THE COSMIC MICROWAVE BACKGROUND ANISOTROPY POWER SPECTRUM FROM THE BEAST EXPERIMENT

The Background Emission Anisotropy Scanning Telescope (BEAST) is a 2.2 m off-axis telescope with an eightelement mixed Q-band (38–45 GHz) and Ka-band (26–36 GHz) focal plane, designed for balloon-borne and ground-basedstudiesofthe cosmicmicrowavebackground(CMB).Herewepresentthe CMB angularpowerspectrumcalculatedfrom682hrofdataobservedwiththeBEASTinstrument.Weuseabinnedpseudo-Cl estimator(the MASTER method). We find results that are consistent with other determinations of the CMB anisotropy for angular wavenumbers l between 100 and 600. We also perform cosmological parameter estimation. The BEAST data alone produce a good constraint on k � 1 � tot ¼� 0:074 � 0:070, consistent with a flat universe. A joint parameter estimation analysis with a number of previous CMB experiments produces results consistent with previous determinations. Subject heading gs: cosmicmicrowavebackground — cosmology:observations — large-scalestructureofunivers