- ID:
- ivo://nasa.heasarc/xmmstack
- Title:
- XMM-Newton Serendipitous Source Catalog from Stacked Observations (4XMM-DR14s)
- Short Name:
- XMMSTACK
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The stacked catalog 4XMM-DR14s has been compiled from 1,751 groups, comprising 10,336 overlapping XMM-Newton observations. They were selected from the public observations taken between 2000 February 1 and 2023 November 16 which overlap by at least one arcminute in radius. It contains 427,524 unique sources, 329,972 of them multiply observed, with positions and source parameters like fluxes in the XMM-Newton standard energy bands, hardness ratios, quality estimate, and information on inter-observation variability. The parameters are directly derived from the simultaneous fit, and, wherever applicable, additionally calculated for each contributing observation. Exposures that do not qualify for source detection, for example because of a high background level, are used for subsequent PSF photometry: source fluxes and flux-related parameters are derived for them at the source position and extent found during source detection. 4XMM-DR14s lists 1,807,316 individual flux measurements (visits) of the 427,524 unique sources. Stacked source detection aims at exploring the multiply observed sky regions and exploit their survey potential, in particular to study the long-term behavior of X-ray emitting sources. It thus makes use of the long(er) effective exposure time per sky area and offers the opportunity to investigate flux variability directly through the source detection process. The main catalog properties are summarized in the table below, the data processing and the stacked source detection are described in the processing summary. To ensure detection quality, background levels are assessed, and event-based astrometric corrections are applied before running source detection. After source detections, problematic detections and detection parameters are flagged by an automated algorithm. All detections are screened visually, and obviously spurious sources are flagged manually. This table contains the parameters of the 427,524 unique sources (provided in this table) derived simultaneously from all of the observations (provided in the associated table of observations referred to as <a href="/W3Browse/xmm-newton/xmmstackob.html">XMMSTACKOB</a>) at the fitted position. The authors referred to the EPIC instruments with the following designations: PN, M1 (MOS1), and M2 (MOS2). The energy bands used in the 4XMM processing were the same as for the 3XMM catalog. The following are the basic energy bands: <pre> 1: 0.2-0.5 keV 2: 0.5-1.0 keV 3: 1.0-2.0 keV 4: 2.0-4.5 keV 5: 4.5-12.0 keV </pre> All-EPIC values cover the energy range 0.2-12.0 keV. The full catalog documentation can be found at <a href="https://xmmssc.aip.de/">https://xmmssc.aip.de/</a>. The following table gives an overview of the statistics of this catalog in comparison with the previous stacked catalogs, 4XMM-DR14s through 3XMM-DR7s: <pre> 4XMM-DR14s 4XMM-DR13s 4XMM-DR12s 4XMM-DR11s 4XMM-DR10s 4XMM-DR9s 3XMM-DR7s Number of stacks 1,751 1,688 1,620 1,475 1,396 1,329 434 Number of observations 10,336 9,796 9,355 8,292 7,803 6,604 789 Time span first to last observation Feb 01, 2000 Feb 01, 2000 Feb 01, 2000 Feb 03, 2000 Feb 03, 2000 Feb 03, 2000 Feb 20, 2000 -- Nov 16,2023 -- Nov 29, 2022 -- Dec 04, 2021 -- Dec 17, 2020 -- Dec 14, 2019 -- Nov 13, 2018 -- Apr 02, 2016 Approximate sky coverage (sq. deg.) 685 650 625 560 540 485 150 Approximate multiply observed sky area(sq. deg) 440 420 400 350 335 300 100 Total number of sources 427,524 401,596 386,043 358,809 335,812 288,191 71,951 Sources with several contributing observations 329,972 310,478 298,626 275,440 256,213 218,283 57,665 Multiply observed sources with flag 0 or 1 276,058 262,842 252,445 233,542 216,999 191,497 55,450 Multiply observed with a total detection 266,129 251,555 241,880 224,178 208,921 181,132 49,935 likelihood of at least six Multiply observed with a total detection 226,219 213,812 205,394 189,556 176,680 153,487 42,077 likelihood of at least ten Total measurements 1,807,316 1,683,264 1,592,263 1,421,966 1,322,299 1,033,264 216,393 Maximum exposures per source 173 170 155 140 140 103 69 Maximum observations per source 77 77 70 65 65 40 23 Maximum on-time per source 2.8 Ms 2.8 Ms 2.8 Ms 2.8 Ms 2.8 Ms 1.9 Ms 1.3 Ms </pre> This database table was last updated by the HEASARC in July 2024. It contains the 4XMM-DR14s source catalog, released by ESA on 2024-07-09 and obtained from the XMM-Newton Survey Science Center Consortium at <a href="https://xmmssc.aip.de/cms/catalogues/4xmm-dr14s/">https://xmmssc.aip.de/cms/catalogues/4xmm-dr14s/</a>. It is <a href="https://xmmssc.aip.de/data/xmmstack_v3.2_4xmmdr14s.fits.gz">also available as a gzipped FITS file</a>. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/xmmssc
