- ID:
- ivo://nasa.heasarc/woodebcat
- Title:
- Wood Interacting Binaries Catalog
- Short Name:
- Wood/Bin
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog, also called the Finding List (FL) of Interacting Binaries (5th edition), was abstracted from the Card Catalog maintained at the University of Florida which contains information on all published, and to the extent available, unpublished work on eclipsing binaries. The Card Catalog originated with Raymond Smith Dugan in the 1930's, who published from it the first edition of "A Finding List for Observers of Eclipsing Variables" (Dugan 1934, Princeton Univ. Obs. Contrib. No. 15). Successive editions of FL were subsequently published by Pierce (1947, Princeton Univ. Obs. Contrib. No. 22), by Wood (1953, Univ. Pennsylvania Astron. Series, Vol. VIII), by Koch et al. (1963, Univ. Pennsylvania Astron. Series, Vol. IX), and by Wood et al. (1980, Univ. Pennsylvania Astron. Series, Vol. XII). The FL was conceived as an aid to observers of eclipsing variables in selecting an observing program efficiently from the collection of all known data in an easy-to-use format. Although this format has changed over the years to meet existing requirements, the basic information content remains the same. The current edition differs from previous ones in the extension of the magnitude limit at minimum light from 13 to 15. In earlier editions, a binary system was not included unless the editors were reasonably certain that the system was indeed an eclipsing or (rarely) an ellipsoidal variable. The fifth edition includes all systems that the editors were fairly certain are either eclipsing or radiometrically variable binaries. The catalog fields are Finding List number; star name; position (given in the original catalog in equinox 1900); blue magnitude at maximum light; bandpass of maximum light; depth of primary minimum in same bandpass; bandpass primary minimum; depth of secondary minimum and its bandpass; spectral class of star eclipsed at primary light and optional uncertainty character; spectral class of star eclipsed at secondary light; most recent reliable epoch of primary minimum; most recent orbital period; duration of primary minimum; duration of totality of primary minimum; BD, CoD, CPD, and HD number; alternate designations of system; and codes indicating the nature of the system. This database was created by the HEASARC in December 1997 based on a computer readable version of the catalog that was obtained from the CDS (their catalog VI/44): a few additions were made by the HEASARC that are listed in the HEASARC_Changes section of the present document. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/woolley
- Title:
- Woolley Catalog of Stars within 25 Parsecs
- Short Name:
- WOOLLEY
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog was constructed at the Royal Greenwich Observatory in order to enlarge the Gliese (1957, Mitt. Astron. Rechen-Inst., Ser. A, No. 8) compilation. It contains data on stars nearer than 25 pc that were not included in that version of Gliese's catalog, plus some additional information that had been published after 1957 on stars which were present in the 1957 version of the Gliese catalog. The electronic version contains essentially all information given in Table Ia of the published Woolley catalog, plus positional data, and most cross references to other catalogs given in Table IIa. The notes flags in Table Ia are not included because the notes are not machine-readable. Omitted from Table IIa are the finding-chart indicators (Lowell G numbers or notes references) and miscellaneous cross identifications to other names and catalog identifiers. Tables Ib and IIb, containing 21 systems originally included in Gliese's (1957) catalog but for which revised parallaxes have placed them farther than 25 pc are not included in the electronic version. Data in the electronic version include the Gliese number (newly added stars by Woolley have numbers beginning with 9001, but new parallaxes have removed 9419 and added 9849 and 9850 from the < 25 parsecs sample), component identifications for multiple systems, parallaxes, annual proper motions, radial velocities, (U,V,W) space velocities, box orbit parameters (omega, e, i), spectral types, UBV data, absolute visual magnitudes, positions, GCTP (General Catalogue of Trigonometric Stellar Parallaxes) and its Supplement (Jenkins 1952, 1963) names, HD, DM, GCRV (General Catalogue of Stellar Radial Velocities, Publ. Carnegie Inst., Washington, No. 601, Wilson 1953) and other catalog identifiers, BS (= HR) (Hoffleit 1964) numbers, and remarks codes for spectroscopic binaries (SB), doubles, variables, etc. Note that there is an entry in this catalog for the Sun, for which many fields, such as RA and Dec, have not been populated. This table was recreated by the HEASARC in December 2002 based on the 21-Jul-1997 version of the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/V/32A">CDS Catalog V/32A</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/wsrtgp
- Title:
- WSRT Galactic Plane Compact 327-MHz Source Catalog
- Short Name:
- WSRTGP
