Abstract:
Pulsar Timing Arrays (PTAs) are astronomical experiments that aim to
detect gravitational waves in the nanohertz frequency regime by
observing an ensemble of millisecond pulsars (MSPs). The Indian Pulsar
Timing Array (InPTA) experiment, operational since 2015, aims to use
the unique strengths of the Giant Metrewave Radio Telescope to help
detect nanohertz gravitational waves. The wide low-frequency coverage
provided by the uGMRT enables very accurate characterization of radio
frequency-dependent effects in the pulsar signal, such as interstellar
dispersion and scattering, which are major sources of noise in PTA
experiments. In this talk, I will provide an overview of the InPTA
experiment and present recent results from the upcoming InPTA data
release 1, which includes precise time-of-arrival and dispersion
measure estimates for 14 MSPs spanning 3.5 years. This dataset forms
the basis of our recent studies and findings, including the 2021
profile change event in PSR J1713+0747, the detection of solar coronal
mass ejection from DM excess in timing measurements of PSR J2145-0750,
the investigation of scatter broadening in the low-frequency profile
of PSR J1643-1224, and the determination of dispersion measures and
ToA residuals in multiple pulsars using the wideband timing technique.
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