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COSMOSFieldX-Ray&FIRDetectedAGNMultiwavelengthPropertiesCatalog
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 .
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Sloan Digital Sky Survey/XMM-Newton Type1 AGN X-Ray and Radio Properties Catalog
공공데이터포털
X-ray emission from active galactic nuclei (AGN) is dominated by the accretion disk around a supermassive black hole. The radio luminosity, however, has not such a clear origin except in the most powerful sources where jets are evident. The origin (and even the very existence) of the local bi-modal distribution in radio-loudness is also a debated issue. By analyzing X-ray, optical and radio properties of a large sample of type 1 AGN and quasars (QSOs) up to z > 2, where the bulk of this population resides, the authors aim to explore the interplay between radio and X-ray emission in AGN, in order to further our knowledge on the origin of radio emission, and its relation to accretion. They analyze a large (~800 sources) sample of type 1 AGN and QSOs selected from the 2XMMi XMM-Newton X-ray source catalog, cross-correlated with the SDSS DR7 spectroscopic catalog, covering a redshift range from z ~ 0.3 to z ~ 2.3. Supermassive black hole masses are estimated from the Mg II emission line, bolometric luminosities from the X-ray data, and radio emission or upper limits from the FIRST catalog. Most of the sources accrete close to the Eddington limit and the distribution in radio-loudness does not appear to have a bi-modal behavior. This study confirms that radio-loud AGN are also X-ray loud, with an X-ray-to-optical ratio up to twice that of radio-quiet objects, even excluding the most extreme strongly jetted sources. By analyzing complementary radio-selected control samples, the authors find evidence that these conclusions are not an effect of the X-ray selection, but are likely a property of the dominant QSO population. The authors of this catalog conclude that their findings are best interpreted in a context where radio emission in AGN, with the exception of a minority of beamed sources, arises from very close to the accretion disk and is therefore heavily linked to X-ray emission. They also speculate that the radio-loud/radio-quiet dichotomy might either be an evolutionary effect that developed well after the QSO peak epoch, or an effect of incompleteness in small samples. Basic information and derived properties are presented for the sample of X-ray selected type 1 AGN (as well as for the 11 X-ray undetected type 1 AGN in the "control sample"): coordinates, redshift, X-ray and radio fluxes, optical magnitudes, from the SDSS, 2XMMi, and FIRST catalogs; continuum luminosities at 3000 Angstroms and in the X-ray band, black hole masses, bolometric luminosities, Eddington ratios; for the sources falling in the FIRST field, optical fluxes at 2500 and 4400 Angstroms, X-ray-to-optical index, radio classification, and the ratios between the radio and the UV, optical, and X-ray fluxes. This table was created by the HEASARC in October 2012 based on CDS Catalog J/A+A/545/A66 files table3.dat, table4.dat and table5.dat. This is a service provided by NASA HEASARC .
CHAMP/SDSS Nearby Low-Luminosity AGN Catalog
공공데이터포털
The combination of the Sloan Digital Sky Survey (SDSS) and the Chandra Multiwavelength Project (ChaMP; Green et al. 2004, ApJS, 150, 43) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relations between X-ray nuclear emission, nebular line emission, black hole masses, and the properties of the associated stellar populations. The authors provide X-ray spectral fits and valid uncertainties for all the galaxies with counts ranging from 2 to 1325 (mean 76, median 19). They present in their paper novel constraints that both X-ray luminosity LX and X-ray spectral energy distribution bring to the galaxy evolutionary sequence HII -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. In particular, the authors show that both LX and Gamma, the slope of the power law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ~ 0, or at low-luminosity active galactic nucleus (AGN) levels, there is an anticorrelation between Gamma and L/LEdd, opposite to the trend which is exhibited by high-z AGN (quasars). The turning point in the Gamma - L/LEdd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/LEdd ~ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that the authors have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anticorrelation the authors find between Gamma and L/LEdd may instead indicate that stronger accretion correlates with greater absorption. Therefore, the trend for softer spectra toward more luminous, high-redshift, and strongly accreting (L/LEdd >~ 0.01) AGNs/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections. The