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands has been used to survey the section of the galactic plane from +42 to +92 degrees Galactic Longitude l at a radio frequency of 327 MHz. Twenty-three overlapping synthesis fields were observed in the Galactic Latitude b band of |b| < 1.6 degrees. Each field was observed at two epochs, several years apart, to identify variable sources. Intensity data from the separate epochs were combined, and the resulting images mosaicked to produce a single image of the entire survey region. The sensitivity of the mosaic is typically a few mJy, corresponding to a detection level as low as 10 mJy/beam. The spatial resolution is 1' by 1' * cosec(Dec). The survey image provided the first high resolution view of the Galaxy at low radio frequencies, and included sections of the Sagittarius and Cygnus arms. These sections contain numerous extended features, among them supernova remnants, H II regions, "bubbles" of thermal emission, and large patches of amorphous galactic thermal emission. The inter-arm region is characterized by lower densities of extended features, but numerous discrete compact radio sources, most of which are background objects such as quasars and other types of active galactic nuclei. However, the resolution, sensitivity and low frequency of this survey make it ideal for detecting weak, non-thermal compact galactic sources, e.g. compact, low surface brightness SNRs and radio stars. Inspection of the survey image has produced a catalog of nearly 4000 discrete sources with sizes of less than about 3'. Gaussian model parameters for each compact source in the mosaicked images were obtained using the AIPS routine IMFIT. The background-removed intensity distribution of each source was fitted by a 2-dimensional Gaussian, parametrized by the source position, peak intensity, major and minor axes, and the position angle of the major axis. The catalog contains all sources having peak intensity > 5 times the rms noise level measured in the surrounding area of the image, and lists RA, Dec, flux density, and, if the source is resolved, the deconvolved major and minor axis and the position angle of the source. Sources were identified based on visual inspection of the images. In practice, a source had to have dimensions of less than a few arcminutes to be classified as a compact source. Most (85%) of the sources are either unresolved or only slightly resolved (major axis < 60"), but some sources have dimensions as large as 6'. A source was considered resolved if the area of its Gaussian model was greater than the area of the beam by more than 4 times its uncertainty. Approximately 15% of the sources are resolved, with dimensions of 1'- 3'. The spatial distribution of resolved sources shows concentrations toward the spiral arms and follows the warping of the Galactic disk over the length of the survey region, indicating that a sizable fraction is Galactic. In the reference paper, spectral indices are calculated for 1313 sources detected in other radio surveys at frequencies greater than 408 MHz. The resolved sources exhibit a bimodal spectral index distribution, with distinct non-thermal and thermal populations. Comparison with the IRAS Point Source Catalogue results in 118 identifications between WSRT and IRAS sources, which are listed in Table 1 of the reference paper. Most of these are thermal radio sources associated with compact Galactic objects such as H II regions and planetary nebulae. A search for variability among 2148 of the compact sources has resulted in 29 candidate low-frequency variable sources, which are listed in Table 2 of the reference paper. See the project website at <a href="http://www.ras.ucalgary.ca/wsrt_survey.html">http://www.ras.ucalgary.ca/wsrt_survey.html</a> for the WSRTGP images available in JPEG, PostScript, and FITS formats. This table was created by the HEASARC in February 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/107/239">CDS Catalog J/ApJS/107/239</a> file wsrt.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/w40sfrcxo
- Title:
- W 40 Star-Forming Region Chandra X-Ray Point Source Catalog
- Short Name:
- W40SFRCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The young stellar cluster illuminating the W40 H II region, one of the nearest massive star-forming regions (SFRs), has been observed with the ACIS detector on board the Chandra X-ray Observatory. Due to its high obscuration, this is a poorly studied stellar cluster with only a handful of bright stars visible in the optical band, including three OB stars identified as primary excitation sources. The authors detect 225 X-ray sources, of which 85% are confidently identified as young stellar members of the region. Two potential distances of the cluster, 260 pc and 600 pc, are used in the paper. Supposing the X-ray luminosity function of SFRs to be universal, it supports a 600 pc distance as a lower limit for W40 and a total population of at least 600 stars down to 0.1 M<sub>sun</sub> under the assumption of a coeval population with a uniform obscuration. In fact, there is strong spatial variation in K<sub>s</sub>-band-excess disk fraction and non-uniform obscuration due to a dust lane that is identified in absorption in optical, infrared, and X-ray. The dust lane is likely part of a ring of material which includes the molecular core within W40. In contrast to the likely ongoing star formation in the dust lane, the molecular core is inactive. The star cluster has a spherical morphology, an isothermal sphere density profile, and mass segregation down to 1.5 M<sub>sun</sub>. However, other cluster properties, including a <= 1 Myr age estimate and ongoing star formation, indicate that the cluster is not dynamically relaxed. X-ray diffuse emission and a powerful flare from a young stellar object are also reported in the reference paper. This table was created by the HEASARC in March 2011 based on electronic versions of Tables, 1, 2 and 4 of the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xbootesoid
