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:
07 Mar 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:
07 Mar 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:
07 Mar 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:
07 Mar 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 .
The authors have obtained 17 epochs of Chandra High Resolution Camera (HRC) snapshot images, each covering most of the M31 disk. The data cover a total baseline of ~2.5 yr and contain a mean effective exposure of 17 ks. The authors measured the mean fluxes and long-term light curves for 166 objects detected in these data. At least 25% of the sources show significant variability. The cumulative luminosity function (CLF) of the disk sources is well fitted by a power law with a slope comparable to those observed in typical elliptical galaxies. The CLF of the bulge is a broken power law similar to measurements made by previous surveys. The authors note several sources in the southwestern disk with L<sub>X</sub> > 10<sup>37</sup> ergs s<sup>-1</sup>. They cross-correlate all of their sources with published optical and radio catalogs, as well as new optical data, finding counterpart candidates for 55 sources. In addition, 17 sources are likely X-ray transients. Finally, the frequency of bright X-ray transients in the M31 bulge suggests that the ratio of neutron star to black hole primaries in low-mass X-ray binaries (NS/BH) is 1. The data for this project were originally part of a survey program to look for X-ray transients in M31. Nearly every month from 1999 November to 2001 February, Chandra took HRC-I images of five fields covering most of M31. Observations were then made every few months until 2002 June. The details of the 81 Chandra observations are summarized in Table 1 of the reference paper, which is available in a machine-readable form at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J_ApJ/609/735/">http://cdsarc.u-strasbg.fr/ftp/cats/J_ApJ/609/735/</a>. The authors combined all the data into three data sets using the task merge_all. One set contained the data for the northern half of the galaxy, another contained the southern half, and the last contained the center. The authors searched for sources in the three data sets using the CIAO task wavdetect. They ran this task searching for sources on four size scales: 1, 2, 4, and 8 pixels. The pixels in the merged images were 1 arcsecond in the central 18 arcmin by 18 arcmin and 2 arcsec outside of this region. By searching on several scales, wavdetect is able to overcome the large changes in the size of the Chandra PSF from about 0.5 arcsec near the center of the field to over 10 arcsec in the outer regions of the field. A total of 166 sources were detected above their 3.5-sigma detection threshold. This table was created by the HEASARC in September 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/609">CDS Catalog J/ApJ/609</a>, 735 file table2.dat . This is a service provided by NASA HEASARC .
M 83 Chandra X-Ray Binary Classifications Using HST
Short Name:
M83XRBCXO
Date:
07 Mar 2025
Publisher:
NASA/GSFC HEASARC
Description:
Building on recent work by Chandar+ (2020, J/ApJ/890/150), the authors constructed X-ray luminosity functions (XLFs) for different classes of X-ray binary (XRB) donors in the nearby star-forming galaxy M 83. Rather than classifying low-versus high-mass XRBs based on the scaling of the number of X-ray sources with stellar mass and star formation rate, respectively, this catalog utilized multi-band Hubble Space Telescope imaging data to classify each Chandra-detected compact X-ray source as a low-mass (i.e., donor mass < ~3M<sub>sun</sub>), high-mass (donor mass > ~8M<sub>sun</sub>), or intermediate-mass XRB based on either the location of its candidate counterpart on optical color-magnitude diagrams or the age of its host star cluster. In addition to the standard (single and/or truncated) power-law functional shape, the authors approximated the resulting XLFs with a Schechter function. They identified a marginally significant (at the 1-sigma to 2-sigma level) exponential downturn for the high-mass XRB XLF, at l~38.48<sub>-0.33</sub><sup>+0.52</sup> (in log CGS units). In contrast, the low- and intermediate-mass XRB XLFs, as well as the total XLF of M 83, are formally consistent with sampling statistics from a single power law. This method suggests a non-negligible contribution from low- and possibly intermediate-mass XRBs to the total XRB XLF of M 83, i.e., between 20% and 50%, in broad agreement with X-ray-based XLFs. More generally, the authors caution against considerable contamination from X-ray emitting supernova remnants to the published, X-ray-based XLFs of M 83, and possibly all actively star-forming galaxies. This table presents a fully classified catalog of X-ray sources in M 83 that builds upon the deep Chandra ACIS imaging data published in Lehmer+ 2019 (J/ApJS/243/3). Out of a total of 456 point-like sources brighter than 10<sup>35</sup>erg/s, this work restricts the analysis to the 325 objects that fall within the M 83 HST footprint. HST observations of M 83 were taken with the WFC3/UVIS instrument, spanning seven fields that each cover approximately 162" x 162" for a total mosaic area of ~43 arcmin<sup>2</sup>. All observations were obtained between 2009 August and 2012 September by R. O'Connell (Prop ID. 11360) and W. Blair (Prop ID. 12513), with exposure times ranging from ~1.2 to 2.7 ks for each image. Images were downloaded from the Hubble Legacy Archive (HLA). In general, BVI images are created using the F438W, F547M, and F814W filters. The central field, which includes the galaxy nucleus, uses the broader F555W V-band filter, rather than F547M. The authors also use U-band images (F336W) to help calculate cluster ages. This table was created by the HEASARC in March 2023 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/912/31">CDS Catalog J/ApJ/912/31</a> file tablea2.dat. This is a service provided by NASA HEASARC .
This table contains a list of discrete sources found in a 60-ks Chandra ACIS-S observation of the isolated edge-on spiral galaxy NGC 3556 (M108). In the reference paper in which the authors present this table, they also give a multiwavelength analysis of the various discrete X-ray sources and of the diffuse X-ray features. Among 33 discrete X-ray sources detected within the I<sub>B</sub> = 25 mag arcsec<sup>-2</sup> isophotal ellipse of the galaxy, the authors identify a candidate for the galactic nucleus, an ultraluminous X-ray source that might be an accreting intermediate-mass black hole, a possible X-ray binary with a radio counterpart, and two radio-bright giant H II regions. They also detect large amounts of extraplanar diffuse X-ray emission, which extend about 10 kpc radially in the disk and >~4 kpc away from the galactic plane. The diffuse X-ray emission exhibits significant substructures, possibly representing various blown-out superbubbles or chimneys of hot gas heated in massive star-forming regions. This Chandra observation of NGC 3556 (observation ID 2025) was taken between 2001 September 8 and 9 for an exposure of 60 ks. The ACIS-S instrument was at the focal plane of the telescope. This table was created by the HEASARC in August 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/598/969">CDS Catalog J/ApJ/598/969</a> file table2.dat. This is a service provided by NASA HEASARC .