- Title:
- XMM-Newton Serendipitous Source Catalog (4XMM-DR14 Version)
- Short Name:
- XMM/SSC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XMMSSC table contains the Fourth XMM-Newton Serendipitous Source Catalog, Fourteenth Data Release, or 4XMM-DR14. 4XMM-DR14 is the fourth-generation catalog of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory, and has been created by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA. It is an incremental version of the the 4XMM catalog and contains 621 more observations and 51,884 more detections than the preceding 4XMM-DR13 catalog, which was made public in July 2023. In addition, the team provides spectra and lightcurves for more than 18,775 more detections than in 4XMM-DR13. The catalog contains source detections drawn from a total of 13,864 XMM-Newton EPIC observations made between 2000 February 1 and 2023 December 31; all datasets included were publicly available by 2023 December 31 but not all public observations are included in this catalog. For net exposure time >= 1ksec, the net area of the catalog fields taking account of the substantial overlaps between observations is ~1,383 deg<sup>2</sup>. 4XMM-DR13 contains 1,035,832 X-ray detections above the processing likelihood threshold of 6. These X-ray detections relate to 692,109 unique X-ray sources. A significant fraction of sources (135,324, 20%) have more than one detection in the catalog (up to 90 repeat observations in the most extreme case). The catalog distinguishes between extended emission and point-like detections. Parameters of detections of extended sources are only reliable up to the maximum extent measure of 80 arcseconds. There are 96,553 detections of extended emission, of which 22,147 are 'clean' (in the sense that they were not flagged). Due to intrinsic features of the instrumentation as well as some shortcomings of the source detection process, some detections are considered to be spurious or their parameters are considered to be unreliable. It is recommended to use a detection flag and an observation flag as filters to obtain what can be considered a 'clean' sample. There are 897,091 out of 1,035,832 detections that are considered to be clean (i.e., summary flag < 3). For 372,313 detections, EPIC time series and 372,603 detections, EPIC spectra were automatically extracted during processing, and a chi<sup>2</sup>-variability test was applied to the time series. 8,380 detections in the catalog are considered variable, within the timespan of the specific observation, at a probability of 10<sup>-5</sup> or less based on the null-hypothesis that the source is constant. Of these, 6,307 have a summary flag <3. The median flux (in the total photon-energy band 0.2 - 12 keV) of the catalog detections is ~ 2.2 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s; in the soft energy band (0.2 - 2 keV) the median flux is ~ 5.2 x 10<sup>-15</sup>, and in the hard band (2 - 12 keV) it is ~1.2 x 10<sup>-14</sup>. About 23% have fluxes below 1 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s. The flux values from the three EPIC cameras are, overall, in agreement to ~10% for most energy bands. The median positional accuracy of the catalog point source detections is generally < 1.57 arcseconds (with a standard deviation of 1.43 arcseconds). With 4XMM-DR14, the team also released 4XMM-DR14s, available from HEASARC as <a href="/W3Browse/xmm-newton/xmmstack.html">XMMSTACK</a>, a new version of the stacked catalog built from 10,336 4XMM-DR14 overlapping observations. 4XMM-DR14s contains 1,751 stacks (or groups). Most of the stacks are composed of 2 observations and the largest has 372. The catalog contains 427,524 sources, of which 329,972 have several contributing observations. Stacking observations allows yet fainter sources to be detected in sky regions observed more than once, increasing the number of detections and uncovering long-term variability on repeatedly observed objects. 4XMM-DR14s reaches a depth of ~2.5 x 10<sup>-15</sup> and ~6.8 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s in the soft (0.2-2keV) and hard (2-12 keV) X-ray band, respectively. The energy bands used in the 4XMM-DR14 processing were the same as for the 3XMM catalog. The following are the basic energy bands: <pre> 1 = 0.2 - 0.5 keV 2 = 0.5 - 1.0 keV 3 = 1.0 - 2.0 keV 4 = 2.0 - 4.5 keV 5 = 4.5 - 12.0 keV </pre> while these are the broad energy bands: <pre> 6 = 0.2 - 2.0 keV soft band, no images made 7 = 2.0 - 12.0 keV hard band, no images made 8 = 0.2 - 12.0 keV total band 9 = 0.5 - 4.5 keV XID band </pre> This database table was last updated by the HEASARC in July 2024. It contains the 4XMM-DR14 catalog, released by ESA on 