- 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.
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- ID:
- ivo://CDS.VizieR/IX/53
- Title:
- XMM-Newton slew survey Source Catalogue, version 2.0
- Short Name:
- IX/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- XMMSL2 is the second catalogue of X-ray sources found in slew data taken from the European Space Agency's (ESA) XMM-Newton observatory, and has been constructed by members of the XMM SOC and the EPIC consortium on behalf of ESA. This release uses results of work which has been carried out within the framework of the EXTraS project ("Exploring the X-ray variable and Transient Sky"), funded from the EU's Seventh Framework Programme under grant agreement no.607452. This is the first release of XMMSL2 which contains data taken between revolutions 314 and 2758. The previous catalogue was called XMMSL1_Delta6 and contained slews up to revolution 2441. The release includes two FITS files. A full catalogue (xmmsl2_total.fits.gz), containing 72352 detections found with a likelihood of DET_ML>8 and a "clean" catalogue (xmmsl2_clean.fits.gz) where all known bad sources have been removed and where the detection limit has been raised to DET_ML>10.5 in general and DET_ML>15.5 for sources found in images with a higher than usual background. Efforts have been made to identify spurious detections and 3017 have been flagged as such in the full catalogue.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A74
- Title:
- XMM-Newton spectral-fit redshift catalogue
- Short Name:
- J/A+A/645/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since its launch in 1999, the XMM-Newton mission has compiled the largest catalogue of serendipitous X-ray sources, with the 3XMM being the third version of this catalogue. This is because of the combination of a large effective area (5000cm^2^ at 1keV) and a wide field of view (30 arcmin). The 3XMM-DR6 catalogue contains about 470000 unique X-ray sources over an area of 982deg^2^. A significant fraction of these (100178 sources) have reliable optical, near/mid-IR counterparts in the SDSS, PANSTARRS, VIDEO, UKIDSS and WISE surveys. In a previous paper we have presented photometric redshifts for these sources using the TPZ machine learning algorithm. About one fourth of these (22677) have adequate photon statistics so that a reliable X-ray spectrum can be extracted. Obviously, owing to both the X-ray counts selection and the optical counterpart constraint, the sample above is biased towards the bright sources. Here, we present XMMFITCAT-Z: a spectral fit catalogue for these sources using the Bayesian X-ray Analysis (BXA) technique. As a science demonstration of the potential of the present catalogue, we comment on the optical and mid-IR colours of the 765 X-ray absorbed sources with N_H_>10^22^cm^-2^. We show that a considerable fraction of X-ray selected AGN would not be classified as AGN following the mid-IR W1-W2 vs. W2 selection criterion. These are AGN with lower luminosities, where the contribution of the host galaxy to the MIR emission is non-negligible. Only one third of obscured AGN in X-rays present red colours or r-W2>6. Then it appears that the r-W2 criterion, often used in the literature for the selection of obscured AGN, produces very different X-ray absorbed AGN samples compared to the standard X-ray selection criteria.
- ID:
- ivo://CDS.VizieR/J/A+A/495/733
- Title:
- XMM-Newton spectral survey of M31 disc
- Short Name:
- J/A+A/495/733
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a complete spectral survey of the X-ray point sources detected in five XMM-Newton observations along the major axis of M 31 but avoiding the central bulge, aimed at establishing the population characteristics of X-ray sources in this galaxy. We obtained background subtracted spectra and lightcurves for each of the 335 X-ray point sources detected across the five observations from 2002. We also correlate our source list with those of earlier X-ray surveys and radio, optical and infra-red catalogues. Sources with more than 50 source counts are individually spectrally fit in order to create the most accurate luminosity functions of M 31 to date.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A12
- Title:
- XMM-Newton SSC survey of Galactic Plane
- Short Name:
- J/A+A/553/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- 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 (LX=10^27-34^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 LX population at large distances. We report on 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{deg}, distributed over a large range in Galactic longitudes and covering a summed area of 4deg^2^. The flux limit of our survey is 2x10^-15^erg/cm^2^/s in the soft (0.5-2keV) band and 1x10^-14^erg/cm^2^/s in the hard (2-12keV) band. We detect a total of 1319 individual X-ray sources. Using optical follow-up observations supplemented by cross-correlation with a large range of multi-wavelength archival catalogues we 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-M at maximum distances of ~1kpc. The number of identified active stars increases towards late spectral types, reaching a maximum at K. Using infrared colours we classify 18% of the stars as giants. The observed distributions of FX/FV, X-ray and infrared colours indicates that our sample is dominated by a young (100Myr) to intermediate (600Myr) age population with a small contribution of close main sequence or evolved binaries. We find other interesting objects such as cataclysmic variables (d~0.6-2kpc), low luminosity high mass stars (likely belonging to the class of {gamma}-Cas-like systems, d~1.5-7kpc), 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, we have constructed logN(>S)-logS 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{deg} to b=0{deg} at an X-ray flux of 2x10^-14^erg/cm^2^/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 coronae that are also detected in the soft band. At b=0{deg} the surface density of hard sources brighter than 1x10^-13^erg/cm^2^/s steeply increases by one order of magnitude from l=20{deg} to the Galactic centre region (l=0.9{deg}).
- 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.
- 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.
- 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).
- 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.
21620. 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.
