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NGC 300 Chandra X-Ray Point Source Catalog

This table contains the source catalog from a new Chandra ACIS-I observation of the nearby (2.0 Mpc) SA(s)d spiral galaxy NGC 300 which was obtained as part of the Chandra Local Volume Survey (CLVS). This 63-ks exposure covers ~88% of the D<sub>25</sub> isophote (R ~ 6.3 kpc) and yields a catalog of 95 X-ray point sources detected at high significance down to a limiting unabsorbed 0.35-8 keV luminosity of ~ 10<sup>36</sup> erg/s. Sources were cross-correlated with a previous XMM-Newton catalog, and the authors find 75 "X-ray transient candidate" sources that were detected by one observatory, but not the other. They derive an X-ray scale length of 1.7 +/- 0.2 kpc and a recent star formation rate of 0.12 M<sub>sun</sub>/yr in excellent agreement with optical observations. Deep, multi-color imaging from the Hubble Space Telescope, covering ~ 32% of this Chandra field, was used to search for optical counterparts to the X-ray sources, and the authors have developed a new source classification scheme to determine which sources are likely X-ray binaries, supernova remnants, and background active galactic nucleus candidates. In the reference paper, the authors present the X-ray luminosity functions (XLFs) at different X-ray energies, and find the total NGC 300 X-ray point-source population to be consistent with other late-type galaxies hosting young stellar populations (<~ 50 Myr). They find that the XLF of sources associated with older stellar populations has a steeper slope than the XLF of X-ray sources coinciding with young stellar populations, consistent with theoretical predictions. NGC 300 was observed on 2010 September 25 for 63 ks using ACIS-I during the Chandra X-Ray Observatory Cycle 12, observation ID 12238. The source detection strategy that was used is described in Section 2.3 of the reference paper. ACIS-Extract (AE) was run a final time on the source list that was produces after an initial run of wavdetect followed by several iterations of AE, and the Poisson probability of not being a source (pns) value was computed in each of the following nine energy bands: 0.5 - 8.0, 0.5 - 2.0, 2.0 - 8.0, 0.5 - 1.0, 1.0 - 2.0, 2.0 - 4.0, 4.0 - 8.0, 0.35 - 1.0 and 0.35 - 8.0 keV. To be included in the final NGC 300 catalog, a source was required to have a pns value less than 4 x 10<sup>-6</sup> in any of the nine energy bands; if only the 0.35 - 8 keV band were considered, ~4% of significant sources would have been lost. The final CLVS source catalog for NGC 300 contains 95 sources. This table was initially created by the HEASARC in September 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/758/15/">CDS Catalog J/ApJ/758/15/</a> files table4.dat, table5.dat, table6.dat and table7.dat containing the X-ray properties of the 95 Chandra point sources found in this study. The information on the optical counterparts to (some of) the Chandra X-ray sources and on the X-ray point source classification (presented in Tables 16 and 17, respectively, of the reference paper) is not included herein. It was updated in September 2015 to include the unabsorbed 0.35-8.0 keV energy fluxes (in the parameter herein called b4_flux) from the second reference paper. This is a service provided by NASA HEASARC .

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Lockman Hole XMM-Newton X-Ray Point Source Catalog

The Lockman Hole represents the sky area of lowest Galactic line-of-sight columns density. It was observed by the XMM-Newton X-ray observatory in 18 pointings performed between April 2000 and December 2002. The total exposure time spent on the field was 1.16 Ms (EPIC pn detector; EPIC MOS detector: 1.30 Ms). The effective exposure after removal of times of high particle background is 637 ks (EPIC pn detector; EPIC MOS detector: 765 ks). The catalog lists positions, count rates, fluxes, hardness ratios, and partial optical classifications of 409 X-ray point sources detected in the central 0.196 square degrees of the field down to a detection likelihood threshold in the full energy band of 10 (3.9 sigma), up to 4 of which may be spurious according to the authors' Monte Carlo simulations. The analysis was performed using the XMM-Newton SAS data analysis package version 6.0. This table was created by the HEASARC in May 2008 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/479/283">CDS Catalog J/A+A/479/283</a> file table3.dat. This is a service provided by NASA HEASARC .

