CONSTRAINTS ON THE HIGH-ℓ POWER SPECTRUM OF MILLIMETER-WAVE ANISOTROPIES FROM APEX-SZ

We present measurements of the angular power spectrum of millimeter wave with the APEX-SZ instrument. APEX-SZ has mapped 0. 8 square degrees sky at a frequency of 150 GHz with an angular resolution of 1'. These new significantly improve the constraints on anisotropy power at 150 over the range of angular multipoles 3000 < l < 10, 000, limiting the total signal in a flat band power to be less than 105 microK² at 95%. We expect both submillimeter-bright, dusty galaxies and to a lesser extent CMB anisotropies from the Sunyaev-Zel'dovich effect (SZE) to contribute to the observed power. Subtracting the SZE power expected for sigma₈=0. 8 and masking bright sources, the best fit for the remaining power is Cₗ = 1. 1^+0. 9-₀. ₈ x 10^-5 micro K² (1. 7^+1. 4-₁. ₃ Jy² sr^-1). This agrees well with model predictions for due to submillimeter-bright, dusty galaxies. Comparing this power to the detected by BLAST at 600 GHz, we find the frequency dependence of the fluxes to be Sₙu ~ nu^2. 6^{+0. 4-₀. ₂} if both experiments measure same population of sources. Simultaneously fitting for the amplitude of the power spectrum and a Poisson distributed point source population, we place upper limit on the matter fluctuation amplitude of sigma₈ < 1. 18 at 95%.