Detection and Flux Density Measurements of the Millisecond Pulsar J2145-0750 below 100 MHz

TL;DR

This paper reports the first detection of pulsed emission from a millisecond pulsar below 100 MHz, providing flux density measurements and analyzing spectral properties that suggest a spectral break around 730 MHz.

Contribution

It presents the lowest frequency detection of pulsed emission from a millisecond pulsar and analyzes its flux density spectrum for the first time.

Findings

Pulse profile similar to higher frequencies

Flux density spectrum shows a possible spectral break

Spectral curvature with a rollover around 730 MHz

Abstract

We present flux density measurements and pulse profiles for the millisecond pulsar PSR J2145-0750 spanning 37 to 81 MHz using data obtained from the first station of the Long Wavelength Array. These measurements represent the lowest frequency detection of pulsed emission from a millisecond pulsar to date. We find that the pulse profile is similar to that observed at 102 MHz. We also find that the flux density spectrum between ~40 MHz to 5 GHz is suggestive of a break and may be better fit by a model that includes spectral curvature with a rollover around 730 MHz rather than a single power law.