Orateur
Description
Taurus is a balloon-borne CMB experiment, planning to launch in 2027. It will fly from Wanaka, New Zealand, as the payload of a NASA Super Pressure Balloon in the stratosphere of the Southern Hemisphere, giving it a view of more than half of the sky. By imaging at night for several weeks with its three refractor telescopes, Taurus will map the polarized microwave emission of the sky in four bands centred around 150, 220, 280 and 350GHz with around 10000 cryogenic TES detectors in total. The large sky fraction, the scanning strategy and design choices will enable Taurus to determine the E-mode spectrum at these four frequencies on large angular scales (l<30). Thanks to the low atmospheric loading in the stratosphere, we expect the high-frequency bands of Taurus to give us the best estimates of the dust power spectrum on those large angular scales, enabling us to break the degeneracy between As and τ, the optical depth of reionization. We forecast that, alone or combined with other data, Taurus will reach a smaller uncertainty on τ than Planck, giving future experiments like CMB-S4 a critical element to determine the sum of neutrino masses.