2024-07-09 and obtained from the XMM-Newton Survey Science Center Consortium (<a href="http://xmmssc.irap.omp.eu/Catalogue/4XMM-DR14/4XMM_DR14.html">http://xmmssc.irap.omp.eu/Catalogue/4XMM-DR14/4XMM_DR14.html</a>). It is also available as a gzipped FITS file at <a href="https://heasarc.gsfc.nasa.gov/FTP/xmm/data/catalogues/4XMM_DR13cat_v1.0.fits.gz">https://heasarc.gsfc.nasa.gov/FTP/xmm/data/catalogues/4XMM_DR13cat_v1.0.fits.gz</a>. <p> The previous versions of the Serendipitous Source Catalog, 3XMM-DR5, 3XMM-DR6, 3XMM-DR7, 3XMM-DR8, 4XMM-DR9, 4XMM-DR10, 4XMM-DR11, 4XMM-DR12, and 4XMM-DR13 are also available in the same directory for comparison purposes as the files 3XMM_DR5cat_v1.0.fits.gz, 3XMM_DR6cat_v1.0.fits.gz, 3XMM_DR7cat_v1.0.fits.gz, 3XMM_DR8_cat_v1.0.fits.gz, 4XMM_DR9_cat_v1.0.fits.gz, 4XMM_DR10cat_v1.0.fits.gz, 4XMM_DR11cat_v1.0.fits.gz, and 4XMM_DR12cat_v1.0.fits.gz, 4XMM_DR13cat_v1.0.fits.gz, respectively. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmslewcln
- Title:
- XMM-Newton Slew Survey Clean Source Catalog, v3.0
- Short Name:
- XMMSlewClean
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the 'clean' sample of sources from the third catalog of X-ray sources found in slew data taken by the European Space Agency's XMM-Newton Observatory, XMMSL3 or XMMSLEW, Version 3.0. It has been created by the XMM-Newton Survey Science Center (SSC) on behalf of ESA, building on previous work carried out by the XMM-Newton SOC. The core <a href="/W3Browse/xmm-newton/xmmslewful.html">XMMSL3</a> catalog contains detections drawn from 3120 XMM-Newton pn slew observations, covering an energy interval from 0.2 keV to 12 keV. These observations were made between 2000 August 26 and 2023 August 11. All slew observations are public. A full discussion of the differences between XMMSL3 and XMMSL2 is given in Section 12 of the <a href="http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/XMMSL3_Catalogue_User_Guide.html">XMMSL3 Users Guide</a>. This database table was first created by the HEASARC in August 2007 based on the FITS version of XMMSL1D1 (v1.1) of the XMM Slew Catalog. The current version was ingested in February 2025 and is based on the FITS version of XMMSL3 (v3.0) of the XMM Slew Catalog obtained from the following URLs: <a href="http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/xmmsl3_v1.0.fits">http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/xmmsl3_v1.0.fits</a> (the total sample). This catalog contains only the entries from that FITS file which have VAL_FLAG = 'CLEAN SAMPLE'. <p> The HEASARC has endeavored to retain the same parameter names as in the ESA version, but some names have been changed so as to conform to the standard HEASARC parameter naming conventions, e.g., all error parameter names which ended in "_err" in the ESA version end in "_error" in this HEASARC version. For other parameters which have had their names changed, their original ESA names are listed in square brackets in their descriptions below. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmslewegs
- Title:
- XMM-Newton Slew Survey Extragalactic Sample
- Short Name:
- XMMSLEWEGS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ongoing XMM-Newton Slew Survey (XSS) provides coverage of a significant fraction of the sky in a broad X-ray bandpass. Although shallow by contemporary standards, in the "classical" 2-10 keV band of X-ray astronomy the XSS provides significantly better sensitivity than any currently available all-sky survey. The authors investigate the source content of the XSS, focusing on detections in the hard 2-10 keV band down to a very low threshold (>= 4 counts net of background). At the faint end, the survey reaches a flux sensitivity of roughly 3 x 10<sup>-12</sup> erg/cm<sup>2</sup>/s (2-10 keV). The starting point was a sample of 487 sources detected in the XSS (up to and including release XMMSL1d2) at high galactic latitude in the hard band. Through cross-correlation with published source catalogs from surveys spanning the electromagnetic spectrum from radio through to gamma-rays, they find that 45% of the sources have likely identifications with normal/active galaxies. A further 18% are associated with other classes of X-ray object (nearby coronally active stars, accreting binaries, clusters of galaxies), leaving 37% of the XSS sources with no current identification. The authors go on to define an XSS extragalactic sample comprised of 219 galaxies and active galaxies selected in the XSS hard band. They investigate the properties of this extragalactic sample including its X-ray log N - log S distribution, and it is this sample that is contained in this table. The authors find that, in the low-count limit, the XSS is, as expected, strongly affected by Eddington bias. There is also a very strong