An improved approach to measuring H_0 using X-ray and SZ observations of galaxy clusters
Abstract
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 (1995) 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\pm8km/s/Mpc for a cosmology with Omega_m=0.3 and Omega_Lambda=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.
Keywords
Cite
@article{arxiv.astro-ph/0405374,
title = {An improved approach to measuring H_0 using X-ray and SZ observations of galaxy clusters},
author = {R. W. Schmidt and S. W. Allen and A. C. Fabian},
journal= {arXiv preprint arXiv:astro-ph/0405374},
year = {2009}
}
Comments
9 pages, 2 figures, 4 tables. Accepted for publication in MNRAS