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M 31 XMM-Newton Spectral Survey X-Ray Point Source Catalog

This table contains the results of a complete spectral survey of the X-ray point sources detected in five XMM-Newton observations along the major axis of M 31 but avoiding the central bulge, aimed at establishing the population characteristics of X-ray sources in this galaxy. One observation of each disc field of M 31 was taken using the EPIC pn and MOS cameras on XMM-Newton in January and June 2002. The authors obtained background-subtracted spectra and lightcurves for each of the 335 X-ray point sources detected across the five observations from 2002. They also correlate their source list with those of earlier X-ray surveys and radio, optical and infra-red catalogs. Sources with more than 50 source counts are individually spectrally fit in order to create the most accurate luminosity functions of M 31 to date. Based on the spectral fitting of these sources with a power law model, the authors observe a broad range of best-fit photon index. From this distribution of best-fit index, they identify 16 strong high mass X-ray binary system candidates in M 31. They show the first cumulative luminosity functions created using the best-fit spectral model to each source with more than 50 source counts in the disc of M 31. The cumulative luminosity functions show a distinct flattening in the X-ray luminosity L<sub>X</sub> interval 37.0 <~ log L<sub>X</sub> erg s<sup>-1</sup> <~ 37.5. Such a feature may also be present in the X-ray populations of several other galaxies, but at a much lower statistical significance. The authors investigate the number of AGN present in their source list and find that, above L<sub>X</sub> ~1.4 x 10<sup>36</sup> erg s<sup>-1</sup>, the observed population is statistically dominated by the point source population of M 31. This table was created by the HEASARC in October 2009 based on the electronic version of Table A1 from the reference paper which was obtained from the CDS (their catalog J/A+A/495/733 file tablea1.dat. This is a service provided by NASA HEASARC .

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Chandra ACIS Survey for X-Ray AGN in Nearby Galaxies

The authors searched the public archive of the Chandra X-ray Observatory as of 2016 March and assembled a sample of 719 galaxies within 50 Mpc with available Advanced CCD Imaging Spectrometer observations. By cross-correlation with the optical or near-infrared nuclei of these galaxies, 314 of them are identified to have an X-ray active galactic nucleus (AGN). The majority of them are low-luminosity AGNs and are unlikely X-ray binaries based upon their spatial distribution and luminosity functions. The AGN fraction is around 60% for elliptical galaxies and early-type spirals, but drops to roughly 20% for Sc and later types, consistent with previous findings in the optical. However, the X-ray survey is more powerful in finding weak AGNs, especially from regions with active star formation that may mask the optical AGN signature. For example, 31% of the H II nuclei are found to harbor an X-ray AGN. For most objects, a single power-law model subject to interstellar absorption is adequate to fit the spectrum, and the typical photon index is found to be around 1.8. For galaxies with a non-detection, their stacked Chandra image shows an X-ray excess with a luminosity of a few times 10<sup>37</sup> erg/s on average around the nuclear region, possibly composed of faint X-ray binaries. This paper reports on the technique and results of the survey; in-depth analysis and discussion of the results were to be reported in forthcoming papers, e.g., She et al. (2017, ApJ, 842, 131). The sample was assembled based on Chandra/ACIS observations that were publicly available as of 2016 March. The authors first generated a full list of ACIS observations, and then searched in the NASA/IPAC Extragalactic Database (NED) for galaxies within 50 Mpc whose nuclear positions were less than 8 arcminutes from the aim point of any Chandra observation. The adopted distances were taken from NED, in the following order of priority: surface brightness fluctuations, Cepheid variables, tip of the red giant branch, Type Ia supernovae, the fundamental plane, Faber-Jackson relation, Tully-Fisher relation. If more than one reference is available for the distance by the same means, the latest one is selected, unless otherwise specified. Whenever possible, the authors obtain positions of the galaxy nuclei based on measurements from near-infrared images, which suffer from less obscuration by dust or confusion from young star-forming regions. Most of the data come from the Two-Micron All Sky Survey (2MASS) extended source catalog (Skrutskie et al. 2006, AJ, 131, 1163), or NED otherwise. In a few cases, the NED positions come from radio observations. The authors discarded galaxies whose nuclear positions in NED were obtained from X-ray observations. This table was created by the HEASARC in September 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/835/223">CDS Catalog J/ApJ/835/223</a> files table1.dat, table2.dat and table4.dat. This is a service provided by NASA HEASARC .

