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This content will become publicly available on May 23, 2019

Title: Halo Profiles and the Concentration–Mass Relation for a ΛCDM Universe

Profiles of dark matter-dominated halos at the group and cluster scales play an important role in modern cosmology. Using results from two very large cosmological N-body simulations, which increase the available volume at their mass resolution by roughly two orders of magnitude, we robustly determine the halo concentration-mass (c-M) relation over a wide range of masses, employing multiple methods of concentration measurement. We then characterize individual halo profiles, as well as stacked profiles, relevant for galaxy-galaxy lensing and next-generation cluster surveys; the redshift range covered is 0 ≤ z ≤ 4, with a minimum halo mass of M 200c ~ 2 x 10 11 M . Despite the complexity of a proper description of a halo (environmental effects, merger history, nonsphericity, relaxation state), when the mass is scaled by the nonlinear mass scale M *(z), we find that a simple non-power-law form for the c-M/M * relation provides an excellent description of our simulation results across eight decades in M/M * and for 0 ≤ z ≤ 4. Over the mass range covered, the c-M relation has two asymptotic forms: an approximate power law below a mass threshold M/M * ~500-1000, transitioning to a constant value, c 0 ~ 3more » at higher masses. The relaxed halo fraction decreases with mass, transitioning to a constant value of ~0.5 above the same mass threshold. We compare Navarro-Frenk-White (NFW) and Einasto fits to stacked profiles in narrow mass bins at different redshifts; as expected, the Einasto profile provides a better description of the simulation results. At cluster scales at low redshift, however, both NFW and Einasto profiles are in very good agreement with the simulation results, consistent with recent weak lensing observations.« less
ORCiD logo [1] ;  [2] ; ORCiD logo [2] ;  [1] ;  [3] ;  [3] ;  [4]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). HEP Division; Univ. of Chicago, IL (United States). Dept. of Physics
  2. Argonne National Lab. (ANL), Argonne, IL (United States). HEP Division and MCS Division; Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics
  3. Argonne National Lab. (ANL), Argonne, IL (United States). HEP Division and ALCF Division
  4. Argonne National Lab. (ANL), Argonne, IL (United States). ALCF Division
Publication Date:
Grant/Contract Number:
AC02-06CH11357; AC05-00OR22725; DGE-1144082; DGE-1746045
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 859; Journal Issue: 1; Journal ID: ISSN 1538-4357
Institute of Physics (IOP)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21); USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF)
Contributing Orgs:
Leibniz Inst. for Astrophysics Potsdam (AIP), Potsdam (Germany)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; dark matter; galaxies: clusters: general; gravitational lensing: weak; methods: numerical
OSTI Identifier: