GMRT Galactic Plane Pulsar and Transient Survey and the Discovery of PSR J1838+1523

TL;DR

This paper reports a blind pulsar survey with GMRT at 325 MHz, discovering 28 pulsars including a new one, PSR J1838+1523, highlighting the importance of low-frequency surveys for detecting steep spectrum pulsars.

Contribution

The paper presents the discovery of a new pulsar through a low-frequency survey and provides its timing solution, emphasizing the role of low-frequency observations in pulsar detection.

Findings

Discovered 28 pulsars, including a new one, PSR J1838+1523.

Measured flux densities at multiple frequencies, indicating a steep spectral index.

Showed that low-frequency surveys can detect pulsars missed by high-frequency surveys.

Abstract

We report the results of a blind pulsar survey carried out with the Giant Metrewave Radio Telescope (GMRT) at 325 MHz. The survey covered about 10\% of the region between Galactic longitude 45$^{\circ} < l <$ 135$^{\circ}$ and Galactic latitude 1$^{\circ} < |b| <$ 10$^{\circ}$ with a dwell time of 1800 s, resulting in the detection of 28 pulsars. One of these, PSR J1838+1523, was previously unknown and has a period of 549 ms and a dispersion measure of 68 pc cm\sups{$-$3}. We also present the timing solution of this pulsar obtained from multi-frequency timing observations carried out with the GMRT and the Ooty Radio Telescope. The measured flux density of this pulsar is 4.3$\pm$1.8 and 1.2$\pm$0.7 mJy at 325 and 610 MHz, respectively. This implies a spectral index of $-$2$\pm$0.8, thus making the expected flux density at 1.4 GHz to be about 0.2 mJy, which would be just detectable in the high frequency pulsar surveys like the Northern High Time Resolution Universe pulsar survey. This discovery underlines the importance of low frequency pulsar surveys in detecting steep spectrum pulsars, thus providing complementary coverage of the pulsar population.