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24901. 2XMMi/SDSS Galaxy Cluster Survey. III.
ID:
ivo://CDS.VizieR/J/A+A/564/A54
Title:
2XMMi/SDSS Galaxy Cluster Survey. III.
Short Name:
J/A+A/564/A54
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 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 catalogue 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. We 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 catalogues yielded 264 systems with available redshifts. The present redshift measurements are consistent with the published values. The current cluster sample extends the optically confirmed cluster sample from our cluster survey by 67 objects. Moreover, it provides spectroscopic confirmation for 78 clusters among our 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, we estimated the X-ray luminosities and masses of the cluster sample.
24902. XMM-LSS at 240MHz and 610MHz
ID:
ivo://CDS.VizieR/J/A+A/471/1105
Title:
XMM-LSS at 240MHz and 610MHz
Short Name:
J/A+A/471/1105
Date:
21 Oct 2021
Publisher:
CDS
Description:
The low-frequency radio survey of the XMM-Large Scale Structure (XMM-LSS) field aims to study the connection between the extragalactic radio source populations and their environment as traced by X-ray and optical emission. In this paper we present new radio observations of the XMM-LSS field carried out using the Giant Meterwave Radio Telescope at 240 and 610MHz. These observations complement the observations presented by Cohen at al. (2003, Cat. <J/ApJ/591/640>) and Tasse et al. (2006, Cat. <J/A+A/456/791>) at 74 and 325MHz with the Very Large Array. At 240 and 610MHz, we reach noise levels of ~2.5 and ~0.3mJy/beam, leading to the detection of 466 and 769 sources over 18.0 and 12.7 degree^2^ with resolutions of 14.7arcsec and 6.5arcsec respectively. Combining these data with the available source lists at 74, 325 (Tasse et al., 2006, Cat. <J/A+A/456/791>) and 1400MHz (NVSS), we build a multifrequency catalogue containing 1611 radio sources. We check for consistency of the astrometry and flux density estimates. We fit a simple synchrotron radiation model to the flux density measurements of the 318 radio sources being detected in at least 4 bands. While ~26% of them show signature of spectral ageing, ~6% show self absorption.
24903. XMM-LSS catalogue. Version I.
ID:
ivo://CDS.VizieR/J/MNRAS/382/279
Title:
XMM-LSS catalogue. Version I.
Short Name:
J/MNRAS/382/279
Date:
21 Oct 2021
Publisher:
CDS
Description:
We provide the source list for the first 5.5 surveyed square degrees of the XMM-LSS, with a total of 3385 point-like or extended sources above a detection likelihood of 15 in either 0.5-2 or 2-10keV bands. The table at CDS contains the main parameters, while further parameters and data products (X-ray images and optical thumbnails) are available in the Milan XMM-LSS database site.
24904. XMM-LSS catalogue. Version II.
ID:
ivo://CDS.VizieR/J/MNRAS/429/1652
Title:
XMM-LSS catalogue. Version II.
Short Name:
J/MNRAS/429/1652
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the final release of the multiwavelength XMM-Large Scale Structure (LSS) data set, covering the full survey area of 11.1deg^2^, with X-ray data processed with the latest XMM-LSS pipeline version. The present publication supersedes the catalogue from the first paper in this series, pertaining to the initial 5deg^2^. We provide X-ray source lists in the customary energy bands (0.5-2 and 2-10keV) for a total of 6721 objects in the deep full-exposure catalogue and 5572 in the catalogue limited to 10ks, above a detection likelihood of 15 in at least one band. We also provide a multiwavelength catalogue, cross-correlating our list with infrared, near-infrared, optical and ultraviolet catalogues. Customary data products, such as X-ray fits images and thumbnail images from the Canada-France-Hawaii Telescope Legacy Survey and the Spitzer Wide-Area Infrared Extragalactic Survey, are made available, together with our data base in Milan, which can be queried interactively.
24905. XMM-LSS field at 74 and 325MHz
ID:
ivo://CDS.VizieR/J/A+A/456/791
Title:
XMM-LSS field at 74 and 325MHz
Short Name:
J/A+A/456/791
Date:
21 Oct 2021
Publisher:
CDS
Description:
The XMM Large Scale Structure survey (XMM-LSS) is an X-ray survey aimed at studying the large scale structure of the Universe. The XMM-LSS field is currently being followed up using observations across a wide range of wavelengths, and in this paper we present the observational results of a low frequency radio survey of the XMM-LSS field using the Very Large Array at 74 and 325MHz. This survey will map out the locations of the extragalactic radio sources relative to the large scale structure as traced by the X-ray emission. This is of particular interest because radio galaxies and radio loud AGN show strong and complex interactions with their small and larger scale environment, and different classes of radio galaxies are suggested to lie at different places with respect to the large scale structure.
24906. 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.
