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[Context]: The XMM-Newton Survey Science Centre Consortium (SSC) develops software in close collaboration with the Science Operations Centre to perform a pipeline analysis of all XMM-Newton observations. In celebration of the twentieth anniversary of the XMM-Newton launch, the SSC has compiled the fourth generation of serendipitous source catalogues, 4XMM., [Aims]: The catalogue described here, 4XMM-DR9s, explores sky areas that were observed more than once by XMM-Newton. These observations are bundled in groups referred to as stacks. Stacking leads to a higher sensitivity, resulting in newly discovered sources and better constrained source parameters, and unveils long-term brightness variations., [Methods]: The 4XMM-DR9s catalogue was constructed from simultaneous source detection on overlapping observations. As a novel feature, positional rectification was applied beforehand. Observations with all filters and suitable camera settings were included. Exposures with a high background were discarded. The high-background thresholds were determined through a statistical analysis of all exposures in each instrument configuration. The X-ray background maps used in source detection were modelled via an adaptive smoothing procedure with newly determined parameters. Source fluxes were derived for all contributing observations, irrespective of whether the source would be detectable in an individual observation., [Results]: The new catalogue lists the X-ray sources detected in 1329 stacks with 6604 contributing observations over repeatedly covered 300 square degrees in the sky. Most stacks are composed of two observations, the largest one comprises 352 observations. We find 288 191 sources of which 218 283 were observed several times. The number of observations of a source ranges from 1 to 40. Auxiliary products, like X-ray full-band and false-colour images, long-term X-ray light curves, and optical finding charts, are published as well., [Conclusions]: 4XMM-DR9s contains new detections and is considered a prime resource to explore long-term variability of X-ray sources discovered by XMM-Newton. Regular incremental releases, including new public observations, are planned.

[Context] XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitously in the individual observations. This series is now augmented by a catalogue dedicated to X-ray sources detected in spatially overlapping XMM-Newton observations. [Aims] The aim of this catalogue is to explore repeatedly observed sky regions. It thus makes use of the long(er) effective exposure time per sky area and offers the opportunity to investigate long-term flux variability directly through the source-detection process. [Methods] A new standardised strategy for simultaneous source detection on multiple observations was introduced, including an adaptive-smoothing method to describe the image background. It was coded as a new task within the XMM-Newton Science Analysis System and used to compile a catalogue of sources from 434 stacks comprising 1789 overlapping XMM-Newton observations that entered the 3XMM-DR7 catalogue, have a low background and full-frame readout of all EPIC cameras. [Results] The first stacked catalogue is called 3XMM-DR7s. It contains 71 951 unique sources with positions and parameters such as fluxes, hardness ratios, quality estimates, and information on inter-observation variability, directly derived from a simultaneous fit. Source parameters are calculated for the stack and for each contributing observation. About 15% of the sources are new with respect to 3XMM-DR7. Through stacked source detection, the parameters of repeatedly observed sources are determined with higher accuracy than in the individual observations. The method is more sensitive to faint sources and tends to produce fewer spurious detections. [Conclusions] With this first stacked catalogue we demonstrate the feasibility and benefit of the approach. It supplements the large data base of XMM-Newton detections with additional, in particular faint, sources and adds variability informatio

The black hole binary, V404 Cygni, went into outburst in 2015 June, after 26 years of X-ray quiescence. We observed the outburst with the Neil Gehrels Swift observatory. We present optical/UV observations taken with the Swift Ultra-violet Optical Telescope, and compare them with the X-ray observations obtained with the Swift X-ray Telescope. We find that dust extinction affecting the optical/UV does not correlate with absorption due to neutral hydrogen that affects the X-ray emission. We suggest there is a small inhomogeneous high-density absorber containing a negligible amount of dust, close to the black hole. Overall, temporal variations in the optical/UV appear to trace those in the X-rays. During some epochs we observe an optical time-lag of (15–35) s. For both the optical/UV and X-rays, the amplitude of the variations correlates with flux, but this correlation is less significant in the optical/UV. The variability in the light curves may be produced by a complex combination of processes. Some of the X-ray variability may be due to the presence of a local, inhomogeneous and dust-free absorber, while variability visible in both the X-ray and optical/UV may instead be driven by the accretion flow: the X-rays are produced in the inner accretion disc, some of which are reprocessed to the optical/UV; and/or the X-ray and optical/UV emission is produced within the jet. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

