A First Estimate of Radio Halo Statistics from Large-Scale Cosmological Simulation
- Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept. of Physics; Inst. d'Astrophysique de Paris, Paris (France). UPMC, and CNRS; Ohio State Univ., Columbus, OH (United States). Center for Cosmology and Astro-Particle Physics
- Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States). Dept. of Astronomy, and National Center for Supercomputing Applications
In this paper, we present a first estimate based on a cosmological gas dynamics simulation of galaxy cluster radio halo counts to be expected in forthcoming low-frequency radio surveys. Our estimate is based on a FLASH simulation of the ΛCDM model for which we have assigned radio power to clusters via a model that relates radio emissivity to cluster magnetic field strength, intracluster turbulence, and density. We vary several free parameters of this model and find that radio halo number counts vary by up to a factor of two for average magnetic fields ranging from 0.2 to 3.1 μG. However, we predict significantly fewer low-frequency radio halos than expected from previous semi-analytic estimates, although this discrepancy could be explained by frequency-dependent radio halo probabilities as predicted in reacceleration models. We find that upcoming surveys will have difficulty in distinguishing models because of large uncertainties and low number counts. Additionally, according to our modeling we find that expected number counts can be degenerate with both reacceleration and hadronic secondary models of cosmic-ray generation. We find that relations between radio power and mass and X-ray luminosity may be used to distinguish models, and by building mock radio sky maps we demonstrate that surveys such as LOFAR may have sufficient resolution and sensitivity to break this model degeneracy by imaging many individual clusters.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- AC05-00OR22725; FG02-97ER25308
- OSTI ID:
- 1565014
- Journal Information:
- The Astrophysical Journal, Vol. 759, Issue 2; ISSN 0004-637X
- Publisher:
- Institute of Physics (IOP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Radio halos in future surveys in the radio continuum
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journal | November 2012 |
On the physics of radio haloes in galaxy clusters: scaling relations and luminosity functions
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journal | December 2013 |
The dividends of investing in computational software design: A case study
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journal | November 2017 |
On the Physics of Radio Halos in Galaxy Clusters: Scaling Relations and Luminosity Functions | text | January 2013 |
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