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eROSITA eFEDS Hard X-Ray (2.3-5.0 keV) Source Catalog

The eROSITA X-ray telescope on board the Spectrum-Roentgen-Gamma (SRG) observatory combines a large field of view and collecting area in the energy range ~0.2 to ~8.0 keV with the capability to perform uniform scanning observations of large sky areas. SRG/eROSITA performed scanning observations of the ~140 square degrees eROSITA Final Equatorial Depth Survey (eFEDS) field as part of its performance verification phase. The observing time was chosen to slightly exceed the depth of equatorial fields after the completion of the eROSITA all-sky survey. The authors present a catalog of detected X-ray sources in the eFEDS field providing source positions and extent information, as well as fluxes in multiple energy bands and document a suite of tools and procedures developed for eROSITA data processing and analysis, validated and optimized by the eFEDS work. A multi-stage source detection procedure was optimized and calibrated by performing realistic simulations of the eROSITA eFEDS observations. The authors cross-matched the eROSITA eFEDS source catalog with previous XMM-ATLAS observations, confirming excellent agreement of the eROSITA and XMM-ATLAS source fluxes. This table presents the hard band sample of 246 sources detected in the energy range 2.3-5.0 keV above a detection likelihood of 10. These sources were detected in three bands (0.2-0.6, 0.6-2.3, and 2.3-5keV) with detect_likelihood >=5 and extent_likelihood = 0 (i.e. point sources). The linked <a href="/W3Browse/erosita/efedsmain.html">EFEDSMAIN</a> table presents the primary catalog of 27910 X-ray sources, including 542 with significant spatial extent, detected in the 0.2-2.3 keV energy range with detection likelihoods >=6 , corresponding to a (point source) flux limit of ~6.5 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s in the 0.5-2.0 keV energy band (80% completeness). A supplementary catalog contains 4774 low-significance source candidates with detection likelihoods between 5 and 6. The dedicated data analysis software package, calibration database, and calibrated data products are described in an appendix. Additional information for the eROSITA early data release observations is available at the <a href="https://erosita.mpe.mpg.de/edr/">eROSITA-DE EDR website</a>. This database table was originally ingested by the HEASARC in August 2022 and is based upon the "eROSITA/eFEDS hard catalogue" file downloaded from the eROSITA-DE Early Data Release <a href="https://erosita.mpe.mpg.de/edr/eROSITAObservations/Catalogues/">catalogs web page</a>. It was revised in June 2024 in order to rename the right ascension, declination, and their related positional uncertainty parameters to match the parameter naming convention used in other eROSITA catalogs. In some cases, the HEASARC has altered the original field names, as per HEASARC conventions, and provides the original field names in square brackets. This is a service provided by NASA HEASARC .

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ChIcAGO Survey Chandra X-Ray Source Catalog

This table contains results from the 'Chasing the Identification of ASCA Galactic Objects' (ChIcAGO) survey, which is designed to identify the unknown X-ray sources discovered during the ASCA Galactic Plane Survey (AGPS). Little is known about most of the AGPS sources, especially those that emit primarily in hard X-rays (2-10 keV) within the X-ray flux range from ~ 10<sup>-13</sup> to 10<sup>-11</sup> erg cm<sup>-2</sup> s<sup>-1</sup>. In ChIcAGO, the sub-arcsecond localization capabilities of Chandra have been combined with a detailed multi-wavelength follow-up program, with the ultimate goal of classifying the > 100 unidentified sources in the AGPS. Overall to date, 93 unidentified AGPS sources have been observed with Chandra as part of the ChIcAGO survey. A total of 253 X-ray point sources have been detected in these Chandra observations within 3 arcminutes of the original ASCA positions. The authors have identified infrared and optical counterparts to the majority of these sources, using both new observations and catalogs from existing Galactic plane surveys. X-ray and infrared population statistics for the X-ray point sources detected in the Chandra observations reveal that the primary populations of Galactic plane X-ray sources that emit in the X-ray flux range from ~ 10<sup>-13</sup> to 10<sup>-11</sup> erg cm<sup>-2</sup> s<sup>-1</sup> are active stellar coronae, massive stars with strong stellar winds that are possibly in colliding wind binaries, X-ray binaries, and magnetars. There is also another primary population that is still unidentified but, on the basis of its X-ray and infrared properties, likely comprises partly Galactic sources and partly active galactic nuclei. A total of 93 AGPS sources have been observed with Chandra as part of the ChIcAGO survey, of which 84 were imaged with ACIS-S and 9 were imaged with HRC-I. The ChIcAGO Chandra observations took place over a 3.5 yr period, from 2007 January to 2010 July. The Chandra exposure times ranged from ~ 1 to 10 ks. All the details of these Chandra observations are listed in Table 1 of the reference paper. The initial automated analysis of these Chandra observations was conducted using the ChIcAGO Multi-wavelength Analysis Pipeline (MAP), described in Section 2.2 of the reference paper. ChIcAGO MAP takes the ACIS-S or HRC-I Chandra observation of an AGPS source field and detects and analyzes all point sources within 3 arcminutes, equivalent to the largest likely position error, for the original AGPS source positions supplied by Sugizaki et al. (2001, ApJS, 134, 77). The authors then performed a more detailed X-ray analysis and counterpart study for those 74 sources with > 20 X-ray counts, as such sources are approximately within the original AGPS sources X-ray flux range (see Sections 3.2 and 3.3 of the reference paper). Infrared and optical follow-up were primarily performed on those ChIcAGO sources having > 20 X-ray counts. In order to determine which optical and infrared sources are counterparts to ChIcAGO sources, the authors used a technique similar to that described by Zhao et al. (2005, ApJS, 161, 429), using their Equation (11). If the separation between a ChIcAGO source's wavdetect position and its possible counterpart is less than the quadratic sum of their 3-sigma positional errors and the 3-sigma Chandra pointing error, then the X-ray and optical (or infrared) sources are likely to be associated. The 1-sigma positional errors for all sources in the 2MASS PSC and GLIMPSE catalogs are 0.1 arcseconds and 0.3 arcseconds, respectively. USNO B has an astrometric accuracy of < 0.25 arcseconds. The authors have assumed that the error distributions of the Chandra observations, Chandra pointing, and USNO B Catalog are all Gaussian for the purposes of identifying possible counterparts to the ChIcAGO sources. This table was created by the HEASARC in June 2014 based on electronic versions of Tables 1, 2 and 12 from the reference paper which were obtained from the ApJS website. This is a service provided by NASA HEASARC .

