Temperature angular power spectrum of the primary CMB from Planck, showing a precise measurement of seven acoustic peaks that are well-fitted by a six-parameter ΛCDM model (the model plotted is the one labelled [Planck+WP+highL] in Planck Collaboration XVI 2014). The shaded area around the best-fit curve represents cosmic/sample variance, including the sky cut used. The error bars on individual points also include cosmic variance. The horizontal axis is logarithmic up to ℓ = 50, and linear beyond. The vertical scale is ℓ(ℓ + 1)C_l/ 2π. The measured spectrum shown here is exactly the same as the one shown in Fig. 1 of Planck Collaboration XVI (2014), but it has been rebinned to show better the low-ℓ region.