We study a sample of six X-ray-selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray-selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index ¿ = 0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, ¿OX, of the X-ray-selected BALQSOs, have a mean value of <¿OX> = 1.69 ± 0.05, which is similar to that found for X-ray-selected and optically selected non-BAL QSOs of a similar ultraviolet luminosity. In contrast, optically selected BALQSOs typically have much larger ¿OX and so are characterized as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray spectra are absorbed by a similar degree to that seen in optically selected BALQSO samples; X-ray absorption appears to be ubiquitous in BALQSOs, but X-ray weakness is not. We argue that BALQSOs sit at one end of a spectrum of X-ray absorption properties in QSOs related to the degree of ultraviolet absorption in C IV 1550 Å.

[Context]: Thanks to the large collecting area (3 × ∼1500 cm at 1.5 keV) and wide field of view (30′ across in full field mode) of the X-ray cameras on board the European Space Agency X-ray observatory XMM-Newton, each individual pointing can result in the detection of up to several hundred X-ray sources, most of which are newly discovered objects. Since XMM-Newton has now been in orbit for more than 15 yr, hundreds of thousands of sources have been detected. [Aims]: Recently, many improvements in the XMM-Newton data reduction algorithms have been made. These include enhanced source characterisation and reduced spurious source detections, refined astrometric precision of sources, greater net sensitivity for source detection, and the extraction of spectra and time series for fainter sources, both with better signal-to-noise. Thanks to these enhancements, the quality of the catalogue products has been much improved over earlier catalogues. Furthermore, almost 50% more observations are in the public domain compared to 2XMMi-DR3, allowing the XMM-Newton Survey Science Centre to produce a much larger and better quality X-ray source catalogue. [Methods]: The XMM-Newton Survey Science Centre has developed a pipeline to reduce the XMM-Newton data automatically. Using the latest version of this pipeline, along with better calibration, a new version of the catalogue has been produced, using XMM-Newton X-ray observations made public on or before 2013 December 31. Manual screening of all of the X-ray detections ensures the highest data quality. This catalogue is known as 3XMM. [Results]: In the latest release of the 3XMM catalogue, 3XMM-DR5, there are 565 962 X-ray detections comprising 396 910 unique X-ray sources. Spectra and lightcurves are provided for the 133 000 brightest sources. For all detections, the positions on the sky, a measure of the quality of the detection, and an evaluation of the X-ray variability is provided, along with the fluxes and count rates in 7 X-ray

We present a detailed investigation of a sample of 5 X-ray and submmluminous QSOs at z~2, when the highest rates of star formation and growth of black holes are known to occur. Hence, they are good laboratories to investigate the co-evolution of star formation and AGN. We analyze here their Spectral Energy Distributions (SEDs), including new PACS and SPIRE Herschel data, together with our existing and archival X-ray-optical-NIR-MIR observations. Both AGN (direct and reprocessed) and Star Formation (SF) emission are needed to model their SEDs. From the SEDs, their UV-optical and X-ray spectra we have estimated the mass of their black holes (MBH ~ 109 - 1010 M) and their intrinsic AGN bolometric luminosities (Lbol ~ 1013 - 1014 L). Their black hole masses are very close to the maximum observed local black hole mass, so they cannot grow much more. These objects show indeed very high Star Formation Rates (SFR ~ 1000 M/yr). From the current SFR and their massive BH, we infer that their host galaxies have to be already quite massive, or they would not have time to reach the local BH-to-bulge mass relation by the present time. Finally, from the SEDs and the X-ray spectra we have found tantalizing evidence for a correlation between the column density of the ionized gas detected in X-rays and the SFR, which would be evidence for a link between AGN and SF processes.

The 3XMM-DR4 catalogue is the third generation catalogue of serendipitous X-ray sources from the European Space Agency's (ESA) XMM-Newton observatory, and has been created by the XMM-Newton Survey Science Centre (SSC) on behalf of ESA. Released in July 2013, 3XMM-DR4 contains 531261 detections from 372728 unique sources observed in 7427 XMM-Newton observations, about 50% more than in the preceding 2XMMi-DR3 catalogue, made public in April 2010. We review some of the key science-driven algorithmic and calibration changes to the processing pipeline adopted to enhance the scientific quality of the catalogue, such as the optimised filtering of background flares, improvements to the astrometric analysis and upgrades to the catalogue construction process. Examples of the gains obtained are illustrated.