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RCW 49 Chandra X-Ray Point Source Catalog

This table contains the list of X-ray sources detected in a high-resolution X-ray imaging study of the stellar population in the Galactic massive star-forming region RCW 49 and its central OB association Westerlund 2. The authors obtained a ~ 40 ks X-ray image of a ~ 17' x 17' field using the Chandra X-Ray Observatory and deep NIR images using the Infrared Survey Facility in a concentric ~ 8.3' x 8.3' region. They detected 468 X-ray sources with a photometric significance >=1.0 and a 1% or less chance of being a background fluctuation, and identified optical, near-infrared (NIR), and Spitzer mid-infrared (MIR) counterparts for 379 of them. The unprecedented spatial resolution and sensitivity of the X-ray image, enhanced by optical and infrared imaging data, yielded the following results: (1) The central OB association Westerlund 2 is resolved for the first time in the X-ray band. X-ray emission is detected from all spectroscopically identified early-type stars in this region. (2) Most (~ 86%) X-ray sources with optical or infrared identifications are cluster members in comparison with a control field in the Galactic plane. (3) A loose constraint (2-5 kpc) for the distance to RCW 49 is derived from the mean X-ray luminosity of T Tauri stars. (4) The cluster X-ray population consists of low-mass pre-main-sequence and early-type stars as obtained from X-ray and NIR photometry. About 30 new OB star candidates are identified. (5) The authors estimate a cluster radius of 6' - 7' based on the X-ray surface number density profiles. (6) A large fraction (~ 90%) of cluster members are identified individually using complimentary X-ray and MIR excess emission. (7) The brightest five X-ray sources, two Wolf-Rayet stars and three O stars, have hard thermal spectra. The X-ray observation of RCW 49 was carried out using the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory from 2003 August 23 UT 18:20 to August 24 UT 4:54. Four imaging array (ACIS-I) chips covered a 17 by 17 arcminutes field centered at (R.A., Dec.) = (10h24m00.5s, -57d 45' 18") in the equinox J2000.0 for a 36.7 ks exposure. ACIS-I covers the 0.5 - 8.0 keV energy band with a spectral resolution of ~ 150 eV at 6 keV and a point-spread function (PSF) radius of ~ 0.5" within ~ 2' of the on-axis position, degrading to ~ 6" at a 10' off-axis angle. The data were taken with the very faint telemetry mode and the timed exposure CCD operation with a frame time of 3.2 s. Sources with photometric significance of larger than 2 were fitted with an absorbed thin thermal plasma model. The abundance was fixed to be 0.3 times the solar value. Fits lacking uncertainties, fits with large uncertainties, and fits with frozen parameters should be viewed merely as splines to the data to obtain rough estimates of the X-ray luminosities: the listed parameter values are considered unreliable in such cases. The authors also conducted NIR observations on 2004 December 25 and 28 using the Simultaneous three-color Infrared Imager for Unbiased Surveys (SIRIUS) mounted on the Cassegrain focus of the IRSF 1.4 m telescope at the South African Astronomical Observatory. SIRIUS is a NIR imager capable of obtaining simultaneous images in the J, H, and K<sub>s</sub> bands. The instrument is equipped with three HAWAII arrays of 1024 by 1024 pixels. The pixel scale of 0.45" is an excellent match with the on-axis spatial resolution of Chandra. The authors covered 8.3 by 8.3 arcminute fields at two positions, one aimed at RCW 49 (10h24m01.9s, -57d 45' 31") and the other at a control region. This table was created by the HEASARC in October 2007 based on the versions of Tables 1, 2, and 3 from the paper which were obtained from the electronic ApJ website. This is a service provided by NASA HEASARC .

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M 33 Chandra X-Ray Point Source Catalog

This database table contains a source list for three Chandra observations of the Local Group galaxy M 33. The observations were centered on the nucleus and on the star-forming region NGC 604. A total of 261 sources were detected in an area of about 0.2 square degrees down to a flux limit of 3 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, which corresponds to a luminosity of ~2 x 10<sup>34</sup> erg/s at a distance of 840 kpc. The luminosity functions of the X-ray sources observed in M 33 have been constructed and are consistent with those of other star-forming galaxies, taking into account background contamination. In addition, the combination of X-ray color analysis and the existence of "blue" optical counterparts strongly indicates that the X-ray point source population in M 33 consists of young objects. Above 3 x 10<sup>35</sup> erg/s, there are few X-ray sources in the locus of the X-ray hardness ratio diagram that is generally populated by low-mass X-ray binaries. Notice that each of the 261 X-ray sources in the source list has 3 entries in this table, one for each separate Chandra observation, making a total of 783 entries. The Chandra datasets from which this source list was compiled are available by <a href="/db-perl/W3Browse/w3query.pl?tablehead=name%3Dheasarc_chanmaster&sortvar=obsid&bparam_obsid=786%3B+1730%3B+2023">querying CHANMASTER for obsids 786, 1730, and 2023</a>. This table was created by the HEASARC in December 2005 based on the machine-readable version of Table 3 in the above-mentioned Grimm et al. (2005) reference obtained from the ApJ Electronic Edition website. This is a service provided by NASA HEASARC .

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NGC 2264 XMM-Newton X-Ray Point Source Catalog

This table contains (some of) the results from an X-ray imaging survey of the young cluster NGC 2264, carried out with the European Photon Imaging Cameras (EPIC) on board the XMM-Newton spacecraft. XMM-Newton EPIC observations were made separately of the northern and southern portions of NGC 2264 on 2001 March 20 and 2002 March 17 - 18, respectively. Details concerning the two pointings are summarized in Table 1 of the reference paper. The nominal integration time was 42 ks for both observations. The three EPIC cameras were operated in full window mode. To prevent contamination of the X-ray images by the XUV and EUV emission of the optically and UV-bright sources in the field of view, the thick filter was used, which imposes a strong cut-off in the response at the lower energies. The X-ray data are merged with extant optical and near-infrared photometry, spectral classifications, H-alpha emission strengths, and rotation periods to examine the interrelationships between coronal and chromospheric activity, rotation, stellar mass, and internal structure for a statistically significant sample of pre-main-sequence stars. Out of the 316 distinct point-like sources that were detected at >= 3-sigma levels in one or more of six EPIC images, a total of 300 distinct X-ray sources can be identified with optical or near-infrared counterparts. The sources are concentrated within three regions of the cluster: in the vicinity of S Mon, within the large emission/reflection nebulosity southwest of S Mon, and along the broad ridge of molecular gas that extends from the Cone Nebula to the NGC 2264 IRS 2 field. From the extinction-corrected color-magnitude diagram of the cluster, ages and masses for the optically identified X-ray sources are derived. A median age of ~ 2.5 Myr and an apparent age dispersion of ~ 5 Myr are suggested by pre-main-sequence evolutionary models. The X-ray luminosity of the detected sources appears well-correlated with bolometric luminosity, although there is considerable scatter in the relationship. Stellar mass contributes significantly to this dispersion, while isochronal age and rotation do not. X-ray luminosity and mass are well correlated such that L<sub>X</sub> ~ (M/M<sub>solar</sub>)<sup>1.5</sup>, which is similar to the relationship found within the younger Orion Nebula Cluster. No strong evidence is found for a correlation between E(H-K), the near-infrared color excess, and the fractional X-ray luminosity, which suggests that optically thick dust disks have little direct influence on the observed X-ray activity levels. Among the X-ray-detected weak-line T Tauri stars, the fractional X-ray luminosity, L<sub>X</sub>/L<sub>bol</sub>, is moderately well correlated with the fractional H-alpha luminosity, L<sub>H(alpha)</sub>/L<sub>bol</sub>, but only at the 2-sigma level of significance. The cumulative distribution functions for the X-ray luminosities of the X-ray-detected classical and weak-line T Tauri stars within the cluster are comparable, assuming the demarcation between the two classes is at an H-alpha equivalent width of 10 Angstroms. However, if the non-detections in X-rays for the entire sample of H-alpha emitters known within the cluster are taken into account, then the cumulative distribution functions of these two groups are clearly different, such that classical T Tauri stars are underdetected by at least a factor of 2 relative to the weak-line T Tauri stars. Examining a small subsample of X-ray-detected stars that are probable accretors based on the presence of strong H-alpha emission and near-infrared excess, the authors conclude that definitive non-accretors are ~ 1.6 times more X-ray luminous than their accreting counterparts. In agreement with earlier published findings for the Orion Nebula Cluster, the authors find a slight positive correlation (valid at the 2-sigma confidence level) between L<sub>X</sub>/L<sub>bol</sub> and the rotation period in NGC 2264 stars. The lack of a strong anti-correlation between X-ray activity and rotation period in the stellar population of NGC 2264 suggests that either the deeply convective T Tauri stars are rotationally saturated or that the physical mechanism responsible for generating magnetic fields in pre-main-sequence stars is distinct from the one that operates in evolved main-sequence stars. This table was created by the HEASARC in September 2007 based on the electronic version of Table 2 from the reference paper which was obtained from the electronic AJ site. This is a service provided by NASA HEASARC .

