view Abstract Citations (32) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Arcminute Fluctuations in the Microwave Background from Clusters of Galaxies Markevitch, M. ; Blumenthal, G. R. ; Forman, W. ; Jones, C. ; Sunyaev, R. A. Abstract Lower limits on the cosmological density parameter {OMEGA}, in the framework of self-similar cluster evolution, are derived from observed upper limits to the cosmic microwave background anisotropy on arcminute scales. We also consider models with no cluster evolution. Using the present-epoch X-ray cluster data, we simulate images of the cosmic microwave background radiation (CMBR) fluctuations produced by Compton scattering of the background photons with hot gas in clusters, under conservative assumptions about radiative cooling and the gas density profile. Simulated images calculated for different values of {OMEGA} and for a range of spectra of primordial density fluctuations are convolved with the antenna patterns from two experiments and compared with observations. Combining the two experiments the 95% confidence lower limit for {OMEGA} is found to be ~1/10 for a primordial fluctuation spectral index n = -1 (which approximates the CDM mass spectrum for clusters), while for n = 0 it is 1/7; and for n = +1 the limit is {OMEGA} > 1/5, if the gas density profile extends to 5 core radii. With the less conservative assumption that the gas density extends to 8 core radii, we derive lower limits on {OMEGA} of 1/5, 1/3, and 0.6 (for n = - 1, 0, and +1). These limits assume a Hubble constant of 50 km s^-1^ Mpc^-1^, but changing H_0_ from 50 to 75 km s^-1^ Mpc^-1^ modifies the confidence levels by only a few percent. Publication: The Astrophysical Journal Pub Date: August 1992 DOI: 10.1086/171655 Bibcode: 1992ApJ...395..326M Keywords: Antenna Radiation Patterns; Compton Effect; Galactic Clusters; Hubble Constant; Relic Radiation; Astronomical Models; Monte Carlo Method; Red Shift; Astrophysics; COSMOLOGY: COSMIC MICROWAVE BACKGROUND; COSMOLOGY: THEORY; GALAXIES: CLUSTERING full text sources ADS | data products SIMBAD (5) NED (3)