Producing Synthetic Maps of Dust Polarization using Velocity Channel Gradient Technique

TL;DR

This paper introduces a novel method to generate synthetic dust polarization maps using HI data and the Velocity Channel Gradient technique, aiding in foreground removal for CMB B-mode detection.

Contribution

The paper presents a new approach to produce dust polarization maps from HI data using VChG, improving predictions of dust foregrounds in CMB studies.

Findings

Good correspondence between synthetic maps and PLANCK polarization data.

Method effectively predicts both direction and degree of dust polarization.

Applicable to high-resolution HI data for better foreground modeling.

Abstract

In modern cosmology, many efforts have been put to detect primordial B-mode of cosmic microwave background (CMB) polarization from the gravitational waves generated during inflation. Considering the foreground dust contamination of microwave polarization maps, it is essential to obtain a precise prediction for polarization in dust emission. In this work, we show a new method to produce synthetic maps of dust polarization in magnetized turbulent ISM from more abundant high-resolution HI data. By using Velocity Channel Gradient (VChG) technique, we are able to predict both direction and degree of dust polarization by investigating spectroscopic HI information in position-position-velocity (PPV) space. We applied our approach to The Galactic Arecibo L-band feed Array HI (GALFA-HI) data, and find a good correspondence between synthesized maps and PLANCK's polarization measurements at 353 GHz.