- ID:
- ivo://nasa.heasarc/smcpscxmm
- Title:
- Small Magellanic Cloud XMM-Newton Point Source Catalog
- Short Name:
- SMCPSCXMM
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XMM-Newton survey of the Small Magellanic Cloud (SMC) yielded complete coverage of the bar and eastern wing in the 0.2-12.0 keV energy band. In addition to the main-field (5.58 deg<sup>2</sup>), available outer fields were included in the catalogue, yielding a total field area of 6.32 deg<sup>2</sup>. This catalog comprises 3,053 unique X-ray point sources and sources with moderate extent that have been reduced from 5,236 individual detections found in 100 observations between April 2000 and April 2010 (the details of these exposures are given in Table B.1 of the reference paper). For 927 sources, there were detections at multiple epochs, with some SMC fields observed up to 36 times. The detected sources have a median position uncertainty of 1.3 arcseconds (1 sigma) and limiting fluxes down to ~1 x 10<sup>-14</sup> erg/s/cm<sup>2</sup> in the 0.2-4.5 keV band, corresponding to X-ray luminosities of ~5 x 10<sup>33</sup> erg/s for sources located in the SMC. Sources have been classified using X-ray hardness ratios, X-ray variability, and their multi-wavelength properties. In their paper, the authors discuss the statistical properties of the detected X-ray sources, like the spatial distribution, X-ray color diagrams, luminosity functions, and time variability. They have identified 49 SMC high-mass X-ray binaries (HMXB), four super-soft X-ray sources (SSS), 34 foreground stars, and 72 active galactic nuclei (AGN) behind the SMC. In addition, they found candidates for SMC HMXBs (45) and faint SSSs (8) as well as AGN (2092) and galaxy clusters (13). Notice that X-ray sources with high extent (>40 arcseconds), e.g. supernova remnants and galaxy clusters, have been previously presented by Haberl et al. (2012, A&A, 545, A128) and are not included in this table. To investigate the spectral behavior of all sources, the authors used hardness ratios HR<sub>i</sub> (i = 1, 2, 3, 4), defined by HR<sub>i</sub> = (R<sub>i+1</sub> - R<sub>i</sub>)/(R<sub>i+1</sub> + R<sub>i</sub>), where R<sub>i</sub> is the count rate in energy band i as defined by: <pre> Band Energy Range 1 0.2-0.5 keV 2 0.5-1.0 keV 3 1.0-2.0 keV 4 2.0-4.5 keV 5 4.5-12. keV </pre> To increase statistics, the authors also calculated average HR_i<sub>s</sub>, combining all available instruments and observations. HR<sub>i</sub> is not given if both rates R<sub>i</sub> and R<sub>i+1</sub> are null or if the 1-sigma uncertainty of Delta(HR<sub>i</sub>) covers the complete HR interval from -1 to +1. To convert an individual count rate R<sub>i</sub> of an energy band i into a setup-independent, observed flux F<sub>i</sub>, the authors calculated energy conversion factors (ECFs) f<sub>i</sub> = R<sub>i</sub>/F<sub>i</sub> , as described in Sect. A.3 of the reference paper. For the calculation, they assumed a universal spectrum for all sources, described by a power-law model with a photon index of 1.7 and a photo-electric foreground absorption by the Galaxy of N<sub>H,Gal</sub> = 6 x 10<sup>20</sup> cm<sup>-2</sup> (average for the SMC main field in the H I map of Dickey & Lockman 1990, ARAA, 28, 215). In addition to the fluxes for each detection, the authors calculated flux upper limits F<sub>UL</sub> for each observation and source, if the source was observed but not detected in an individual observation. As for the initial source detection, they used the emldetect task to fit sources, but kept the source positions fixed at the master positions and accepted all detection likelihoods in order to get an upper limit for the flux. This table was created by the HEASARC in October 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/558/A3">CDS Catalog J/A+A/558/A3</a> file smc_src.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/sxdscat
- Title:
- Subaru/XMM-Newton Deep Survey X-Ray Source List
- Short Name:
- SXDSCAT