bias in the XSS against the detection of extended sources, most notably clusters of galaxies. A significant fraction of the detections at and around the low-count limit may be spurious. Nevertheless, it is possible to use the XSS to extract a reasonably robust sample of extragalactic sources, excluding galaxy clusters. The differential log N - log S relation of these extragalactic sources matches very well to the HEAO-1 A2 all-sky survey measurements at bright fluxes and to the 2XMM source counts at the faint end. The substantial sky coverage afforded by the XSS makes this survey a valuable resource for studying X-ray bright source samples, including those selected specifically in the hard 2 - 10 keV band. This table was created by the HEASARC in December 2012, based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/548/A99">CDS Catalog J/A+A/548/A99</a> file tablea1.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmslewful
- Title:
- XMM-Newton Slew Survey Full Source Catalog, v3.0
- Short Name:
- XMMSlewFull
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the 'total' sample of sources from the third catalog of X-ray sources found in slew data taken by the European Space Agency's XMM-Newton Observatory, XMMSL3 or XMMSLEW, Version 3.0. It has been created by the XMM-Newton Survey Science Center (SSC) on behalf of ESA, building on previous work carried out by the XMM-Newton SOC. It is an incremental version of the XMMSL2 catalog but contains 50% more observations than the previous version, including 8.5 additional years of data, using modified software and slightly revised screening methodology and therefore has been given a major version increment. It contains 1006 more observations for a total of 3120 observations and 68,383 more detections (for a total of 140,735 detections) than the preceding XMMSL2 catalog, which was made public in March 2017. This release of XMMSL3 contains detections drawn from 3120 XMM-Newton pn slew observations, covering an energy interval from 0.2 keV to 12 keV. These observations were made between 2000 August 26 and 2023 August 11. All slew observations are public. A full discussion of the differences between XMMSL3 and XMMSL2 is given in Section 12 of the <a href="http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/XMMSL3_Catalogue_User_Guide.html">XMMSL3 Users Guide</a>. This database table was first created by the HEASARC in August 2007 based on the FITS version of XMMSL1D1 (v1.1) of the XMM Slew Catalog. The current version was ingested in February 2025 and is based on the FITS version of XMMSL3 (v3.0) of the XMM Slew Catalog obtained from the following URLs: <a href="http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/xmmsl3_v1.0.fits">http://xmmssc.irap.omp.eu/Catalogue/XMMSL3/xmmsl3_v1.0.fits</a> (the total sample). <p> The HEASARC has endeavored to retain the same parameter names as in the ESA version, but some names have been changed so as to conform to the standard HEASARC parameter naming conventions, e.g., all error parameter names which ended in "_err" in the ESA version end in "_error" in this HEASARC version. For other parameters which have had their names changed, their original ESA names are listed in square brackets in their descriptions below. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmatlas
- Title:
- XMM-Newton Survey Catalog in the Herschel-ATLAS Field
- Short Name:
- XMMATLAS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 deg<sup>2</sup> in five far-infrared and sub-mm bands, 16 deg<sup>2</sup> 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 deg<sup>2</sup> with flux limits of 2 x 10<sup>-15</sup>, 6 x 10<sup>-15</sup>, and 9 x 10<sup>-15</sup> erg/s/cm<sup>2</sup> 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<sup>-2</sup>. 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 deg<sup>2</sup> 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 extent), while reported in this table for all sources, are actually only interesting for supplementary sources, according to the authors. This table was created by the HEASARC in May 2015 based on the union of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/577/A121">CDS Catalog J/A+A/577/A121</a> files main.dat (which contain 1816 sources detected by both detection algorithms) and suppl.dat (which contains 234 'supplementary' sources detected only by the wavelet detection algorithm ewavelet). It thus contains a total of 2050 sources. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmsscgps
- Title:
- XMM-Newton Survey Science Center Survey of the Galactic Plane
- Short Name:
- XMMSSCGPS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood, the population of low-to-medium X-ray luminosity (L<sub>X</sub> = 10<sup>27</sup> - 10<sup>34</sup> erg/s) sources remains much less studied, our knowledge being mostly based on the observation of local members. The advent of wide-field and high-sensitivity X-ray telescopes such as XMM-Newton now offers the opportunity to observe this low-to-medium L<sub>X</sub> population at large distances. This study reports the results of a Galactic plane survey conducted by the XMM-Newton Survey Science Centre (SSC). Beyond its astrophysical goals, this survey aims at gathering a representative sample of identified X-ray sources at low latitude that can be used later on to statistically identify the rest of the serendipitous sources discovered in the Milky Way. The survey is based on 26 XMM-Newton observations, obtained at |b| < 20 degrees, distributed over a large range in Galactic longitudes and covering a summed area of 4 deg<sup>2</sup>. The flux limit of this survey is 2 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s in the soft (0.5 - 2 keV) band and 1 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s in the hard (2 - 1 2keV) band. A total of 1319 individual X-ray sources have been detected. Using optical follow-up observations supplemented by cross-correlation with a large range of multi-wavelength archival catalogs, the authors identify 316 X-ray sources. This constitutes the largest group of spectroscopically identified low-latitude X-ray sources at this flux level. The majority of the identified X-ray sources are active coronae with spectral types in the range A to M at maximum distances of ~1 kpc. The number of identified active stars increases towards late spectral types, reaching a maximum at K. Using infrared colors, the authors classify 18% of the stars as giants. The observed distributions of F<sub>X</sub>/F<sub>V</sub>, X-ray and infrared colors indicates that their sample is dominated by a young (100 Myr) to intermediate (600 Myr) age population with a small contribution of close main-sequence or evolved binaries. The authors find other interesting objects such as cataclysmic variables (d ~ 0.6 - 2 kpc), low-luminosity high-mass stars (likely belonging to the class of Gamma-Cas-like systems, d ~ 1.5 - 7 kpc), T Tauri and Herbig-Ae stars. A handful of extragalactic sources located in the highest Galactic latitude fields could be optically identified. For the 20 fields observed with the EPIC pn camera, the authors have constructed log N(>S) - log S curves in the soft and hard bands. In the soft band, the majority of the sources are positively identified with active coronae and the fraction of stars increases by about one order of magnitude from b = 60 degrees to b = 0 degrees at an X-ray flux of 2 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s. The hard band is dominated by extragalactic sources, but there is a small contribution from a hard Galactic population formed by CVs, HMXB candidates or Gamma-Cas-like systems and by some active coronal stars that are also detected in the soft band. At b = 0 degrees, the surface density of hard sources brighter than 1 x 10<sup>-13</sup> erg/cm<sup>2</sup>/s steeply increases by one order of magnitude from l = 20 degrees to the Galactic center region (l = 0.9 degrees). This HEASARC table contains 739 X-ray sources detected in the 26 different fields observed in this study and listed in Tables 8 - 33, inclusive, of the reference paper. These 739 sources have the best XMM quality, i.e. the summary flag sum_flag which contains information about flags set automatically and manually for a given source is zero, meaning that there are no negative flags for the source detection, have either a 2MASS, USNO, GSC, or SDSS counterpart, whatever the probability of identification is, or have some information via SIMBAD or the authors own imaging or spectroscopic observations. For each X-ray source, its X-ray parameters are summarized, listing the pn count rates, and information on optical and infrared counterparts is provided. The properties of the 26 target fields are given in Table 1 of the reference paper, along with the breakdown of source classes in each field. This table was created by the HEASARC in May 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/553/A12">CDS Catalog J/A+A/553/A12</a>, the 26 files table8.dat to table33.dat, inclusive. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xwas
- Title:
- XMM-Newton Wide Angle Survey
- Short Name:
