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851. 2XMMi/SDSS Galaxy Cluster Survey. II.
ID:
ivo://CDS.VizieR/J/A+A/558/A75
Title:
2XMMi/SDSS Galaxy Cluster Survey. II.
Short Name:
J/A+A/558/A75
Date:
21 Oct 2021
Publisher:
CDS
Description:
We compile a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton serendipitous source catalogue (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). The X-ray cluster candidates were selected from the 2XMMi-DR3 catalogue in the footprint of the SDSS-DR7. We 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. 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 0.03-0.70 (median z=0.32). In this paper, we present the catalogue of X-ray-selected galaxy groups and clusters from the 2XMMi/SDSS galaxy cluster survey. The catalogue has two subsamples: (i) a cluster sample comprising 345 objects with their X-ray spectroscopic temperature and flux from the spectral fitting, and (ii) a cluster sample consisting of 185 systems with their X-ray flux from the 2XMMi-DR3 catalogue, because their X-ray data are insufficient for spectral fitting. The updated L_X_-T relation of the current sample with X-ray spectroscopic parameters is presented. We see no evidence for evolution in the slope and intrinsic scatter of the L_X_-T relation with redshift when excluding the low-luminosity groups
852. XMM-LSS field. New XMM-Newton point-source cat.
ID:
ivo://CDS.VizieR/J/MNRAS/478/2132
Title:
XMM-LSS field. New XMM-Newton point-source cat.
Short Name:
J/MNRAS/478/2132
Date:
08 Feb 2022 13:36:34
Publisher:
CDS
Description:
We present an X-ray point-source catalogue from the XMM-Large Scale Structure (XMM-LSS) survey region, one of the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS) fields. We target the XMM-LSS region with 1.3Ms of new XMM-Newton AO-15 observations, transforming the archival X-ray coverage in this region into a 5.3deg^2^ contiguous field with uniform X-ray coverage totaling 2.7Ms of flare-filtered exposure, with a 46ks median PN exposure time. We provide an X-ray catalogue of 5242 sources detected in the soft (0.5-2keV), hard (2-10keV), and/or full (0.5-10keV) bands with a 1 per cent expected spurious fraction determined from simulations. A total of 2381 new X-ray sources are detected compared to previous source catalogues in the same area. Our survey has flux limits of 1.7x10^-15^, 1.3x10^-14^, and 6.5x10^-15^erg/cm^2^/s over 90 per cent of its area in the soft, hard, and full bands, respectively, which is comparable to those of the XMM-COSMOS survey. We identify multiwavelength counterpart candidates for 99.9 per cent of the X-ray sources, of which 93 per cent are considered as reliable based on their matching likelihood ratios. The reliabilities of these high-likelihood-ratio counterparts are further confirmed to be ~=97 per cent reliable based on deep Chandra coverage over ~=5 per cent of the XMM-LSS region. Results of multiwavelength identifications are also included in the source catalogue, along with basic optical-to-infrared photometry and spectroscopic redshifts from publicly available surveys. We compute photometric redshifts for X-ray sources in 4.5 deg^2^ of our field where forced-aperture multiband photometry is available; >70 per cent of the X-ray sources in this subfield have either spectroscopic or high-quality photometric redshifts.
853. XMM-Newton serendipitous survey. IV
ID:
ivo://CDS.VizieR/J/A+A/476/1191
Title:
XMM-Newton serendipitous survey. IV
Short Name:
J/A+A/476/1191
Date:
21 Oct 2021
Publisher:
CDS
Description:
X-ray sources at intermediate fluxes (a few x10^-14^erg/cm^2^/s) with a sky density of ~100deg^-2^ are responsible for a significant fraction of the cosmic X-ray background at various energies below 10keV. The aim of this paper is to provide an unbiased and quantitative description of the X-ray source population at these fluxes and in various X-ray energy bands. We present the XMM-Newton Medium sensitivity Survey (XMS), including a total of 318 X-ray sources found among the serendipitous content of 25 XMM-Newton target fields. The XMS comprises four largely overlapping source samples selected at soft (0.5-2keV), intermediate (0.5-4.5keV), hard (2-10keV) and ultra-hard (4.5-7.5keV) bands, the first three of them being flux-limited.
