Hydrodynamical Simulation of Clusters of Galaxies in X–Ray, mm, and submm Bands: Determination of Peculiar Velocity and the Hubble Constant
نویسندگان
چکیده
We have performed a series of simulations of clusters of galaxies on the basis of the smoothed particle hydrodynamics technique in a spatially-flat cold dark matter universe with Ω = 0.3, λ = 0.7, and H0 = 70km/s/Mpc as one of the most successful representative cosmological scenarios. In particular, we focus on the Sunyaev–Zel’dovich effect in submm and mm bands, and estimate the reliability of the estimates of the global Hubble constant H0 and the peculiar velocity of clusters vr. Our simulations indicate that fractional uncertainties of the estimates of H0 amount to ∼ 20% mainly due to the departure from the isothermal and spherical gas density distribution. We find a systematic underestimate bias of H0 by ∼ 20% for clusters z ≈ 1, but not at z ≈ 0. The gas temperature drop in the central regions of our simulated clusters leads to the underestimate bias of vr by ∼ 5% at z ≈ 0 and by ∼ 15% at z ≈ 1 in addition to the statistical errors of the comparable amount due to the non-spherical gas profile. Subject headings: Cosmology – Dark matter – Hydrodynamics Galaxies: clusters of – Galaxies: X-rays – Numerical methods Publications of the Astronomical Society of Japan (1998), in press
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تاریخ انتشار 1998