with both Chandra and XMM-Newton data. This survey consists of 121 NuSTAR observations for a total exposure of ~3 Ms. To fully exploit these data, the authors developed a new detection strategy, carefully tested through extensive simulations. The survey sensitivity at 20% completeness is 5.9, 2.9, and 6.4 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the 3-24, 3-8 and 8-24 keV bands, respectively. By combining detections in 3 bands, the survey consists of a sample of 91 NuSTAR sources with luminosities ~ 10<sup>42</sup> - 10<sup>45.5</sup> erg s<sup>-1</sup>and redshifts z ~ 0.04-2.5. Thirty-two sources are detected in the 8-24 keV band with fluxes ~100 times fainter than sources detected by Swift-BAT. Of the 91 detections, all but 4 are associated with a Chandra and/or XMM-Newton point-like counterpart. One source is associated with an extended lower energy X-ray source. The authors present the X-ray (hardness ratio and luminosity)and optical-to-X-ray properties. The observed fraction of candidate Compton-thick active galactic nuclei measured from the hardness ratio is between 13% - 20%. In their paper, the authors discuss the spectral properties of the source named NuSTAR J100259+0220.5 (source number 330) at a redshift z = 0.044, which has the highest hardness ratio in the entire sample. The measured column density exceeds 10<sup>24</sup> cm<sup>-2</sup>, implying the source is Compton-thick. This source was not previously recognized as such without the data at energies >10 keV. This table was created by the HEASARC in August 2015 based on the the machine-readable versions of Table 5 (the COSMOS Field NuSTAR source catalog) that was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/nugalcen
- Title:
- NuSTAR Hard X-Ray Survey of the Galactic Center
- Short Name:
- NUGALCEN
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the the first survey results of hard X-ray point sources in the Galactic Center (GC) region obtained by NuSTAR. The authors have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg<sup>2</sup> region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. They identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ~4 x 10<sup>32</sup> and ~8 x 10<sup>32</sup> erg/s at the GC (8 kpc) in the 3-10 and 10-40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources suggests that magnetic cataclysmic variables constitute a large fraction (>40% - 60%). Both spectral analysis and logN - logS distributions of the NuSTAR sources indicate that the X-ray spectra of the NuSTAR sources should have kT > 20 keV on average for a single-temperature thermal plasma model or an average photon index of Gamma = 1.5 - 2 for a power-law model. These findings suggest that the GC X-ray source population may contain a larger fraction of XBs with high plasma temperatures than the field population. The observations of the GC region with NuSTAR began in 2012 July, shortly after its launch. The original survey strategy for the GC region was to match the central 2 degree x 0.7 degree region covered by the Chandra X-ray Observatory (Wang et al. 2002, Nature, 415, 148; Muno et al. 2009, ApJS, 181, 110). The field of views (FOVs) of neighboring NuSTAR observations in the survey were designed to overlap with each other by ~40%. Multiple observations of the same region with relatively large FOV offsets tend to average out the vignetting effects of each observation, enabling a more uniform coverage of the region. Multiple observations are also suitable for monitoring long term X-ray variability of sources in the region. Even when observing a single target, the NuSTAR observation is often broken up into two or more segments with relatively large pointing offsets to allow an efficient subtraction of a detector coordinate-dependent background component (e.g., Mori et al. 2013, ApJ, 770, L23). This table was created by the HEASARC in March 2018, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/825/132">CDS Catalog J/ApJ/825/132</a> files table2.dat, table3.dat, table4.dat and table5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/numaster
- Title:
- NuSTAR Master Catalog
- Short Name:
- NUMASTER