24907. XMM-LSS field optical identifications
ID:
ivo://CDS.VizieR/J/A+A/490/879
Title:
XMM-LSS field optical identifications
Short Name:
J/A+A/490/879
Date:
21 Oct 2021
Publisher:
CDS
Description:
The XMM-Large Scale Structure survey field (XMM-LSS) is an extragalactic window surveyed in the X-ray with the XMM-Newton satellite. It has also been observed in the optical with the Canada-France Hawaii Telescope (CFHTLS survey), and in the infrared with the Spitzer Space Telescope (SWIRE survey). These surveys have been carried out to study the structure and evolution of both baryonic and dark matter on cosmological scales. In two previous papers, we presented deep low frequency radio surveys of the XMM-LSS field, with limiting flux density levels of ~4 and ~1.5mJy/beam at 325 and 610MHz respectively (5{sigma}). These radio surveys were motivated by the need to understand the various connections between the host galaxies of radio sources and their environments. In this paper, we identify optical counterparts to the low frequency radio sources, using the CFHTLS optical catalogue and images, that have an i-band limiting magnitude of i_AB_~25.
24908. XMM-LSS field X-ray sources classification
ID:
ivo://CDS.VizieR/J/A+A/557/A81
Title:
XMM-LSS field X-ray sources classification
Short Name:
J/A+A/557/A81
Date:
21 Oct 2021
Publisher:
CDS
Description:
The XMM-Large Scale Structure survey (XMM-LSS), covering an area of 11.1 sq. deg., contains more than 6000 X-ray point-like sources detected with XMM-Newton to a flux of 3x10^-15^erg/s/cm^2^ in the [0.5-2]keV band. The vast majority of these sources have optical (CFHTLS), infrared (SWIRE IRAC and MIPS), near-infrared (UKIDSS) and/or ultraviolet (GALEX) counterparts. We wish to investigate the environmental properties of the different types of the XMM-LSS X-ray sources by defining their environment using the i'-band CFHTLS W1 catalog of optical galaxies to a magnitude limit of 23.5mag. We have classified 4435 X-ray selected sources on the basis of their spectra, SEDs, and X-ray luminosity, and estimated their photometric redshifts, which have a 4-11 band photometry with an accuracy of sigma_dz_/(1+z_sp_)=0.076 with 22.6% outliers for i'<26mag. We estimated the local overdensities of 777 X-ray sources that have spectro-z or photo-z calculated by using more than seven bands (accuracy of sigma_dz_/(1+z_sp_)=0.061 with 13.8% outliers) within the volume-limited region defined by 0.1<z<0.85 and -23.5<M_i'_<-20. Although X-ray sources may be found in variety of environments, a high fraction (~55-60%), as verified by comparing with the random expectations, reside in overdense regions. The galaxy overdensities within which X-ray sources reside show a positive recent redshift evolution (at least for the range studied; z<0.85). We also find that X-ray selected galaxies, when compared to AGN, inhabit significantly higher galaxy overdensities, although their spatial extent appear to be smaller than that of AGN. Hard AGN (HR>-0.2) are located in more overdense regions than soft AGN (HR<-0.2), which is clearly seen in both redshift ranges, although it appears to be stronger in the higher redshift range (0.55<z<0.85). Furthermore, the galaxy overdensities (with {delta}>1.5) within which soft AGN are embedded appear to evolve more rapidly compared to the corresponding overdensities around hard AGN.
24909. XMM-LSS low-frequency radio counterparts
ID:
ivo://CDS.VizieR/J/ApJ/591/640
Title:
XMM-LSS low-frequency radio counterparts
Short Name:
J/ApJ/591/640
Date:
21 Oct 2021
Publisher:
CDS
Description:
The XMM Large-Scale Structure Survey (XMM-LSS) is a major project to map the large-scale structure of the universe out to cosmological distances. An 8x8 region will be surveyed by XMM with planned optical follow-up to produce a three-dimensional map of many hundreds of clusters out to a redshift of z=1. To explore the relation of the large-scale structure to the location and properties of extragalactic radio sources, the XMM-LSS project also includes a low-frequency radio survey of this region. This combination will provide unprecedented insight into how the radio source formation and evolution are affected by the local environment. Here we present preliminary results from our 325 and 74MHz surveys in this region. At 325MHz, we have a flux limit of 4mJy/beam, a resolution of 6.3", and a total of 256 source detections over 5.6deg^2^. At 74MHz, we have a flux limit of 275mJy/beam, a resolution of 30", and a total of 211 source detections over 110deg^2^. We describe these results and explore what they tell us about the population of extragalactic low-frequency radio sources. The 74MHz survey represents the first presentation of a deep, subarcminute resolution survey at such a low frequency. This was made possible by recent advances in both hardware and data reduction algorithms, which we describe in detail.
24910. XMM-LSS survey: AGN classifications
ID:
ivo://CDS.VizieR/J/A+A/474/473
Title:
XMM-LSS survey: AGN classifications
Short Name:
J/A+A/474/473
Date:
21 Oct 2021
Publisher:
CDS
Description:
Our goal is to characterize AGN populations by comparing their X-ray and optical classifications within the framework of the standard orientation-based unified scheme. We present a sample of 99 spectroscopically identified (R<=22mag) X-ray selected point sources in the XMM-LSS survey which are significantly detected (>=3{sigma}) in the [2-10]keV band with fluxes between 8x10^-15^ and 8x10^-14^erg/s/cm^2^, and which have more than 80 counts. We have compared their X-ray and optical classifications. To this end, we performed an X-ray spectral analysis for all of these 99 X-ray sources in order to assess whether they are intrinsically absorbed or not. The X-ray classification is based on the measured intrinsic column density. The optical classification is based on the measured FWHM of the permitted emission lines, the absence of broad lines being due to obscuration within the framework of the standard AGN unified scheme.

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