Tracking dispersion measure variations of timing array pulsars with the GMRT

TL;DR

This study monitors dispersion measure variations in 11 millisecond pulsars over three years using GMRT, revealing precise measurements, solar wind effects, and comparisons with other data sets.

Contribution

It provides high-accuracy DM variation measurements over an extended period, including solar wind effects, and compares results with other pulsar timing arrays.

Findings

DM estimates accurate to 5x10^(-4) cm^(-3) pc

DM fluctuations are comparable with PPTA data

Solar wind and corona effects are observed and modeled

Abstract

We present the results from nearly three years of monitoring of the variations in dispersion measure (DM) along the line-of-sight to 11 millisecond pulsars using the Giant Metrewave Radio Telescope (GMRT). These results demonstrate accuracies of single epoch DM estimates of the order of 5x10^(-4) cm^(-3) pc. A preliminary comparison with the Parkes Pulsar Timing Array (PPTA) data shows that the measured DM fluctuations are comparable. We show effects of DM variations due to the solar wind and solar corona and compare with the existing models.