- ID:
- ivo://CDS.VizieR/J/MNRAS/352/131
- Title:
- 13+38 XMM-Newton/ROSAT 1.4GHz radio catalog
- Short Name:
- J/MNRAS/352/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to determine the relationship between the faint X-ray and faint radio source populations, and hence to help understand the X-ray and radio emission mechanisms in those faint source populations, we have made a deep 1.4-GHz Very Large Array radio survey of the 13h+38{deg} XMMNewton/ROSAT X-ray Survey Area. From a combined data set of 10-h, B-configuration data and 14-h, A-configuration data, maps with 3.35-arcsec resolution and a noise limit of 7.5Jy were constructed. A complete sample of 449 sources was detected within a 30-arcmin diameter region above a 4 detection limit of 30Jy, at the map centre, making this one of the deepest radio surveys at this frequency. The differential source count shows a significant upturn at submilliJansky flux densities, similar to that seen in other deep surveys at 1.4GHz (e.g. the Phoenix survey, Cat. <J/MNRAS/296/839>), but larger than that seen in the Hubble Deep Field (HDF) which may have been selected to be underdense. This upturn is well modelled by the emergence of a population of medium-redshift star-forming galaxies which dominate at faint flux densities. The brighter source counts are well modelled by active galactic nuclei.
Number of results to display per page
Search Results
- 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.
- 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.
- 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/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).
4227. 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.
4228. 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A28
- Title:
- XMM northern disc of M31 sources
- Short Name:
- J/A+A/620/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out new observations of two fields in the star-forming northern ring of M31 with XMM-Newton with two exposures of about 100 ks each. A previous XMM-Newton survey of the entire M31 galaxy revealed extended diffuse X-ray emission in these regions. We study the population of X-ray sources in the northern disc of M31 by compiling a complete list of X-ray sources down to a sensitivity limit of ~7x10^34^erg/s (0.5-2.0keV) and improve the identification of the X-ray sources. The major objective of the observing programme was the study of the hot phase of the interstellar medium (ISM) in M31. The analysis of the diffuse emission and the study of the ISM is presented in a separate paper. We analysed the spectral properties of all detected sources using hardness ratios and spectra if the statistics were high enough. We also checked for variability. In order to classify the sources detected in the new deep XMM-Newton observations, we cross-correlated the source list with the source catalogue of a new survey of the northern disc of M31 carried out with the Chandra X-ray Observatory and the Hubble Space Telescope (Panchromatic Hubble Andromeda Treasury, PHAT) as well as with other existing catalogues We detected a total of 389 sources in the two fields of the northern disc ofM31 observed with XMM-Newton.We identified 43 foreground stars and candidates and 50 background sources. Based on the comparison to the results of the Chandra/PHAT survey, we classify 24 hard X-ray sources as new candidates for X-ray binaries (XRBs). In total, we identified 34 X-ray binaries and candidates and 18 supernova remnants (SNRs) and candidates. We studied the spectral properties of the four brightest SNRs and confirmed five new X-ray SNRs. Three of the four SNRs, for which a spectral analysis was performed, show emission mainly below 2 keV, which is consistent with shocked ISM. The spectra of two of them also require an additional component with a higher temperature. The SNR [SPH11] 1535 has a harder spectrum and might suggest that there is a pulsar-wind nebula inside the SNR. For all SNRs in the observed fields, we measured the X-ray flux or calculated upper limits. We also carried out short-term and long-term variability studies of the X-ray sources and found five new sources showing clear variability. In addition, we studied the spectral properties of the transient source SWIFT J004420.1+413702, which shows significant variation in flux over a period of seven months (June 2015 to January 2016) and associated change in absorption. Based on the likely optical counterpart detected in the Chandra/PHAT survey, the source is classified as a low-mass X-ray binary.
