Development of calibration strategies for the Simons Observatory

Abstract

The Simons Observatory (SO) is a set of cosmic microwave background instruments that will be deployed in the Atacama Desert in Chile. The key science goals include setting new constraints on cosmic inflation, measuring large scale structure with gravitational lensing, and constraining neutrino masses. Meeting these science goals with SO requires high sensitivity and improved calibration techniques. In this paper, we highlight a few of the most important instrument calibrations, including spectral response, gain stability, and polarization angle calibrations. We present their requirements for SO and experimental techniques that can be employed to reach those requirements.

Studies of Systematic Uncertainties for Simons Observatory: Detector Array Effects

“…This paper is part of a series of papers on the systematic and calibration studies for SO. [5][6][7] We are combining the detailed results of the full SO systematics and calibration studies into a comprehensive study that will be released in a series of future papers to the community for use in developing future CMB experiments such as CMB-S4. Here we take an in-depth look at several of the most important detector array systematics, and note that further information on detector array systematic effects that are not included in this paper will be included in the full systematics study papers.…”

Simulating instrumental systematics of Cosmic Microwave Background experiments with s4cmb

“…It is designed to analyze real data, to guide the design of future instruments that require the estimation of specific systematic effects, as well as to increase the realism of simulated data sets required in the development of data analysis methods. The package has already been used in a number of scientific (Puglisi et al 2018;Mirmelstein et al 2020) and technical publications (Salatino et al 2018;Crowley et al 2018;Gallardo et al 2018;Bryan et al 2018). It adopts several commonly used libraries in astronomy (astropy (Astropy Collaboration 2013), healpy (Zonca et al 2019), ephem (Rhodes, n.d.), pyslalib (Ransom 2010)) and uses functions based on low-level languages wrapped in Python (e.g., Fortran with f2py) for speeding up the most critical part of the code without losing the flexibility provided by a simple Python user-friendly interface.…”

Systematic uncertainties in the Simons Observatory: optical effects and sensitivity considerations

“…This systematic can be computed from theory and compared to measurements. Bryan et al 2018 13 discusses calibration techniques for future CMB observatories.…”

“…This paper is part of a series of papers on the systematic and calibration studies for SO. [11][12][13] We are combining the detailed results of the full SO systematics and calibration studies into a comprehensive study that will be released in a series of future papers to the community for use in developing future experiments like CMB-S4.…”