Open AccessAn improved approach to measuring H 0 using X‐ray and SZ observations of galaxy clusters
Author(s) -
Schmidt R. W.,
Allen S. W.,
Fabian A. C.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.08032.x
Subject(s) - physics , astrophysics , galaxy cluster , virial theorem , radius , galaxy , hubble's law , cosmic microwave background , cluster (spacecraft) , cosmology , sunyaev–zel'dovich effect , astronomy , dark energy , computer security , anisotropy , quantum mechanics , computer science , programming language
We present an improved method for predicting the Sunyaev–Zeldovich (SZ) effect in galaxy clusters from spatially resolved, spectroscopic X‐ray data. Using the deprojected electron density and temperature profiles measured within a fraction of the virial radius, and assuming a Navarro–Frenk–White mass model, we show how the pressure profile of the X‐ray gas can be extrapolated to large radii, allowing the Comptonization parameter profile for the cluster to be predicted precisely. We apply our method to Chandra observations of three X‐ray‐luminous, dynamically relaxed clusters with published SZ data: RX J1347.5–1145, Abell 1835 and Abell 478. Combining the predicted and observed SZ signals, we determine improved estimates for the Hubble constant from each cluster and obtain a weighted mean of H 0 = 69 ± 8 km s −1 Mpc −1 for a cosmology with Ω m = 0.3 and Ω Λ = 0.7 . This result is in good agreement with independent findings from the Hubble Key Project and the combination of cosmic microwave background and galaxy cluster data.