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17661. XMM-Newton survey of the ELAIS-S1 field. II.
ID:
ivo://CDS.VizieR/J/A+A/488/417
Title:
XMM-Newton survey of the ELAIS-S1 field. II.
Short Name:
J/A+A/488/417
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the optical identifications and a multi-band catalogue of a sample of 478 X-ray sources detected in the XMM-Newton and Chandra surveys of the central 0.6deg^2^ of the ELAIS-S1 field. The most likely optical/infrared counterpart of each X-ray source was identified using the chance coincidence probability in the R and IRAC 3.6 micron bands.This method was complemented by the precise positions obtained through Chandra observations. We were able to associate a counterpart to each X-ray source in the catalogue. Approximately 94% of them are detected in the R band, while the remaining are blank fields in the optical down to R~24.5, but have a near-infrared counterpart detected by IRAC within 6 arcsec from the XMM-Newton centroid. The multi-band catalogue, produced using the positions of the identified optical counterparts, contains photometry in ten photometric bands, from B to the MIPS 24 micron band. The spectroscopic follow-up allowed us to determine the redshift and classification for 237 sources (~50% of the sample) brighter than R=24. The spectroscopic redshifts were complemented by reliable photometric redshifts for 68 sources. We classified 47% of the sources with spectroscopic redshift as broad-line active galactic nuclei (BL AGNs) with z=0.1-3.5, while sources without broad-lines (NOT BL AGNs) are about 46% of the spectroscopic sample and are found up to z=2.6. The remaining fraction is represented by extended X-ray sources and stars. We spectroscopically identified 11 type 2 QSOs among the sources with X/O>8, with redshift between 0.9 and 2.6, high 2-10keV luminosity (logLx>=43.8erg/s) and hard X-ray colors suggesting large absorbing columns at the rest frame (logN_H_ up to 23.6cm^-2^). BL AGNs show on average blue optical-to-near-infrared colors, softer X-ray colors and X-ray-to-optical colors typical of optically selected AGNs. Conversely, narrow-line sources show redder optical colors, harder X-ray flux ratio and span a wider range of X-ray-to-optical colors. On average the Spectral Energy Distributions (SEDs) of high-luminosity BL AGNs resemble the power-law typical of unobscured AGNs. The SEDs of NOT BLAGNs are dominated by the galaxy emission in the optical/near-infrared, and show a rise in the mid-infrared which suggests the presence of an obscured active nucleus. We study the infrared-to-optical colors and near-infrared SEDs to infer the properties of the AGN host galaxies.
17662. XMM-Newton survey of two Upper Scorpius regions
ID:
ivo://CDS.VizieR/J/A+A/459/199
Title:
XMM-Newton survey of two Upper Scorpius regions
Short Name:
J/A+A/459/199
Date:
21 Oct 2021
Publisher:
CDS
Description:
We studied X-ray emission from young stars by analyzing the deep XMM-Newton observations of two regions of the Upper Scorpius association with an age of 5Myr. Based on near infrared and optical photometry we identified 22 Upper Scorpius photometric members among the 224 detected X-ray sources. We derived coronal properties of Upper Scorpius stars by performing X-ray spectral and timing analyses. The study of four strong and isolated stellar flares allowed us to derive the length of the flaring loops.
