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Measuring H₀ using X-ray and SZ effect observations of dynamically relaxed galaxy clusters

Wan, Jenny T. and Mantz, Adam B. and Sayers, Jack and Allen, Steven W. and Morris, R. Glenn and Golwala, Sunil R. (2021) Measuring H₀ using X-ray and SZ effect observations of dynamically relaxed galaxy clusters. . (Unpublished)

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We use a sample of 14 massive, dynamically relaxed galaxy clusters to constrain the Hubble Constant, H₀, by combining X-ray and Sunyaev-Zel'dovich (SZ) effect signals measured with Chandra, Planck and Bolocam. This is the first such analysis to marginalize over an empirical, data-driven prior on the overall accuracy of X-ray temperature measurements, while our restriction to the most relaxed, massive clusters also minimizes astrophysical systematics. For a cosmological-constant model with Ω_m = 0.3 and Ω_Λ = 0.7, we find H₀ = 67.3^(+21.3)_(−13.3) km/s/Mpc, limited by the temperature calibration uncertainty (compared to the statistically limited constraint of H₀ = 72.3^(+7.6)_(−7.6) km/s/Mpc). The intrinsic scatter in the X-ray/SZ pressure ratio is found to be 13±4 per cent (10±3 per cent when two clusters with significant galactic dust emission are removed from the sample), consistent with being primarily due to triaxiality and projection. We discuss the prospects for reducing the dominant systematic limitation to this analysis, with improved X-ray calibration and/or precise measurements of the relativistic SZ effect providing a plausible route to per cent level constraints on H₀.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Mantz, Adam B.0000-0002-8031-1217
Sayers, Jack0000-0002-8213-3784
Golwala, Sunil R.0000-0002-1098-7174
Additional Information:We thank Michael Zemcov for useful discussions regarding the Herschel-SPIRE SZ effect data. JW was supported by a Robert L. Blinkenberg Caltech Summer Undergraduate Research Fellowship and the Kavli Institute for Particle Astrophysics and Cosmology. We acknowledge support from the U.S. Department of Energy under contract number DE-AC02-76SF00515, and and from the National Aeronautics and Space Administration under Grant No. 80NSSC18K0920 issued through the ROSES 2017 Astrophysics Data Analysis Program. Data Availability: The Chandra data underlying this article are available from the Chandra Data Archive. The Planck and Bolocam data products can be obtained from the NASA/IPAC Infrared Science Archive (footnotes 3–4 provide direct URLs).
Group:Astronomy Department
Funding AgencyGrant Number
Caltech Summer Undergraduate Research Fellowship (SURF)UNSPECIFIED
Kavli Institute for Particle Astrophysics and CosmologyUNSPECIFIED
Department of Energy (DOE)DE-AC02-76SF00515
Subject Keywords:cosmological parameters – cosmology: observations – distance scale – galaxies: clusters: general – X-rays: galaxies: clusters
Record Number:CaltechAUTHORS:20210331-083800968
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108590
Deposited By: Tony Diaz
Deposited On:31 Mar 2021 15:51
Last Modified:31 Mar 2021 15:51

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