Faraday rotation measures of northern-hemisphere pulsars using CHIME/Pulsar

TL;DR

This study uses CHIME data to measure Faraday rotation of northern pulsars, significantly expanding the RM catalog and enhancing understanding of Galactic magnetic fields.

Contribution

It provides 55 new RMs and improved uncertainties for 25 pulsars, leveraging CHIME's low frequency and high cadence observations.

Findings

55 new pulsar RMs added to the catalog

Improved RM uncertainties for 25 pulsars

Enhanced understanding of Galactic magnetic structure

Abstract

Using commissioning data from the first year of operation of the Canadian Hydrogen Intensity Mapping Experiment's (CHIME) Pulsar backend system, we conduct a systematic analysis of the Faraday Rotation Measure (RM) of the northern hemisphere pulsars detected by CHIME. We present 55 new RMs as well as obtain improved RM uncertainties for 25 further pulsars. CHIME's low observing frequency and wide bandwidth between 400-800 MHz contribute to the precision of our measurements, whereas the high cadence observation provide extremely high signal-to-noise co-added data. Our results represent a significant increase of the pulsar RM census, particularly regarding the northern hemisphere. These new RMs are for sources that are located in the Galactic plane out to 10 kpc, as well as off the plane to a scale height of ~16 kpc. This improved knowledge of the Faraday sky will contribute to future Galactic large-scale magnetic structure and ionosphere modelling.