- XWAS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from the XMM-Newton Wide Angle Survey (XWAS), viz., a new catalog of almost a thousand X-ray sources that have been spectroscopically identified through optical observations. The sources lie in high-galactic latitude (|b| > 20 degrees) XMM-Newton fields mainly in the southern hemisphere. A sample of X-ray sources detected in 68 XMM-Newton pointed observations was selected for optical multi-fiber spectroscopy. Optical counterparts and corresponding photometry of the X-ray sources were obtained from the SuperCOSMOS Sky Survey. Candidates for spectroscopy were initially selected with magnitudes down to R ~ 21, with preference for X-ray sources having a flux F<sub>0.5-4.5keV</sub> >= 10<sup>-14</sup> erg/s/cm<sup>2</sup>. Optical spectroscopic observations were made using the Two Degree Field of the Anglo-Australian Telescope, and the resulting spectra were classified based on optical emission lines. The authors have identified through optical spectroscopy 940 X-ray sources over a solid angle Omega ~ 11.8 deg<sup>2</sup> of the sky. Source populations in their sample can be summarized as 65% broad-line active galactic nuclei (BLAGN), 16% narrow emission-line galaxies (NELGs), 6% absorption-line galaxies (ALGs) and 13% stars. An active nucleus is also likely to be present in the large majority of the X-ray sources spectroscopically classified as NELGs or ALGs. Optical images are available for all of the XWAS fields in the SuperCOSMOS Sky Survey (Hambly et al., 2001, MNRAS, 326, 1279). This table was created by the HEASARC in May 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/557/A123">CDS Catalog J/A+A/557/A123</a> file xwas_cat.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmxassist
- Title:
- XMM-Newton XAssist Source List
- Short Name:
- XMM/XAssist
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains the latest XMM-Newton XAssist source list. XAssist is a NASA-funded project for the automation of X-ray astrophysics, with emphasis on galaxies. It is capable of data reprocessing, source detection, and preliminary spatial, temporal, and spectral analysis for all sources with sufficient counts. The bulk of the system is written in Python, which in turn drives underlying software to process the XMM-Newton data. Pipelines running on XMM-Newton observations of galaxies have generated the source list which comprises this HEASARC table. The pipeline also includes fields requested by users for various projects, most notably observations of a sample of quasars and several deep field observations have been processed. Note that the pipline processing is completely automated; therefore, users should visually inspect the results of any queries. This table was first created by the HEASARC in July 2005 based on the XMM source list available at the XAssist website. In December 2012, the HEASARC switched over to using the "pipeline5" XMM source list. It is updated on a weekly basis when and if the XAssist source list file at <a href="https://asd.gsfc.nasa.gov/xassist/pipeline5/xmm/master_srclist.csv">https://asd.gsfc.nasa.gov/xassist/pipeline5/xmm/master_srclist.csv</a> is updated. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmssclwbs
- Title:
- XMM-Newton 2XMMi-DR3 Selected Source Classifications Catalog
- Short Name:
- XMMSSCLWBS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have carried out a classification of 4,330 X-ray sources in the 2XMMi-DR3 catalog. The sources were selected under the requirement of being a point source with multiple XMM-Newton observations and at least one detection with a signal-to-noise ratio larger than 20. For about one-third of the sources, the authors are able to obtain reliable source types from the literature. They mostly correspond to various types of stars (611), active galactic nuclei (AGNs, 753), and compact object systems (138) containing white dwarfs, neutron stars, and stellar-mass black holes. The authors find that about 99% of stars can be separated from other source types based on their low X-ray-to-IR flux ratios and frequent X-ray flares. AGNs have remarkably similar X-ray spectra, with the power-law photon index centered around 1.91 +/- 0.31, and their 0.2-4.5 keV flux long-term variation factors have a median of 1.48, with 98.5% being less than 10. In contrast, 70% of compact object systems can be very soft or hard, highly variable in X-rays, and/or have very large X-ray-to-IR flux ratios, separating them from AGNs. Using these results, the authors derive a source type classification scheme to classify the other sources and find 644 candidate stars, 1,376 candidate AGNs, and 202 candidate compact object systems, whose false identification probabilities are estimated to be about 1%, 3%, and 18%, respectively. There are still 320 sources associated with nearby galaxies and 151 in the Galactic plane, which the authors expect to be mostly compact object systems or background AGNs. There are also 100 candidate ultraluminous X-ray sources. They are found to be much less variable than other accreting compact objects. This table was created by the HEASARC in October 2012 based on an electronic version of Table 4 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