17663. XMM-Newton Survey Science Center Survey of the Galactic Plane
ID:
ivo://nasa.heasarc/xmmsscgps
Title:
XMM-Newton Survey Science Center Survey of the Galactic Plane
Short Name:
XMMSSCGPS
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood, the population of low-to-medium X-ray luminosity (L<sub>X</sub> = 10<sup>27</sup> - 10<sup>34</sup> erg/s) sources remains much less studied, our knowledge being mostly based on the observation of local members. The advent of wide-field and high-sensitivity X-ray telescopes such as XMM-Newton now offers the opportunity to observe this low-to-medium L<sub>X</sub> population at large distances. This study reports the results of a Galactic plane survey conducted by the XMM-Newton Survey Science Centre (SSC). Beyond its astrophysical goals, this survey aims at gathering a representative sample of identified X-ray sources at low latitude that can be used later on to statistically identify the rest of the serendipitous sources discovered in the Milky Way. The survey is based on 26 XMM-Newton observations, obtained at |b| < 20 degrees, distributed over a large range in Galactic longitudes and covering a summed area of 4 deg<sup>2</sup>. The flux limit of this survey is 2 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s in the soft (0.5 - 2 keV) band and 1 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s in the hard (2 - 1 2keV) band. A total of 1319 individual X-ray sources have been detected. Using optical follow-up observations supplemented by cross-correlation with a large range of multi-wavelength archival catalogs, the authors identify 316 X-ray sources. This constitutes the largest group of spectroscopically identified low-latitude X-ray sources at this flux level. The majority of the identified X-ray sources are active coronae with spectral types in the range A to M at maximum distances of ~1 kpc. The number of identified active stars increases towards late spectral types, reaching a maximum at K. Using infrared colors, the authors classify 18% of the stars as giants. The observed distributions of F<sub>X</sub>/F<sub>V</sub>, X-ray and infrared colors indicates that their sample is dominated by a young (100 Myr) to intermediate (600 Myr) age population with a small contribution of close main-sequence or evolved binaries. The authors find other interesting objects such as cataclysmic variables (d ~ 0.6 - 2 kpc), low-luminosity high-mass stars (likely belonging to the class of Gamma-Cas-like systems, d ~ 1.5 - 7 kpc), T Tauri and Herbig-Ae stars. A handful of extragalactic sources located in the highest Galactic latitude fields could be optically identified. For the 20 fields observed with the EPIC pn camera, the authors have constructed log N(>S) - log S curves in the soft and hard bands. In the soft band, the majority of the sources are positively identified with active coronae and the fraction of stars increases by about one order of magnitude from b = 60 degrees to b = 0 degrees at an X-ray flux of 2 x 10<sup>-14</sup> erg/cm<sup>2</sup>/s. The hard band is dominated by extragalactic sources, but there is a small contribution from a hard Galactic population formed by CVs, HMXB candidates or Gamma-Cas-like systems and by some active coronal stars that are also detected in the soft band. At b = 0 degrees, the surface density of hard sources brighter than 1 x 10<sup>-13</sup> erg/cm<sup>2</sup>/s steeply increases by one order of magnitude from l = 20 degrees to the Galactic center region (l = 0.9 degrees). This HEASARC table contains 739 X-ray sources detected in the 26 different fields observed in this study and listed in Tables 8 - 33, inclusive, of the reference paper. These 739 sources have the best XMM quality, i.e. the summary flag sum_flag which contains information about flags set automatically and manually for a given source is zero, meaning that there are no negative flags for the source detection, have either a 2MASS, USNO, GSC, or SDSS counterpart, whatever the probability of identification is, or have some information via SIMBAD or the authors own imaging or spectroscopic observations. For each X-ray source, its X-ray parameters are summarized, listing the pn count rates, and information on optical and infrared counterparts is provided. The properties of the 26 target fields are given in Table 1 of the reference paper, along with the breakdown of source classes in each field. This table was created by the HEASARC in May 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/553/A12">CDS Catalog J/A+A/553/A12</a>, the 26 files table8.dat to table33.dat, inclusive. This is a service provided by NASA HEASARC .
17664. XMM-Newton Wide Angle Survey
ID:
ivo://nasa.heasarc/xwas
Title:
XMM-Newton Wide Angle Survey
Short Name:
XWAS
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
This table contains results from the XMM-Newton Wide Angle Survey (XWAS), viz., a new catalog of almost a thousand X-ray sources that have been spectroscopically identified through optical observations. The sources lie in high-galactic latitude (|b| > 20 degrees) XMM-Newton fields mainly in the southern hemisphere. A sample of X-ray sources detected in 68 XMM-Newton pointed observations was selected for optical multi-fiber spectroscopy. Optical counterparts and corresponding photometry of the X-ray sources were obtained from the SuperCOSMOS Sky Survey. Candidates for spectroscopy were initially selected with magnitudes down to R ~ 21, with preference for X-ray sources having a flux F<sub>0.5-4.5keV</sub> >= 10<sup>-14</sup> erg/s/cm<sup>2</sup>. Optical spectroscopic observations were made using the Two Degree Field of the Anglo-Australian Telescope, and the resulting spectra were classified based on optical emission lines. The authors have identified through optical spectroscopy 940 X-ray sources over a solid angle Omega ~ 11.8 deg<sup>2</sup> of the sky. Source populations in their sample can be summarized as 65% broad-line active galactic nuclei (BLAGN), 16% narrow emission-line galaxies (NELGs), 6% absorption-line galaxies (ALGs) and 13% stars. An active nucleus is also likely to be present in the large majority of the X-ray sources spectroscopically classified as NELGs or ALGs. Optical images are available for all of the XWAS fields in the SuperCOSMOS Sky Survey (Hambly et al., 2001, MNRAS, 326, 1279). This table was created by the HEASARC in May 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/557/A123">CDS Catalog J/A+A/557/A123</a> file xwas_cat.dat. This is a service provided by NASA HEASARC .
