The RADIO database table is a periodically revised master catalog that contains selected parameters from a number of the HEASARC database tables that have information on radio source flux densities. The contents of this RADIO master catalog are listed in alphabetical order in the References section of this document. Each entry in RADIO has a parameter called `database_table` which indicates the originating database table from which the entry was copied. Users should check out the original database table if they want to examine all of the parameters that are available in that particular database table for the particular source(s) in which they are interested. Two of the component database tables of RADIO, DIXON and KUEHR, are compilations of radio observations, and individual sources can have multiple entries, representing either observations at different frequencies or multiple observations at the same frequency. In the latter case, notice, the flux density quoted in the RADIO database is an average of the individual flux densities at that particular frequency in the originating database. To see all of the individual entries for a source in RADIO from either of these two component databases, the corresponding entries in the DIXON and KUEHR database tables should be examined. The HEASARC in certain instances has included radio sources for which the quoted value for the specified band is an upper limit rather than a detection. The HEASARC recommends that the user should always check the original tables to get the complete information about the properties of the sources listed in the RADIO master source list. This database table is periodically updated by the HEASARC whenever one of the component database tables is modified or a new component database table is added. This is a service provided by NASA HEASARC .
The XRAY database table contains selected parameters from almost all HEASARC X-ray catalogs that have source positions located to better than a few arcminutes. The XRAY database table was created by copying all of the entries and common parameters from the tables listed in the Component Tables section. The XRAY database table has many entries but relatively few parameters; it provides users with general information about X-ray sources, obtained from a variety of catalogs. XRAY is especially suitable for cone searches and cross-correlations with other databases. Each entry in XRAY has a parameter called 'database_table' which indicates from which original database the entry was copied; users can browse that original table should they wish to examine all of the parameter fields for a particular entry. For some entries in XRAY, some of the parameter fields may be blank (or have zero values); this indicates that the original database table did not contain that particular parameter or that it had this same value there. The HEASARC in certain instances has included X-ray sources for which the quoted value for the specified band is an upper limit rather than a detection. The HEASARC recommends that the user should always check the original tables to get the complete information about the properties of the sources listed in the XRAY master source list. This master catalog is updated periodically whenever one of the component database tables is modified or a new component database table is added. This is a service provided by NASA HEASARC .
MAXI/GSC 7-Year High and Low Galactic Latitude Source Catalog (3MAXI)
Short Name:
MAXIGSC7YR
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table combines the published X-ray source catalogs of the high galactic latitude (|b| > 10<sup>o</sup>), Kawamuro et 2018, and the low galactic latitude (|b| < 10<sup>o</sup>), Hori et al. 2018, based on 7 years of MAXI Gas Slit Camera (GSC) data from 2009 August 13 to 2016 July 31. The low galactic latitude catalog contains 221 sources with a significance threshold > 6.5 sigma. The low galactic faintest source has a flux of 5.2 x 10<sup>-12</sup> erg cm<sup>-2</sup> s<sup>-1</sup> (or an intensity of 0.43 mCrab) in the 4-10 keV band. The high galactic latitude catalog contains 686 sources detected at significances >= 6.5 sigma in the 4-10 keV band. The high galactic 4-10 keV sensitivity reaches ~0.48 mCrab, or ~5.9 x 10<sup>-12</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, over half of the survey area. The same data-screening criteria were applied to obtain the low and high galactic catalogs. In their papers the authors describe the detection method, the statistical quantities derived for each source and their variability. To derive a counterpart, each source was cross-matched with the Swift/BAT 105-month catalog (BAT105; Oh et al. 2018), the Uhuru fourth catalog (4U; Forman et al. 1978), the RXTE All-Sky Monitor long-term observed source table (XTEASMLONG16), Meta-Catalog of X-Ray Detected Clusters of Galaxies (MCXC; Piffaretti et al. 2011), the XMM-Newton Slew Survey Catalog (XMMSL217), and the ROSAT All-Sky Survey Bright Source