Speaker
Description
The second data release (DR2) of the Indian Pulsar Timing Array (InPTA) represents a major milestone in precision pulsar timing using the upgraded Giant Metrewave Radio Telescope (uGMRT). Combining seven years of simultaneous dual-band observations (300–500 MHz and 1260–1460 MHz) of 27 millisecond pulsars (MSPs), InPTA DR2 provides one of the most sensitive low-frequency datasets currently available within the International Pulsar Timing Array. The release includes sub-banded times of arrival (ToAs), high-precision dispersion measure (DM) estimates, and updated timing ephemerides. Reprocessing of the entire dataset has significantly improved the characterisation of frequency-dependent delays and DM variations, which is essential for mitigating interstellar and solar-wind-induced noise in pulsar timing. Beyond timing refinements, InPTA DR2 has enabled the identification of astrophysical “outliers” in the low-frequency DM time series. Two particularly striking cases are presented: (1) evidence of a coronal mass ejection (CME) signature detected through DM excursions in PSR J1022+1001, a pulsar lying very close to the ecliptic plane; and (2) a possible mode-changing event in PSR J2145−0750, inferred from its multi-component pulse morphology and anomalous DM behaviour. These findings illustrate the unique strength of uGMRT’s low-frequency capability in probing solar and pulsar-magnetospheric plasma processes.
This presentation will summarise the DR2 dataset, highlight improvements in timing precision and DM modelling, and discuss the astrophysical insights unlocked through InPTA’s dual-band strategy.
| Stream | Science or Engineering |
|---|