17665. XMM-Newton Wide Angle Survey (XWAS)
ID:
ivo://CDS.VizieR/J/A+A/557/A123
Title:
XMM-Newton Wide Angle Survey (XWAS)
Short Name:
J/A+A/557/A123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the XMM-Newton Wide Angle Survey (XWAS), a new catalogue of almost a thousand X-ray sources spectroscopically identified through optical observations. Sources lie in high-galactic latitude (|b|>20deg) XMM-Newton fields mainly in the southern hemisphere. A sample of X-ray sources detected in 68 XMM-Newton pointed observations was selected for optical multi-fibre spectroscopy. Optical counterparts and corresponding photometry of the X-ray sources were obtained from the SuperCOSMOS Sky Survey. Candidates for spectroscopy were initially selected with magnitudes down to R~21, with preference for X-ray sources having a flux F_0.5-4.5keV_>=10^-14^erg/s/cm2. Optical spectroscopic observations were made using the Two Degree Field of the Anglo Australian Telescope, and the resulting spectra were classified based on optical emission lines. We have identified through optical spectroscopy 940 X-ray sources over {Omega}~11.8deg^2^ of the sky. Source populations in our sample can be summarised as 65% broad line active galactic nuclei (BLAGN), 16% narrow emission line galaxies (NELGs), 6% absorption line galaxies (ALGs) and 13% stars. An active nucleus is also likely to be present in the large majority of the X-ray sources spectroscopically classified as NELGs or ALGs.
17666. XMM-Newton wide-field survey in COSMOS field
ID:
ivo://CDS.VizieR/J/A+A/497/635
Title:
XMM-Newton wide-field survey in COSMOS field
Short Name:
J/A+A/497/635
Date:
21 Oct 2021
Publisher:
CDS
Description:
The COSMOS survey is a multiwavelength survey aimed to study the evolution of galaxies, AGN and large scale structures. Within this survey XMM-COSMOS a powerful tool to detect AGN and galaxy clusters. The XMM-COSMOS is a deep X-ray survey over the full 2deg^2^ of the COSMOS area. It consists of 55 XMM-Newton pointings for a total exposure of ~1.5Ms with an average vignetting-corrected depth of 40ks across the field of view and a sky coverage of 2.13deg^2^. The analysis was performed using the XMM-SAS data analysis package in the 0.5-2keV, 2-10keV and 5-10keV energy bands. Source detection has been performed using a maximum likelihood technique especially designed for raster scan surveys. The completeness of the catalogue as well as logN-logS and source density maps have been calibrated using Monte Carlo simulations.
17667. XMM-Newton XAssist Source List
ID:
ivo://nasa.heasarc/xmmxassist
Title:
XMM-Newton XAssist Source List
Short Name:
XMM/XAssist
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
This database table contains the latest XMM-Newton XAssist source list. XAssist is a NASA-funded project for the automation of X-ray astrophysics, with emphasis on galaxies. It is capable of data reprocessing, source detection, and preliminary spatial, temporal, and spectral analysis for all sources with sufficient counts. The bulk of the system is written in Python, which in turn drives underlying software to process the XMM-Newton data. Pipelines running on XMM-Newton observations of galaxies have generated the source list which comprises this HEASARC table. The pipeline also includes fields requested by users for various projects, most notably observations of a sample of quasars and several deep field observations have been processed. Note that the pipline processing is completely automated; therefore, users should visually inspect the results of any queries. This table was first created by the HEASARC in July 2005 based on the XMM source list available at the XAssist website. In December 2012, the HEASARC switched over to using the "pipeline5" XMM source list. It is updated on a weekly basis when and if the XAssist source list file at <a href="https://asd.gsfc.nasa.gov/xassist/pipeline5/xmm/master_srclist.csv">https://asd.gsfc.nasa.gov/xassist/pipeline5/xmm/master_srclist.csv</a> is updated. This is a service provided by NASA HEASARC .
