TY - JOUR
T1 - The extraordinary amount of substructure in the Hubble Frontier Fields cluster Abell 2744
AU - Jauzac, M.
AU - Eckert, D.
AU - Schwinn, J.
AU - Harvey, D.
AU - Baugh, C. M.
AU - Robertson, A.
AU - Bose, S.
AU - Massey, R.
AU - Owers, M.
AU - Ebeling, H.
AU - Shan, H. Y.
AU - Jullo, E.
AU - Kneib, J. P.
AU - Richard, J.
AU - Atek, H.
AU - Clément, B.
AU - Egami, E.
AU - Israel, H.
AU - Knowles, K.
AU - Limousin, M.
AU - Natarajan, P.
AU - Rexroth, M.
AU - Taylor, P.
AU - Tchernin, C.
N1 - Funding Information:
This work was supported by the Science and Technology Facilities Council [grant number ST/L00075X/1, ST/K501979/1 & ST/K501979/1] and used the DiRAC Data Centric system at Durham University, operated by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk [www.dirac.ac.uk]). This equipment was funded by BIS National E-infrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure. MJ, DE, and HI thank T. Erben and M. Klein for their help with the WFI data. MJ, ML, and EJ acknowledge the Mésocentre d'Aix-Marseille Université (project number: 14b030). This study also benefited from the facilities offered by CeSAM (Centre de donnéeS Astrophysique de Marseille, http://lam.oamp.fr/cesam/). MJ thanks Stéphane Arnouts for his inputs and a fruitful discussion. MJ thanks Céline Boehm for carefully reading this paper and sharing her expertise to improve it. MJ thanks Ian Smail, Alastair Edge, Simon Morris, David Alexander, Richard Bower, and Mark Swinbank for a detailed discussion. JS thanks Matthias Bartelmann for helpful discussions and providing his libastro library for calculating the merger rates. DH acknowledges the funding support from the Swiss National Science Foundation (SNSF). CMB acknowledges a Research Fellowship from the Leverhulme Trust. RM is supported by the Royal Society. MO acknowledges the funding support from the Australian Research Council through a Future Fellowship (FT140100255). HYS acknowledges the support fromMarie-Curie International Incoming Fellowship (FP7-PEOPLE-2012-IIF/327561) and NSFC of China under grants 11103011. J-PK acknowledges support from the ERC advanced grant LIDA. JR acknowledges support from the ERC starting grant CALENDS and the CIG grant 294074. ML acknowledges the Centre National de la Recherche Scientifique (CNRS) for its support. PN acknowledges support from the National Science Foundation via the grant AST-1044455, AST-1044455, and a theory grant from the Space Telescope Science Institute HST-AR-12144.01-A. CT acknowledges the financial support from the Swiss National Science Foundation.
Funding Information:
This work was supported by the Science and Technology Facilities Council [grant number ST/L00075X/1, ST/K501979/1 & ST/K501979/1] and used the DiRAC Data Centric system at Durham University, operated by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk [www.dirac.ac.uk]). This equipment was funded by BIS National E-infrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure. MJ, DE, and HI thank T. Erben and M. Klein for their help with the WFI data. MJ, ML, and EJ acknowledge the M?socentre d'Aix-Marseille Universit? (project number: 14b030). This study also benefited from the facilities offered by CeSAM (Centre de donn?eS Astrophysique de Marseille, http://lam.oamp.fr/cesam/). MJ thanks St?phane Arnouts for his inputs and a fruitful discussion. MJ thanks C?line Boehm for carefully reading this paper and sharing her expertise to improve it. MJ thanks Ian Smail, Alastair Edge, Simon Morris, David Alexander, Richard Bower, and Mark Swinbank for a detailed discussion. JS thanks Matthias Bartelmann for helpful discussions and providing his libastro library for calculating the merger rates. DH acknowledges the funding support from the Swiss National Science Foundation (SNSF). CMB acknowledges a Research Fellowship from the Leverhulme Trust. RM is supported by the Royal Society. MO acknowledges the funding support from the Australian Research Council through a Future Fellowship (FT140100255). HYS acknowledges the support fromMarie-Curie International Incoming Fellowship (FP7-PEOPLE-2012-IIF/327561) and NSFC of China under grants 11103011. J-PK acknowledges support from the ERC advanced grant LIDA. JR acknowledges support from the ERC starting grant CALENDS and the CIG grant 294074. ML acknowledges the Centre National de la Recherche Scientifique (CNRS) for its support. PN acknowledges support from the National Science Foundation via the grant AST-1044455, AST-1044455, and a theory grant from the Space Telescope Science Institute HST-AR-12144.01-A. CT acknowledges the financial support from the Swiss National Science Foundation.
