- ID:
- ivo://nasa.heasarc/zcat
- Title:
- CfA Redshift Catalog (June 1995 Version)
- Short Name:
- CFAZ
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ZCAT database contains the CfA Redshift Catalog, which incorporates much of the latest velocity data from the Whipple Observatory and other sources, as well as velocities from earlier compilations such as the "Second Reference Catalog" of de Vaucouleurs, de Vaucouleurs, and Corwin; the "Index of Galaxy Spectra" of Gisler and Friel; and the "Catalog of Radial Velocities of Galaxies" of Palumbo, Tanzella-Nitti, and Vettolani. It includes BT magnitudes, some UGC numbers, and increased "accuracy" in the velocity source information. The data presented here have primarily been assembled for the purpose of studying the large scale structure of the universe, and, as such, are nearly complete in redshift information, but are not necessarily complete in such categories as diameter, magnitude, and cross-references to other catalogues. The original HEASARC version was constructed based on an earlier version of the catalog and was released on November 15, 1996. The HEASARC created the current version of ZCAT in February 2001 based on CDS/ADC Catalog VII/193, "The CfA Redshift Catalogue", Version June 1995, tables <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/193/zcat.dat">https://cdsarc.cds.unistra.fr/ftp/cats/VII/193/zcat.dat</a> and zbig.dat. The former table contains the main body of the CFA Redshift Catalog (57536 objects) and entries from it are distinguishable in the current database by having either listed radial velocity values but not redshifts or neither, while the latter table contains 1202 high-redshift galaxies (distinguishable in the current database by their having listed redshift values but not radial velocities). This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/cfa2s
- Title:
- CfA Redshift Survey: South Galactic Cap Data
- Short Name:
- CfARed.S.
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Center for Astrophysics (CfA) Redshift Survey South Galactic Cap (CFA2S) Catalog contains redshifts for a sample of about 4300 galaxies with blue (Zwicky B(0) type) magnitude <= 15.5 covering the range from 20 h to 4h in right ascension and from -2.5 deg to 90 deg in declination. This sample is complete for all galaxies in the merge of the Zwicky et al. and Nilson catalogs in the south Galactic cap. Redshifts for 2964 of these were measured as part of the second CfA Redshift Survey. The data reveal large voids in the foreground and background of the Perseus-Pisces Supercluster. The largest of these voids lies at a mean velocity ~ 8000km/s, has diameter of ~ 5000km/s, and is enclosed by a complex of dense structures. The large structure known as the Perseus-Pisces Supercluster forms the near side of this complex. On the far side of this large void, at a mean velocity of ~ 12000km/s, there is another coherent dense wall. The structures in this survey support the view that galaxies generally lie on surfaces surrounding or nearly surrounding low-density regions or voids. This table was created by the HEASARC in March 2005 based on CDS table J/ApJS/121/287/cfa2s.dat.gz This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cbatpicagn
- Title:
- CGRO BATSE-Observed Piccinotti Sample of Active Galactic Nuclei
- Short Name:
- GRO/Piccinott
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Compton Gamma-Ray Observatory (CGRO) BATSE Earth-occultation data have been used by Malizia et al. (1999, ApJ, 519, 637) to search for emission in the 20-100 keV band from all sources in the Piccinotti sample (Piccinotti et al. 1982, ApJ, 253, 485: the HEASARC A2PIC database), which represents the only complete 20-10 keV survey to date of the extragalactic sky down to a limiting flux of 3.1 x 10<sup>-11</sup> ergs cm<sup>-2</sup> s<sup>-1</sup>. Nearly 4 years of observations have been analyzed to reach a 5-sigma confidence level of about 7.8 x 10<sup>-11</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> in the band considered. Of the 36 sources in the sample, 14 have been detected above the 5-sigma confidence level, while marginal detection (3 <= sigma <= 5) can be claimed for 13 sources; for nine objects, 2 sigma upper limits are reported. A comparison of BATSE results with data at higher energies is used to estimate the robustness of the data analysis. While the detection level of each source is reliable, the flux measurement may be overestimated in some sources by as much as 35%, probably because of incomplete data cleaning. Comparison of BATSE fluxes with X-ray fluxes obtained in the 2-10 keV range and averaged over years indicates that a canonical power law of photon index 1.7 gives a good description of the broadband spectra of bright active galactic nuclei (AGNs) and that spectral breaks preferentially occur above 100 keV. This HEASARC database was created in October 1999 based primarily on Table 1 of Malizia et al. (1999), together with the positions and HEAO-1 designations taken from the original Piccinotti Catalog (Piccinotti et al. 1982, ApJ, 253, 485: the HEASARC A2PIC database). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ccosrssfag