We have assembled a sample of five X-ray-absorbed and submm-luminous type 1 QSOs at z ∼ 2 which are simultaneously growing their central black holes through accretion and forming stars copiously. We present here the analysis of their rest-frame UV-to-submm spectral energy distributions (SEDs), including new Herschel data. Both AGN (direct and reprocessed) and star formation (SF) emission are needed to model their SEDs. From the SEDs and their UV–optical spectra we have estimated the masses of their black holes MBH ∼ 109–1010 M⊙, their intrinsic AGN bolometric luminosities LBOL ∼ (0.8–20) × 1013 L⊙, Eddington ratios LBOL/LEdd ∼ 0.1–1.1 and bolometric corrections LBOL/LX,2−10∼30−500LBOL/LX,2−10∼30−500. These values are common among optically and X-ray-selected type 1 QSOs (except for RX J1249), except for the bolometric corrections, which are higher. These objects show very high far-infrared luminosities LFIR ∼ (2–8) × 1012 M⊙ and star formation rates SFR ∼1000 M⊙ yr−1. From their LFIR and the shape of their FIR–submm emission we have estimated star-forming dust masses of MDUST ∼ 109 M⊙. We have found evidence of a tentative correlation between the gas column densities of the ionized absorbers detected in X-ray (NHionNHion) and SFR. Our computed black hole masses are amongst the most massive known.

We present a detailed study of a X -ray selected sample of 5 submillimeter bright QSOs at z∼2, where the highest rates of star formation (SF) and further growth of black holes (BH) occur. Therefore, this sample is a great laboratory to investigate the co-evolution of star formation and AGN. We present here the analysis of the spectral energy distributions (SED) of the 5 QSOS, including new data from Herschel PACS and SPIRE. Both AGN components (direct and reprocessed) and like Star Formation (SF) are needed to model its SED. From the SED and their UV-optical spectra we have estimated the mass of the black hole (MBH=109−1010MSUN) and bolometric luminosities of AGN (LBOL=(0.8−20)×1013LSUN). These objects show very high luminosities in the far infrared range (at the H/ULIRG levels) and very high rates of SF (SFR = 400-1400 MSUN/y). Known their current SFR and their BH masses, we deduce that their host galaxies must be already very massive, or would not have time to get to the local relation between BH mass and bulge. Finally, we found evidence of a possible correlation between the column density of ionized gas detected in X-rays (NHion) and SFR, which would provide a link between AGN and SF processes.

[Aims]: This programme is aimed at obtaining one of the largest X-ray selected samples of identified active galactic nuclei to date in order to characterise such a population at intermediate fluxes, where most of the Universe's accretion power originates.We present the XMM-NewtonWide Angle Survey (XWAS), a new catalogue of almost a thousand X-ray sources spectroscopically identified through optical observations. [Methods]: A sample of X-ray sources detected in 68 XMM-Newton pointed observations was selected for optical multi-fibre spectroscopy. Optical counterparts and corresponding photometry of the X-ray sources were obtained from the SuperCOSMOS Sky Survey. Candidates for spectroscopy were initially selected with magnitudes down to R ~ 21, with preference for X-ray sources having a flux F0.5-4.5keV = 10-14 erg s-1 cm-2. Optical spectroscopic observations were made using the Two Degree Field of the Anglo Australian Telescope, and the resulting spectra were classified based on optical emission lines. [Results]: We have identified through optical spectroscopy 940 X-ray sources over O ~ 11.8 deg2 of the sky. Source populations in our sample can be summarised as 65% broad line active galactic nuclei (BLAGN), 16% narrow emission line galaxies (NELGs), 6% absorption line galaxies (ALGs) and 13% stars. An active nucleus is also likely to be present in the large majority of the X-ray sources spectroscopically classified as NELGs or ALGs. Sources lie in high-galactic latitude (|b| 20 deg) XMM-Newton fields mainly in the southern hemisphere. Owing to the large parameter space in redshift (0 = z = 4.25) and flux (10-15 = F0.5-4.5keV = 10-12 erg s-1 cm-2) covered by the XWAS this work provides an excellent resource for the further study of subsamples and particular cases. The overall properties of the extragalactic objects are presented in this paper. These include the redshift and luminosity distributions, optical and X-ray colours and X-ray-to-optical flux ratios. © ESO 201