Filters

20202

More filters

20212
Reset filters

Settings

Author: Schwope, A. × Subject: surveys ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    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).
  • Thumbnail Image
    Item
    The final SDSS-IV/SPIDERS X-ray point source spectroscopic catalogue
    (Les Ulis : EDP Sciences, 2020) Comparat, J.; Merloni, A.; Dwelly, T.; Salvato, M.; Schwope, A.; Coffey, D.; Wolf, J.; Arcodia, R.; Liu, T.; Buchner, J.; Nandra, K.; Georgakakis, A.; Clerc, N.; Brusa, M.; Brownstein, J.R.; Schneider, D.P.; Pan, K.; Bizyaev, D.
    Aims. We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources. Methods. We describe the SPIDERS X-ray Point Source Spectroscopic Catalogue, considering its store of 11 092 observed spectra drawn from a parent sample of 14 759 ROSAT and XMM sources over an area of 5129 deg2 covered in SDSS-IV by the eBOSS survey. Results. This programme represents the largest systematic spectroscopic observation of an X-ray selected sample. A total of 10 970 (98.9%) of the observed objects are classified and 10 849 (97.8%) have secure redshifts. The majority of the spectra (10 070 objects) are active galactic nuclei (AGN), 522 are cluster galaxies, and 294 are stars. Conclusions. The observed AGN redshift distribution is in good agreement with simulations based on empirical models for AGN activation and duty cycle. Forming composite spectra of type 1 AGN as a function of the mass and accretion rate of their black holes reveals systematic differences in the H-beta emission line profiles. This study paves the way for systematic spectroscopic observations of sources that are potentially to be discovered in the upcoming eROSITA survey over a large section of the sky.