- Title:
- Chandra COSMOS Radio-Selected Star-Forming Galaxies and AGN Catalog
- Short Name:
- CCOSRSSFAG
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- X-ray surveys contain sizable numbers of star-forming galaxies, beyond the AGN which usually make up the majority of detections. Many methods to separate the two populations are used in the literature, based on X-ray and multi-wavelength properties. The authors aim at a detailed test of the classification schemes and to study the X-ray properties of the resulting samples. They build on a sample of galaxies selected at 1.4 GHz in the VLA-COSMOS survey, classified by Smolcic et al. (2008, ApJS, 177, 14) according to their optical colors and also observed by Chandra. A similarly selected control sample of AGN is also used for comparison. The authors review some X-ray based classification criteria and check how they affect the sample composition. The efficiency of the classification scheme devised by Smolcic et al. (2008) is such that ~30% of composite/misclassified objects are expected because of the higher X-ray brightness of AGN with respect to galaxies. The latter fraction is actually 50% in the X-ray detected sources, while it is expected to be much lower among X-ray undetected sources. Indeed, the analysis of the stacked spectrum of undetected sources shows, consistently, strongly different properties between the AGN and galaxy samples. X-ray based selection criteria are then used to refine both samples. The radio/X-ray luminosity correlation for star-forming (SF) galaxies is found to hold with the same X-ray/radio ratio valid for nearby galaxies. Some evolution of the ratio may be possible for sources at high redshift or high luminosity, though it is likely explained by a bias arising from the radio selection. Finally, in their paper the authors discuss the X-ray number counts of star-forming galaxies from the VLA- and C-COSMOS surveys according to different selection criteria, and compare them to the similar determination from the Chandra Deep Fields. The classification scheme proposed here may find application in future works and surveys. This table contains the catalogs of radio-selected SF- and AGN-candidate sources with an X-ray detection in C-COSMOS which were contained in Tables 2 and 3 of the reference paper, respectively. The HEASARC has merged these into a single table, adding a new parameter sample which is set to 'SFG' for radio-selected SF-candidate sources from Table 2 and to 'AGN' for the AGN-candidate sources from Table 3. This table was created by the HEASARC in June 2012 based on CDS table J/A+A/542/A16 files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cosmosvlba
- Title:
- COSMOS Field VLBA Observations 1.4-GHz Source Catalog
- Short Name:
- COSMOSVLBA
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of a project using wide-field Very Long Baseline Interferometry (VLBI) observations at 1.4 GHz of 2,865 known radio sources in the Cosmic Evolution Survey (COSMOS) field, a field which has exceptional multi-wavelength coverage. The main objective of this study is to identify the active galactic nuclei (AGN) in this field. Wide-field VLBI observations were made of all known radio sources in the COSMOS field at 1.4 GHz using the Very Long Baseline Array (VLBA). The authors also collected complementary multiwavelength information from the literature for the VLBA-detected sources.The combination of the number of sources, sensitivity, angular resolution and the area covered by this project are unprecedented. A catalog which contains the VLBI-detected sources is presented, the main purpose of which is to be used as an AGN catalog. the complementary multiwavelength (optical, infrared and X-ray) information of the VLBI-detected sources is also presented. The authors have detected 468 radio sources, expected to be AGN, with the VLBA. This is, to date, the largest sample assembled of VLBI-detected sources in the