17668. XMM-Newton 2XMMi-DR3 Selected Source Classifications Catalog
ID:
ivo://nasa.heasarc/xmmssclwbs
Title:
XMM-Newton 2XMMi-DR3 Selected Source Classifications Catalog
Short Name:
XMMSSCLWBS
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
The authors have carried out a classification of 4,330 X-ray sources in the 2XMMi-DR3 catalog. The sources were selected under the requirement of being a point source with multiple XMM-Newton observations and at least one detection with a signal-to-noise ratio larger than 20. For about one-third of the sources, the authors are able to obtain reliable source types from the literature. They mostly correspond to various types of stars (611), active galactic nuclei (AGNs, 753), and compact object systems (138) containing white dwarfs, neutron stars, and stellar-mass black holes. The authors find that about 99% of stars can be separated from other source types based on their low X-ray-to-IR flux ratios and frequent X-ray flares. AGNs have remarkably similar X-ray spectra, with the power-law photon index centered around 1.91 +/- 0.31, and their 0.2-4.5 keV flux long-term variation factors have a median of 1.48, with 98.5% being less than 10. In contrast, 70% of compact object systems can be very soft or hard, highly variable in X-rays, and/or have very large X-ray-to-IR flux ratios, separating them from AGNs. Using these results, the authors derive a source type classification scheme to classify the other sources and find 644 candidate stars, 1,376 candidate AGNs, and 202 candidate compact object systems, whose false identification probabilities are estimated to be about 1%, 3%, and 18%, respectively. There are still 320 sources associated with nearby galaxies and 151 in the Galactic plane, which the authors expect to be mostly compact object systems or background AGNs. There are also 100 candidate ultraluminous X-ray sources. They are found to be much less variable than other accreting compact objects. This table was created by the HEASARC in October 2012 based on an electronic version of Table 4 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
17669. XMM-Newton 2XMMi-DR3 Selected Source Detections Catalog
ID:
ivo://nasa.heasarc/xmmssclwbd
Title:
XMM-Newton 2XMMi-DR3 Selected Source Detections Catalog
Short Name:
XMMSSCLWBD
Date:
01 Nov 2024
Publisher:
NASA/GSFC HEASARC
Description:
The authors have carried out a classification of 4,330 X-ray sources in the 2XMMi-DR3 catalog. The sources were selected under the requirement of being a point source with multiple XMM-Newton observations and at least one detection with a signal-to-noise ratio larger than 20. For about one-third of the sources, the authors are able to obtain reliable source types from the literature. They mostly correspond to various types of stars (611), active galactic nuclei (AGNs, 753), and compact object systems (138) containing white dwarfs, neutron stars, and stellar-mass black holes. The authors find that about 99% of stars can be separated from other source types based on their low X-ray-to-IR flux ratios and frequent X-ray flares. AGNs have remarkably similar X-ray spectra, with the power-law photon index centered around 1.91 +/- 0.31, and their 0.2-4.5 keV flux long-term variation factors have a median of 1.48, with 98.5% being less than 10. In contrast, 70% of compact object systems can be very soft or hard, highly variable in X-rays, and/or have very large X-ray-to-IR flux ratios, separating them from AGNs. Using these results, the authors derive a source type classification scheme to classify the other sources and find 644 candidate stars, 1,376 candidate AGNs, and 202 candidate compact object systems, whose false identification probabilities are estimated to be about 1%, 3%, and 18%, respectively. There are still 320 sources associated with nearby galaxies and 151 in the Galactic plane, which the authors expect to be mostly compact object systems or background AGNs. There are also 100 candidate ultraluminous X-ray sources. They are found to be much less variable than other accreting compact objects. This table contains the list of 19,637 detections of the 4,330 unique X-ray sources which comprise the authors' sample. The list of 4,330 unique X-ray sources and their classifications is also available as the HEASARC XMMSSCLWBS table. This table was created by the HEASARC in October 2012 based on an electronic version of Table 3 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
17670. XMM-Newton X-ray sources in NGC 6553
ID:
ivo://CDS.VizieR/J/ApJ/738/129
Title:
XMM-Newton X-ray sources in NGC 6553
Short Name:
J/ApJ/738/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper reports the search for quiescent low-mass X-ray binaries (qLMXBs) in the globular cluster (GC) NGC 6553 using an XMM-Newton observation designed specifically for that purpose. We spectrally identify one candidate qLMXB in the core of the cluster, based on the consistency of the spectrum with a neutron star H-atmosphere model at the distance of NGC 6553. Specifically, the best-fit radius found using the three XMM European Photon Imaging Camera spectra is R_NS_=6.3^+2.3^_-0.8_ km (for M_NS_=1.4 M_{sun}_) and the best-fit temperature is kT_eff_=136^+21^_-34_ eV. Both physical parameters are in accordance with typical values of previously identified qLMXBs in GC and in the field, i.e., R_NS_~5-20 km and kT_eff_=50-150 eV. A power-law (PL) component with a photon index {Gamma}=2.1^+0.5^_-0.8_ is also required for the spectral fit and contributes ~33% of the total flux of the X-ray source. A detailed analysis supports the hypothesis that the PL component originates from nearby sources in the core, unresolved with XMM. The analysis of an archived Chandra observation provides marginal additional support to the stated hypothesis. Finally, a catalog of all the sources detected within the XMM field of view is presented here.

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