Catalog (1RXS; Voges et al. 1999). Seven of the sources in the low galactic latitudes were detected by binning the data differently (source numbers 215-221 in the catalog named 73-day sources), and, similarly, four of the sources in the high galactic latitude catalog named transient sources. The parameters in the combined table include the source name (3MAXI), the position and its error, the detection significances and fluxes in the 4-10 keV, 3-4 keV bands and 10-20 keV bands the hardness ratios (HR1: 3-4 keV, 4-10 keV and HR2: 4-10 keV, 10-20 keV), excess variance in the 4-10 keV lightcurve and information on the likely counterpart. The high galactic catalogs also reports the flux in the 3-10 keV, an additional hardness (HR3: 3-10 keV and 10-20 keV) and an additional parameter representing variability. The hardness ratios are defined as H-S/H+S were S and H are the soft- and hard-band fluxes, respectively. This table was created by the HEASARC in April 2021. It is a combination of the 7-year low- and high-latitude MAXI source catalogs published on ApJS. The data for the low-galactic latitude and the high-galactic latitude were downloaded from the ApJS electronic version of the Hori et al. 2018 ApJS 235,7 and Kawamuro et al. 2018 ApJS 238,33 papers respectively. The low-latitude data included in this table are from tables 4, 5, 6, 7 of the Hori paper that report the X-ray sources detected (214 sources, table 4), their possible identification (table 5), the transient sources discovered binning the data on 73 days period (7 sources, table 5) and their identification (table 6). The high-latitude data included in this table are from the tables 1,2,3 of the Kawamuro paper that report the X-ray sources detected (682 sources in table 1), their identifications (table 2), and the transient sources (4 sources in table 3). The low and high galactic latitude source catalogs provide for each individual source similar parameters for the X-ray properties with the high-latitude having three additional parameters, specifically, the flux in the 3-10 keV energy range, the 3-10/10-20-keV hardness ratio, and a time variability test. These parameters are kept in the HEASARC combined table and set to "blank" values for the low-latitude sources. The four sources in the high-latitude catalog named transient sources have only fluxes in the 4-10 keV band and no other fluxes in the other energy bands or the hardness ratio are reported. The HEASARC combined table includes a field to identify whether the source is from the low-latitude paper or the high-latitude paper and also maintains the source numbers that were published in the original catalogs. This is a service provided by NASA HEASARC .
The MAXIMASTER database table records high-level information of the Monitor of All-sky X-ray Image (MAXI) observations and provides access to the data archive. MAXI is a Japanese experiment located at the International Space Station (ISS), designed to continuously monitor, through a systematic survey, X-ray sources as the ISS orbits Earth. MAXI was launched by the space shuttle Endeavour on 2009 July 16, then mounted on port No. 1 on JEM-EF on July 24. After the electric power was turned on, MAXI started nominal observations on 2009 August 3. The MAXI data are a copy of the MAXI data processing; the output of which is hosted at the DARTS archive located at ISAS (<a href="https://darts.isas.jaxa.jp/astro/maxi/">https://darts.isas.jaxa.jp/astro/maxi/</a>). This catalog is then generated at the HEASARC by collecting high-level information from the data and is updated regularly during operation. This is a service provided by NASA HEASARC .
MAXI/SSC Catalog of X-Ray Sources in 0.7-7.0 keV Band
Short Name:
MAXISSCCAT
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains the first source catalog of the Solid-state Slit Camera (SSC) of the Monitor of All-sky X-ray Image (MAXI) mission located on the International Space Station, using the 45 months of data from 2010 August 1 to 2014 April 30 in the 0.7-7.0 keV band. Sources were searched for in two energy bands, 0.7-1.85 keV (the soft band) and 1.85-7.0 keV (the hard band), limiting sensitivities of 3 and 4 mCrab, respectively, were achieved, and 140 and 138 sources were detected in the soft and hard energy bands, respectively. Combining the two energy bands, 170 sources are listed in the MAXI/SSC catalog. All but 2 sources are identified, with 22 galaxies (including AGNs), 29 cluster of galaxies, 21 supernova remnants, 75 X-ray binaries, 8 stars, 5 isolated pulsars, and 9 non-categorized objects. Comparing the soft-band fluxes at the brightest end in this catalog with the ROSAT survey, which was performed about 20 years ago, 10% of the catalogued sources are found to have changed flux since the ROSAT era. This table was created by the HEASARC in December 2016 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/PASJ/68/S32">CDS Catalog J/PASJ/68/S32</a> file table5.dat. This is a service provided by NASA HEASARC .