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the X-ray source catalog in the Subaru/XMM-Newton Deep Survey (SXDS). A continuous area of 1.14 deg<sup>2</sup> centered at R.A.= 02h 18m and Dec =- 05 degrees is mapped by seven pointings with XMM-Newton covering the 0.2 - 10 keV band. From the combined images of the EPIC pn and MOS cameras, the authors have detected 866, 1114, 645, and 136 sources with sensitivity limits of 6 x 10<sup>-16</sup>, 8 x 10<sup>-16</sup>, 3 x 10<sup>-15</sup>, and 5 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> in the 0.5 - 2, 0.5 - 4.5, 2 - 10, and 4.5 - 10 keV bands, respectively, with detection likelihood >=7 (corresponding to a confidence level of 99.91%). The catalog consists of 1245 sources in total, including 32 extended-source candidates. The averaged log N-log S relations are in good agreement with previous results, bridging the flux range between Chandra deep surveys and brighter surveys. The log N-log S relations show significant spatial variation among pointings on a scale of 0.2 deg<sup>2</sup>. Analyzing the autocorrelation function, the authors detect significant clustering signals from the 0.5 - 2 keV band sample, which can be fit with a power-law form (theta/theta<sub>c</sub>)<sup>(-0.8)</sup> with a correlation length of theta<sub>c</sub> of 5.9 (+1.0, -0.9) arcsec when the integral constraint term is included. In the 2 - 10 keV band, however, the clustering is not significant, with a 90% upper limit of theta<sub>c</sub> < 1.5 arcsec. This table was created by the HEASARC in November 2008 based on an electronic version of Table 2 of the reference paper obtained from the Astrophysical Journal website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/taurusxmm
- Title:
- Taurus Molecular Cloud XMM-Newton X-Ray Source Catalog
- Short Name:
- TAURUSXMM
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) surveys the most populated ~5 square degrees of the Taurus Molecular Cloud, using the XMM-Newton X-ray observatory to study the thermal structure, variability, and long-term evolution of hot plasma, to investigate the magnetic dynamo, and to search for new potential members of the association. The authors present overall correlations with fundamental stellar parameters that were derived from the previous literature. The present overview paper introduces the project and provides the basic results from the X-ray analysis of all sources detected in the XEST survey. Comprehensive tables in the published paper summarize the stellar properties of all the targets surveyed. The survey goes deeper than previous X-ray surveys of Taurus by about an order of magnitude and for the first time systematically accesses very faint and strongly absorbed TMC objects. The authors find a detection rate of 85% and 98% for classical and weak-line T Tauri stars (CTTS and WTTS), respectively, and identify about half of the surveyed protostars and brown dwarfs. Overall, 136 out of 169 surveyed stellar systems were detected. The authors describe an X-ray luminosity vs. mass correlation, discuss the distribution of X-ray-to-bolometric luminosity ratios, and show evidence for lower X-ray luminosities in CTTS compared to WTTS. The complete catalog of all X-ray sources (stellar and non-stellar) detected in the 28 XEST fields is presented in this table. The catalog provides X-ray coordinates, their uncertainties, X-ray count rates and their uncertainties, and X-ray hardness ratios for 2347 detected X-ray sources. If two XEST fields overlap, the same sources may have been identified twice, with different XEST IDs assigned, notice. This table was created by the HEASARC in July 2007 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/468/353">CDS Catalog J/A+A/468/353</a> file table14.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/upprscoxmm
- Title:
- Upper Sco XMM-Newton X-Ray Point Source Catalog
- Short Name:
- UPPRSCOXMM
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors studied the X-ray emission from young stars by analyzing the deep (a ~53 ks exposure centered at a J2000.0 RA and Dec of 16 14 00.0, -23 00 00 and a ~43 ks exposure at 15 56 25.0, -23 37 47) XMM-Newton observations of two regions of the Upper Scorpius (USco) subgroup of the Scorpius-Centaurus (Sco-Cen) association which is estimated to have an age of 5 Myr. Portions of the USco association were observed in the optical with the CTIO Curtis Schmidt telescope and the Danish 1.54m telescope. This table contains all the X-ray sources detected in the two XMM-Newton observations, as well as their near-IR counterparts from the 2MASS and DENIS catalogs, and their optical counterparts from the CTIO and Danish 1.54 m observations. Based on the near-infrared and optical photometry, 22 Upper Scorpius photometric members have been identified among the 224 detected X-ray sources. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/459/199">CDS catalog J/A+A/459/199</a> files tabled1.dat and table2.dat. 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:
- 02 May 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:
- 02 May 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/xmmt2flare
- Title:
- 2XMM Flares Detected from Tycho-2 Stars
- Short Name:
- XMMT2FLARE
- Date:
- 02 May 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 .
