A Millimeter/Submillimeter Search for the Sunyaev-Zel'dovich Effect in the Coma Cluster

Abstract

Observations from the first flight of the Medium Scale Anisotropy Measurement (MSAM1-92) are analyzed to search for the Sunyaev-Zel'dovich (SZ) effect towards the Coma cluster. This balloon-borne instrument uses a $28\arcmin$ FWHM beam and a three position chopping pattern with a throw of $\pm40\arcmin$. With spectral channels at 5.7, 9.3, 16.5, and 22.6~\icm, the observations simultaneously sample the frequency range where the SZ spectral distortion in the intensity transitions from a decrement to an increment and where the fractional intensity change is substantially larger than in the Rayleigh-Jeans region. We set limits on the Comptonization parameter integrated over our antenna pattern, $\Delta y\le 8.0\times 10^{-5}$($2\sigma$). For a spherically symmetric isothermal model, this implies a central Comptonization parameter, $y_o\le 2.0\times 10^{-4}$, or a central electron density, $n_o\le 5.8\times 10^{-3}$cm${}^{-3}{h}_{50}$, a result consistent with central densities implied by X-ray brightness measurements and central Comptonization estimates from lower frequency observations of the SZ effect.

arXiv comment11 pages, LaTeX+aasms4 package, 1 PostScript figure. Submitted to Ap.J Letters

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Cited by in corpus (7)

• The Sunyaev-Zel'dovich Effect
• Planck intermediate results. X. Physics of the hot gas in the Coma cluster
• MITO measurements of the Sunyaev-Zeldovich Effect in the Coma cluster of galaxies
• Triple Experiment Spectrum of the Sunyaev-Zeldovich Effect in the Coma Cluster: H_0
• On cooling flows and the Sunyaev-Zel'dovich effect
• Constraints on structure formation models from Sunyaev-Zel'dovich Effect
• The Sunyaev-Zeldovich MITO Project