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Kvant TTM/COMIS X-Ray Source Catalog

A catalog of X-ray sources in the 2-30 keV energy band as observed by the TTM/COMIS (Coded Mask Imaging Spectrometer) telescope onboard the Mir-Kvant observatory is presented. Brief information about the 67 sources detected at a confidence level higher than 4 sigma between 1988 and 1998 is provided. X-ray properties and characteristic spectra of different types of sources are briefly described in the reference paper. This table was created by the HEASARC in April 2011 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/PAZh/26/355">CDS catalog J/PAZh/26/355</a> file table1.dat. This is a service provided by NASA HEASARC .

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eROSITA All-Sky Survey (First 6 Months) X-Ray (0.2-2.3 keV) Source Catalog

The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. The authors present catalogs of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky whose proprietary data rights lie with the German eROSITA Consortium. With nearly 930000 entries detected in the most sensitive 0.2-2.3keV energy range, the eRASS1 main catalog increases the number of known X-ray sources in the published literature by more than 60%, and provides a comprehensive inventory of all classes of X-ray celestial objects, covering a wide range of physical processes. A smaller catalog, <a href="/W3Browse/erosita/erass1hard.html">eRASS1HARD</a>, contains all X-ray sources detected in the 2.3-5 keV band with detection likelihood DET_LIKE > 12. The 5466 sources detected in the less sensitive but harder 2.3-5keV band is the result of the first true imaging survey of the entire sky above 2keV. The sources in the hard catalog (only the strongly associated ones) have been linked to eRASS1HARD in this catalog. The reference paper presents methods to identify and flag potential spurious sources in the catalogs, which were applied for this work, and the authors tested and validated the astrometric accuracy via cross-comparison with other X-ray and multi-wavelength catalogs. They show that the number counts of X-ray sources in eRASS1 are consistent with those derived over narrower fields by past X-ray surveys of a similar depth, and they explore the number counts variation as a function of the location in the sky. Adopting a uniform all-sky flux limit (at 50% completeness) of F<sub>(0.5-2keV)</sub> > 5 x 10<sup>-14</sup> erg/s/cm<sup>2</sup>, the authors estimate that the eROSITA all-sky survey resolves into individual sources about 20% of the cosmic X-ray background in the 1-2keV range. The catalogs form part of the first data release (DR1) of the SRG/eROSITA all-sky survey. Beyond the X-ray catalogs, DR1 contains all detected and calibrated event files, source products (light curves and spectra), and all-sky maps. The data files are linked to the table and also accessible from the <a href="/docs/srg/erosita/">HEASARC eROSITA</a> and <a href="https://erosita.mpe.mpg.de/dr1/">eROSITA-DE ERASS1</a> websites. The catalog uses the following designation for indicating the bands for the different measurement: <pre> Band Energy range (keV) 0,1 0.2 - 2.3 P1 0.2 - 0.5 P2 0.5 - 1.0 P3 1.0 - 2.0 P4 2.0 - 5.0 P5 5.0 - 8.0 P6 4.0 - 10.0 P7 5.1 - 6.1 P8 6.2 - 7.1 P9 7.2 - 8.2 S 0.5 - 2.0 </pre> This database table was ingested by the HEASARC in June 2024 and is based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/682/A34">CDS Catalog J/A+A/682/A34</a> file erass1-m.dat. In some cases, the HEASARC has altered the original field names, as per HEASARC conventions, and provides the original field names in square brackets. This is a service provided by NASA HEASARC .

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M 51 Chandra X-Ray Discrete Source Catalog

This table contains the results of two Chandra observations (separated by 1 year) of the population of X-ray sources in the spiral galaxy M 51 (NGC 5194 and NGC 5195). One hundred and thirteen X-ray sources have been detected in an 8.4' x 8.4'(20.4 x 20.4kpc) region, and 84 and 12 of them project within the disks of NGC 5194 and NGC 5195, respectively. Nine and 28 sources have luminosities exceeding 1 x 10<sup>39</sup> erg/s (ultraluminous X-ray sources or ULXs) and 1 x 10<sup>38</sup> erg/s in the 0.5 - 8 keV band, respectively, assuming that they are associated with M 51. The number of ULXs is much higher than found in most normal spiral and elliptical galaxies. Most of the X-ray sources and all seven of the ULXs in NGC 5194 are located in, or close to, a spiral arm, suggesting a connection with recent star formation. The Chandra observations of M 51 were performed on 2000 June 20 and 2001 June 23 with the ACIS instrument. The background was stable in both observations, and effective exposure times of 14.9 and 26.8ks were obtained for the observations in 2000 and 2001, respectively. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/601/735">CDS catalog J/ApJ/601/735</a> files table2.dat, table3.dat and table4.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

AllWISE Counterparts and Gaia Matches to ROSAT/2RXS X-Ray Sources

This table contains the 132,254 AllWISE counterparts and/or Gaia matches to 106,573 X-ray sources detected in the ROSAT 2RXS survey with Galactic latitude |b| > 15 degrees. These are the brightest X-ray sources in the sky, but their position uncertainties and the sparse multi-wavelength coverage until now rendered the identification of their counterparts a demanding task with uncertain results. New all-sky multi-wavelength surveys of sufficient depth, like AllWISE and Gaia, and a new Bayesian statistics-based algorithm, NWAY, allow us, for the first time, to provide reliable counterpart associations. NWAY extends previous distance- and sky density-based association methods and, using one or more priors (e.g. colors, magnitudes), weights the probability that sources from two or more catalogs are simultaneously associated on the basis of their observable characteristics. Here, counterparts have been determined using a Wide-field Infrared Survey Explorer (WISE) color-magnitude prior. A reference sample of 4,524 XMM/Chandra and Swift X-ray sources demonstrates a reliability of 94.7 per cent for 2RXS sources. Combining the results of this work and of the matching of XMM-Newton Slew Survey, Version 2 (XMMSL2) sources also reported in this study (the results of the latter are available as the HEASARC's database table NWAYAWGXMM) with Chandra-COSMOS data, the authors propose a new separation between stars and AGN in the X-ray/WISE flux-magnitude plane, that is valid over six orders of magnitude. The authors also release the NWAY code and its user manual. NWAY was extensively tested with XMM-COSMOS data. Using two different sets of priors, the authors find an agreement of 96 per cent and 99 per cent with published Likelihood Ratio methods. Their results were achieved faster and without any follow-up visual inspection. With the advent of deep and wide area surveys in X-rays (e.g. SRG/eROSITA, Athena/WFI) and radio (ASKAP/EMU, LOFAR, APERTIF, etc.), NWAY will provide a powerful and reliable counterpart identification tool. For all the available options, see the NWAY manual at <a href="https://github.com/JohannesBuchner/nway/raw/master/doc/nway-manual.pdf">https://github.com/JohannesBuchner/nway/raw/master/doc/nway-manual.pdf</a>. This table was created by the HEASARC in February 2018 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/473/4937">CDS catalog J/MNRAS/473/4937</a> file 2rxswg.dat. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

M 31 Central Field Chandra HRI X-Ray Point Source Catalog

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 .

restrictednotspecifiedApr 2025View details →
nasa20/100

Monoceros R2 Cloud Chandra X-Ray Point Source Catalog

The Monoceros R2 (Mon R2) Cloud X-Ray Point Source Catalog contains the results of the Chandra ACIS-I observation of the central region of this high-mass star-forming region (SFR), which lies at a distance of 830pc. With a deep exposure of ~ 100 ks, the authors detected 368 X-ray sources, ~80% of which were identified with near-infrared (NIR) counterparts. They systematically analyzed the spectra and time variability of most of the X-ray emitting sources and provide a comprehensive X-ray source catalog for the first time. Using the J-, H- and K-bands magnitudes of the NIR counterparts, they have estimated the evolutionary phase, classical T Tauri (CTT) stars and weak-lined T Tauri (WTT) stars, and the masses of the X-ray emitting sources, and have analyzed their X-ray properties as a function of age and mass. They found a marginal hint that CTT stars have a slightly higher temperature (2.4 keV) that of WTT stars (2.0 keV). A significant fraction of the high- and intermediate-mass sources have time variability and high plasma temperatures (2.7 keV) simailar to those of the low-mass stars (2.0 keV). This supports earlier proposals that high- and intermediate-mass young stellar objects emit X-rays via magnetic activity. The authors also found a significant difference in the spatial distribution between X-ray and NIR sources. This table was created by the HEASARC in January 2007 based on CDS table J/PASJ/55/635/table1.dat This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
nasa20/100