- Title:
- XBOOTES:NDWFSBootesFieldOptical&NearIRCounterparts
- Short Name:
- XBOOTESOID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XBootes Survey is a 5 ks Chandra survey of the Bootes Field of the NOAO Deep Wide-Field Survey (NDWFS). This survey is unique in that it is the largest (9.3 square degrees) contiguous region imaged in X-ray with complementary deep optical and near-infrared (near-IR) observations. The authors present a catalog of the optical counterparts to the 3213 X-ray point sources detected in the XBootes survey. Using a Bayesian identification scheme, they successfully identified optical counterparts for 98% of the X-ray point sources. The optical colors suggest that the optically detected galaxies are a combination of z < 1 massive early-type galaxies and bluer star-forming galaxies whose optical AGN emission is faint or obscured, whereas the majority of the optically detected point sources are likely quasars over a large redshift range. This large-area, X-ray-bright, optically deep survey enables the authors to select a large subsample of sources (773) with high X-ray to optical flux ratios (f<sub>X</sub>/f<sub>o</sub> > 10). These objects are likely high-redshift and/or dust-obscured AGNs. These sources have generally harder X-ray spectra than sources with 0.1 < f<sub>X</sub>/f<sub>o</sub> < 10. Of the 73 X-ray sources with no optical counterpart in the NDWFS catalog, 47 are truly optically blank down to R ~ 25.5 (the average 50% completeness limit of the NDWFS R-band catalogs). These sources are also likely to be high-redshift and/or dust-obscured AGNs. The 9.3 square degrees region of sky chosen to match the area covered with the NDWFS was observed by ACIS-I on the Chandra X-Ray Observatory over a 2 week time interval in 2003 March and April. The data were taken in 126 separate pointings, each observed for ~ 5 ks. The CIAO 3.0.2 wavelet detection algorithm (wavdetect; Freeman et al. 2002) was used to detect X-ray sources in the total (0.5 - 7.0 keV) band data. A probability threshold of 5 x 10-5 was chosen as the best compromise between maximizing the completeness while minimizing the number of spurious detections. The X-ray catalog comprises 3293 unique X-ray sources with >= 4 counts in the total-band images (Paper II). The authors expect only ~ 35 of these sources to be spurious in the full survey (Paper II). For the matching with cataloged optical counterparts, the authors only considered the 3213 X-ray sources that overlap with the NDWFS area. The authors include all multiply matched sources with >1% probability of being the correct optical counterpart. This table contains the X-ray and optical characteristics of the matched optical/X-ray catalog for the Chandra sources in the XBootes and NDWFS survey, and is Version 1.0, dated 21st June 2005. This table was created in November 2006 by the HEASARC based on the file xbootes_cat_xray_opt_IR_21jun_v1.0.txt obtained from the NOAO ftp area <a href="https://www.noao.edu/noao/noaodeep/XBootesPublic/">https://www.noao.edu/noao/noaodeep/XBootesPublic/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xbootes
- Title:
- XBOOTES: NDWFS Bootes Field X-Ray Point Source Catalog
- Short Name:
- XBootes
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XBootes table contains the X-Ray point source catalog from a Chandra survey of the 9 square degrees Bootes field of the NOAO Deep Wide-Field Survey (NDWFS). This XBootes survey consists of 126 separate contiguous ACIS-I observations each of approximately 5000 s in duration. These unique Chandra observations allowed the authors to search for large-scale structure and to calculate X-ray source statistics over a wide, contiguous field of view with arcsecond angular resolution and uniform coverage. Optical spectroscopic follow-up observations and the rich NDWFS data set will allow the authors to identify and classify these X-ray-selected sources. Using wavelet decomposition, they have detected 4642 point sources with n >= 2 counts. In order to keep their detections ~ 99% reliable, they have limited their list to sources with n >= 4 counts. For a 5000 s observation and assuming a canonical unabsorbed active galactic nucleus (AGN) type X-ray spectrum, a 4 count on-axis source corresponds to a flux of 4.7 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> in the soft (0.5-2 keV) band, 1.5 x 10<sup>-14</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> in the hard (2-7 keV) band, and 7.8 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> in the full (0.5-7 keV) band. The full 0.5-7 keV band n >= 4 count list contained in this HEASARC table has 3293 point sources. In addition to the point sources, 43 extended sources (not included in this HEASARC table) have been detected, consistent with the depth of these observations and the number counts of clusters. Presented here in the X-ray point source catalog for the XBootes survey are the source positions, X-ray fluxes, hardness ratios, and their uncertainties, for the 3293 sources with >= 4 counts in the full band. This table was created by the HEASARC in February 2006 based on the machine-readable version of Table 3 in the above paper which was obtained from the electronic ApJ website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmcosmoid
- Title:
- XMM-COSMOS Catalog of Optical/IR Counterparts
- Short Name:
- XMMCOSMOID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the final optical identifications of the medium-depth (~60 ks), contiguous (2 degree<sup>2</sup>) XMM-Newton survey of the COSMOS field. XMM-Newton has detected ~1800 X-ray sources down to limiting fluxes of ~5 x 10<sup>-16</sup>, ~3 x 10<sup>-15</sup>, and ~7 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the 0.5-2 keV, 2-10 keV, and 5-10 keV bands, respectively (~1 x 10<sup>-15</sup>, ~6 x 10<sup>-15</sup>, and ~1 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, in the three bands, respectively, over 50% of the area). The work is complemented by an extensive collection of multi-wavelength data from 24 microns to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for >~50% of the sample, and high-quality photometric redshifts for the rest. The XMM-Newton and multi-wavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%) have MIPS 24 um detections. Thanks to the redshift completeness (almost 100%) the authors were able to constrain the high-luminosity tail of the X-ray luminosity function confirming that the peak of the number density of log L<sub>X</sub> > 44.5 active galactic nuclei (AGNs) is at z ~ 2. Spectroscopically identified obscured and unobscured AGNs, as well as normal and star-forming galaxies, present well-defined optical and infrared properties. The authors devised a robust method to identify a sample of ~150 high-redshift (z > 1), obscured AGN candidates for which optical spectroscopy is not available. They were able to determine that the fraction of the obscured AGN population at the highest (L<sub>X</sub> > 10<sup>44</sup> erg s<sup>-1</sup>) X-ray luminosity is ~15%-30% when selection effects are taken into account, providing an important observational constraint for X-ray background synthesis. The authors studied in detail the optical spectrum and the overall spectral energy distribution of a prototypical Type 2 QSO (source number 2028), caught in a stage transitioning from being starburst dominated to AGN dominated, which was possible to isolate only thanks to the combination of X-ray and infrared observations. This table was created by the HEASARC in July 2010 based on the electronic version of Table 2 from the paper which was obtained from the Astrophysical Journal web site. <p> The HEASARC has made some changes to this material in order to make it more compliant with CDS/IAU Nomenclature and HEASARC table standards: <p> (i) The original naming convention suggested by the authors used a prefix of 'XMMC_' and the J2000.0 RA and Dec position in decimal degrees to 10<sup>-5</sup> degrees precision, e.g., XMMC_150.10515+1.98082'; the HEASARC has replaced these names by alternative new ones (in the alt_name parameter) of the form 'XMMU JHHMMSS.s+DDMMSS' where the prefix is the usual one for XMM-Newton sources and the remainder of the field is the J2000.0 equatorial coordinates truncated to 0.1 seconds of time in RA and to 1 arcsecond in Declination; <p> (ii) We have used for the alt_name parameter the naming convention recommended by the Dictionary of Nomenclature of Celestial Objects for XMM-COSMOS sources, viz. the "XMMC' prefix and the source (XID) number, e.g., "XMMC 2028'. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmcosmagn
- Title:
- XMM-COSMOS Catalog of X-Ray Selected Type 1 AGN
- Short Name:
- XMMCOSMAGN
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results from a study of the X-ray to optical properties of a sample of 545 X-ray selected Type 1 AGN, from the XMM-Newton Cosmic Evolution (XMM-COSMOS) survey, over a wide range of redshifts (0.04 < z < 4.25) and X-ray luminosities (40.6 <= log(L<sub>2-10keV</sub>) <= 45.3). About 60% of them are spectroscopically identified Type 1 AGN, while the others have a reliable photometric redshift and are classified as Type 1 AGN on the basis of their multi-band Spectral Energy Distributions (SEDs). In the reference, the authors discuss the relationship between UV and X-ray luminosity, as parametrized by the X-ray to optical-UX alpha<sub>ox</sub> spectral slope, and its dependence on redshift and luminosity. Herein optical and X-ray properties for 545 Type 1 AGN in XMM-COSMOS are presented. For each source, X-ray ID, spectroscopic redshift, photometric redshift, upper error on the photometric redshift, lower error on the photometric redshift, logarithm of the monochromatic luminosity at 2500 Angstroms, logarithm of the monochromatic luminosity at 2 keV, alpha<sub>ox</sub>, logarithm of the 2-10 keV luminosity, logarithm of the bolometric luminosity in solar units, bolometric correction, photometric classification, logarithm of the Eddington ratio, logarithm of the black hole mass in solar masses, and a flag for the 2-10 keV detection (flag = 1 [343 entries] means a detection in the 2-10 keV band, while flag = 0 is for 2-10 keV upper limits) are given. This table was created by the HEASARC in May 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/512/A34">CDS catalog J/A+A/512/A34</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmcty2agn
