The ORT and the uGMRT Pulsar Monitoring Program : Pulsar Timing Irregularities & the Gaussian Process Realization

TL;DR

This paper presents new pulsar timing observations from ORT and uGMRT, analyzing glitches and timing noise, introducing a novel glitch verification method, and reporting first-time measurements of certain pulsar behaviors.

Contribution

It provides new timing noise and glitch measurements for pulsars, including first-time reports and a novel method to distinguish glitches from timing noise.

Findings

Detected five glitches in four pulsars.

Reported first-time timing noise analysis for 17 pulsars.

Introduced a new glitch verification approach.

Abstract

The spin-down law of pulsars is generally perturbed by two types of timing irregularities: glitches and timing noise. Glitches are sudden changes in the rotational frequency of pulsars, while timing noise is a discernible stochastic wandering in the phase, period, or spin-down rate of a pulsar. We present the timing results of a sample of glitching pulsars observed using the Ooty Radio Telescope (ORT) and the upgraded Giant Metrewave Radio Telescope (uGMRT). Our findings include timing noise analysis for 17 pulsars, with seven being reported for the first time. We detected five glitches in four pulsars and a glitch-like event in PSR J1825-0935. The frequency evolution of glitch in pulsars, J0742-2822 and J1740-3015, is presented for the first time. Additionally, we report timing noise results for three glitching pulsars. The timing noise was analyzed separately in the pre-glitch region and post-glitch regions. We observed an increase in the red noise parameters in the post-glitch regions, where exponential recovery was considered in the noise analysis. Timing noise can introduce ambiguities in the correct evaluation of glitch observations. Hence, it is important to consider timing noise in glitch analysis. We propose an innovative glitch verification approach designed to discern between a glitch and strong timing noise. The novel glitch analysis technique is also demonstrated using the observed data.