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Title: THE CONTRIBUTION OF HALOS WITH DIFFERENT MASS RATIOS TO THE OVERALL GROWTH OF CLUSTER-SIZED HALOS

We provide a new observational test for a key prediction of the ΛCDM cosmological model: the contributions of mergers with different halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this test by dynamically analyzing 7 galaxy clusters, spanning the redshift range 0.13 < z{sub c} < 0.45 and caustic mass range 0.4-1.5 10{sup 15} h{sub 0.73}{sup -1} M{sub ☉}, with an average of 293 spectroscopically confirmed bound galaxies to each cluster. The large radial coverage (a few virial radii), which covers the whole infall region, with a high number of spectroscopically identified galaxies enables this new study. For each cluster, we identify bound galaxies. Out of these galaxies, we identify infalling and accreted halos and estimate their masses and their dynamical states. Using the estimated masses, we derive the contribution of different mass ratios to cluster-sized halo growth. For mass ratios between ∼0.2 and ∼0.7, we find a ∼1σ agreement with ΛCDM expectations based on the Millennium simulations I and II. At low mass ratios, ∼< 0.2, our derived contribution is underestimated since the detection efficiency decreases at low masses, ∼2 × 10{sup 14} h{sub 0.73}{sup -1} M{sub ☉}. At large mass ratios, ∼> 0.7, we do not detectmore » halos probably because our sample, which was chosen to be quite X-ray relaxed, is biased against large mass ratios. Therefore, at large mass ratios, the derived contribution is also underestimated.« less
Authors:
; ;  [1] ; ;  [2] ;  [3] ; ; ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14] more »; « less
  1. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
  2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States)
  3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  4. INAF/Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, I-34143 Trieste (Italy)
  5. Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-2320 (United States)
  6. Carnegie Institute for Science, Carnegie Observatories, Pasadena, CA (United States)
  7. INAF/Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy)
  8. European Southern Observatory, Karl-Schwarzschild Strasse 2, D-85748 Garching (Germany)
  9. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China)
  10. Department of Physics, Texas Tech University, Box 41051, Lubbock, TX 79409-1051 (United States)
  11. INAF, Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)
  12. Center for Cosmology and Astro-Particle Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210 (United States)
  13. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States)
  14. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
Publication Date:
OSTI Identifier:
22270775
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 776; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; COMPUTERIZED SIMULATION; COSMOLOGICAL CONSTANT; COSMOLOGICAL MODELS; GALAXIES; GALAXY CLUSTERS; MASS; NONLUMINOUS MATTER; RED SHIFT; X RADIATION