cross-match of all ChaMP sky regions imaged by Chandra/ACIS with the SDSS DR4 spectroscopic footprint results in a parent sample of 15,955 galaxies on or near a chip and a subset of 199 sources that are X-ray detected. Among those, only 107 sources have an off-axis angle (OAA) Theta <0.2 degrees and avoid ccd=8 due to high serial readout noise; these 107 objects comprise the main sample that the authors employ for this study and that are listed in this table. The authors performed direct spectral fits to the X-ray counts distribution using the full instrument calibration, known redshift, and Galactic 21-cm column nHGal. Source spectra were extracted from circular regions with radii corresponding to energy encircled fractions of ~90%, while the background region encompasses a 20 arcsec annulus, centered on the source, with separation 4 arcsecs, from the source region. Any nearby sources were excised, from both the source and the background regions. The spectral fitting was done via yaxx ('Yet Another X-ray eXtractor': Aldcroft 2006, BAAS, 38, 376), an automated script that employs the CIAO Sherpa tool. Each spectrum was fitted in the range 0.5 - 8 keV by two different models: (1) a single power law plus absorption fixed at the Galactic 21-cm value (model 'PL'), and (2) a fixed power law of photon index Gamma = 1.9 plus intrinsic absorption of column nH (model 'PLfix'). For the nine objects with more than 200 counts, the authors employed a third model in which both the slope of the power law and the intrinsic absorption were free to vary (model 'PL_abs'). This table was created by the HEASARC in January 2012 based on CDS Catalog J/ApJ/705/1336/ file table1.dat. This is a service provided by NASA
XMM-Newton Survey Catalog in the Herschel-ATLAS Field
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Wide area X-ray and far-infrared surveys are a fundamental tool to investigate the link between AGN growth and star formation, especially in the low-redshift universe (z < 1). The Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) has covered 550 deg2 in five far-infrared and sub-mm bands, 16 deg2 of which have been presented in the Science Demonstration Phase (SDP) catalogue. The reference paper cited below introduces the XMM-Newton observations in the H-ATLAS SDP area, covering 7.1 deg2 with flux limits of 2 x 10-15, 6 x 10-15, and 9 x 10-15 erg/s/cm2 in the 0.5-2, 0.5-8 and 2-8keV bands, respectively. The paper presents the source detection techniques and the "main" catalog, which includes 1700, 1582 and 814 sources detected by EMLDetect in the 0.5-8, 0.5-2 and 2-8keV bands, respectively; the number of unique sources is 1816. The authors extract spectra and derive fluxes from power-law fits for 398 sources with more than 40 counts in the 0.5-8 keV band. They compare the best-fit fluxes with those in the catalog, which were obtained assuming a common photon index Gamma of 1.7; the authors find no bulk difference between the fluxes, and a moderate dispersion s of 0.33 dex. Using wherever possible the fluxes from the spectral fits, the authors derive the 2-10 keV Log N-Log S distribution, which is consistent with a Euclidean distribution. Finally, they release the computer code for the tools which they developed for this project. Sources were detected with a two-stage process. With the first pass at low significance, the authors got a list of candidate detections; and on the second pass they raised the significance threshold and derived accurate source parameters. Between the two passes, and because the second pass needs an input catalog, they identified the sources detected in more than one band. In the first pass, the SAS wavelet detection program ewavelet was run separately on each of the 0.5-2, 2-8 and 0.5-8 keV images of the entire mosaic, with a significance threshold of 4 sigma and the default wavelet scales (minimum 2 pixels, maximum 8 pixels, with a pixel size of 4). All parameters in this catalog which were derived from ewavelet have been given a prefix of 'wav' in this HEASARC representation so as to distinguish them from the parameters derived using EMLDetect. In the second pass, the authors used the SAS EMLDetect program to validate the detections, refine the coordinates and obtain maximum-likelihood estimates of the source counts, count rates and fluxes. The EMLDetect minimum likelihood was set at L = 4.6, as in Ranalli et al. (2013, A&A, 555, A42), which corresponds to a false-detection probability of 1.01 x 10-2. Together with the 4-sigma threshold for ewavelet, for the final catalog this yields a joint significance between 4 sigma and 5 sigma, but which cannot be further constrained without simulations. This table contains the X-ray sources which were detected in the 