sub-mJy regime. They find a detection fraction of 20% +/- 1%, considering only those sources from the input catalog which were in principle detectable with the VLBA (2,361). As a function of the VLA flux density, the detection fraction is higher for higher flux densities, since at high flux densities a source could be detected even if the VLBI core accounts for a small percentage of the total flux density. As a function of redshift, the authors see no evolution of the detection fraction over the redshift range 0.5 < z < 3. In addition, they find that faint radio sources typically have a greater fraction of their radio luminosity in a compact core: ~70% of the sub-mJy sources detected with the VLBA have more than half of their total radio luminosity in a VLBI-scale component, whereas this is true for only ~30% of the sources that are brighter than 10 mJy. This suggests that fainter radio sources differ intrinsically from brighter ones. Across the entire sample, the authors find the predominant morphological classification of the host galaxies of the VLBA-detected sources to be early type (57%), although this varies with redshift and at z > 1.5 they find that spiral galaxies become the most prevalent (48%). The number of detections is high enough to study the faint radio population with statistically significant numbers. The authors demonstrate that wide-field VLBI observations, together with new calibration methods such as multi-source self-calibration and mosaicking, result in information which is difficult or impossible to obtain otherwise. This table contains 504 entries, including the 468 VLBA-detected sources and, for sources with multiple components, entries for the individual components. Among the detected sources, there are 452 single, 13 double, 2 triple and 1 quadruple source. Source entries have no suffix in their vlba_source_id, e.g., 'C3293', whereas component entries have a, b, c or d suffixes, e.g., 'C0090a' (and a value of 2 for the multi_cpt_flag parameter). This table was created by the HEASARC in December 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/607/A132">CDS Catalog J/A+A/607/A132</a> files vlba_cat.dat and vlba_mw.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cosxfirmwc
- Title:
- COSMOSFieldX-Ray&FIRDetectedAGNMultiwavelengthPropertiesCatalog
- Short Name:
- COSXFIRMWC
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The coeval AGN and galaxy evolution and the observed local relations between super-massive black holes (SMBHs) and galaxy properties suggest some connection or feedback between SMBH growth and galaxy build-up. The authors looked for correlations between properties of X-ray detected AGN and their far-infrared (FIR) detected host galaxies, to find quantitative evidences for this connection, highly debated in recent years. They exploit the rich multi-wavelength data set (from X-ray to FIR) that is available in the COSMOS field for a large sample (692 sources) of AGN and their hosts, in the redshift range 0.1 < z < 4, and use X-ray data to select AGN and determine their properties (intrinsic luminosity and nuclear obscuration), and broad-band (from UV to FIR) spectral energy distribution (SED) fitting to derive host galaxy properties, viz., the stellar mass (M<sub>*</sub>) and the star formation rate (SFR). The authors find that the AGN 2-10 keV luminosity (L<sub>X</sub>) and the host galaxy 8-1000 um star formation luminosity (L<sup>SF</sup><sub>IR</sub>) are significantly correlated. However, the average host L<sup>SF</sup><sub>IR</sub> has a flat distribution in bins of AGN L<sub>X</sub>, while the average AGN L<sub>X</sub> increases in bins of host L<sup>SF</sup><sub>IR</sub>, with a logarithmic slope of ~ 0.7, in the redshifts range 0.4 < z < 1.2. In the reference paper, the authors also discuss the comparison between the distribution of these two quantities and the predictions from hydrodynamical simulations. Finally, they find that the average column density (N<sub>H</sub>) shows a positive correlation with the host M<sub>*</sub>, at all redshifts, but not with the SFR (or L<sup>SF</sup><sub>IR</sub>). This translates into a negative correlation with specific SFR. These results are in agreement with the idea that BH accretion and SFRs are correlated, but occur with different variability time scales. The presence of a positive correlation between N<sub>H</sub> and host M<sub>*</sub> suggests that the X-ray N<sub>H</sub> is not entirely due to the circumnuclear obscuring torus, but may also include a contribution from the host galaxy. This table summarizes the multiwavelength properties of the 692 AGN-host systems detected in the COSMOS field both in the X-ray and in the FIR (the X-FIR sample). This table was created by the HEASARC in July 2017, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/602/A123">CDS Catalog J/A+A/602/A123</a> file table1.dat, which contains the multiwavelength properties of the 692 sources in the X-FIR sample. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sixdfgs