854. XMM-Newton Slew Survey in 2-10keV
ID:
ivo://CDS.VizieR/J/A+A/548/A99
Title:
XMM-Newton Slew Survey in 2-10keV
Short Name:
J/A+A/548/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
The on-going XMM-Newton Slew Survey (XSS) provides coverage of a significant fraction of the sky in a broad X-ray bandpass. Although shallow by contemporary standards, in the "classical" 2-10keV band of X-ray astronomy, the XSS provides significantly better sensitivity than any currently available all-sky survey. We investigate the source content of the XSS, focussing on detections in the hard 2-10keV band down to a very low threshold (>=4counts net of background). At the faint end, the survey reaches a flux sensitivity of roughly 3x10^-12^erg/cm^2^/s (2-10keV). Our starting point was a sample of 487 sources detected in the XSS (up to and including release XMMSL1d2) at high galactic latitude in the hard band. Through cross-correlation with published source catalogues from surveys spanning the electromagnetic spectrum from radio through to gamma-rays, we find that 45% of the sources have likely identifications with normal/active galaxies. A further 18% are associated with other classes of X-ray object (nearby coronally active stars, accreting binaries, clusters of galaxies), leaving 37% of the XSS sources with no current identification. We go on to define an XSS extragalactic sample comprised of 219 galaxies and active galaxies selected in the XSS hard band. We investigate the properties of this extragalactic sample including its X-ray logN-logS distribution. We find that in the low-count limit, the XSS is, as expected, strongly affected by Eddington bias. There is also a very strong bias in the XSS against the detection of extended sources, most notably clusters of galaxies. A significant fraction of the detections at and around the low-count limit may be spurious. Nevertheless, it is possible to use the XSS to extract a reasonably robust sample of extragalactic sources, excluding galaxy clusters. The differential logN-logS relation of these extragalactic sources matches very well to the HEAO-1 A2 all-sky survey measurements at bright fluxes and to the 2XMM source counts at the faint end. The substantial sky coverage afforded by the XSS makes this survey a valuable resource for studying X-ray bright source samples, including those selected specifically in the hard 2-10keV band.
855. XMMOMCDFS catalogue
ID:
ivo://CDS.VizieR/J/A+A/574/A49
Title:
XMMOMCDFS catalogue
Short Name:
J/A+A/574/A49
Date:
21 Oct 2021
Publisher:
CDS
Description:
The XMM-Newton X-ray observatory has performed repeated observations of the CDFS in 33 epochs (2001-2010) through the XMM-CDFS Deep Survey. During the X-ray observations, XMM-OM targeted the central 17x17arcmin^2^ region of the X-ray field of view, providing simultaneous optical/UV coverage of the CDFS. The resulting set of data can be taken into account to build an XMM-OM catalogue of the CDFS, filling the UV spectral coverage between the optical surveys and GALEX observations. We present the UV catalogue of the XMM-CDFS Deep Survey. Its main purpose is to provide complementary UV average photometric measurements of known optical/UV sources in the CDFS, taking advantage of the unique characteristics of the survey. The data reduction is intended also to improve the standard source detection on individual observations, by cataloguing faint sources through the stacking of their exposure images. We reprocessed the XMM-OM data of the survey and we stacked the exposures from consecutive observations using the standard SAS tools to process the data obtained during single observations. Average measurements of detections with SAS good quality flags from individual observations and from stacked images have been joined to compile the catalogue. Sources have been validated through the cross-identification within the EIS and COMBO-17 surveys. Photometric data of 1129 CDFS sources are provided into the catalogue, and optical/UV/X-ray photometric and spectroscopic information from other surveys are also included. The stacking extends the detection limits by ~1 mag in the three UV bands, contributing 30% of the catalogued UV sources. The comparison with the available measurements in similar spectral bands confirms the validity of the XMM-OM calibration. The combined COMBO-17/X-ray classification of the "intermediate" sources (e.g. optically diluted and/or X-ray absorbed AGN) is also discussed.
856. X-ray emitters in the Groth-Westphal strip
ID:
ivo://CDS.VizieR/J/ApJ/706/810
Title:
X-ray emitters in the Groth-Westphal strip
Short Name:
J/ApJ/706/810
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Groth field is one of the sky regions that will be targeted by the OSIRIS Tunable Filter Emission Line Object survey in the optical 820nm and 920nm atmospheric windows. In the present paper, public Chandra X-ray data with total exposure time of 200ks are analyzed and combined with optical broadband data of the Groth field, in order to study a set of optical structural parameters of the X-ray emitters and its relation with X-ray properties. To this aim, we processed the raw, public X-ray data using the Chandra Interactive Analysis of Observations, and determined and analyzed different structural parameters, in order to produce a morphological classification of X-ray sources. We present the morphology of 340 X-ray emitters with optical counterpart detected. Objects have been classified by X-ray type using a diagnostic diagram relating X-ray-to-optical ratio (X/O) to hardness ratio. We did not find any clear correlation between X-ray and morphological types. We analyzed the angular clustering of X-ray sources with optical counterpart using two-point correlation functions. A significant positive angular clustering was obtained from a preliminary analysis of four subsamples of the X-ray sources catalog. The clustering signal of the optically extended counterparts is similar to that of strongly clustered populations like red and very red galaxies, suggesting that the environment plays an important role in active galactic nuclei phenomena. Finally, we combined optical structural parameters with other X-ray and optical properties, and we confirmed an anticorrelation between the X/O ratio and the Abraham concentration index, which might suggest that early-type galaxies have lower Eddington rates than those of late-type galaxies.