7.1 deg2 XMM-Newton observations of the H-ATLAS field. The 1816 sources which were detected by both programs were presented in the main table in the reference paper (and are included in this HEASARC table where they are indicated by a value of the source_sample parameter of 'main'), while the 234 sources which were only detected by ewavelet were presented in the supplementary table in the reference paper (and are included in this HEASARC table where they are indicated by a value of the source_sample parameter of 'supp'). The same parameters were present in both the main and supplementary tables in the reference paper, but those parameters which came from EMLDetect are empty for the sources in the supplementary table. The parameters obtained using ewavelet (those parameters with the 'wav' prefix in their names) containing the source properties (counts, count rates, fluxes, exposure times, background, wavelet detection scale and source
ELAIS S1 Field XMM-Newton X-Ray Source Catalog
공공데이터포털
The formation and evolution of cosmic structures can be probed by studying the evolution of the luminosity function of the Active Galactic Nuclei (AGNs), galaxies and clusters of galaxies and of the clustering of the X-ray active Universe, compared to the IR-UV active Universe. To this purpose, the authors have surveyed with XMM-Newton the central ~0.6 deg2 region of the ELAIS-S1 field down to flux limits of ~5.5 x 10-16 erg cm-2 s-1 (0.5-2 keV, soft band, S), ~2 x 10-15 erg cm-2 s-1 (2-10 keV, hard band, H), and ~4 x 10-15 erg cm-2 s-1 (5-10 keV, ultra-hard band, HH). They present here the analysis of the XMM-Newton observations, the number counts in different energy bands and the clustering properties of the X-ray sources. They have detected a total of 478 sources, 395 and 205 of which detected in the S and H bands respectively. They identified 7 clearly extended sources and estimated their redshift through X-ray spectral fits with thermal models. In four cases the redshift is consistent with z = 0.4, so they may have detected a large scale structure formed by groups and clusters of galaxies through their hot intra-cluster gas emission. The relative density of the S band sources is higher near the clusters and groups at z ~ 0.4 and extends toward East and the South/West. This suggests that the structure is complex, with a size comparable to the full XMM-Newton field. Conversely, the highest relative source densities of the H band sources are located in the central-west region of the field. The mosaic of four partially overlapping deep XMM-Newton pointings covers a large (~0.6 deg2) and contiguous area of the ELAIS-S1 region. The pointings are named
 ELAIS-S1-A (RA=8.91912, DE=-43.31344, J2000), ELAIS-S1-B (RA=8.92154, DE=-43.65575, J2000), ELAIS-S1-C (RA=8.42195, DE=-43.30488, J2000) and ELAIS-S1-D (RA=8.42375, DE=-43.65327, J2000). 
The X-ray observations were performed on May 2003 through July 2003 with XMM-Newton's European Photon Imaging Camera (EPIC) and two MOS-CCD cameras. This table was created by the HEASARC in June 2008 based on the
CDS Catalog J/A+A/457/501 files elaisxmm.dat and catalog.dat. This is a service provided by NASA HEASARC .
Prajwal Voraganti Padmanabh - Parkes observations for project P1381 semester 2025OCTS 02
공공데이터포털
The Galactic bulge is theorized to host a rich population of millisecond pulsars (MSPs), but direct detections have been severely hampered by high interstellar scattering, dispersion, and background noise near the Galactic center. These MSPs, if confirmed, would serve as powerful tools for testing gravity, studying dense matter, and probing gravitational waves. A key indirect tracer of this population is the Fermi GeV excess (FGE), an unresolved gamma-ray signal possibly originating from thousands of faint MSPs. However, the lack of direct detections has limited our ability to test this hypothesis. The MeerKAT Galactic Bulge Survey (MGBS) is the most sensitive pulsar search yet of this region, targeting the bulge MSP population. Early results from MGBS have already revealed several promising MSP candidates. We propose to use Murriyang to conduct targeted follow-up observations of three of the most compelling candidates from MGBS. Our goals are to confirm the pulsations, refine key parameters such as spectral indices and orbital characteristics, and strengthen their association with the bulge. Confirming even a handful of bulge MSPs would have wide-reaching impact: constraining the origin of the FGE, testing dark matter interpretations, refining models of Galactic structure, and improving predictions for low-frequency gravitational wave backgrounds. This proposal is a critical next step toward establishing a long-sought bulge MSP population and unlocking new physics from the inner Galaxy.