- Title:
- 6dFGS Galaxy Survey Final Redshift Release Catalog
- Short Name:
- SIXDFGS
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The final redshift release of the 6dF Galaxy Survey (6dFGS) is a combined redshift and peculiar velocity survey over the southern sky (|b| > 10 degrees). Its 136,304 spectra have yielded 110,256 new extragalactic redshifts and a new catalogue of 125,071 galaxies making near-complete samples with limits in (K, H, J, r<sub>F</sub>, b<sub>J</sub>) (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. The catalog includes basic data for the galaxies in the 6dFGS with redshifts, using the best 6dFGS redshifts (radial velocity quality flag Q =3 or 4) plus available redshifts from SDSS, 2dFGRS and ZCAT (124,647 entries in all). It supersedes the previous DR2 version (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/249">CDS Cat. VII/249</a>). The home page of of the 6dFGS database is <a href="http://www-wfau.roe.ac.uk/6dFGS">http://www-wfau.roe.ac.uk/6dFGS</a>. Any use of these data should explicitly state that they come from the Final Release of 6dFGS and cite both the 6dGS DR3 paper (Jones et al. 2009, MNRAS, 399, 683) as well as the original 6dFGS survey paper (Jones et al. 2004, MNRAS, 355, 747). This table was created by the HEASARC in March 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/259">CDS Catalog VII/259</a> file 6dfgs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/twodfqsoz
- Title:
- 2dF QSO Redshift (2QZ) Survey
- Short Name:
- TWODFQSOZ
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The final catalog of the 2dF QSO Redshift Survey (2QZ) is based on Anglo-Australian Telescope 2dF spectroscopic observations of 44,576 color-selected (u, b<sub>J</sub>, r) objects with 18.25 < b<sub>J</sub> < 20.85 selected from automated plate measurement scans of UK Schmidt Telescope (UKST) photographic plates. The 2QZ comprises 23,338 quasi-stellar objects (QSOs), 12,292 galactic stars (including 2,071 white dwarfs) and 4,558 compact narrow emission-line galaxies. The authors obtained a reliable spectroscopic identification for 86 per cent of objects observed with 2dF. They also report on the 6dF QSO Redshift Survey (6QZ), based on UKST 6dF observations of 1,564 brighter (16 < b<sub>J</sub> < 18.25) sources selected from the same photographic input catalog. In total, the authors identified 322 QSOs spectroscopically in the 6QZ. The completed 2QZ is, by more than a factor of 50, the largest homogeneous QSO catalog ever constructed at these faint limits (b<sub>J</sub> < 20.85) and high QSO surface densities (35 QSOs/deg<sup>2</sup>). As such, it represents an important resource in the study of the Universe at moderate-to-high redshifts. The survey area comprised 30 UKST fields, arranged in two 75 degrees by 5 degrees declination strips, one passing across the South Galactic Gap centered on Dec = -30 degrees (the SGP strip), and the other across the North Galactic Gap centered on Dec = 0 degrees (referred to in the reference paper as the equatorial strip, but also known as the NGP strip. The total survey area is 721.6 deg<sup>2</sup>, when allowance is made for regions of sky excised around bright stars. Spectroscopic observations of the input catalogue were made with the 2dF instrument at the Anglo-Australian Telescope (AAT; the 2QZ sample) and the 6dF instrument at the UKST (the 6QZ sample). 2dF spectroscopic observations began in January 1997 and were completed in April 2002. Six-degree Field observations were performed over the period 2001 March-2002 September. This online catalog was created by the HEASARC in October 2010 based on the machine-readable table 2qz.dat obtained from the CDS (their catalog VII/241). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/etgalxray
- Title:
- Early-Type Galaxies X-Ray Luminosities Catalog
- Short Name:
- ETGALXRAY
