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17601. XMM-Newton survey in COSMOS field. I.
ID:
ivo://CDS.VizieR/J/ApJS/172/29
Title:
XMM-Newton survey in COSMOS field. I.
Short Name:
J/ApJS/172/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first set of XMM-Newton EPIC observations in the 2deg^2^ COSMOS field. The strength of the COSMOS project is the unprecedented combination of a large solid angle and sensitivity over the whole multi-wavelength spectrum. The XMM-Newton observations are very efficient in localizing and identifying active galactic nuclei (AGNs) and clusters, as well as groups of galaxies. One of the primary goals of the XMM-Newton Cosmos survey is to study the coevolution of active galactic nuclei as a function of their environment in the cosmic web. Here we present the log of observations, images, and a summary of first research highlights for the first pass of 25 XMM-Newton pointings across the field. In the existing data set we have detected 1416 new X-ray sources in the 0.52, 24.5, and 4.5-10keV bands to an equivalent 0.5-2keV flux limit of 7x10^-16^erg/cm^2^/s. The number of sources is expected to grow to almost 2000 in the final coverage of the survey. From an X-ray color-color analysis we identify a population of heavily obscured, partially leaky or reflecting absorbers, most of which are likely to be nearby, Compton-thick AGNs.
17602. XMM-Newton survey in COSMOS field. IV.
ID:
ivo://CDS.VizieR/J/ApJS/172/368
Title:
XMM-Newton survey in COSMOS field. IV.
Short Name:
J/ApJS/172/368
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed spectral analysis of pointlike X-ray sources in the XMM-Newton COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%). The remaining ~4% of the sources require a more complex modeling by incorporating additional components to the power law. For sources with more than 180 net counts (bright sample), we allowed both the photon spectral index Gamma and the equivalent hydrogen column NH to be free parameters. For fainter sources, we fix Gamma to the average value and allow NH to vary. The mean spectral index of the 82 sources in the bright sample is <Gamma>=2.06+/-0.08, with an intrinsic dispersion of ~0.24. Each of these sources has fractional errors on the value of Gamma below 20%. As expected, the distribution of intrinsic absorbing column densities is markedly different between AGNs with or without broad optical emission lines. We find within our sample four type 2 QSO candidates (L_X_>10^44^erg/s, NH>10^22^cm^-2^), with a spectral energy distribution well reproduced by a composite Seyfert 2 spectrum, that demonstrates the strength of the wide-field COSMOS XMM-Newton survey to detect these rare and underrepresented sources. In addition, we have identified a Compton-thick (NH>1.5x10^24^cm^-2^) AGN at z=0.1248. Its X-ray spectrum is well fitted by a pure reflection model and a significant Fe K{alpha} line at rest-frame energy of 6.4keV.
17603. XMM-Newton survey in the Marano Field. I.
ID:
ivo://CDS.VizieR/J/A+A/466/41
Title:
XMM-Newton survey in the Marano Field. I.
Short Name:
J/A+A/466/41
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on a medium deep XMM-Newton survey of the Marano Field and optical follow-up observations. The mosaicked XMM-Newton pointings in this optical quasar survey field cover 0.6 deg2 with a total of 120ks good observation time. We detected 328 X-ray sources in total. The turnover flux of our sample is f_X_~5x10^-15^erg/cm2/s in the 0.2-10keV band. With VLT FORS1 and FORS2 spectroscopy we classified 96 new X-ray counterparts. The central 0.28deg^2^, where detailed optical follow-up observations were performed, contain 170 X-ray sources (detection likelihood ML>10), out of which 48 had already been detected by ROSAT. In this region we recover 23 out of 29 optically selected quasars. With a total of 110 classifications in our core sample we reach a completeness of ~65%. About one-third of the XMM-Newton sources are classified as type II AGN with redshifts mostly below 1.0. Furthermore, we detect five high redshift type II AGN (2.2<=z<=2.8).