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing instruments far beyond the ~10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. The observatory was placed into a 600-km altitude, 6 degree inclination circular orbit, and consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. NuSTAR has completed its two-year primary science mission, and, with an expected orbit lifetime of more than 10 years, the opportunity for proposing observations as part of the General Observer (GO) program is now available, with observations beginning in 2015. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR offers opportunities for a broad range of science investigations, ranging from probing cosmic ray origins to studying the extreme physics around compact objects to mapping micro-flares on the surface of the Sun. NuSTAR also responds to targets of opportunity including supernovae and gamma-ray bursts. This table contains a list of (a) unobserved targets that are planned or have been accepted for observation by NuSTAR in the future and (b) NuSTAR observations which have been processed and successfully validated by the NuSTAR Science Operation Center. The data from these observations may or may not be public and the user should check the value of the public_date parameter to determine the status of a specified data set. Only those ObsIDs which have a public_date in the past will have data publicly available. Observations with a public_date parameter value which is either blank or a date in the future have been ingested into the HEASARC archive but will remain encrypted until their public date. Entries with the status field set to 'accepted' are targets approved for scheduling, and the planned exposure time given in the exposure_a (and exposure_b) parameter will have a negative value for those targets. This database table is based on information supplied by the NuSTAR Project at Caltech. It is automatically updated on a regular basis. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/nustarssc
- Title:
- NuSTAR Serendipitous Survey 40-Month Primary Source Catalog
- Short Name:
- NUSTARSSC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) Serendipitous Survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg<sup>2</sup>, and 498 sources (the abstract of the reference paper states that there are 497 sources) detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from the authors' extensive campaign of ground-based spectroscopic follow-up. The authors characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift from z = 0.002 to 3.4 (median redshift z of 0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from log (f<sub>3-24keV</sub>) ~ -14 to -11 (in units of erg s<sup>-1</sup> cm<sup>-2</sup>), and in rest-frame 10-40 keV luminosity, from log (L_10-40keV) ~ 39 to 46 (in units of erg s<sup>-1</sup>), with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT observations. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ~15% at the highest luminosities (L<sub>X</sub> > 10<sup>44</sup> erg s<sup>-1</sup>) to ~80% at the lowest luminosities (L<sub>X</sub> < 10<sup>43</sup> erg s<sup>-1</sup>). The authors' optical spectroscopic analysis finds that the observed fraction of optically obscured AGN (i.e., the type 2 fraction) is F_Type 2_ = 53 (+14, -15) per cent, for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by <10 keV X-ray missions. This table contains the Primary NuSTAR Serendipitous Source Catalog of 498 sources found using the source detection procedure described in Section 2.3 of the reference paper, and listed in Table 5 (op. cit.). Additional information on these Primary Catalog sources that the authors obtained using optical spectroscopy is available in Table 6 of the reference paper (q.v.). This table does not contain the 64 sources in the Secondary NuSTAR Serendipitous Source Catalog that were found using wavdetect and that are listed in Table 7 of the reference paper: this is available in the HEASARC database as a separate table, dubbed <a href="/W3Browse/nustar/nustarssc2.html">NUSTARSSC2</a>. This table was created by the HEASARC in July 2017 based on the machine-readable version of Table 5 from the reference paper, the Primary NuSTAR Serendipitous Source Catalog, that was obtsined from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/nustarssc2
- Title:
- NuSTAR Serendipitous Survey 40-Month Secondary Source Catalog
- Short Name:
- NUSTARSSC2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the science results from the Nuclear Spectroscopic Telescope Array (NuSTAR) Serendipitous Survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg<sup>2</sup>. The primary catalog (available as the HEASARC <a href="/W3Browse/nustar/nustarssc.html">NUSTARSSC</a> table) contains 498 sources (the abstract of the reference paper states that there are 497 sources) detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from the authors' extensive campaign of ground-based spectroscopic follow-up. The authors characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift from z = 0.002 to 3.4 (median redshift z of 0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from log (f_3-24_keV) ~ -14 to -11 (in units of erg s<sup>-1</sup> cm<sup>-2</sup>), and in rest-frame 10-40 keV luminosity, from log (L<sub>10-40keV</sub>) ~ 39 to 46 (in units of erg s<sup>-1</sup>), with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT observations. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ~15% at the highest luminosities (L<sub>X</sub> > 10<sup>44</sup> erg s<sup>-1</sup>) to ~80% at the lowest luminosities (L<sub>X</sub> < 10<sup>43</sup> erg s<sup>-1</sup>). The authors' optical spectroscopic analysis finds that the observed fraction of optically obscured AGN (i.e., the type 2 fraction) is F<sub>Type2</sub> = 53 (+14, -15) per cent, for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by < 10 keV X-ray missions. This table contains the Secondary NuSTAR Serendipitous Source Catalog of 64 sources found using wavdetect to search for significant emission peaks in the FPMA and FPMB data separately (see Section 2.1.1 of Alexander et al. 2013, ApJ, 773, 125) and in the combined A+B data. These sources are listed in Table 7 of the reference paper. This method was developed alongside the primary one (Section 2.3 of the reference paper) in order to investigate the optimum source detection methodologies for NuSTAR and to identify sources in regions of the NuSTAR coverage that are automatically excluded in the primary source detection. The authors emphasize that these secondary sources are not used in any of the science analyses presented in their paper. Nevertheless, these secondary sources are robust NuSTAR detections, some of which will be incorporated in future NuSTAR studies, and for many of them (35 out of the 43 sources with spectroscopic identifications) the authors have obtained new spectroscopic redshifts and classifications through their follow-up program. The X-ray photometric parameters for 4 sources are left blank as in these cases the A+B data prohibit reliable photometric constraints. Additional information on these Secondary Catalog sources that the authors obtained using optical spectroscopy is available in Table 8 of the reference paper (q.v.). This table does NOT contain the the 498 sources in the <a href="/W3Browse/nustar/nustarssc.html">Primary NuSTAR Serendipitous Source Catalog</a> that were found using the source detection procedure described in Section 2.3 of the reference paper, and that are listed in Table 5 (op. cit.). This table was created by the HEASARC in July 2017 based on the machine-readable version of Table 7 from the reference paper, the Secondary NuSTAR Serendipitous Source Catalog, that was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/nuecdfscat
- Title:
- NuSTAR Survey of Extended Chandra Deep Field South (ECDF-S) Source Catalog
- Short Name:
- NUECDFSCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the source catalog from the Nuclear Spectroscopic Telescope Array (NuSTAR) survey of the Extended Chandra Deep Field South (hereafter, ECDFS), that is currently the deepest contiguous component of the NuSTAR extragalactic survey program. The survey covers the full ~30' x 30' area of this field to a maximum depth of ~360 ks (~220 ks when corrected for vignetting at 3 - 24 keV), reaching sensitivity limits of ~1.3 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> (3 - 8 keV), ~3.4 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> (8 - 24 keV), and ~3.0 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> (3 - 24 keV). A total of 54 sources are detected over the full field, although five of these are found to lie below our significance threshold once contaminating flux from neighboring (i.e., blended) sources is taken into account. Of the remaining 49 that are significant, 19 are detected in the 8 - 24 keV band. The 8 - 24 to 3 - 8 keV band ratios of the 12 sources that are detected in both bands span the range 0.39 - 1.7, corresponding to a photon index (Gamma) range of about 0.5 - 2.3, with a median photon index of 1.70 +/- 0.52. The redshifts of the 49 sources in the main sample span the range z = 0.21 - 2.7, and their rest-frame 10 - 40 keV luminosities (derived from the observed 8 - 24 keV fluxes) span the range L<sub>10-40keV</sub> ~ (0.7 - 300) x 10<sup>43</sup>erg/s, sampling below the "knee" of the X-ray luminosity function out to z ~ 0.8 - 1. Finally, the authors identify one NuSTAR source that has neither a Chandra nor an XMM-Newton counterpart, but that shows evidence of nuclear activity at infrared wavelengths and thus may represent a genuine, new X-ray source detected by NuSTAR in the ECDFS. The NuSTAR ECDFS survey consists of observations from two separate passes. Observations making up the first pass were taken between 2012 September and December, and those making up the second pass were taken roughly six months later, between 2013 March and April. For their cosmological calculations, the authors adopt a Hubble constant H<sub>0</sub> of 71 km s<sup>-1</sup> Mpc <sup>-1</sup>, Omega<sub>M</sub> of 0.27, and Omega<sub>Lambda</sub> of 0.73. This table was created by the HEASARC in September 2017 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/808/184">CDS Catalog J/ApJ/808/184</a> file catalog.dat. 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 .
