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Author: Lin, D. × Type: Article ×

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    Two new magnetic cataclysmic variables discovered in the 3XMM catalogue
    (Les Ulis : EDP Sciences, 2018) Webb, N.A.; Schwope, A.; Zolotukhin, I.; Lin, D.; Rosen, S.R.
    Context. X-ray catalogues provide a wealth of information on many source types, ranging from compact objects to galaxies, clusters of galaxies, stars, and even planets. Thanks to the huge volume of X-ray sources provided in the 3XMM catalogue, along with many source specific products, many new examples from rare classes of sources can be identified. Aims. Through visualising spectra and lightcurves from about 80 observations included in the incremental part of the 3XMM catalogue, 3XMM-DR5, as part of the quality control of the catalogue, we identified two new X-ray sources, 3XMM J183333.1+225136 and 3XMM J184916.1+652943, that were highly variable. This work aims to investigate their nature. Methods. Through simple model fitting of the X-ray spectra and analysis of the X-ray lightcurves of 3XMM J183333.1+225136 and 3XMM J184916.1+652943, along with complementary photometry from the XMM-Newton Optical Monitor, Pan-STARRS and the Stella/WiFSIP and Large Binocular Telescope (LBT) spectra, we suggest that the two sources might be magnetic cataclysmic variables (CVs) of the polar type and we determine some of their properties. Results. Both CVs have very hard spectra, showing no soft excess. They are both situated in the local neighbourhood, located within ∼1 kpc. 3XMM J183333.1+225136 has an orbital period of 2.15 h. It shows features in the lightcurve that may be a total eclipse of the white dwarf. 3XMM J184916.1+652943 has an orbital period of 1.6 h. Given that only a small sky area was searched to identify these CVs, future sensitive all sky surveys such as the eROSITA project should be very successful at uncovering large numbers of such sources.
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    The XMM-Newton serendipitous survey : IX. The fourth XMM-Newton serendipitous source catalogue
    (Les Ulis : EDP Sciences, 2020) Webb, N.A.; Coriat, M.; Traulsen, I.; Ballet, J.; Motch, C.; Carrera, F.J.; Koliopanos, F.; Authier, J.; de la Calle, I.; Ceballos, M.T.; Colomo, E.; Chuard, D.; Freyberg, M.; Garcia, T.; Kolehmainen, M.; Lamer, G.; Lin, D.; Maggi, P.; Michel, L.; Page, C.G.; Page, M.J.; Perea-Calderon, J.V.; Pineau, F.-X.; Rodriguez, P.; Rosen, S.R.; Santos Lleo, M.; Saxton, R.D.; Schwope, A.; Tomás, L.; Watson, M.G.; Zakardjian, A.
    Context. Sky surveys produce enormous quantities of data on extensive regions of the sky. The easiest way to access this information is through catalogues of standardised data products. XMM-Newton has been surveying the sky in the X-ray, ultra-violet, and optical bands for 20 years. Aims. The XMM-Newton Survey Science Centre has been producing standardised data products and catalogues to facilitate access to the serendipitous X-ray sky. Methods. Using improved calibration and enhanced software, we re-reduced all of the 14 041 XMM-Newton X-ray observations, of which 11 204 observations contained data with at least one detection and with these we created a new, high quality version of the XMM-Newton serendipitous source catalogue, 4XMM-DR9. Results. 4XMM-DR9 contains 810 795 detections down to a detection significance of 3σ, of which 550 124 are unique sources, which cover 1152 degrees2 (2.85%) of the sky. Filtering 4XMM-DR9 to retain only the cleanest sources with at least a 5σ detection significance leaves 433 612 detections. Of these detections, 99.6% have no pileup. Furthermore, 336 columns of information on each detection are provided, along with images. The quality of the source detection is shown to have improved significantly with respect to previous versions of the catalogues. Spectra and lightcurves are also made available for more than 288 000 of the brightest sources (36% of all detections).