Study of pulsar flux density and its variability with Parkes data archive

TL;DR

This study measures and analyzes flux density and variability of 151 pulsars at 1.4 GHz using Parkes data, revealing insights into pulsar spectra, interstellar medium effects, and scintillation timescales.

Contribution

It provides a large dataset of pulsar flux densities and variability metrics, recommending their inclusion in the pulsar catalogue and exploring ISM effects on pulsar signals.

Findings

Modulation index negatively correlates with dispersion measure.

Refractive scintillation timescales differ from theoretical models.

Some pulsars show flat structure-function, indicating complex variability.

Abstract

We present average flux density measurements of 151 radio pulsars at 1.4 GHz with the Parkes 'Murriyang' radio telescope. We recommend our results be included in the next version of the ATNF pulsar catalogue. The large sample of pulsars together with their wide dispersion measure (DM) range make this data set useful for studying variability of flux density, pulsar spectra, and interstellar medium (ISM). We derive the modulation indices and structure-function from the flux density time series for 95 and 54 pulsars, respectively. We suggest the modulation index also be included in the next version of the pulsar catalogue to manifest the variability of pulsar flux density. The modulation index of flow density and DM are negatively correlated. The refractive scintillation (RISS) timescales or its lower bound for a set of 15 pulsars are derived. They are very different from theoretical expectations, implying the complicated properties of the ISM along different lines of sight. The structure-function for other pulsars is flat. The RISS parameters for some of these pulsars possibly could be derived with different observing strategies in the future.