17604. XMM-Newton survey of local OVII absorbers
ID:
ivo://CDS.VizieR/J/ApJS/217/21
Title:
XMM-Newton survey of local OVII absorbers
Short Name:
J/ApJS/217/21
Date:
21 Oct 2021
Publisher:
CDS
Description:
Highly ionized, z=0 metal absorption lines detected in the X-ray spectra of background active galactic nuclei (AGNs) provide an effective method to probe the hot (T~10^6^K) gas and its metal content in and around the Milky Way. We present an all-sky survey of the K_{alpha}_ transition of the local OVII absorption lines obtained by Voigt-profile fitting archival XMM-Newton observations. A total of 43 AGNs were selected, among which 12 are BL Lac-type AGNs, and the rest are Seyfert 1 galaxies. At above the 3{sigma} level the local OVII absorption lines were detected in 21 AGNs, among which 7 were newly discovered in this work. The sky covering fraction, defined as the ratio between the number of detections and the sample size, increases from about 40% for all targets to 100% for the brightest targets, suggesting a uniform distribution of the OVII absorbers. We correlate the line equivalent width with the Galactic coordinates and do not find any strong correlations between these quantities. Some AGNs have warm absorbers that may complicate the analysis of the local X-ray absorber since the recession velocity can be compensated by the outflow velocity, especially for nearby targets. We discuss the potential impact of warm absorbers on our analysis.
17605. XMM-Newton survey of M33
ID:
ivo://CDS.VizieR/J/A+A/426/11
Title:
XMM-Newton survey of M33
Short Name:
J/A+A/426/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
In an XMM-Newton raster observation of the bright Local Group spiral galaxy M 33 we study the population of X-ray sources (X-ray binaries, supernova remnants) down to a 0.2-4.5keV luminosity of 10^35^erg/s - more than a factor of 10 deeper than earlier ROSAT observations. EPIC hardness ratios and optical and radio information are used to distinguish between different source classes. The survey detects 408 sources in an area of 0.80 square degree. We correlate these newly detected sources with earlier M 33 X-ray catalogues and information from optical, infra-red and radio wavelengths. As M 33 sources we detect 21 supernova remnants (SNR) and 23 SNR candidates, 5 super-soft sources and 2 X-ray binaries (XRBs). There are 267 sources classified as hard, which may either be XRBs or Crab-like SNRs in M 33 or background AGN. The 44 confirmed and candidate SNRs more than double the number of X-ray detected SNRs in M 33. 16 of these are proposed as SNR candidates from the X-ray data for the first time. On the other hand, there are several sources not connected to M 33: five foreground stars, 30 foreground star candidates, 12 active galactic nucleus candidates, one background galaxy and one background galaxy candidate. Extrapolating from deep field observations we would expect 175 to 210 background sources in this field. This indicates that about half of the sources detected are within M 33.
17606. XMM-Newton survey of M33
ID:
ivo://CDS.VizieR/J/A+A/448/1247
Title:
XMM-Newton survey of M33
Short Name:
J/A+A/448/1247
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the individual observations of a deep XMM-Newton survey of the Local Group spiral galaxy M33. We detected a total of 350 sources with fluxes (in the 0.2-4.5keV energy band) in the range 6.7x10^-16^-1.5x10^-11^erg/s. This comprehensive study considers flux variability, spectral characteristics, and classification of the detected objects. Thirty-nine objects in our catalogue are new sources, while 311 were already detected in a previous analysis of most of the same data using combined images. We present improved positions of these sources and the X-ray parameters of each source in each individual observation that covers the source. We then used these parameters to systematically search for flux variability on time scales of hours to months or years. The long-term light-curves were generated for the 61 sources showing a significant variability of the (0.2-4.5)keV flux, by a factor of 1.2 to 144. The detected variability was then used to classify 8 new X-ray binary candidates in M33. Together with the hardness ratio method and cross-correlation with optical, infrared, and radio data, we also classify or confirm previous classification of 25 supernova remnants and candidates, 2 X-ray binaries, and 11 super-soft source candidates (7 of which are new SSS candidates). In addition, we classify 13 active galactic nuclei and background galaxies, 6 stars, and 23 foreground star candidates in the direction of M33. Further 206 objects are classified as 'hard', approximately half of which are sources intrinsic to M33. The relative contribution of the classified XRB and SSS in M33 is now comparable to M31. The luminosity distribution of SNRs in both spiral galaxies is almost the same, although the number of the detected SNRs in M33 remains much higher.
