50-250 MHz Pulsar Census with an SKA-Low prototype station: Spectra and Polarization

TL;DR

This study presents the largest low-frequency pulsar survey in the southern hemisphere using an SKA-Low prototype, detecting 120 pulsars and providing detailed spectral and polarization data to improve understanding of pulsar emission, ISM, and ionosphere.

Contribution

It offers new low-frequency pulsar detections, improved dispersion and rotation measures, and comprehensive polarimetric profiles, enhancing pulsar and interstellar medium studies.

Findings

Detected 120 pulsars, including 28 new low-frequency sources.

Improved dispersion measures for 110 pulsars, median correction 0.1 pc cm^-3.

Measured significant Faraday rotation in 40 pulsars, with phase-resolved RM variation in one.

Abstract

Low-frequency pulsar observations are crucial for understanding pulsar emission spectra and population physics, as well as for probing the interstellar medium (ISM) and Earth's ionosphere. We report the largest low-frequency pulsar census conducted in the southern hemisphere, covering 50-250 MHz, using the EDA2, an SKA-Low prototype station. In this survey, we detected 120 pulsars, including 23 first-time detections below 150 MHz and 5 below 100 MHz. For each source, we provide integrated pulse profiles and flux-density measurements across five sub-bands spanning 50-250 MHz. We also obtained improved dispersion measure (DM) values for 110 pulsars, with a median absolute DM correction of about 0.1 pc cm^-3. We measured significant Faraday rotation for 40 pulsars with improved rotation measure (RM) values for 4 pulsars, as well as phase-resolved RM variation in J1453-6413. Full-polarimetric pulse profiles are provided for all these pulsars, with multi-frequency polarimetric data for 20 of them. These results will enhance future SKA-Low science: refining pulsar population models, informing survey strategies, and advancing characterization of both the ISM and the ionosphere through low-frequency pulsar monitoring.