The authors explore the population of X-ray point sources in the bulge of M 31 so as to contrast properties of various subpopulations, such as persistent and transient sources and primordial LMXBs and dynamically formed ones. Based on the data from 26 archival Chandra ACIS observations with aim-points within 10 arcminutes of the center of M 31 (J2000 coordinates of 00:42:44.31, +41:16:09.4), the authors study the source content and properties of various subpopulations of X-ray sources to a maximum distance of 12 arcminutes from the center of M 31. To a limiting luminosity of ~10<sup>35</sup> erg s<sup>-1</sup>, the authors find 263 X-ray point sources, with ~1/3 of these being background galaxies. A study of the spatial distribution and the luminosity function of the X-ray sources shows that the distribution of primordial LMXBs is consistent with the distribution of the K-band light and that their luminosity function flattens below ~10<sup>37</sup> erg s<sup>-1</sup> to the dN/dL ~ L<sup>-1</sup> law in agreement with the behavior found earlier for LMXBs in the Milky Way and in Cen A. Within a radius of 12 arcminutes, the luminosity function is independent of distance to the center of M 31, in contrast to earlier Chandra studies. The LMXBs located in globular clusters and within ~1 arcminute from the center of M 31 are presumably created via dynamical interactions. The dynamical origin of the r < 1 arcminute sources is strongly suggested by their radial distribution which follows the rho<sub>*</sub><sup>2</sup> profile rather than the K-band light distribution. Their luminosity function shows a prominent fall-off below log(L<sub>X</sub>) <~ 36.5. Although the statistics are insufficient to claim a genuine low-luminosity cut-off in the luminosity function, the best fit power-law with a slope of -0.6 +/- 0.2 is significantly flatter than the dN/dL ~ L<sup>-1</sup> law. The authors also searched for transients and found 28 sources that varied by a factor larger than 20. Their spatial distribution follows the distribution of the persistent LMXBs within the accuracy allowed by the limited number of transients. This HEASARC table was created in March 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/468/49">CDS catalog J/A+A/468/49</a> file table2.dat. This is a service provided by NASA HEASARC .
The Web Version of the McCook-Sion White Dwarf Catalog contains in excess of 500 more entries than the previous published version, the 4th Edition (1999) of the Villanova White Dwarf Catalog. It is a catalog of white dwarfs which have been identified spectroscopically. For each degenerate star, the following data entries with references are provided: (1) catalog coordinate designation or WD number, (2) the right ascension and declination, (3) the spectral type based upon the new system, (4) a catalog symbol denoting binary membership, (5) proper motion and position angle, (6) broad-band UBV Photometry, V, B-V, U-B, (7) multichannel spectrophotometry, V(MC), g-r, (8) Stromgren narrow-band photometry y, b-y, u-b, (9) an absolute visual magnitude based upon the best available color-magnitude calibration or trigonometric parallax, (10) the observed radial velocity uncorrected for gravitational redshift or solar motion, and (11) the trigonometric parallax, with mean error, when available. Note that finding charts for many of the white dwarfs present in this catalog can be found at the following URLs: <pre> <a href="http://procyon.lpl.arizona.edu/WD/charts/">http://procyon.lpl.arizona.edu/WD/charts/</a> <a href="http://deneb.astro.warwick.ac.uk/phsaap/wdcharts/">http://deneb.astro.warwick.ac.uk/phsaap/wdcharts/</a> </pre> The second URL contains the finding charts from T.R. Marsh. This is list with about 600 charts. The University of Arizona charts currently have about 2000 charts, but that list is a work in progress with the intent of eventually having all charts available. As discussed in more detail in the HEASARC_Implementation section, this HEASARC representation of the White Dwarf Catalog contains only a subset of the data presented in either the printed version or the version available at the Villanova website, but is intended to be suitable for cross-identification purposes with other catalogs, e.g., of X-ray sources. The original sources for this catalog should always be consulted for the full set of information that is available for these white dwarfs. This database table is based on the Web version of the Villanova White Dwarf Catalog. It was initially created by the HEASARC in May 2003. It is based on the files WD00-07.txt, WD08-15.txt, WD16-23.txt, and WDNewStars.txt obtained from <pre> <a href="ftp://astronomy.villanova.edu/mccook/Current%20Web%20Version%20of%20WD%20Catalog/">ftp://astronomy.villanova.edu/mccook/Current%20Web%20Version%20of%20WD%20Catalog/</a> </pre> It is automatically updated periodically whenever the catalog's authors update these files. This is a service provided by NASA HEASARC .