- ID:
- ivo://nasa.heasarc/xmmsdssgcs
- Title:
- 2XMMi/SDSS Galaxy Cluster Survey
- Short Name:
- XMMSDSSGCS
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have compiled a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton Serendipitous Source Catalog (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). In their paper, they present an analysis of the X-ray properties of this new sample with particular emphasis on the X-ray luminosity-temperature (L<sub>X</sub> - T) relation. The X-ray cluster candidates were selected from the 2XMMi-DR3 catalog in the footprint of the SDSS-DR7. The authors developed a finding algorithm to search for overdensities of galaxies at the positions of the X-ray cluster candidates in the photometric redshift space and to measure the redshifts of the clusters from the SDSS data. For optically confirmed clusters with good quality X-ray data, they derived the X-ray flux, luminosity, and temperature from proper spectral fits, while the X-ray flux for clusters with low-quality X-ray data was obtained from the 2XMMi-DR3 catalogue. The detection algorithm provides the photometric redshift of 530 galaxy clusters. Of these, 310 clusters have a spectroscopic redshift for at least one member galaxy. About 75 percent of the optically confirmed cluster sample are newly discovered X-ray clusters. Moreover, 301 systems are known as optically selected clusters in the literature while the remainder are new discoveries in X-ray and optical bands. The optically confirmed cluster sample spans a wide redshift range 0.03 to 0.70 (median z = 0.32). In this paper, they present the catalog of X-ray-selected galaxy groups and clusters from the 2XMMi/SDSS galaxy cluster survey. The catalog has two subsamples: (i) a cluster sample comprising 345 objects with their X-ray spectroscopic temperature and flux from the spectral fitting; (these objects are identified by having values for the table_sample parameter of 1 in this HEASARC implementation of the catalog) and (ii) a cluster sample consisting of 185 systems with their X-ray flux from the 2XMMi-DR3 catalog, because their X-ray data are insufficient for spectral fitting (these objects are identified by having values for the table_sample parameter of 2 herein). For each cluster, the catalog also provides the X-ray bolometric luminosity and the cluster mass at R<sub>500</sub> based on scaling relations and the position of the likely brightest cluster galaxy (BCG). The updated L<sub>X</sub> - T relation of the current sample with X-ray spectroscopic parameters is presented in the paper. The authors found the slope of the L<sub>X</sub> - T relation to be consistent with published ones. They see no evidence for evolution in the slope and intrinsic scatter of the L<sub>X</sub> - T relation with redshift when excluding the low-luminosity groups. This catalog of X-ray selected galaxy clusters and groups supersedes and subsumes the first release of the 2XMMi/SDSS Galaxy Cluster Survey, comprising 175 clusters of galaxies, which was presented in Takey et al. (2011, A&A, 534, A120). This table was created by the HEASARC in October 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/558/A75">CDS catalog J/A+A/558/A75</a> files table1.dat and table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmsdssgce
- Title:
- 2XMMi/SDSS Galaxy Cluster Survey Extension
- Short Name:
- XMMSDSSGCE
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from the analysis of a sample of 383 X-ray selected galaxy groups and clusters with spectroscopic redshift measurements (up to z ~ 0.79) from the 2XMMi/SDSS Galaxy Cluster Survey. The X-ray cluster candidates were selected as serendipitously detected sources from the 2XMMi-DR3 catalog that were located in the footprint of the Sloan Digital Sky Survey (SDSS-DR7). The cluster galaxies with available spectroscopic redshifts were selected from the SDSS-DR10. The authors developed an algorithm for identifying the cluster candidates that are associated with spectroscopically targeted luminous red galaxies and for constraining the cluster spectroscopic redshift. A cross-correlation of the constructed cluster sample with published optically selected cluster catalogs yielded 264 systems with available redshifts. The present redshift measurements (presented in reference paper III) are consistent with the published values. The current cluster sample extends the optically confirmed cluster sample from the authors' cluster survey by 67 objects. Moreover, it provides spectroscopic confirmation for 78 clusters among their published cluster sample, which previously had only photometric redshifts. Of the new cluster sample that comprises 67 systems, 55 objects are newly X-ray discovered clusters and 52 systems are sources newly discovered as galaxy clusters in optical and X-ray wavelengths. Based on the measured redshifts and the fluxes given in the 2XMMi-DR3 catalogue, the authors have estimated the X-ray luminosities and masses of the cluster sample. This table contains 145 entries, 67 of which are new (as of Paper III) optically confirmed clusters (marked by values of ref_source = 'Paper III') and 78 of which are clusters from Paper II which have now been spectroscopically confirmed (marked by values of ref_source = 'Paper II'). The tabular information on the 530 clusters that was presented in Paper II of this set of papers is available as the HEASARC <a href="/W3Browse/xmm-newton/xmmsdssgcs.html">XMMSDSSGCS table</a>). The following parameters were obtained from the current optical-band cluster detection algorithm: sdss_dr10_bcg_id, sdss_dr10_bcg_ra, sdss_dr10_bcg_dec, bcg_rmag, redshift, num_spect_members, phot_redshift, num_phot_members, and spatial_offset. This table was created by the HEASARC in July 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/564/A54">CDS catalog J/A+A/564/A54</a> file table1.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmao
- Title:
- XMM-Newton Accepted Targets
- Short Name:
- XMMAO
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains the current target list of the X-ray Multi-Mirror Newton (XMM-Newton) mission including those in (i) the routine calibration plan, (ii) the Guaranteed Time Observation (GTO) program, (iii) the triggered target candidates or ToOs accepted for the First through the Twentieth-Fourth Announcements of Opportunity (AO-1 through AO-24) programs, (iv) the AO-1 through AO-24 Guest Observer (GO) program targets with priority A or B, (v) the AO-1 through AO-19 GO program targets with priority C which have been observed, (vi) the AO-20 through AO-24 GO program targets with priority C, and (vii) the targets granted by agreement of the ESA Director of Science and the National Space Agency of Japan, following the loss of the original Astro-E spacecraft. For complete and authoritative information on the XMM-Newton mission, policies, and data archive, refer to the web pages of the European Space Agency's (ESA's) XMM-Newton Science Operations Center at <a href="http://xmm.esac.esa.int/">http://xmm.esac.esa.int/</a> and of NASA's XMM-Newton Guest Observer Facility at <a href="http://heasarc.gsfc.nasa.gov/docs/xmm/xmmgof.html">http://heasarc.gsfc.nasa.gov/docs/xmm/xmmgof.html</a> Notice that all priority C targets from AOs 1 through 19 which were never observed by XMM-Newton (and hence have expired) have been removed from this table. To check which targets have either already been observed by XMM-Newton or are on the short-term schedule to be observed in the next few weeks, users should examine the <a href="/db-perl/W3Browse/w3table.pl?tablehead=name%3Dxmmmaster&Action=More+Options">XMMMASTER</a> table which is also contained in Browse. To find out which targets are currently scheduled to be observed in the next three months, the user should check the XMM-Newton Advanced Plan at <a href="http://xmm.esac.esa.int/external/xmm_sched/advance_plan.shtml">http://xmm.esac.esa.int/external/xmm_sched/advance_plan.shtml</a> While abstracts are available for most proposals, there are a number of targets for which the HEASARC lacks the corresponding abstracts: e.g., the abstracts for AO-2 Guest Observer targets which have non-US PIs are not available. This database table was last updated by the HEASARC in December 2024, when AO-24's accepted targets were added. <p> AO-23's accepted targets were added in November 2023. <p> AO-22's accepted targets were added in November 2022. <p> AO-21's accepted targets were added and AO-19's unobserved priority C targets were removed in December 2021. <p> AO-20's accepted targets were added and AO-18's unobserved priority C targets were removed in December 2020. <p> AO-19's accepted targets were added and AO-17's unobserved priority C targets were removed in April 2020. <p> In June 2019, many duplicate entries were removed. <p> AO-18's accepted targets were added and AO-16's unobserved priority C targets were removed in November 2018. <p> AO-17's accepted targets were added and AO-15's unobserved priority C targets were removed in November 2017. <p> AO-16's accepted targets were added and AO-14's unobserved priority C targets were removed in December 2016. <p> AO-15's accepted targets were added and AO-13's unobserved priority C targets were removed in December 2015. <p> In August 2015, proposal titles were added. <p> AO-14's accepted targets were added and AO-12's unobserved priority C targets were removed in December 2014. <p> AO-13's accepted targets were added and AO-11's unobserved priority C targets were removed in December 2013. <p> AO-12's accepted targets were added and AO-10's unobserved priority C targets were removed in December 2012. <p> AO-11's accepted targets were added and AO-9's unobserved priority C targets were removed in December 2011. <p> AO-10's accepted targets were added and AO-8's unobserved priority C targets were removed in December 2010. <p> AO-9's accepted targets were added and AO-7's unobserved priority C targets were removed in January 2010. <p> AO-8's accepted targets were added and AO-6's unobserved priority C targets were removed in December 2008. <p> AO-7's accepted targets were added and AO-5's unobserved priority C targets were removed in January 2008. <p> AO-6's accepted targets were added in January 2007, and, in November 2006, an effort was made to remove most of the unobserved priority C targets from previous AOs. This is a service provided by NASA HEASARC .