Core or Cusps: The Central Dark Matter Profile of a Strong Lensing Cluster with a Bright Central Image at Redshift 1
- Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)
- Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
- Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland)
- Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)
- George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
- Department of Physics and Astronomy, Pevensey Building, University of Sussex, Brighton BN1 9QH (United Kingdom)
- Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)
- Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)
- CNRS, UMR 7095, Institut d’Astrophysique de Paris, F-75014, Paris (France)
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
- Kavli Institute for Particle Astrophysics and Cosmology, P.O. Box 2450, Stanford University, Stanford, CA 94305 (United States)
We report on SPT-CLJ2011-5228, a giant system of arcs created by a cluster at z = 1.06. The arc system is notable for the presence of a bright central image. The source is a Lyman break galaxy at z {sub s} = 2.39 and the mass enclosed within the Einstein ring of radius 14 arcsec is ∼10{sup 14.2} M{sub ⊙}. We perform a full reconstruction of the light profile of the lensed images to precisely infer the parameters of the mass distribution. The brightness of the central image demands that the central total density profile of the lens be shallow. By fitting the dark matter as a generalized Navarro–Frenk–White profile—with a free parameter for the inner density slope—we find that the break radius is 270{sub −76}{sup +48} kpc, and that the inner density falls with radius to the power −0.38 ± 0.04 at 68% confidence. Such a shallow profile is in strong tension with our understanding of relaxed cold dark matter halos; dark matter-only simulations predict that the inner density should fall as r{sup −1}. The tension can be alleviated if this cluster is in fact a merger; a two-halo model can also reconstruct the data, with both clumps (density varying as r{sup −0.8} and r{sup −1.0}) much more consistent with predictions from dark matter-only simulations. At the resolution of our Dark Energy Survey imaging, we are unable to choose between these two models, but we make predictions for forthcoming Hubble Space Telescope imaging that will decisively distinguish between them.
- OSTI ID:
- 22876024
- Journal Information:
- Astrophysical Journal, Vol. 843, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Inner dark matter distribution of the Cosmic Horseshoe (J1148+1930) with gravitational lensing and dynamics
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journal | October 2019 |
Properties of Subhalos in the Interacting Dark Matter Scenario
|
journal | September 2019 |
| The inner dark matter distribution of the Cosmic Horseshoe (J1148+1930) with gravitational lensing and dynamics | text | January 2019 |
| Properties of subhalos in the interacting dark matter scenario | text | January 2019 |
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