857. X-ray emitting normal galaxies from BMW-HRI
ID:
ivo://CDS.VizieR/J/A+A/435/799
Title:
X-ray emitting normal galaxies from BMW-HRI
Short Name:
J/A+A/435/799
Date:
21 Oct 2021
Publisher:
CDS
Description:
We obtained a sample of 143 normal galaxies with X-ray luminosity in the range 10^38^-10^43^erg/s from the cross-correlation of the ROSAT HRI Brera Multi-scale Wavelet (BMW-HRI) Catalogue with the Lyon-Meudon Extragalactic Database (LEDA). We find that the average X-ray properties of this sample are in good agreement with those of other samples of galaxies in the literature. We selected a complete flux limited serendipitous sample of 32 galaxies from which we derived the logN-logS distribution of normal galaxies in the flux range 1.1-110x10^-14^erg/cm^2^/s. The resulting distribution is consistent with the Euclidean -1.5 slope. Comparisons with other samples, such as the Extended Medium Sensitivity Survey, the ROSAT All Sky Survey, the XMM-Newton/2dF survey, and the Chandra Deep Field Survey indicate that the logN-logS distribution of normal galaxies is consistent with a Euclidean slope over a flux range of about 6 decades. Description:
858. X-ray ETGs properties in the Chandra COSMOS survey
ID:
ivo://CDS.VizieR/J/ApJ/790/16
Title:
X-ray ETGs properties in the Chandra COSMOS survey
Short Name:
J/ApJ/790/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study a sample of 69 X-ray detected early-type galaxies (ETGs), selected from the Chandra COSMOS survey, to explore the relation between the X-ray luminosity of hot gaseous halos (L_X, gas_) and the integrated stellar luminosity (L_K_) of the galaxies, in a range of redshift extending out to z = 1.5. In the local universe, a tight, steep relationship has been established between these two quantities (L_x.gas_ ~ L_K_^4.5^), suggesting the presence of largely virialized halos in X-ray luminous systems. We use well-established relations from the study of local universe ETGs, together with the expected evolution of the X-ray emission, to subtract the contribution of low-mass X-ray binary populations from the X-ray luminosity of our sample. Our selection minimizes the presence of active galactic nuclei (AGNs), yielding a sample representative of normal passive COSMOS ETGs; therefore, the resulting luminosity should be representative of gaseous halos, although we cannot exclude other sources such as obscured AGNs or enhanced X-ray emission connected with embedded star formation in the higher-z galaxies. We find that most of the galaxies with estimated L_X_< 10^42^ erg/s and z < 0.55 follow the L_X, gas_-L_K_ relation of local universe ETGs. For these galaxies, the gravitational mass can be estimated with a certain degree of confidence from the local virial relation. However, the more luminous (10^42^ erg/s <L_X_< 10^43.5^ erg/s) and distant galaxies present significantly larger scatter; these galaxies also tend to have younger stellar ages. The divergence from the local L_X, gas_-L_K_relation in these galaxies implies significantly enhanced X-ray emission up to a factor of 100 larger than predicted from the local relation. We discuss the implications of this result for the presence of hidden AGNs, and the evolution of hot halos, in nuclear and star formation feedback.
859. X-ray group of galaxies in AEGIS
ID:
ivo://CDS.VizieR/J/ApJ/765/117
Title:
X-ray group of galaxies in AEGIS
Short Name:
J/ApJ/765/117
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray-selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100% of reliable sources, leading to a catalog of 52 galaxy groups. These groups span the redshift range z~0.066-1.544 and virial mass range M_200_~1.3-13.3x10^13^^M_{sun}_. For the 49 extended sources that lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of the cut. A velocity-dispersion-based virial radius can cause a larger overestimation of velocity dispersion in comparison to an X-ray-based virial radius for low-mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, an overestimation of velocity dispersion can be created in the case of the existence of significant substructure and compactness in X-ray emission, which mostly occur in low-mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method for DEEP2 data in this field.
860. X-ray luminosities of early-type galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/328/461
Title:
X-ray luminosities of early-type galaxies
Short Name:
J/MNRAS/328/461
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalogue of X-ray luminosities for 401 early-type galaxies, of which 136 are based on newly analysed ROSAT PSPC pointed observations (Cat. <IX/30>). The remaining luminosities are taken from the literature and converted to a common energy band, spectral model and distance scale. Using this sample we fit the L_X_/L_B_ relation for early-type galaxies and find a best-fit slope for the catalogue of ~2.2. We demonstrate the influence of group-dominant galaxies on the fit and present evidence that the relation is not well modelled by a single power-law fit. We also derive estimates of the contribution to galaxy X-ray luminosities from discrete-sources and conclude that they provide L_(discrete-source-contribution)_/L_B_~29.5erg/s/L_B{sun}_. We compare this result with luminosities from our catalogue. Lastly, we examine the influence of environment on galaxy X-ray luminosity and on the form of the L_X_/L_B_ relation. We conclude that although environment undoubtedly affects the X-ray properties of individual galaxies, particularly those in the centres of groups and clusters, it does not change the nature of whole populations.

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