M 31 Central Field Chandra HRI X-Ray Point Source Catalog
Short Name:
M31CFCXO
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
The central field of the Andromeda galaxy (M 31) was monitored from 2006 to 2012 using the Chandra HRC-I detector (about 0.1 - 10 keV energy range) with the main aim of detecting X-rays from optical novae. The authors present a systematic analysis of all X-ray sources found in the 41 nova monitoring observations, along with 23 M 31 central field HRC-I observations available from the Chandra data archive starting in December 1999. Based on these observations, they studied the X-ray long-term variability of the source population and especially of the X-ray binaries in M31. The authors created a catalog of sources detected in the 64 available observations that adds up to a total exposure time of about 1 Ms. To study the variability, they developed a processing pipeline to derive long-term Chandra HRC-I light curves for each source over the 13 years of observations, and also searched for extended X-ray sources in the merged images. This table contains the point-source catalog of 318 X-ray sources with detailed long-term variability information, 28 of which are published for the first time. The spatial and temporal resolution of the catalog allows the authors to classify 115 X-ray binary candidates showing high X-ray variability or even outbursts, as well as 14 globular cluster X-ray binary candidates showing no significant variability. The analysis may suggest that outburst sources are less frequent in globular clusters than in the field of M 31. Seven supernova remnants (not included in the point-source catalog) were detected, one of which is a new candidate, and also the first X-rays from a known radio supernova remnant were resolved. In addition to 33 known optical nova/X-ray source correlations, the authors discovered one previously unknown super-soft X-ray outburst and several new nova candidates. A large sample of detailed long-term X-ray light curves of sources in the M31 central field has been obtained in this study (see Appendix B.1 of the reference paper), which helps in understanding the X-ray population of our neighboring spiral galaxy M 31. Based on all the available Chandra HRC-I observations (see Table A.1 in the reference paper for the complete list), a source catalog has been created (available in this HEASARC table) and the energy flux of each source in every individual observation derived (these are not available in this HEASARC table, but are obtainable at the CDS: for more details, see the files <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A%2BA/555/A65/ReadMe">https://cdsarc.cds.unistra.fr/ftp/cats/J/A%2BA/555/A65/ReadMe</a> and <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J_A%2BA/555/A65/table2.dat.gz">https://cdsarc.cds.unistra.fr/ftp/cats/J_A%2BA/555/A65/table2.dat.gz</a>). One thing to be aware of is that, in the latter file, upper limits are denoted by a '>' symbol rather than the more usual '<' symbol!). These fluxes were calculated assuming a generic power law spectrum and Galactic foreground absorption for each source. This table was created by the HEASARC in August 2013 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/555/A65">CDS catalog J/A+A/555/A65</a> files table1.dat and xcorr.dat. This is a service provided by NASA HEASARC .
