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The Atacama Cosmology Telescope: Dynamical Masses for 44 SZ-Selected Galaxy Clusters over 755 Square DegreesWe present galaxy velocity dispersions and dynamical mass estimates for 44 galaxy clusters selected via the Sunyaev-Zeldovich (SZ) effect by the Atacama Cosmology Telescope. Dynamical masses for 18 clusters are reported here for the first time. Using N-body simulations, we model the different observing strategies used to measure the velocity dispersions and account for systematic effects resulting from these strategies. We find that the galaxy velocity distributions may be treated as isotropic, and that an aperture correction of up to 7 per cent in the velocity dispersion is required if the spectroscopic galaxy sample is sufficiently concentrated towards the cluster centre. Accounting for the radial profile of the velocity dispersion in simulations enables consistent dynamical mass estimates regardless of the observing strategy. Cluster masses M200 are in the range (1 - 15) times 10 (sup 14) Solar Masses. Comparing with masses estimated from the SZ distortion assuming a gas pressure profile derived from X-ray observations gives a mean SZ-to-dynamical mass ratio of 1:10 plus or minus 0:13, but there is an additional 0.14 systematic uncertainty due to the unknown velocity bias; the statistical uncertainty is dominated by the scatter in the mass-velocity dispersion scaling relation. This ratio is consistent with previous determinations at these mass scales.
Document ID
20160009140
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Sifon, Cristobal
(Leiden Univ. Netherlands)
Battaglia, Nick
(Princeton Univ. Princeton, NJ, United States)
Hasselfield, Matthew
(Pennsylvania State Univ. University Park, PA, United States)
Menanteau, Felipe
(Illinois Univ. at Urbana-Champaign Urbana, IL, United States)
Barrientos, L. Felipe
(Pontificia Univ. Catolica de Chile Santiago, Chile)
Bond, J. Richard
(Canadian Inst. for Theoretical Astrophysics Toronto, Ontario, Canada)
Crichton, Devin
(Johns Hopkins Univ. Baltimore, MD, United States)
Devlin, Mark J.
(Pennsylvania Univ. Philadelphia, PA, United States)
Dunner, Rolando
(Pontificia Univ. Catolica de Chile Santiago, Chile)
Hilton, Matt
(KwaZulu-Natal Univ. Durban, South Africa)
Wollack, Edward J.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
July 19, 2016
Publication Date
May 30, 2016
Publication Information
Publication: Monthly Notices of the Royal Astronomical Society
Volume: 461
Issue: 1
Subject Category
Astrophysics
Report/Patent Number
GSFC-E-DAA-TN33689
Funding Number(s)
CONTRACT_GRANT: NSF AST-0408698
CONTRACT_GRANT: FONDECYT 1120676
CONTRACT_GRANT: NSF AST-0965625
CONTRACT_GRANT: NSF 1312380
CONTRACT_GRANT: NSF PHY-0855887
CONTRACT_GRANT: NSF PHY-1214379
CONTRACT_GRANT: EC-FP7-279396
Distribution Limits
Public
Copyright
Other
Keywords
Sunyaev-Zeldovich (SZ)
X-ray observations
N-body simulations
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