17607. XMM-Newton survey of M31 centre field
ID:
ivo://CDS.VizieR/J/A+A/480/599
Title:
XMM-Newton survey of M31 centre field
Short Name:
J/A+A/480/599
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an extension to our XMM-Newton X-ray source catalogue of M 31, containing 39 newly found sources. In order to classify and identify more of the sources we search for X-ray time variability in XMM-Newton archival data the M31 centre field. As source list we use our extended catalogue based on observations covering the time span from June 2000 to July 2004. We then determine the flux or at least an upper limit at the source positions for each observation. Deriving the flux ratios for the different observations and searching for the maximum flux difference we determine variability factors. We also calculated the significance of the flux ratios. Using hardness ratios, X-ray variability and cross correlations with catalogues in the X-ray, optical, infrared and radio regimes, we detected three super soft source candidates, one supernova remnant and six supernova remnant candidates, one globular cluster candidate, three X-ray binaries and four X-ray binary candidates. Additionally we identified one foreground star candidate and classified fifteen sources with hard spectra, which may either be X-ray binaries or Crab-like supernova remnants in M31 or background active galactic nuclei. The remaining five sources stay unidentified or without classification. Based on the time variability results we suggest six sources, which were former classified as "hard", to be X-ray binary candidates. The classification of one source (XMMM31 J004236.7+411349) as supernova remnant, has to be rejected due to the distinct time variability we found. We now classify this source as a foreground star.
17608. XMM-Newton survey of SA 57
ID:
ivo://CDS.VizieR/J/A+A/469/1211
Title:
XMM-Newton survey of SA 57
Short Name:
J/A+A/469/1211
Date:
21 Oct 2021
Publisher:
CDS
Description:
The maximum number density of Active Galactic Nuclei (AGNs), as deduced from X-ray studies, occurs at z>=1, with lower luminosity objects peaking at smaller redshifts. Optical studies lead to a different evolutionary behaviour, with a number density peaking at z~2 independently of the intrinsic luminosity, but this result is limited to active nuclei brighter than the host galaxy. A selection based on optical variability can detect low luminosity AGNs (LLAGNs), where the host galaxy light prevents the identification by non-stellar colours. We want to collect X-ray data in a field where it exists an optically-selected sample of "variable galaxies", i.e. variable objects with diffuse appearance, to investigate the X-ray and optical properties of the population of AGNs, particularly of low luminosity ones, where the host galaxy is visible. We observed a field of ~0.2{deg}^2^ in the Selected Area 57, for 67ks with XMM-Newton. We detected X-ray sources, and we correlated the list with a photographic survey of SA 57, complete to B_J_~23 and with available spectroscopic data. We obtained a catalogue of 140 X-ray sources to limiting fluxes 5x10^-16^, 2x10^-15^erg/cm^2^/s in the 0.5-2keV and 2-10keV respectively, 98 of which are identified in the optical bands. The X-ray detection of part of the variability-selected candidates confirms their AGN nature. Diffuse variable objects populate the low luminosity side of the sample. Only 25/44 optically-selected QSOs are detected in X-rays. 15% of all QSOs in the field have X/O<0.1.
17609. XMM-Newton survey of the ELAIS-S1 field
ID:
ivo://CDS.VizieR/J/A+A/457/501
Title:
XMM-Newton survey of the ELAIS-S1 field
Short Name:
J/A+A/457/501
Date:
21 Oct 2021
Publisher:
CDS
Description:
The formation and evolution of cosmic structures can be probed by studying the evolution of the luminosity function of the Active Galactic Nuclei (AGNs), galaxies and clusters of galaxies and of the clustering of the X-ray active Universe, compared to the IR-UV active Universe. To this purpose, we have surveyed with XMM-Newton the central ~0.6{deg}^2^ region of the ELAIS-S1 field down to flux limits of ~5.5x10^-16^erg/cm^2^/s (0.5-2keV, soft band, S), ~2x10^-15^erg/cm^2^/s (2-10keV, hard band, H), and ~4x10^-15^erg/cm^2^/s (5-10keV, ultra hard band, HH). We present here the analysis of the XMM-Newton observations, the number counts in different energy bands and the clustering properties of the X-ray sources.
17610. 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.

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