Simulation of the Far-Infrared Polarimetry Approach Envisioned for the PRIMA Mission

TL;DR

This paper presents a simulation study of the PRIMA mission's far-infrared polarimetry approach, demonstrating its potential for ultra-deep polarization mapping of interstellar dust and magnetic fields with high accuracy.

Contribution

It introduces a new end-to-end simulation framework for the PRIMA polarimetric imager, validating its capability to accurately recover polarization maps under realistic noise conditions.

Findings

High-fidelity recovery of simulated polarization maps

Effective mitigation of systematic effects

Near fundamental limits detection of Stokes parameters

Abstract

Interest in the study of magnetic fields and the properties of interstellar dust, explored through increasingly capable far-IR/submillimeter polarimetry, along with maturing detector technology, have set the stage for a transformative leap in polarization mapping capability using a cryogenic space telescope. We describe the approach pursued by the proposed Probe far-Infrared Mission for Astrophysics (PRIMA) to make ultra-deep maps of intensity and polarization in four bands in the 91-232 micron range. A simple, polarimetry-optimized PRIMA Polarimetric Imager (PPI) is designed for this purpose, consisting of arrays of single-polarization Kinetic Inductance Detectors oriented with three angles which allow measurement of Stokes I, Q, and U in single scans. In this study, we develop an end-to-end observation simulator to perform a realistic test of the approach for the case of mapping a nearby galaxy. The observations take advantage of a beam-steering mirror to perform efficient, two-dimensional, crossing scans. Map making is based on 'destriping' approaches demonstrated for Herschel/SPIRE and Planck. Taking worst-case assumptions for detector sensitivity including 1/f noise, we find excellent recovery of simulated input astrophysical maps, with I, Q, and U detected at near fundamental limits. We describe how PPI performs detector relative calibration and mitigates the key systematic effects to accomplish PRIMA polarization science goals.