Star-Forming Galaxies High-Mass X-Ray Binaries Catalog
공공데이터포털
Based on a homogeneous set of X-ray, infrared and ultraviolet observations from Chandra, Spitzer, GALEX and 2MASS archives, the authors studied populations of high-mass X-ray binaries (HMXBs) in a sample of 29 nearby star-forming galaxies and their relation with the star formation rate (SFR). In agreement with previous results, the authors find that HMXBs are a good tracer of the recent star formation activity in the host galaxy and their collective luminosity and number scale with the SFR, in particular, LX ~ 2.6 x 1039 x SFR. However, the scaling relations still bear a rather large dispersion of rms ~ 0.4 dex, which the authors believe is of a physical origin. This table contains the catalog of 1055 compact X-ray sources detected within the D25 ellipse for galaxies of this sample which the authors used to construct the average X-ray luminosity function (XLF) of HMXBs with substantially improved statistical accuracy and better control of systematic effects than achieved in previous studies. The XLF follows a power law with slope of 1.6 in the log(LX) ~ 35 - 40 luminosity range with a moderately significant evidence for a break or cut-off at LX ~ 1040 erg/s. As before, the authors did not find any features at the Eddington limit for a neutron star or a stellar mass black hole. In their paper, the authors discuss the implications of their results for the theory of binary evolution. In particular, they estimate the fraction of compact objects that once during their lifetime experienced an X-ray active phase powered by accretion from a high mass companion and obtain a rather large number, fX ~ 0.2 x (0.1 Myr/taux), where taux is the life time of the X-ray active phase. This is about 4 orders of magnitude more frequent than in low-mass X-ray binaries (LMXBs). The authors also derive constrains on the mass distribution of the secondary star in HMXBs. Note that, in their paper, the authors estimate that ~ 300 of the 1055 sources are likely to be background AGNs (cosmic X-ray background or CXB sources) and that the majority (<~ 700) of the remaining ~ 750 sources are young HMXB systems associated with star formation in their host galaxies. This table was created by the HEASARC in March 2012 based on CDS Catalog J/MNRAS/419/2095 file hmxb.dat. This is a service provided by NASA HEASARC .
Prajwal Voraganti Padmanabh - Parkes observations for project P1381 semester 2025OCTS 01
공공데이터포털
The Galactic bulge is theorized to host a rich population of millisecond pulsars (MSPs), but direct detections have been severely hampered by high interstellar scattering, dispersion, and background noise near the Galactic center. These MSPs, if confirmed, would serve as powerful tools for testing gravity, studying dense matter, and probing gravitational waves. A key indirect tracer of this population is the Fermi GeV excess (FGE), an unresolved gamma-ray signal possibly originating from thousands of faint MSPs. However, the lack of direct detections has limited our ability to test this hypothesis. The MeerKAT Galactic Bulge Survey (MGBS) is the most sensitive pulsar search yet of this region, targeting the bulge MSP population. Early results from MGBS have already revealed several promising MSP candidates. We propose to use Murriyang to conduct targeted follow-up observations of three of the most compelling candidates from MGBS. Our goals are to confirm the pulsations, refine key parameters such as spectral indices and orbital characteristics, and strengthen their association with the bulge. Confirming even a handful of bulge MSPs would have wide-reaching impact: constraining the origin of the FGE, testing dark matter interpretations, refining models of Galactic structure, and improving predictions for low-frequency gravitational wave backgrounds. This proposal is a critical next step toward establishing a long-sought bulge MSP population and unlocking new physics from the inner Galaxy.
Prajwal Voraganti Padmanabh - Parkes observations for project P1381 semester 2025OCTS 03
공공데이터포털
The Galactic bulge is theorized to host a rich population of millisecond pulsars (MSPs), but direct detections have been severely hampered by high interstellar scattering, dispersion, and background noise near the Galactic center. These MSPs, if confirmed, would serve as powerful tools for testing gravity, studying dense matter, and probing gravitational waves. A key indirect tracer of this population is the Fermi GeV excess (FGE), an unresolved gamma-ray signal possibly originating from thousands of faint MSPs. However, the lack of direct detections has limited our ability to test this hypothesis. The MeerKAT Galactic Bulge Survey (MGBS) is the most sensitive pulsar search yet of this region, targeting the bulge MSP population. Early results from MGBS have already revealed several promising MSP candidates. We propose to use Murriyang to conduct targeted follow-up observations of three of the most compelling candidates from MGBS. Our goals are to confirm the pulsations, refine key parameters such as spectral indices and orbital characteristics, and strengthen their association with the bulge. Confirming even a handful of bulge MSPs would have wide-reaching impact: constraining the origin of the FGE, testing dark matter interpretations, refining models of Galactic structure, and improving predictions for low-frequency gravitational wave backgrounds. This proposal is a critical next step toward establishing a long-sought bulge MSP population and unlocking new physics from the inner Galaxy.