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of X-ray luminosities for 401 early-type galaxies (and 24 other galaxies which were listed in previuous studies as early but which have LEDA T-types >= -1.5), of which 136 are based on newly analysed ROSAT PSPC pointed observations. The remaining luminosities are taken from the literature and converted to a common energy band, spectral model and distance scale. In their paper, the authors use this sample to fit the L<sub>X</sub>/L<sub>B</sub> relation for early-type galaxies and find a best-fit slope for the catalog of ~ 2.2. The authors demonstrate the influence of group-dominant galaxies on the fit and present evidence that the relation is not well modeled by a single power-law fit. They also derive estimates of the contribution to galaxy X-ray luminosities from discrete-sources and conclude that they provide L<sub>(discrete-source-contribution)</sub>/L<sub>B</sub> ~ 29.5 erg s<sup>-1</sup>/L<sub>Bsun</sub>. The authors compare this result with luminosities from their catalog. Lastly, they examine the influence of environment on galaxy X-ray luminosity and on the form of the L<sub>X</sub>/L<sub>B</sub> relation. They conclude that although environment undoubtedly affects the X-ray properties of individual galaxies, particularly those in the centres of groups and clusters, it does not change the nature of whole populations. The sample of early-type galaxies was selected from the Lyon-Meudon Extragalactic Data Archive (LEDA). This catalog at that time contained information on ~ 100,000 galaxies, of which ~ 40,000 had redshift and morphological data. Galaxies were selected using the following criteria: (i) Morphological Type T < -1.5 (i.e. E, E-S0 and S0 galaxies). (ii) Virgo-corrected recession velocity V <= 9,000 km s<sup>-1</sup>. (iii) Apparent Magnitude B<sub>T</sub> <= 13.5. The redshift and apparent magnitude restrictions were chosen in order to minimize the effects of incompleteness on their sample. The LEDA catalogue is known to be 90 per cent complete at B<sub>T</sub> = 14.5, so the selection should be close to statistical completeness. The selection process produced ~ 700 objects. The authors then cross-correlated this list with a list of public ROSAT PSPC pointings. Only pointings within 30 arcminutes of the target were accepted, as, further off-axis, the PSPC point-spread function becomes large enough to make analysis problematic. This left 209 galaxies with X-ray data available. The authors also added data from previously published catalogs, ROSAT PSPC All-Sky Survey values from Beuing et al. (1999, MNRAS, 302, 209), and Einstein IPC values from Fabbiano et al. (1992, ApJS, 80, 531) and Roberts et al. (1991, ApJS, 75, 751). These other references use a range of models to fit the data, different wavebands, distances and blue luminosities. O'Sullivan et al. corrected for these differences by converting the catalogs to a common set of values, as used for their own results. All of the X-ray luminosities have been converted to a common format based on a reliable distance scale (assuming H<sub>0</sub> = 75 km s<sup>-1</sup> Mpc<sup>-1</sup>), and correcting for differences in spectral fitting techniques and waveband. This table was created by the HEASARC in October 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/328/461">CDS catalog J/MNRAS/328/461</a> file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/eingalclus
- Title:
- Einstein Observatory Clusters of Galaxies Catalog
- Short Name:
- Einstein/Clus
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Observatory Clusters of Galaxies Catalog presents the X-ray characteristics of a sample of 368 clusters of galaxies with redshifts less than 0.2 which were observed with the Einstein Imaging Proportional Counter (IPC). For each cluster, the authors measured the 0.5 - 4.5 keV counting rate and computed the 0.5 - 4.5 keV source luminosity, as well as the bolometric luminosity within fixed metric radii. They detected 85% of Abell clusters with z < 0.1, demonstrating that the large majority of these optically selected clusters are not the results of chance superpositions. For 163 clusters, they measured their X-ray surface brightness profiles and determined their core radii. For about 230 clusters, they then used either their measured core radii and beta values, or mean values derived for this sample, to measure central gas densities and gas masses. They used estimated or measured cluster gas temperatures, along with the derived gas-density profiles, to estimate total cluster masses, under the assumptions that the gas is isothermal and in hydrostatic equilibrium. This table was created by the HEASARC in June 2005 based on the merger of CDS tables J/ApJ/511/65/table3.dat and table4.dat. This is a service provided by NASA HEASARC .
