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Title: Bicep/Keck XV: The Bicep3 Cosmic Microwave Background Polarimeter and the First Three-year Data Set

We report on the design and performance of the Bicep3instrument and its first three-year data set collected from 2016 to 2018. Bicep3is a 52 cm aperture refracting telescope designed to observe the polarization of the cosmic microwave background (CMB) on degree angular scales at 95 GHz. It started science observation at the South Pole in 2016 with 2400 antenna-coupled transition-edge sensor bolometers. The receiver first demonstrated new technologies such as large-diameter alumina optics, Zotefoam infrared filters, and flux-activated SQUIDs, allowing ∼10× higher optical throughput compared to theKeckdesign. Bicep3achieved instrument noise equivalent temperatures of 9.2, 6.8, and 7.1μKCMBsand reached StokesQandUmap depths of 5.9, 4.4, and 4.4μK arcmin in 2016, 2017, and 2018, respectively. The combined three-year data set achieved a polarization map depth of 2.8μK arcmin over an effective area of 585 square degrees, which is the deepest CMB polarization map made to date at 95 GHz.

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Award ID(s):
1639040 1638957 1638970 1638978 1836010 2220445
Author(s) / Creator(s):
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DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Medium: X Size: Article No. 77
["Article No. 77"]
Sponsoring Org:
National Science Foundation
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