M 31 Central Region Chandra X-Ray Point Source Catalog
Short Name:
Chan/M31
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table countains the M 31 Central Region Catalog of Chandra X-Ray Point Sources. It is based on Chandra observations of the central region of M 31. By combining eight Chandra ACIS-I observations which were taken between 1999 and 2001, the authors have identified 204 X-ray sources within the central ~17'x17' region of M 31, with a detection limit of ~2x10<sup>35</sup> erg/s. Of these 204 X-ray sources, 22 are identified with globular clusters, two with supernova remnants, nine with planetary nebulae, and nine with supersoft sources. By comparing individual images, about 50% of the sources were found to be variable on timescales of months. The authors also found 13 transients, with light curves showing a variety of shapes. They also extracted the energy spectra of the 20 brightest sources; they can be well fitted by a single power law with a mean photon index of 1.8. The spectral shapes of 12 sources were variable, suggesting that they went through state changes. All sources in the catalog have S/N > 2.5 and only five have S/N < 3.0. The detection limit for the sources varies across the image due to the variation of exposure time, background, and instrumental PSF, and is highest near the edges, where the PSF broadens rapidly and the exposure time is lowest. Over the inner 4' of the field, the detection limit is 2.1 x 10<sup>-4</sup> ct/s, which is equivalent to an X-ray luminosity of about 2 x 10<sup>35</sup> erg/s. Additional information about optical identifications and cross-correlated ROSAT X-ray sources not provided in this HEASARC table is available in the published paper (Tables 4 and 5) and/or the CDS at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/">https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/</a> (table4.dat & table5.dat). This table was created by the HEASARC in October 2004 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/table2">CDS Catalog J/ApJ/577/738/table2</a>.dat. This is a service provided by NASA HEASARC .
M 33 Chandra ACIS Survey (ChASeM33) Final Source Catalog
Short Name:
M33CHASE
Date:
25 Apr 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains the final source catalog of the Chandra ACIS Survey of M33 (ChASeM33). With a total exposure time of 1.4 Ms, ChASeM33 covers ~70% of the D<sub>25</sub> isophote (radial extent ~ 4.0 kpc) of M33 and provides the deepest, most complete, and detailed look at a spiral galaxy in X-rays. The source catalog includes 662 sources, reaches a limiting unabsorbed luminosity of ~2.4 x 10<sup>34</sup> erg s<sup>-1</sup> in the 0.35-8.0 keV energy band, and contains source positions, source net counts, fluxes and significances in several energy bands, and information on source variability. The analysis challenges posed by ChASeM33 and the techniques adopted to address these challenges are discussed. To constrain the nature of the detected X-ray source, hardness ratios were constructed and spectra were fit for 254 sources, follow-up Multiple Mirror Telescope (MMT) spectra of 116 sources were acquired, and cross-correlations with previous X-ray catalogs and other multi-wavelength data were generated. Based on this effort, 183 of the 662 ChASeM33 sources could be identified. Finally, in the reference paper, the luminosity function (LF) for the detected point sources as well as the one for the X-ray binaries (XRBs) in M33 were presented. The LFs in the soft band (0.5-2.0 keV) and the hard band (2.0-8.0 keV) have a limiting luminosity at the 90% completeness limit of 4.0 x 10<sup>34</sup> erg s<sup>-1</sup> and 1.6 x 10<sup>35</sup> erg s<sup>-1</sup> (for an assumed distance D to M33 of 817 kpc), respectively, which is significantly lower than what was reported by previous XRB population studies in galaxies more distant than M33. The resulting distribution is consistent with a dominant population of high-mass XRBs as would be expected for M33. The list of all the Chandra ACIS observations that were used in the construction of this source catalog is given in table 2 of the 2011 reference paper. X-ray source properties, such as counts, dns values, and photon fluxes were computed in the following energy bands: <pre> Band Energy Range (keV) 1 0.5 - 8.0 2 0.5 - 2.0 3 2.0 - 8.0 4 0.35- 8.0 5 0.35- 1.1 6 1.1 - 2.6 7 2.6 - 8.0 8 0.35- 2.0 </pre> This table was created by the HEASARC in April 2011 based on electronic versions of Tables 3, 4, 5, 6, 7 and 9 from the 2011 reference paper which were obtained from the ApJS web site. This is a service provided by NASA HEASARC .
