Detecting pulsar polarization below 100 MHz with the Long Wavelength Array

Using the first station of the Long Wavelength Array (LWA1), we examine polarized pulsar emission between 25 and 88 MHz. Polarized light from pulsars undergoes Faraday rotation as it passes through the magnetized interstellar medium. Observations from low-frequency telescopes are ideal for obtaining precise rotationmeasures (RMs) because the effect of Faraday rotation is proportional to the square of the observingwavelength.With theseRMs,we obtained polarized pulse profiles to see how polarization changes in the 25-88 MHz range. The RMs were also used to derive values for the electron-density-weighted average Galactic magnetic field along the line of sight. We present RMs and polarization profiles of 15 pulsars acquired using data from LWA1. These results provide newinsight into low-frequency polarization characteristics and pulsar emission heights, and complement measurements at higher frequencies. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.