The SPOTLIGHT Pulsar Search Pipeline: A GPU-Accelerated FFT Approach

Jyotirmoy Das; Jayanta Roy; Nishant Pradeep Deo; Karel Adámek; Wes Armour; Kshitij Bane; Jayaram Chengalur; Kenil Ajudiya; Chahat Dudeja; Sridhar Gajendran; Zhaocheng Gong; Param Joshi; Sanjay Kudale; Arpan Pal; Ujjwal Panda; Adityan S; Raghav Wani; Junhao Zhang; Deepak Bhong; Shelton Gnanaraj; Santaji N. Katore; Mekhala Muley; Harshavardhan Reddy

arXiv · 2607.08854

The SPOTLIGHT Pulsar Search Pipeline: A GPU-Accelerated FFT Approach

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Abstract

We present the pulsar search component of SPOTLIGHT (Survey for sPoradic radiO bursTs via a commensaL multI-beam Gpu-powered Hpc at the gmrT), a GPU-accelerated commensal backend operating at the upgraded Giant Metrewave Radio Telescope (uGMRT). While SPOTLIGHT is primarily designed for real-time detection and localisation of fast radio bursts (FRBs), it simultaneously records a subset of beamformed data products for periodicity searches without requiring dedicated telescope time. To process the large data volumes generated by the survey, we have developed a scalable FFT-based pulsar search pipeline that combines radio-frequency interference mitigation, GPU-accelerated dedispersion and periodicity searches, multi-beam candidate sifting, efficient folding and machine-learning classification. Using population synthesis and archival uGMRT observations, we estimate that a fully operational SPOTLIGHT survey with 160 PC and one IA beam could discover $\sim$ 450 new pulsars, probing both high-sky coverage and faint pulsars over three and a half years of commensal observations. The pipeline has been validated on GMRT Cycle 48 and 49 observations (i.e. April 2025 to Mar 2026), successfully re-detecting numerous known pulsars with a wide range of Period, DM and flux densities, and is currently operational for SPOTLIGHT commensal data processing. We describe the SPOTLIGHT observing system, pulsar survey design, search parameter space, candidate-selection strategy, current status, and future developments. SPOTLIGHT demonstrates the scientific potential of commensal pulsar surveys and serves as a pathfinder for real-time, large-scale pulsar and transient searches in the SKA era.

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Jyotirmoy Das, Jayanta Roy, Nishant Pradeep Deo, Karel Adámek, Wes Armour, Kshitij Bane, Jayaram Chengalur, Kenil Ajudiya, Chahat Dudeja, Sridhar Gajendran, Zhaocheng Gong, Param Joshi, Sanjay Kudale, Arpan Pal, Ujjwal Panda, Adityan S, Raghav Wani, Junhao Zhang, Deepak Bhong, Shelton Gnanaraj, Santaji N. Katore, Mekhala Muley, Harshavardhan Reddy. 2026-07-09. The SPOTLIGHT Pulsar Search Pipeline: A GPU-Accelerated FFT Approach. https://arxiv.org/abs/2607.08854

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