Publisher Copyright:
© 2017 The Author(s).
PY - 2016/12/21
Y1 - 2016/12/21
N2 - We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z = 0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e. at R < 1 Mpc from the brightest cluster galaxy, reveals eight substructures, including the main core. All of these dark matter haloes are detected with a significance of at least 5s and feature masses ranging from 0.5 to 1.4 × 1014 M⊙ within R < 150 kpc. Merten et al. and Medezinski et al. substructures are also detected by us. We measure a slightly higher mass for the main core component than reported previously and attribute the discrepancy to the inclusion of our tightly constrained strong-lensing mass model built on Hubble Frontier Fields data. X-ray data obtained by XMM-Newton reveal four remnant cores, one of them a new detection, and three shocks. Unlike Merten et al., we find all cores to have both dark and luminous counterparts. A comparison with clusters of similarmass in the Millennium XXL simulations yields no objects with as many massive substructures as observed in Abell 2744, confirming that Abell 2744 is an extreme system. We stress that these properties still do not constitute a challenge to Λ cold dark matter, as caveats apply to both the simulation and the observations: for instance, the projected mass measurements from gravitational lensing and the limited resolution of the subhaloes finders. We discuss implications of Abell 2744 for the plausibility of different dark matter candidates and, finally, measure a new upper limit on the self-interaction cross-section of dark matter of σDM < 1.28 cm2 g-1 (68 per cent CL), in good agreement with previous results from Harvey et al.
AB - We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z = 0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e. at R < 1 Mpc from the brightest cluster galaxy, reveals eight substructures, including the main core. All of these dark matter haloes are detected with a significance of at least 5s and feature masses ranging from 0.5 to 1.4 × 1014 M⊙ within R < 150 kpc. Merten et al. and Medezinski et al. substructures are also detected by us. We measure a slightly higher mass for the main core component than reported previously and attribute the discrepancy to the inclusion of our tightly constrained strong-lensing mass model built on Hubble Frontier Fields data. X-ray data obtained by XMM-Newton reveal four remnant cores, one of them a new detection, and three shocks. Unlike Merten et al., we find all cores to have both dark and luminous counterparts. A comparison with clusters of similarmass in the Millennium XXL simulations yields no objects with as many massive substructures as observed in Abell 2744, confirming that Abell 2744 is an extreme system. We stress that these properties still do not constitute a challenge to Λ cold dark matter, as caveats apply to both the simulation and the observations: for instance, the projected mass measurements from gravitational lensing and the limited resolution of the subhaloes finders. We discuss implications of Abell 2744 for the plausibility of different dark matter candidates and, finally, measure a new upper limit on the self-interaction cross-section of dark matter of σDM < 1.28 cm2 g-1 (68 per cent CL), in good agreement with previous results from Harvey et al.
KW - Galaxies: clusters: individual: Abell 2744
KW - Gravitational lensing: strong
KW - Gravitational lensing: weak
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U2 - 10.1093/mnras/stw2251
DO - 10.1093/mnras/stw2251
M3 - Article
AN - SCOPUS:85014332895
SN - 0035-8711
VL - 463
SP - 3876
EP - 3893
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -