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Title: BICEP/Keck. XVII. Line-of-sight Distortion Analysis: Estimates of Gravitational Lensing, Anisotropic Cosmic Birefringence, Patchy Reionization, and Systematic Errors

We present estimates of line-of-sight distortion fields derived from the 95 and 150 GHz data taken by BICEP2, BICEP3, and the Keck Array up to the 2018 observing season, leading to cosmological constraints and a study of instrumental and astrophysical systematics. Cosmological constraints are derived from three of the distortion fields concerning gravitational lensing from large-scale structure, polarization rotation from magnetic fields or an axion-like field, and the screening effect of patchy reionization. We measure an amplitude of the lensing power spectrumALϕϕ=0.95±0.20. We constrain polarization rotation, expressed as the coupling constant of a Chern–Simons electromagnetic termgaγ≤ 2.6 × 10−2/HI, whereHIis the inflationary Hubble parameter, and an amplitude of primordial magnetic fields smoothed over 1 MpcB1Mpc≤ 6.6 nG at 95 GHz. We constrain the rms of optical depth fluctuations in a simple “crinkly surface” model of patchy reionization, findingAτ< 0.19 (2σ) for the coherence scale ofLc= 100. We show that all of the distortion fields of the 95 and 150 GHz polarization maps are consistent with simulations including lensed ΛCDM, dust, and noise, with no evidence for instrumental systematics. In some cases, theEBandTBquadratic estimators presented here are more sensitive than our previous map-based null tests at identifying and rejecting spuriousB-modes that might arise from instrumental effects. Finally, we verify that the standard deprojection filtering in the BICEP/Keck data processing is effective at removing temperature to polarization leakage.

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Award ID(s):
2220445 1638957 2220446 2220444 1836010 1638970 2220447 2220448 1639040
Author(s) / Creator(s):
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Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Page Range / eLocation ID:
Article No. 43
Medium: X
Sponsoring Org:
National Science Foundation
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