- Title:
- XMM-COSMOS X-Ray Selected Type-2 AGN
- Short Name:
- XMMCTY2AGN
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results from a study of the multi-wavelength (from the mid-infrared to the hard X-ray) properties of a sample of 255 spectroscopically identified X-ray selected Type-2 AGN from the XMM-COSMOS survey. Most of them are obscured and the X-ray absorbing column density is determined by either X-ray spectral analyses (for 45% of the sample), or from hardness ratios. Spectral energy distributions (SEDs) were computed for all sources in the sample. The average SEDs in the optical band are dominated by the host-galaxy light, especially at low X-ray luminosities and redshifts. There is also a trend between X-ray and mid-infrared luminosity: the AGN contribution in the infrared is higher at higher X-ray luminosities. The authors have calculated bolometric luminosities, bolometric corrections, stellar masses and star formation rates (SFRs) for these sources using multi-component modeling to properly disentangle the emission associated with stellar light from that due to black hole accretion. For 90% of the sample, they also have the morphological classifications obtained with an upgraded version of the Zurich estimator of structural types (ZEST+). The authors find that, on average, type-2 AGN have lower bolometric corrections than type-1 AGN. Moreover, they confirm that the morphologies of AGN host-galaxies indicate that there is a preference for these type-2 AGN to be hosted in bulge-dominated galaxies with stellar masses greater than 10<sup>10</sup> solar masses. For each source, this table contains the X-ray ID, spectroscopic redshift, logarithm of the 2-10keV luminosity, logarithm of the bolometric luminosity, bolometric correction, logarithm of the stellar mass, star formation rate, absolute magnitude M<sub>U</sub>, absolute magnitude M<sub>V</sub>, absolute magnitude M<sub>J</sub> (Johnson-Kron-Cousin system), and the morphological class. This table was created by the HEASARC in October 2011 based on CDS table J/A+A/534/A110 file table1.dat. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmt2flare
- Title:
- 2XMM Flares Detected from Tycho-2 Stars
- Short Name:
- XMMT2FLARE
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results from a uniform, large-scale survey of X-ray flare emission, based on the XMM-Newton Serendipitous Source Catalog (2XMM) and its associated data products. This survey comprises both XMM-targeted active stars and those observed serendipitously in the half-degree diameter field-of-view of an observation. The 2XMM Catalog and the associated time-series ('light-curve') data products have been used as the basis for the survey of X-ray flares from cool stars in the Hipparcos Tycho-2 catalog. In addition, the authors have generated and analyzed spectrally-resolved (i.e. hardness-ratio) X-ray light-curves. Where available, they have compared XMM OM UV/optical data with the X-ray light-curves. Their sample contains ~130 flares with well-observed profiles; they originate from ~70 stars. The flares range in duration from ~10<sup>3</sup> to ~10<sup>4</sup> s, have peak X-ray fluxes from ~10<sup>-13</sup> to ~10<sup>-11</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, peak X-ray luminosities from ~10<sup>29</sup> to ~10<sup>32</sup> erg s<sup>-1</sup>, and X-ray energy output from ~10<sup>32</sup> to ~10<sup>35</sup> erg. Most of the ~30 serendipitously-observed (target_flag = 'N') stars have little previously reported information. The hardness-ratio plots clearly illustrate the spectral (and hence inferred temperature) variations characteristic of many flares, and provide an easily accessible overview of the data. In the reference paper, the authors present flare frequency distributions from both target and serendipitous observations. The latter provide an unbiased (with respect to stellar activity) study of flare energetics; in addition, they allow the authors to predict the numbers of stellar flares that may be detected in future X-ray wide-field surveys. The serendipitous sample demonstrates the need for care when calculating flaring rates, especially when normalizing the number of flares to a total exposure time, where it is important to consider both the stars seen to flare and those from which variability was not detected (i.e., measured as non-variable), since in the present survey, the latter outnumber the former by more than a factor of ten. This table was created by the HEASARC in September 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/581/A28">CDS Catalog J/A+A/581/A28</a> files tablec1.dat and tablec2.dat. This is a service provided by NASA HEASARC .