XMM-Newton COSMOS X-Ray Point Source Catalog

This table contains the XMM-Newton EPIC COSMOS X-ray point-like source catalog (XMM-COSMOS). The COSMOS survey is a multiwavelength survey aimed to study the evolution of galaxies, AGN and large scale structures. Within this survey, XMM-COSMOS is a powerful tool for detecting AGN and galaxy clusters. The XMM-COSMOS is a deep X-ray survey over the full 2 deg<sup>2</sup> of the COSMOS area. It consists of 55 XMM-Newton pointings for a total exposure of ~1.5 Ms with an average vignetting-corrected depth of 40 ks across the field of view and a sky coverage of 2.13 deg<sup>2</sup>. The analysis was performed using the XMM-SAS data analysis package in the 0.5-2 keV, 2-10 keV and 5-10 keV energy bands. Source detection has been performed using a maximum likelihood technique especially designed for raster scan surveys. The completeness of the catalog as well as log N-log S and source density maps have been calibrated using Monte Carlo simulations. This is the catalogue of point-like X-ray sources detected with the EPIC CCD cameras. The catalogs contains a total of 1887 unique sources detected in at least one band with likelihood parameter det_ml > 10. The survey, which shows unprecedented homogeneity, has a flux limit of ~1.7 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s, ~9.3 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s and ~1.3 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s over 90% of the area (1.92 deg<sup>2</sup>) in the 0.5-2 keV, 2-10 keV and 5-10 keV energy bands, respectively. This table was created by the HEASARC in April 2009 based on the electronic version of Table 3 from the paper which was obtained from the CDS (their catalog J/A+A/497/635 file catalog.dat). It was last updated in May 2010 to correct the source number for XMMU J100100.7+015947 to be XMMC 129, as indicated by SIMBAD. This is a service provided by NASA HEASARC .

restrictednotspecifiedApr 2025View details →
geo16/100

Biological characteristics of gene expression features in pancreatic cancer cell induced by proton and x-ray irradiation III

GEO Series GSE107442. Homo sapiens. 10 samples. Type: Expression profiling by array.

openGEO-OpenDec 2017View details →
geo16/100

The effect of aging on the transcriptional profile of female mice exposed to x-ray radiation

GEO Series GSE133451. Mus musculus. 20 samples. Type: Expression profiling by array.

openGEO-OpenJun 2021View details →
geo16/100

Biological characteristics of gene expression features in pancreatic cancer cell induced by proton and x-ray irradiation I

GEO Series GSE107440. Homo sapiens. 9 samples. Type: Expression profiling by array.

openGEO-OpenDec 2017View details →
geo16/100

Biological response to 2.5 Gy of X-rays in 3-dimensional skin model, Epi-200.

GEO Series GSE23807. Homo sapiens. 18 samples. Type: Expression profiling by array.

openGEO-OpenAug 2011View details →

ScienceDex guides

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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.

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Allen Brain Atlas

Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.

allen-brain-atlas
neuroscienceopenDocumentation, web resources, and API references are available online.
Last verified 2026-04-30Open record

Annotated Behaviour and Observability Dataset (ABODe)

ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.

abode-home-cage
behavioral-neuroscienceopenThe DataShare record exposes download links for annotations, documentation, license text, and the zipped per-snippet data directory.
Last verified 2026-04-30Open record

DANDI Archive for NWB datasets

DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.

dandi-nwb
electrophysiologyopenPublished Dandiset metadata and archive endpoints are available through the production DANDI API.
Last verified 2026-04-30Open record

International Brain Laboratory public data

The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.

ibl
behavioral-neuroscienceopenPublic sessions can be searched and loaded from the IBL public data server through ONE.
Last verified 2026-04-29Open record

OpenNeuro

OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.

openneuro
neuroscienceopenPublished datasets are available on demand over the internet.
Last verified 2026-04-29Open record

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Your academic CV and NIH biosketch

Make your CV in your school's format and your NIH biosketch from it, then download both as Word files.