2XMMi/SDSS Galaxy Cluster Survey
공공데이터포털
The authors have compiled a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton Serendipitous Source Catalog (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). In their paper, they present an analysis of the X-ray properties of this new sample with particular emphasis on the X-ray luminosity-temperature (LX - T) relation. The X-ray cluster candidates were selected from the 2XMMi-DR3 catalog in the footprint of the SDSS-DR7. The authors developed a finding algorithm to search for overdensities of galaxies at the positions of the X-ray cluster candidates in the photometric redshift space and to measure the redshifts of the clusters from the SDSS data. For optically confirmed clusters with good quality X-ray data, they derived the X-ray flux, luminosity, and temperature from proper spectral fits, while the X-ray flux for clusters with low-quality X-ray data was obtained from the 2XMMi-DR3 catalogue. The detection algorithm provides the photometric redshift of 530 galaxy clusters. Of these, 310 clusters have a spectroscopic redshift for at least one member galaxy. About 75 percent of the optically confirmed cluster sample are newly discovered X-ray clusters. Moreover, 301 systems are known as optically selected clusters in the literature while the remainder are new discoveries in X-ray and optical bands. The optically confirmed cluster sample spans a wide redshift range 0.03 to 0.70 (median z = 0.32). In this paper, they present the catalog of X-ray-selected galaxy groups and clusters from the 2XMMi/SDSS galaxy cluster survey. The catalog has two subsamples: (i) a cluster sample comprising 345 objects with their X-ray spectroscopic temperature and flux from the spectral fitting; (these objects are identified by having values for the table_sample parameter of 1 in this HEASARC implementation of the catalog) and (ii) a cluster sample consisting of 185 systems with their X-ray flux from the 2XMMi-DR3 catalog, because their X-ray data are insufficient for spectral fitting (these objects are identified by having values for the table_sample parameter of 2 herein). For each cluster, the catalog also provides the X-ray bolometric luminosity and the cluster mass at R500 based on scaling relations and the position of the likely brightest cluster galaxy (BCG). The updated LX - T relation of the current sample with X-ray spectroscopic parameters is presented in the paper. The authors found the slope of the LX - T relation to be consistent with published ones. They see no evidence for evolution in the slope and intrinsic scatter of the LX - T relation with redshift when excluding the low-luminosity groups. This catalog of X-ray selected galaxy clusters and groups supersedes and subsumes the first release of the 2XMMi/SDSS Galaxy Cluster Survey, comprising 175 clusters of galaxies, which was presented in Takey et al. (2011, A&A, 534, A120). This table was created by the HEASARC in October 2013 based on CDS catalog J/A+A/558/A75 files table1.dat and table2.dat. This is a service provided by NASA HEASARC .
SwiftAGN&ClusterSurvey(SACS)Soft-Band(0.5-2keV)ExtendedSourceCatalog
공공데이터포털
The Swift Active galactic nucleus (AGN) and Cluster Survey (SACS) uses 125 deg2 of Swift X-ray Telescope (XRT) serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4 x 10-15 erg cm-2 s-1) and medium area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. In the reference paper, a catalog of 22,563 point sources and 442 extended sources, and the number counts of the AGN and galaxy cluster populations are presented. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The authors use Wide-field Infrared Survey Explorer (WISE) mid-infrared(MIR) colors to classify the sources. For AGNs, they can roughly separate the point sources into MIR-red and MIR-blue AGNs, finding roughly equal numbers of each type in the soft X-ray band (0.5-2.0 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with previous surveys but span a much larger continuous flux range. Deep optical or IR followup observations of this cluster sample will significantly increase the number of higher redshift (z > 0.5) X-ray-selected clusters. This HEASARC table contains the list of 442 Swift XRT extended sources which were detected in the soft X-ray band image (0.5-2 keV) and contained in Table 4 of the reference paper. The authors defined the extended source catalog as those sources with S/N >= 4 and a minimum net photon count of 20 that are more than 3 sigma from the mean size of point sources for both their off-axis angle and S/N. The authors consider these extended sources to be candidate clusters of galaxies. This table was created by the HEASARC in July 2015 based on an electronic version of Table 4 of the reference paper, the list of Swift XRT extended sources detected in the soft X-ray (0.5-2 keV) band, which was obtained from the ApJS web site. This is a service provided by NASA HEASARC .