Browsing by Author "Graham, Matthew J."

Now showing items 1-6 of 6

    • A new assessment of the completeness of quasar surveys: Implications for the luminosity function 
      Graham, Matthew J.; Clowes, Roger G.; Campusano, Luis E. (UNIV CHICAGO PRESS, 1999-03-01)
      We apply a simple statistical method to estimating the completeness of quasar surveys. It requires that an area has been covered by two or more, preferably different, selection techniques. We use three suitable data sets ...
    • Environments of strong/ultrastrong, ultraviolet Fe II emitting quasars 
      Clowes, Roger G.; Raghunathan, Srinivasan; Söchting, Ilona K.; Graham, Matthew J.; Campusano Brown, Luis (Oxford University Press, 2013-06)
      We have investigated the strength of ultraviolet (UV) Fe II emission from quasars within the environments of large quasar groups (LQGs) in comparison with quasars elsewhere, for 1.1 ≤ ¯zLQG ≤ 1.7, using the DR7QSO catalogue ...
    • Further observations of quasars in ESO/SERC field 927 
      Clowes, Roger G.; Campusano, Luis E.; Graham, Matthew J. (BLACKWELL SCIENCE LTD, 1999-10-11)
      We present the spectra and redshifts of 62 quasars, from observations made with the Cerro Tololo Inter-American Observatory (CTIO) 4-m Blanco Telescope. These quasars form part of a total sample of 118 (with 56 having been ...
    • A structure in the early Universe at z similar to 1.3 that exceeds the homogeneity scale of the R-W concordance ... 
      Clowes, Roger G.; Harris, Kathryn A.; Raghunathan, Srinivasan; Campusano Brown, Luis; Söchting, Ilona K.; Graham, Matthew J. (Oxford University Press on behalf of the Royal Astronomical Society, 2013-03)
      A large quasar group (LQG) of particularly large size and high membership has been identified in the DR7QSO catalogue of the Sloan Digital Sky Survey. It has characteristic size (volume(1/3)) similar to 500 Mpc (proper ...
    • Two close large quasar groups of size ~ 350 Mpc at z ~ 1.2 
      Clowes, Roger G.; Campusano, Luis E.; Graham, Matthew J.; Söchting, Ilona K. (2012)
      The Clowes & Campusano large quasar group (LQG) at ¯z = 1.28 has been re-examined using the quasar data from the DR7QSO catalogue of the Sloan Digital Sky Survey. In the 1991 discovery, the LQG impinged on the northern, ...
    • Ultra Deep Catalogue of Galaxy Structures in the Cosmic Evolution Survey field 
      Söchting, Ilona K.; Coldwell, Georgina V.; Clowes, Roger G.; Campusano Brown, Luis; Graham, Matthew J. (Royal Astronomical Society, 2012-04-03)
      detected using a fully automated search in the Cosmic Evolution Survey field. The detection algorithm is based on density peak extraction from a density distribution sampled usingVoronoi tessellation within overlapping ...